Sprinkler compressor

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slipknotbmg

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We will be installing a air compressor for a plant sprinkler system, to convert the existing "wet" sytem to a "dry" system. Am I correct in thinking the feed for the compressor (emergency panel) can be installed in an existing conduit with general power, as I don't feel art. 695 applies, i.e. 695.1(B)2. Art. 760.26(a) seems to be relevent. Any opinions? Also, bossman want to cord connect to receptacle. Would this be o.k.? Fire Systems are my weakness, lol.
 
Re: Sprinkler compressor

Slipknot, the applicable section would be 700.9(B) if your Emergency Panel is infact an Emergency Panel

700.9 Wiring, Emergency System

(B) Wiring Wiring of two or more emergency circuits supplied from the same source shall be permitted in the same raceway, cable, box, or cabinet. Wiring from an emergency source or emergency source distribution overcurrent protection to emergency loads shall be kept entirely independent of all other wiring and equipment, unless otherwise permitted in (1) through (4):

(1) Wiring from the normal power source located in transfer equipment enclosures

(2) Wiring supplied from two sources in exit or emergency luminaires (lighting fixtures)

(3) Wiring from two sources in a common junction box, attached to exit or emergency luminaires (lighting fixtures)

(4) Wiring within a common junction box attached to unit equipment, containing only the branch circuit supplying the unit equipment and the emergency circuit supplied by the unit equipment

Roger

[ November 21, 2005, 09:56 AM: Message edited by: roger ]
 
Re: Sprinkler compressor

The "Emergency Panel" is part of the optional standby system. It is a "Emergency Recp. Panel" for critical process equipt. I have 1 genset. w/ 2 transfer switches. 1-optional standby and 1-life safety. The plan is to put the compressor on the optional system. Does it need to be on the life safety system? It would not affect the operation of the sprinkler system if it failed, it would just allow the system to become "wet".
 
Re: Sprinkler compressor

I have never really understood the logic behind putting dry sprinkler air compressors on the generator. The compressor is only used to recommission the sprinkler system after it has discharged and put the fire out. I can't think of why that would be such a big emergency.
 
Re: Sprinkler compressor

Originally posted by mdshunk:
I have never really understood the logic behind putting dry sprinkler air compressors on the generator.
Click to expand...
Most if not all dry systems leak air, the compressor maintains the pressure in the system.

During a power failure if the compressor was not powered you could have the pressure drop to a point where the system valve opens making the dry system wet.

[ November 21, 2005, 07:12 PM: Message edited by: iwire ]
 
Re: Sprinkler compressor

Bob,
I agree with you, but if there is a power loss, and the dry system becomes wet, then there will be a trouble and/or alarm condition on the alarm panel.
I do not think a compressor requires special power by national code, unless chosen by the designer.
 
Re: Sprinkler compressor

Originally posted by ron:
I do not think a compressor requires special power by national code, unless chosen by the designer.
Click to expand...
I really do not know either way about the code on this, I was just pointing out why it may be desirable to keep the compressor on line.

That said I can not imagine to many AHJs would have a problem with the compressor being run from an article 700 supply.

I think it could be argued it is greater risk to let the system flood and freeze during a power failure than the risk of the compressor causing problems to the electrical system.

What do you think, would I win or lose that argument? :D
 
Re: Sprinkler compressor

First
Is the building required to have a Legally Required Standby System?

I don't see anywhere (At least in the NEC) that would require the air compressor to be backed up by emergency power?

What would happen if a fire broke out and power was out? Nothing. The system would still function as designed, Clapper would still open and flood the pipes, heads would still go off when they get hot enough. Now it could be a problem if the pipes were in a area subject to freezing temps which could render the system useless if flooded and froze? But if this is not the case I don't think NFPA is concerned about the nuances of having the system flooded and having to drain it as this should be done on a regular schedule to start with.
I have seen many dry systems where there was no emergency systems, that the air compressor was just plugged into a GP receptacle.
Was it right? I'm not sure but I can't see what problem it would cause.
 
Re: Sprinkler compressor

If the system had the compressor on emergency so as to avoid the sprinkler piping from freezing when flooded, then we would have to place some type of heat on Article 700 or 701 too, so that the piping before the deluge valve didn't freeze! :)
 
Re: Sprinkler compressor

Well we usually do put electric unit heaters in sprinkler rooms but I honestly can not remember any of them being on E-Power.
 
Re: Sprinkler compressor

If the compressor ever has to run (other than during initial comissioning or recommissioning of the system), the system has a leak. Backing up the power supply to the generator is a silly end run around fixing a leak. On the other hand, I guess that's what some jockey pumps do for wet systems.

[ November 21, 2005, 08:21 PM: Message edited by: mdshunk ]
 
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