Pat Weldon
Member
Can a circuit breaker that supplies power to a Fire Alarm and Fire suppresion system be locked on? Molded case breaker will trip due to overcurrent. :-?
Lock On
- Thread starter Pat Weldon
- Start date
- Status
- Location
- Massachusetts
Yes you can lock breaker handles on, the NEC even requires that for circuits supplying only EBUs.
As 480 mentioned it does not keep it from tripping.
As 480 mentioned it does not keep it from tripping.
Pat Weldon
Member
Can you tell me in what article in the NEC I can find that ? Thank you very much for your time.
charlie
Senior Member
- Location
- Indianapolis
695.4(B)(2)(2) is a good place to start. Additionally, circuit breakers are to be trip free (240.80 and means that it can be locked in the closed position and still open in the case of overcurrent. Lastly, if there is no place that says you can't lock it, then you can lock it. This is a permissive Code. :smile:Pat Weldon said:
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Funny, I just installed a handle-lock on a breaker this morning for a fire-panel supply circuit I installed yesterday.iwire said:
How far back have breakers had the free-trip requirement? What if the breaker that must be locked on is not of the free-trip design?
This is a GE type TEB breaker, by the way. The lock is a TLD3.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
LarryFine said:
Square D's QO has been trip free since it was introduced in the late 50's.
I remember this topic being discussed when I started in the trade over 30yrs ago.
- Status