Parking Lot lighting wiring sending Fire Control Panel into "trouble"/ "fault".

[craff]

Parking Lot lighting wiring sending Fire Control Panel into "trouble"/ "fault".

Parking Lot lighting- 277/480VAC
FCP signal-10VDC pulse between valves

We were called out to troubleshoot why the Fire Control Panel was routinely going into trouble, only at night, not every night and only within the last month or so. Property is a large big box retail center. The FCP vendor said it must be a electrical issue (knicked wire or ground fault fault). We located the conduit and found the original installer used the same conduit as the 277/480VAC circuits for the lighting. I'm thinking all that voltage is inducing some noise and induction voltage onto the FCP signal wire and causing an " under/overvolt" issue. Any thoughts or revelations are appreciated.

 

[wirenut1980]

Not sure I am sold on induction from the lighting circuit. The lighting is on every night with load probably the same every night. How is the lighting controlled? Is it on one control where they all come on at the same time? If so, I would say look at the fire alarm wiring like the FCP vendor suggested.

 

[gadfly56]

Parking Lot lighting- 277/480VAC
FCP signal-10VDC pulse between valves

We were called out to troubleshoot why the Fire Control Panel was routinely going into trouble, only at night, not every night and only within the last month or so. Property is a large big box retail center. The FCP vendor said it must be a electrical issue (knicked wire or ground fault fault). We located the conduit and found the original installer used the same conduit as the 277/480VAC circuits for the lighting. I'm thinking all that voltage is inducing some noise and induction voltage onto the FCP signal wire and causing an " under/overvolt" issue. Any thoughts or revelations are appreciated.

Do you mean that the power-limited SLC or IDC loops or NAC's are in the same conduit as the 277/480? That's a code violation right there (with some very particular exceptions) and definitely could be the source of a trouble. For addressable panels in particular, if there is enough hash on the line they can't "see" the field devices and will report "device not found" or something similar.