Electricity under fire accident?

This is a very important question especially since it is related to SAFETY.

In hazardous industry, (such as Petroleum Refinery, Petrochemical plants) there is likelihood of continuous presence of flammable vapors in the entire premises. This can result in fire spreading to outside fire affected zone,especially during air currents. In such type of installations, it is necessary to cut off electricity to entire premises even if fire has affected only a zonal area.

In non-hazardous industries,and if the fire can be contained within the affected zone through efficient fire protection / fire fighting, the electricity needs to be cut off only to the affected zone.

The area where Fire has started to be cut off. In most factories where risk and spread of fire is high like petrochemical Industry or Textile normally fire doors are used to contain the fire in that section and isolate other areas. However while designing a system local authority fire regulations aspects to be taken into account like Bomba in Malaysia.In India Tariff advisory committee stipulations may help.A very important and good question.

When an area is under fire, the main thing that comes to mind is to cut off the entire electricity supply by switching off the switch-gear or cut-out fuses. Then put off the fire from the affected zone, examine the extent of damage to the electrical system and isolate the area from the DB(using the MCB). Finally switch back the Switch-gear.

If it is residential apartment it is necessary to cut off based on a zonal area but make sure the emergency DC battery pack is always is functional for the alarm and the exit and other emergency lights.

I will state an observation here. Let's say that we are talking about an industrial facility whose fire sprinkler system is equipped with a booster pump. In these cases one will often find that the booster pump cannot be switched off unless it is done at the booster pump controller, or at the building's main transformer. The logic is that power must remain supplied to the booster pump if all power to the building is cut off. One will often find that the pump is not fused either in order to ensure it maintains power even if it is destroyed during use.

I agree that it would be nice to be able to automatically isolate the electrical power in the event of a fire while leaving the rest of the building with power, but that can be done readily with the use of point disconnects-and they should already be in place. For example-let's say that a large HVAC unit catches fire. Just throw its disconnect and remove the power to the machine. Of course some one must be there to perform this task and be out of harm's way when they attempt it.

The best reference would be the most recent publication of the National Fire Protection Association (N.F.P.A.) documents. I realize that you are not in the U.S.A. but fire and fire safety know no boundaries or borders.

If the moisture caused by the tripping of a fire sprinkler causes concern about its contact with electrically-charged equipment, then a ground fault interruption device can be used. Not cheap, but reliable as long as it is tested per the manufacturer's recommendations.