Maybe I am wrong I will try to find the requirements.

As far as I can recall its not the source of ignition that needs to be killed....the ignition has already happened at the point the ansul trips.

But it is hard to extinguish a fire if heat is still being pumped into the bottom of the fire.

Remember the fire triangle Fuel, Oxygen, Heat.

I have never seen an Ansul system kill the under hood lights.

Bob Badger
Construction & Maintenance Electrician
Massachusetts