Friday, February 18, 2011

Problems in Commercial Kitchens

It has happened again a Kitchen hood Extinguishing system gets accidentally activated
And instead of the Fire Alarm system sounding and calling the Fire Dept. only a trouble signal and then no signal at all. What went wrong someone either the Electrical contractor or the Fire System installer incorrectly wired 120 AC power into the 24 Volt DC fire circuit destroying the panel this time it was a large Institution that handles at risk youth last time it was at a popular Bar and night spot. Both times it was the confusing wiring of the 2 - leaf switch’s 1 for 120 vac and 1 for 24vdc that activates the Fire System and shuts down the hoods fans .The dry powder system at the Institute was over 20 years old and was never activated but was annually tested supposedly by Fire Installing company and the hood servicing company
And no one ever caught the fact after 20 years of inspections the system was wired wrong. In the case of the Bar it was a brand new K-liquid system and the system was damaged as the Electrician grabbed the wrong flying lead wire off of the leaf switch, as he was wiring in the 120 vac hood controls.
UL needs to demand that the design of hood systems contains 2 seprate compartments for wiring like most electrical equiptment as the combining of high and low voltage switches
So close together is an accident waiting to happen especially any time there is a problem with the switches and they need replaced .
Why UL and NFPA have allowed this design to be allowed to be used in this matter is beyond imagination. Talk to any one in the Fire Alarm Industry and they can all tell stories of hoods activating and damaging Fire Systems.
One only has to wonder how many defective installs are out there floating around just waiting for the day it will go off and instead of protecting occupants by evacuating the building and notifying the Fire Dept. instead it puts them at risk because there is a kitchen fire unknown to the occupants, that could be filling the building with smoke.
In some cases the damage to the Fire System is severe enough that the panel is destroyed
And a manual fire signal cannot be sounded to evacuate occupants. In some cases the Fire Systems have actually caught fire.
Of course hood manufacturers need to design a better control box but in the same breathe
Fire Panel manufacturers need to better protect the wiring inputs to there panel possibly by designating specific zones for kitchen hoods. Of course my warning to the industry will once again go unheeded and the lawsuits will keep flying because of inaction by the code makers.

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