Question regarding fire and electric utility

[codequestion]

I have a question in the event of fire in building and need to shut off electric power what does firefighter typcially do call the electric utilit to shut off poeer or go to electric room and find disconnect to shut off power?

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[USMC1302]

Different Fire Departments have different SOP's, but in the areas I worked, we pretty much had every commercial building pre-planned and would enter the building to shut down power if needed. We had a great relationship with the POCO too, but with manpower cutbacks, response times usually were too long to wait, unless lines needed to be cut. We pulled meters in residential settings when necessary too, with their blessing.

 

[meternerd]

Different Fire Departments have different SOP's, but in the areas I worked, we pretty much had every commercial building pre-planned and would enter the building to shut down power if needed. We had a great relationship with the POCO too, but with manpower cutbacks, response times usually were too long to wait, unless lines needed to be cut. We pulled meters in residential settings when necessary too, with their blessing.

Pulling meters seems like a simple way to kill power, but...as a POCO guy, I personally think pulling meters is probably the most dangerous thing we do. Reason being, you have no way of knowing what condition the meter or socket is in or what load is on the meter. Especially when a fire may have caused wiring damage inside the home. The meter is ahead of any protection and the only thing that will interrupt a fault is the transformer fuse, which can be HUGE!. I can see it being OK to do IF you have proper training and also proper PPE in case of a fault. I won't bore you with horror stories, but if you can get the POCO to kill at the pole, do it! Plus, pulling the meter on CT services does nothing to cut power. Do most firemen know how to tell the difference? Just sayin'

 

[Jraef]

The "Six Hand Rule" regarding service disconnects is all about firefighters not having to move their hand more than 6 times to kill all power in a building. That then ostensibly means the firefighters enter the service disconnect area, be it inside a room or not, to kill power that way. That of course is our ELECTRICAL code, the Fire Marshal for any given area may / will have their own SOP.

Side note to that, I got involved a few years ago in an issue here in California when solar started to take off, because firefighters were killing power to a building, then getting shocked by the solar system when chopping into a roof because it was still making electricity even though it didn't go anywhere. So the local Fire Marshall's group started insisting that solar panels had disconnects on the outside, or else some other way of killing power from the panels. Since the panels were DC, the disconnects had to be rated for that (not all are, especially above 250VDC). But homeowners with "solar roofs" (integrated solar cells in shingles) complained about having ugly gray boxes with red handles ruining their esthetics. I was contacted by a big solar roof supplier. We designed a 600VDC contactor system that went UNDER the roof and was controlled by the house power. So when they killed the Main, it dropped out the control power to the contactor coils and killed the DC coming out of the panels. Sold about 100k of those, now they do it differently (but I'm not longer in that world).

 

[gadfly56]

The "Six Hand Rule" regarding service disconnects is all about firefighters not having to move their hand more than 6 times to kill all power in a building. That then ostensibly means the firefighters enter the service disconnect area, be it inside a room or not, to kill power that way. That of course is our ELECTRICAL code, the Fire Marshal for any given area may / will have their own SOP.

Side note to that, I got involved a few years ago in an issue here in California when solar started to take off, because firefighters were killing power to a building, then getting shocked by the solar system when chopping into a roof because it was still making electricity even though it didn't go anywhere. So the local Fire Marshall's group started insisting that solar panels had disconnects on the outside, or else some other way of killing power from the panels. Since the panels were DC, the disconnects had to be rated for that (not all are, especially above 250VDC). But homeowners with "solar roofs" (integrated solar cells in shingles) complained about having ugly gray boxes with red handles ruining their esthetics. I was contacted by a big solar roof supplier. We designed a 600VDC contactor system that went UNDER the roof and was controlled by the house power. So when they killed the Main, it dropped out the control power to the contactor coils and killed the DC coming out of the panels. Sold about 100k of those, now they do it differently (but I'm not longer in that world).

How exactly does that work?? As long as the sun is shining the panels are producing power. Unless there is a cutoff on the bottom side of each panel, you hit a cable you could get lit up, depending where in the string the cut is.

 

[goldstar]

From what I understand, the volunteer fire co's in my area (and I've asked them this question several times) will contact the POCO's to disconnect power and wait until they arrive on site. They'll actually watch the house burn to the ground before they attempt to shut off the service. Same goes for the gas companies. If there's a gas initiated fire the fire co's will wait until the gas co comes out and shuts off the gas line to the house. The gas co's will not shut off the gas feed to the street (for obvious reasons). If they can't find the gas shut off near the street in front of the house they'll actually bring out a back hoe and dig up the lawn to find it.

 

[USMC1302]

Like I said, different areas have different SOP's. If the fire dept has the ability to do pre-plans and inspections with business/property owners, they may know where all the electrical rooms/gas valves are. We try, but are not always notified when changes are made. Valid point about solar, and include stand-by generators. I think there has to be some discretion/common sense used when securing utilities by the fire dept. If there is a direct-imminent hazard, it gets shut down. Our utility is generally great to work with , they just don't have the manpower they used to, so waiting might change a quick stop into a marshmallow roast. That makes no sense. They host training for us annually, and have a pretty good video of what can happen when pulling meters. We still generally have way more PPE being worn than they do when performing similar tasks.