Grounding Fire Sys Cntl Pnl

[PwrBuf]

I am installing an industrial fire control panel in an mcc building and need advise on grounding.
1. The panel is fed from a lighting panel <20' away. Should I pull a ground wire from the lighting panel to ground the fire panel? Do I only bring out a hot and a neutral and use the conduit as the ground path? Does the fire panel need to be connected to buiding steel? I would prefer to just pull a ground from the lighting panel and tie the fire panel ground to that.
2. I have two intrinsically safe barriers on this fire panel that also needed to be ground. Can I connect these to the panel ground provided I meet the 1ohm gnd resistance requirement?
Thanks

 

[alehman]

Read the manufacturer's instuctions carefully. Grounding must be done as specified to maintain intrinsically safe ratings. Lacking other instructions, I would install a separate ground wire.

 

[RajT]

It is perfectly acceptable carry out what you suggested in the first place ie.
The control panel grond connection can be connected to the groung wire of the incoming supply (3c cable with L-N-E)from the lighting DB and grounded in the DB.

As for the IS circuit it too can be connected to the panel ground point and that way you neednot wory about grounding it any further. Contarary to previous thread, it does not need a separate ground in your case.

 

[jbartos]

Question: What kind of conduit is being used?

 

[alehman]

By &quot;separate ground wire&quot;, I meant equipment grounding conductor - a green ground wire other than the conduit which should thypically be connected to the designated grounding point on the chassis. Again - follow the instructions.