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Sunday, October 25, 2009

Hottest Costume of 2009: Illegal Falcon Alien

A Grumpy Dispatcher Original Creation.

My apologies for the image quality, I am not working with my normal tools here.. I had to scrape this together with MS Paint. Ugh.

Anyway... After Falcon Heene (didn't) make the infamous balloon flight in Colorado, I present you with the Illegal Falcon Alien costume.

Thanks, I'll be here all week.

The EMS 2.0 Buzz -- and Requisite Rant

I'm not under any illusions that people are reading this blog to learn what's going on in the fire/EMS universe. That's what Firegeezer and Happy Medic Headquarters and Fire Critic and others in that league are for. I don't hope to ever be that popular, and it is probably best for me to stay that way anyway.

So, no doubt you've heard of EMS 2.0 already. It's the latest buzz, and while I certainly like the concept, it is picking up steam so fast... almost too fast, and I am worried about it spinning out of control before liftoff. I want it to be useful, and not over evolve into a bigger mess than we already have. I have my popcorn handy though... should be fun to watch.

I had an event a few weeks ago that was almost bloggable, but not really. But then again, it was a silly event. And then it further dawned on me that my silly event was obliquely related to EMS 2.0.

Woo hoo! That's enough to go with. And I can use "EMS 2.0" in a blog post! I've arrived!

OK, seriously....

While the aspects of EMS 2.0 I have seen the most of involve a more dynamic outcome-based approach to providing initial contact medical assistance, to best utilize our resources, the aspect getting slightly less coverage as I see it is on the initiation side.

This is of course assuming I know what I am talking about. Perhaps I should stick with the power line stuff.

Anyway... I'm not sure how to move away from our current EMS initiation model, due to the litigation-driven culture we exist in here in the States, but at some point we have to stop throwing resources at problems when they're known to be not needed or not even asked for.

And so here's my silly personal story.

I was minding my own business, driving in the City, when I stumbled upon a two car "T-bone" blocking collision. As I pulled past the vehicles doing the automatic habitual size-up, it looked like all occupants were out, no airbags. It wasn't that hard of a hit.

I pulled off the road and made sure my cell phone was handy, but didn't want to call it in until I had useful information for the 911 dispatchers. As I approached, the drivers were moving their vehicles off the road.

No spills, no major hazards, no traffic problem. Looks like I am not needed. Still, I checked with them to be sure.

One of the drivers asked for law enforcement. All involved explicitly denied any desire for fire or EMS. Now, I am not convinced the brothers in blue are needed, either, for a non-injury accident with no tow truck required. I mean, c'mon, let's trade insurance info and move along. But they asked, I had the phone, I said I'd at least pass along the request.

911 Dispatcher: 911, what is your emergency?
Grumpy Dispatcher: Hi, this is firefighter Grumpy, I'm on scene of a non-injury, non-blocking accident at 45th and Main, and I have one of the drivers requesting law enforcement, if you have any units available.
911: You say there are no injuries?
GD: That's affirmative, all three involved parties are out and not reporting any injuries. One of them is rubbing her neck, but they're all OK.

What the heck, why did I just say that? Dang it, now I've gone and done it.. Crap.

911: You said someone is holding their neck?
GD: (sighing) Yes, but they have already declined medical attention.
911: OK, we're going to go ahead and send fire and medical just to be sure, so they can get refusals.

I had already played the FF card, so if my advice was going to be followed up front, we would not already be this far. No value arguing now.

GD: Well, since they've declined EMS, a Code 1 response is probably appropriate.
911: OK, they're on the way, thanks for calling.



The drivers are exchanging information now. I approach to tell them that fire is on the way even though I said they weren't needed.

A minute or so later, I hear them. Yeah, 'hear'.

Rescue 14, then Engine 14, and then a private Medic arrives. All Code 3, all busting the nearest intersection to get into the parking lot we're in.

I sheepishly apologized to them and gave them the quick rundown. Refusals were obtained. Units returned to service. The guys knew the score, this kind of Code 3 refusal errand is not unusual here.

So at what point do we go back to realizing refusal forms need not be filled out unless crews are on scene in the first place? At what point can a dispatcher follow the advice of a verified FF to modify a response, or to cancel one... or not start one in the first place? If I had been on the radio, the cancel would have been heeded. Why not by phone? I'm still FF Grumpy, so why does my authority change depending on how I communicated?

EMS 2.0, we eagerly await your arrival. We'll be at the dock, waiting. Unless we're on our way hot to get another legal document signed.

Tuesday, October 20, 2009

Identifying the T-Shirt Firefighter in its Natural Habitat

This is a Public Service Message. Don't be a T-Shirt Firefighter (TSF).

I'd like to assist you in identifying a TSF should one be in your vicinity. You may be acclimated to their presence and no longer recognize them. Worse, you may be one and not realize it. Acknowledging you have a problem is the first step to solving it. I recovered. So can you.

A TSF is a firefighter who attaches more importance to wearing a uniform fire department T-shirt than knowing or doing the job itself. TSFs come in all varieties: Career, part-time and volunteer, even non-firefighters have been known to be a TSF. A TSF will wear a uniform T-shirt to all events, even a wedding or funeral, just so everyone 'feels safe' and the ladies know or assume his career.

When wearing a uniform T-Shirt, the TSF will make sure his back (with the largest-possible white lettering "FIRE" etc.) is frequently flashed towards other potential alpha males in the room to discourage them from approaching mating females near the TSF's territory.

Fledgling TSFs may attempt to mimic older, experienced Real Firefighters in ways similar to certain insects that have evolved markings to resemble something different and generally more dangerous in order to ward off enemies. One such method is to repeatedly wash and wear their shirts so that they look well-worn. This leaves the impression that their plumage has naturally faded due to exposure to The Job. This actually is quite easy to accomplish, since they wear the T-Shirt almost every day anyway. It is frequently possible to distinguish the TSF from the Real Firefighter by comparing the relative age of the wearer with the apparent age of the T-Shirt. When the T-Shirt appears older than the wearer, you have likely found a TSF. There are exceptions, as some TSFs live to a fairly old age. Actual Firefighters use old shirts for painting, working out or sleeping, but never on duty or in public.

Sophisticated TSFs that have evolved beyond the basic T-Shirt appearance have developed alternative plumages which come in many forms, a few examples of which are below.

More mature TSFs which desire something additional to display to other potential alpha males than their shirt alone have adapted accessories to this purpose. The preferred accessory is a portable radio, especially when a simple pager would otherwise be adequate. Newer modern compact designs are beginning to gain popularity but there is still no substitute for the unmistakable bulk of the Motorola HT600 or MT1000. Additional radio size can be gained by wearing this radio using a leather wraparound holster hanging off of a belt or a shoulder strap with a reflective stripe, and additional flair can be added by labeling the radio or holster with "METRO FIRE UNIT 565" etc, using reflective or high contrast materials in the largest size possible. This is as close as a pedestrian can come to resembling a Big Red Truck.

Fledgling TSFs can compensate for their lack of radio by obtaining a hand-held scanner from Radio Shack and affixing similar labels to disguise their decoy scanner as a real radio. In all cases, the radio accessory can be enhanced by insisting on wearing two or three pagers and a cell phone alongside it. Seasoned accessorized TSFs usually are unable to wear their pants level due to the resultant drag on one side, and the many accessories may even cause a slight limp over time that can conveniently be implied as an old firefighting injury.

TSFs not satisfied with the radio accessory alone have adopted some behaviors exhibited by the T-Shirt Medic (TSM), namely equipping themselves with pocket CPR mask carriers which are replaced as soon as the printed "CPR MASK" wears off the case. The second most-favored borrowed accessory is the glove pack, rendered most effective if the ends of two gloves are visibly hanging out of the pack. Other variants on this behavior include displaying shears, seatbelt cutters, first aid tape, penlights, etc. It seems inevitable that evolution will eventually result in a day where TSMs will attempt to carry a small six-minute O2 canister strapped to their leg, an ability which will no doubt soon be passed to the most advanced TSFs.

The mating call of TSFs - which they may continue to broadcast despite its dubious effectiveness - is the sound of a pager or radio dispatching a job at the loudest possible volume in any part of their natural environment, which includes worship services, movie theaters, formal dining establishments, etc. A determined TSF also uses the mating call of competing TSFs as well as Real Firefighters by emitting the mating call of every agency within a 50 mile radius as if it were its own, and showing grave concern over "white smoke seen coming from a chimney" for an agency three districts away. When actual mating possibilities seem dubious despite the mating call, the TSF may attempt to save face upon their exit by departing as if off on an important mission, regardless of whose mating call was actually used in the failed attempt.

Now that you can reliably identify the TSF should one have established their habitat near you, you are able to avoid or rehabilitate them as seems prudent to your situation.

That is all. Be safe today.

Sunday, October 18, 2009

Fire Hydrant as Grounding Rod Fail

Deftly blending power grid stuff with fire department stuff yet again... not sure how long I can keep this up!

Actually, attaching your neutral grounding wire to a hydrant is electrically very effective. Obviously, not such a good use of fire protection resources, though.

Saturday, October 17, 2009

Tutorial 8: Introduction to System Protection

What have we learned so far? We know the difference between AC and DC power, how energy is scheduled and accounted for, how it is decided which generators will run and how high, how interconnected power companies help each other out when they lose a unit, and quite a bit about power lines from big transmission to little distribution.
Has this been helpful so far?

Today's topic is in regard to why the system protects itself when bad things happen.

The system protects itself for two reasons: To prevent damage, and to maintain stability (ie. not collapse the whole house of cards). Although the correlation is not precise between fire hydraulics and electrical flows, nonetheless major system disturbances can have far-reaching and disruptive ripple effects that could be compared to the water hammer effect.

Extremely high or low amp flows and voltages pose a real threat of causing permanent damage to everything exposed to the swings, from multi-million dollar substation transformers all the way down to your DVD player. It is far better to instantly disconnect the world and drop the whole potato, because if you save the equipment, you have something to put back together. If you disconnect late, there isn't much point in trying to restore a system made up of fried parts.

When voltages and flows go to pre-programmed extreme limits (by line/equipment faults or simple overflows), protection systems activate to remove elements from the system in order to prevent damage to the transmission infrastructure, and also to prevent damage to customer equipment. It isn't unusual for a 'ripple' to occur when elements are removed, resulting in momentary spikes in flows and voltages, sometimes causing more elements to be removed, causing more ripples, causing.... yeah. There are well-paid transmission protection engineers who spend their careers trying to balance instant protection of the assets with not crashing things worse. Frankly, I find that stuff fascinating, but don't want their job.

It is a testament to those protection engineers that hundreds of major transmission lines and thousands of distribution circuits trip out as a matter of routine every day all across North America for all reasons imaginable, yet system protection isolates the problem so quickly that the vast majority of problems are cleared in seconds or a fraction of a second. Unless it is a distribution circuit that tripped and you're on it with several hundred other people, you don't generally notice that anything happened anywhere else.

The August 2003 Northeast blackout in the United States was a major comedy of errors and things going exactly wrong. How is it described by those dissecting airline disasters? An unfortunate sequential confluence of unforeseen events, or something like that. Super rare. It will happen again, but the 99.999999999% norm is that it doesn't, which is remarkable when you take in the scope and complexity of everything that goes into this machine.

For what it is worth, system disturbances do cause split-second bumps that go by faster than a blink of the eye in areas regional to the problem. Most dispatchers are attuned to that, and see it in a momentary hiccup in the lights several times a day at home and at work, often knowing a trip alarm is coming one or two seconds before it appears on the console, or wryly smirking when seen at home, knowing that some dispatcher is about to get interrupted. Sometimes we see it and the alarm doesn't come in, because it happened on a neighboring system. That said, these happen so fast that almost no one else notices them at all. Which is how we like it.

System protection is done in layers, in a way that breaks up the chain of transmission from the power plant to your breaker panel into many segments. Each segment has something protecting it, and each segment has at least one higher level of protection in place if the first one fails. And if the backup fails, the backup is backed up at the next level. And so on. Sometimes protection settings are not tight enough or sensitive enough (to wit: Must-See Video of Line Fault and Reclose) and issues happen, but the concept is generally very reliable.

I think that's enough for today. It's Saturday. You get the general idea, but no math or excessive technical jargon, nor homework.

What we learned: There's a ton of mysterious stuff set up out there designed to prevent blackouts, by removing faulted and overloaded parts of the grid faster than Barack Obama earns Nobel Peace Prizes. Oops, I said I wasn't gonna do that again. Sorry. And if you know a dispatcher and you see a minor nervous tic once in a while, don't worry about it, they just detected a line fault hundreds of miles away with their spidey sense, that's all.

Technical stuff next time. Don't worry though. It's pretty cool. Well, to some of us. Take it easy for the rest of the day.

(Click this link to see all posts tagged "tutorial")

Friday, October 16, 2009

De-Motivational Poster

I'm not planning to make this blog political or anything, but after recent events I couldn't resist putting this little gem together.


Oops, there went a bunch of followers. I knew I shouldn't have posted anything political. I was no fan of George W, either, OK? Oh well, I'll try to not let it happen again.

The next Tutorial will be forthcoming in the next day or so. In the meantime, stay safe out there.

Saturday, October 10, 2009

Taking Care of the Children

So what do you carry on the Big Red Truck to take care of the kids?

No, I'm not talking about peds and infant-sized airway stuff, small cuffs, or the somewhat horrifying peds BVM and AED pads... I get a small shudder from the thought of the next time I will need any of that stuff. Oh, how those calls just... suck. Having children of your own... well, if you have kids, you know, I don't have to go there.

But that's not what I am asking. What do you have to take care of the kids when they're not the primary reason you're there?

One of the Captains established the 'Kid Kit' several years ago, and it is checked at the beginning of every shift along with everything else on the dailies. The kit includes the kind of stuff many of us are giving out right now during Fire Prevention Week in the states: coloring books, pencils or crayons, stickers, those flimsy fire helmets, and other sundry prizes. Of course we also carry at least one 'Trauma Teddy' on each piece, but that isn't always the thing you need.

We use it fairly often, but one specific episode still stands out to me. We arrived to the home of a female having a nondescript but legitimate medical emergency. There were three small children present and no other caretaker was available. Arriving 2nd due, my personal presence was not really needed. I saw that there are three very worried children observing us, clearly aware that Mommy is quite sick.

Thank you, Captain Bill, for the Kid Kit. I returned with it and showed Mommy what I had in front of the little ones, so they saw that Mommy approved, and then shepherded them all to the kitchen table. Soon all were distracted by coloring books and stickers. A trauma teddy works to comfort, sometimes, but it doesn't distract like a coloring contest with your siblings.

By the time we moved Mommy to the cot and headed to the door, Mommy had made it clear to the kids that a couple of us would be watching them for a bit, something we were happy to do until child services or PD could make the scene. I told the kids, truthfully, that Mommy was going to be OK and probably back home soon. Those kids were so relaxed that they stayed in their seats and waved Mommy goodbye as she was wheeled out.

The popular Trauma Teddy idea is a nice start, but its applications are limited. It doesn't take much to expand that kit a little bit, and the returns are worth it. Happy parents tend to then think highly of us, and are more likely to vote 'yes' for much-needed funding measures, and are more likely to tell their friends to support us as well. We all know how fast bad PR spreads, but good PR makes the rounds, too. The good PR earned with your Kid Kit is worth exponentially more than the monetary cost invested to put it together.

My suggestions for your Kid Kit inventory:
* Coloring Books
* Crayons
* Gimmick Pencils (three-color or bending, etc)
* Erasers
* Rulers (a universal toy!)
* Mini flashlights
* Small wind-up toys
* Play stickers
* Badge stickers
* 911 stickers
* Play fire helmets

Obviously some of these things don't go to the choking-hazard set, but you knew that already.

Give it a try. I bet many of you, especially the fire guys, already have a lot of these things in a supply closet at the station. Throw some of this stuff into a bag and put a rudimentary Kid Kit in service today, and see where it goes from there.

Thursday, October 8, 2009

Wednesday, October 7, 2009

Must-See Video of Line Fault and Reclose

Check this out:

If you've read over the previous two tutorials, you'll note how far above the three phase feeder these wires are, which makes this at least subtransmission voltage. I am guessing by what I can see that the involved circuit is probably 69kV - but don't hold me to that.

These people are entirely too close to this action. If the conductor were to melt and break from the heat of the arcing, the wire would recoil quite a long ways, and fall into the feeder, making more fireworks. These people are living out 'If Only We Knew How Stupid We Were'.

The extended duration of the fault is clear evidence that you cannot always depend on transmission or distribution circuits to clear quickly after a fault. We'll get into system protection and fault clearing in a future tutorial.

In any case, you spent most of your time watching that clip with the sustained arc in the tree, imagining how much power is in there. But then, when it finally 'flashed' at 4:02, that's when the full force of the 69,000 (?) volts coursed through the tree. You can see that I am not overstating the force when I make snippy comments about arms getting blown off.

Finally, it's dead, it's safe. Wrong. You saw it yourself, the line came back to life 10 seconds later through automatic reclosing, and carried the fault current for an additional 5 seconds. In addition, though it didn't seem to happen here, chances are excellent that after the second clearing event, a dispatcher may have waited a minute or so and then manually tried it one more time in case whatever was wrong had time to fall away.

That's all..... 'nuff said.

Thanks to Dave Statter for bringing this to my attention through his blog.

Why Tutorials 6 and 7 are Worthless

It's great and all that you can marginally identify stuff on the pole... as long as things are intact. But when things are intact - speaking mainly to my emergency services brethren - you are far less likely to be involved in the first place. It is when things are not intact that all bets are off. What good is it knowing what's what when it looks like this over the car wreck you're working?

Hands off. Call for backup from the power company. Keep everyone out. But, you knew that already.

Tuesday, October 6, 2009

Tutorial 7: Identifying The Wires, Part II

Welcome back. I have some old material that I wrote a ways back for another cause that I am bringing in here to recycle, in order to expand on the cause of identifying stuff on power poles. I took all of these pictures myself, so am more familiar with what's in them than the generic reference pics I used in the last tutorial.
This is going to be a VERY long post. Go refill your coffee now, get your potty break in, and then come back when you're ready to sit a spell. I am confident that, despite the length of this post, you'll be pleased with the information you pick up from it.

I think it is high time to put in a disclaimer, however.

I am a power dispatcher, but I have never been a lineman. I know enough about this subject to sound like I know what I am talking about, but any lineman knows enough to make me look clueless. If you are dealing with someone on site who should know what they are talking about (power company field employee), don't rate my info better than theirs.

Click on these pictures in order to open them up in a larger window to see better. If you 'right-click' the picture, you should be able to choose to open it in a new window, so you can have the picture up full size while also reading the text.

In this picture, three conductors of this 14kv feeder are coming in from the upper left, and traveling towards the lower right, they are the wires at the very top of the front pole.

Under the top crossarm of the front pole there is a three-phase tap (all three conductors are tapped), and these travel downward in the photo to the pole across the street where they are then on the very top as they go off the left side of the photo. Also, on the right side of the lower crossarm is a single phase tap that travels off the right side of the photo.

So far, all of what has been described is 14kV, bare cable (not insulated).

Now, across the street you see the streetlight on the back pole. Just above where the light attaches is a triplex cable. Off the left side of the photo and out of view is a poletop transformer that steps down the 14kV to something the street light can handle, and the 120v insulated cable coming back from that transformer is wrapped around the neutral to form the triplex. The triplex then extends to the front pole and terminates. You can see on the right side of the front pole that the triplex at one time continued towards the right, but it is no longer in use, as the right side has been disconnected and is bundled back towards itself. The triplex on the left is hot, the triplex on the right is not (I only say this because I know what happens to the triplex off the right side of the photo, it dead-ends at nothing). Also, at the same point on the front pole, you can see the lone neutral wire coming in from the upper left and following the single phase tap off the right side.

Below the neutral is telecom stuff (cable TV and/or telephone) on both poles.

Remember that ANY wire can be hot: Neutral, cable TV, phone. Say for example a power pole is broken as a result of a traffic accident. The innocuous neutral or cable TV line may have whipped backwards and draped over a high voltage line before landing on the ground. Always visually trace the path of wires on the ground to their source regardless of the kind of line that is on the ground! Check for things contacting the guy wires, too!

This is a different section of the same feeder. The 14kV uninsulated conductors are on the top crossarm.

Just below the crossarm is the poletop transformer, stepping the 14kV down to 120V. If you look very closely you can see that only the back of the three phases is tapped by the transformer. A solid rule is that a lone poletop transformer will only be connected to one phase of high voltage. As you go down a feeder you will see how transformers are tapped off of the different phases more or less sequentially (A B C A B C etc) to equalize loading on the three high voltage phases. That little gadget in the tap between the conductor and the transformer is the fused cutout, the fuse is a cylinder not quite 12" long in a spring clip or hinged apparatus. It can be opened/removed to de-energize the transformer and its taps.

Under the transformer the customer taps fan out. These transformers frequently may have only one tap, but there is no reason they can't have several, like this one. Starting with the first one that points almost straight left and going counter-clockwise, the first one goes to a house, the second one goes to the next pole (and thus is on the main neutral) to serve a street light, the third and fourth go to houses. The wire heading sharply down towards the right is just a guy wire. Heading from the transformer off the right are two more lines. One goes to another street light across the street, and then above that you can see the bare neutral going off the right but staying on this side of the street. Remember, all of these insulated cables are at the same potential as household current, so although a hazard exists it's not big time stuff.

Under all of that is telecom.

This is a fused poletop switching point. Each of the three phases has an inline fuse (basically like the poletop fuse in the last post but with a higher rating). The fuses will pop as needed so that the entire feeder doesn't have to go dark for a fault on the far side of the fuses. Since it is a switch, the three fuses are attached to hinges so they can be collectively opened for work clearances on the far side of the switch.

This one is a little more complicated.

You see the familiar three phases on the crossarm on top. On this pole, all three phases are tapped to inline fuses on the right side of the lower crossarm (at a right angle to the upper crossarm), then onto small insulators on the left crossarm and then into individual transformers. This is a large customer requiring three-phase service. The three phases and the neutral are individually tied to the pole instead of them being wrapped together, so you see four wires leading to the customer, but often they will be wrapped together and referred to as quadplex. You can also see that one of the low side lines is tapped for something else since it is running wrapped around the neutral to the far pole for something else.

There is some increased danger here. The three phases are tapped into inline fuses before the lower crossarm, and then converted into insulated cable before heading into the riser tubing and going down the pole underground. Note that there are no transformers in sight on this pole. This means that the cables running down the pole behind a little flimsy sheet metal are a full 14kV. Smack a car into this pole hard enough and/or in the right place and you'll get a dandy light and sound effect show for a second or two until the fuses blow. Long enough to kill you for sure. Tread carefully here.

I think everyone can identify the neutral and cable TV/phone here, right?

Another poletop switch, this one with bladed disconnects on the top of the crossarms, is on the right pole. A three phase customer is tapped off of the pole on the left. Linemen like this kind of switch a little more because it can be opened without a bucket truck. If you look close at the pole on the right you'll see a control rod going down the pole. This can be operated by hand with a hotstick while standing on the ground. Some control handles go all the way to the street level, and in these cases the control is locked in position with a power company padlock.

You might conclude that in an EXTREME emergency, you could theoretically open the switch, but this is a bad idea in every way. Linemen wear linemen's gloves for this kind of switching (for all switching, actually), because you never know when the switch is going to fall apart and something energized falls into the switchgear. Plus, you'd have to know without a doubt that there was no potential from the other side of the switch for it to be worth your trouble. And don't forget some dope might have an incorrectly installed generator on auto start on the dead side which would heat you up a few seconds later. Or... there might be an "auto flop" configuration installed by the power company to automatically energize from somewhere else down the dead line in an attempt to restore some customers after an equipment failure. You can see why there are far more chances of failure than success, plus major personal safety hazards in attempting it. Just put it out of your mind.

The picture on the left is a better angle on the this switch and control rod - that you won't be touching.

Here we have the point that three phases are split into different directions, but they are still elevated distribution voltage.

The three phases come in from the upper right. The left phase can be seen as tapped to the upper wire going off the left. The middle phase dead-ends here. The right phase taps off to the upper wire going off the right. You have to look close to see it, but the second wire that looks like it is right next to the right phase is actually the neutral and goes to a point on the pole about 3' below the crossarm, and it also splits so a neutral is continued with each of the tapped single phases.

The three wires going downward on the left are guy wires. Since this pole is a dead end, there is a lot of tension pulling in one direction, the guy wires make up the difference so the pole is not yanked over.

What you have here is some 34kV subtransmission on the right side tapped to underground. While it is underground and out of sight, it goes off the picture frame about 200' to a large pad-mount transformer where the voltage is reduced to (I think) 8kV. That's still 8,000 volts even on the 'low' side. Then it comes back through the underground and back up the pole on the left before being distributed by feeder to local customers. On both poles you have three phases of either 34kV or 8kV behind a relatively flimsy shield of sheet metal.

Even though there are not major differences in the size of the insulator bells on either the 34kV or 8kV to help you figure out which is which, the different sizes of the cutout fuses ('C'-clamp looking things) mounted below the crossarms gives the difference away. High side, low side, doesn't really matter, it'll all blow your arm off.

This is next to a two-lane 60 MPH highway. Can you imagine what would happen if a vehicle took out one (or both) of these poles and also careened into those propane tanks? Big Fun!

Over here on the left, doesn't look like much, but this is 115kV, about 8 times higher voltage than most of what we've been looking at so far. Note the two shield wires above the three conductors.

This is outside a power plant.  The other wires crossing by are a distribution underbuild (meaning it runs under something larger), of the 14kV variety we've already been learning about .

Over on the right, this is twice as much voltage as above, 230kV. Again, note the shield wires.

On the left, this should keep some people honest... this angle shows that the wires some people are afraid of (because they are on lattice steel structures) can also be found on wooden pole structures that aren't as visually menacing. The voltage is the same on all of these, all 230kV stuff from the same substation. Note the quantity of insulators instead of judging by the structure. Better yet, stay away no matter what.

This is 34kV subtransmission coming in from the upper right and being stepped down to (I think) 8kV distribution. This is a cheap way to get around building a proper substation behind a fence. The box on the second set of poles is a field recloser, the device which will open for a fault farther along the low side and then may attempt to reclose the line one or more times. If the fault self-clears, the customers see an outage of a second or two. If it doesn't clear, the recloser will give up and stay open.

This tower on the left is one of the big dogs, a 500kV line, over twice again as big as the last big line picture earlier in the psot. If this is laying on your structure you better be a long, long way away from it.

As mentioned in the last tutorial, one clue to extremely high voltages is the presence of multiple conductors per phase. In this case, each phase is made up of three cables. You can see little triangular brackets holding them in place along the line. Then there's those really long insulator strings to clue you in.

Once again you can barely make out the shield wires way up on top.

On the right is a close up of the triple conductors on the 500kV line.

The parting shot illustrates another exception to the rules. I kept going on about high voltage transmission lines always being present in threes, and here you can see there are only two conductors on what in every other way looks like high voltage.

This is one of the small handful of high voltage DC transmission lines in North America. Six DC lines tie the Eastern and Western electrical interconnections across the Rockies, two DC lines tie Texas to the rest of the U.S., two DC lines tie Quebec to the world, and there are probably no more than 10 or so major DC lines anywhere else in North America. Other than the interconnection tie points, they always go a long long way (many hundreds of miles) when they are built.

All major AC lines, the stuff that makes up 99.9% of the grid, are three phase and require three conductors to be in service. DC lines are singular, thus you can run either one of these individually, but normally both are in service. So, despite the 'rule of threes', here is a way you can get one or two cables of high voltage, and these run at around 250kV. The long insulator strings should give away the high voltage present, anyway.

What we learned: (1) You can now impress your friends and coworkers by identifying the clutter on poles. Impress them further by showing that you know enough to stay away from all of it no matter what. (2) The Grumpy Dispatcher's posts are waaay too long, except for those nifty FAIL pics he puts up once in a while.

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Monday, October 5, 2009

If Only We Knew How Stupid We Were

If only.... if we knew in advance, some of us wouldn't make so many dumb judgement calls.

Calling upon the topic of the previous post, we were dispatched to a report of... what else... power lines down.

Man, is it just me, or does this power company stuff cross with fire department stuff just a bit too often here?

I arrived with the first Big Red Truck, and one of our newer kids had arrived just ahead of me in his personal vehicle.

An aside. If you're one of the new fire kids, I have a general observation for you: Generally, you have no awareness, no fracking idea of 95% of the crap that will kill you in this job. You're thinking, yeah, that's those other new guys, but I read the trades, I participate in training, I work out, I study on my own... he's not talking to me.

Um... yes, I am in fact talking to you, too. But thanks for your extra effort. It doesn't hurt.

You will spend at least the next 20 or so years being continuously surprised at what, except for the grace of God, almost killed you, that you never imagined coming. Get used to that feeling, respect it, and slow down.

Anyway, back to the story....

I get off the Engine and size up the situation. There is no traffic accident at this intersection, so no clear reason for anything to be on the ground. Red Flag. What happened that I can't see? It might just have done falled down, but I don't know yet. It is telecom wire. The three phase primary and neutral are intact. There are no immediate hazards. By my trained eye, it is "probably" safe.

Then I see new kid, walking right up to the wire. Oh no he isn't....

I call at him to hang back. He, being the new young stud who attends more classes than I do and is on the list to get hired at the nearby City, hesitates for a half second and then ignores me, pretending he didn't hear me.

With apologies to Dave Barry, I swear I am not making this up, he kneels down, reaches out to the wire tentatively, and then does this kind of fast-touch-and-pullback thing... kind of like when you're using the least-intelligent way to see if the burner is really hot. What, you're testing for a buzz to see if it's live?

I don't remember what I said after that to get him to back off, but I admit it probably wasn't professional. Even then, he sauntered back like he was done doing what he wanted on his own terms.  Smooth for a guy who has no idea of how dumb he just was.

I brought him behind the engine, mostly out of view and tore him a new orifice right there. I didn't wear an officer's helmet for nothing. Being ignorantly stupid is marginally excusable, but ignoring an order is most assuredly not. But the issue of obeying orders is merely ancillary to the story... I digress.

So here is the rundown:

#1 - The fact that he was 'testing' the wire tells me he is not able to differentiate between the various wires on the pole, and had no idea what he had in the first place.

#2 - If it had been a live service wire, 120V is still capable of killing, so why dink around with it? The ability to turn around and say 'it's hot!'? For what gain?

#3 - If it had been a live service wire, the electric current could have induced a muscle contraction, which would have resulted in his hand instantly and involuntarily grabbing the wire before he could pull his hand away. And then he'd just be there, holding it. Do I smell burning bacon?

#4 - If it had been the 14kV primary live on the ground: Kaboom. Almost certain death, and although a body would have remained for the funeral, a hose line to clean some of the mess would still be in order.

There were no hazards, no threats to life safety, it wasn't lying in the road, there was no traffic problem and not much of a pedestrian problem. All that risk playing with he knew not what, for zero benefit.

I tried to teach him in later days when I calmed down. I don't know if it stuck.

If only he knew how stupid he was. If he survives long enough, I don't expect him to fully grasp his situation from that day until he's at least 40.

To be fair, I've been doing this for many years, and I am only just beginning to realize how stupid I still am sometimes. I blanche to think about the dumb stuff I've done and somehow survived.

If you're a new kid... whatever you do, it won't be enough. You'll still vitally depend on your officers and mentors, and you'll still need a lot of luck. Do your part to not stack the odds further against you.

Now you know how stupid you are. We all are now and then. Now that you know, there are no excuses. Slow down, really slow down, and hopefully you'll go home after every call. Good luck.

Saturday, October 3, 2009

Tutorial 6: Identifying the Wires

Last time we learned, at a very high level, about the different voltages of power lines used to get electricity from the generation station to your power outlet. Along with that we touched on the concept of voltage as pressure, how it is raised at the generation station so that the electricity can be efficiently moved closer to where it will be consumed, and as it gets closer to the end user, it is gradually dropped in steps, depending on where it is going, until it is stepped down to household current right before it goes into your home.

Please understand that there is so much more, and I mean a lot more, stuff to be learned about this if you're technically minded and interested. I am intentionally only glossing over a lot of this stuff, as my intent is to make you, my patient and suffering readers, merely aware of what is going on, and not trying to make any of you experts. If I am successful in imparting this basic awareness of how stuff works, then it theoretically will make you understand my rants and grumblings. Isn't that pathetic of me? Deliberately teaching you guys so that I can rant, in order that you can nod in empathy and agree, yeah Grumpy, that sure is lame. Manufactured sympathy!

OK, enough reflection. What a buzz kill.

Today, we take a first look at what is on the transmission towers and power poles.

The overriding rule of always is: EVERYTHING IS DANGEROUS AND SHOULD BE CONSIDERED ENERGIZED. Even if you know what it is, don't touch it, EVER. I'll get into that more later.

First up: High voltage transmission. It's easier to sort out.

Pictures 1 and 2 you'll probably want to click on to view full size at some point. Both illustrate the same thing, though. High voltage transmission is always three-phase, meaning each circuit consists literally of three sets of conductor. In Picture 1, there are two circuits on the tower. In Picture 2, each tower has two circuits, for a total of four circuits in this power line corridor.

You'll note that in Picture 1, each phase consists of a bundle of four individual wires, while in Picture 2, each phase consists of two wires. Added wires is like a larger hose, less resistance, better efficiency. Typically, you'll see single wire phases up to 230kV. Two wires per phase starts to appear at 345kV. Three wires at 500kV and up. But there are exceptions. The number of insulator bells also is a good indication of how high the voltage is, but there are different manufacturers, ratings, and sizes of the bells, so the actual number doesn't mean as much as the overall distance. None of this really matters much from our point of view though, as all of these will pretty much flash-roast you if you touch them.

In both Picture 1 and Picture 2, if you look close, you'll see a couple of faint, thin wires at the very top of the structures. These are called static wires or shield wires, and they are grounded at every structure. They are not energized, per se, but you can frequently detect voltage on them due to induction from being so close to the actual power lines. Literally, the invisible magnetic field around the power lines passes close enough to induce voltage in them. Their real purpose is to provide a preferred target for lightning strikes, by being grounded, they draw the lightning bolt away from the power lines themselves. They are not used to carry a current, but they are still entirely unsafe to touch. Sometimes power companies also run fiber optic cables along side or attached to the static wires, because the existing power grid infrastructure provides a ready-made grid useful for laying down an information/data grid. The power company uses a tiny, negligible portion of this bandwidth for data transfer between stations, and can lease the remaining bandwidth to cable, telephone and data providers.

That's basic transmission. Not too complicated. Subtransmission lines, say at voltages down around 34kV-69kV, will be similar in concept if not design. Smaller towers or more often wooden poles, three phases of single-wire, a single static line sometimes but not always. The main thing is that subtransmission usually remains uncomplicated, unlike the distribution stuff we're about to get into.

Picture 3 is a distribution pole. As a rule, the most dangerous stuff is at the top of the pole, and decreases in its danger score as you go down.

From the top down, then....

Three-phase primary, I am guessing somewhere between 8kV-14kV. The wires coming from either direction are installed as dead-ends, and are attached to the ends of the insulator strings. The dead ends from either direction are then connected with "jumpers" that are attached to the wire on each side and are held in place by an insulator on top. Although not preferred compared to an actual line switch, these jumpers can be detached from either side to "open" the circuit.

The sharply angled wires leading down to the right are guy wires, used to brace or hold the pole in place, entirely expected on poles where the circuit takes a turn, and as you can see the three phase is turning slightly to the left at this pole. Without the guy wires, this pole would want to be pulled to the left by the weight and tension of the primary.

The next single wire down is the neutral. It is grounded at frequent intervals along the circuit (ideally at every pole), and leads back to the big transformer neutral at whatever substation(s) this circuit travels to. The neutral is also extended to each customer service drop and ultimately grounded through the grounding rod at every customer site.

When you see the "braided" service drop at your house, there are usually two "hot" wires, with black insulation, wrapped around an un-insulated cable that carries the tension from the pole to your home. This bare cable is also the neutral. Since there are typically three wires total, we call this "triplex".  You can see some of the triplex here, the hot insulated wires coming from a nearby poletop transformer and apparently provided to power the streetlight.

The last wires on the bottom are nondescript telecommunication stuff: Phone, cable TV, etc.

Picture 4 is a single-phase distribution pole with a "fused cutout" and poletop transformer.

Again, from the top down....

Single phase primary.

Hard to make out is where the jumper is attached to the primary, but you can see just to the right of the top insulator, the clamp where the jumper is attached before it runs down to the fused cutout. In plain terms, a 'fused cutout' is a device that can be used to open the circuit leading down to the poletop transformer, and the part that can be opened also serves as a fuse which will blow and cut off power to the transformer if it were to fail.

Poletop transformer.

Neutral and service drop wires.

Clear as a bell or clear as mud?

What I want to leave you with, particularly regarding distribution poles, is this: There are no guarantees of safety about anything. You never know when a high voltage primary is damaged and has dropped down into some of the other stuff. Usually when this happens, if things are grounded properly, the resulting fault will cause a fuse or substation circuit breaker to open. Usually. On the other hand, what if you're touching something "safe" at the moment something "unsafe" falls into it? Depending on the sensitivity of the protection on that circuit, it could take up to several seconds to clear the fault, and in that delay your body would bear the brunt of it: You're dead.

A traffic accident involving a pole can tweak/whiplash all of the lines for blocks in all directions. So let's say you stumble upon a "benign" telecom cable hanging low, and you "know" it is safe, so you grab it to move it out of the way. Little did you know about the car that smacked a pole two blocks away, causing the primary at the wreck to fall onto the telecom, and the recoil/whiplash simultaneously causing the telecom in front of you to break loose from a mount and hang low. You reach out and... hey, where'd all these angels come from?

Until a power company guy is on the scene and says it is safe to touch, keep your hands off of EVERYTHING. Even when he says it is safe, he won't be offended if you ask him to touch stuff first.

Wow... long post. And I'm really only getting started!

What we learned: Forget what you just learned about what is what, all of that stuff can potentially kill you, even when all you see is telecom and no actual electrical power lines are in sight. Leave it all alone, keep people away, and wait for the power company guy.

So... it's time to ask again. Are these generic tutorials helping? Anything you want me to elaborate on? Too much? Not enough? Any requests for a particular topic?

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