multiple services disco grouping

Status
Not open for further replies.
M

muhandas

Senior Member
I'm looking at at an industrial building with 4 services. Assume that the multiple services are permitted in accordance with the exceptions of 230.2. Three of the shunt-trip discos for these services, however, are located at various external locations of the building and one is inside but close to an entrance. Assume further that these discos are identified as required by 230.2(E). My question is the following. It seems to me that the discos ought to be grouped close to one another because IMHO it would be unreasonable for responders to an emergency to have to run around the building and read the various plaques but I cannot find an NEC requirement that I can use to justify this. The reference to 225.37 doesn't address grouping specifically and in any event 225.34 addresses branch circuits and feeders, not services. Can you help by pointing me to requirement(s) I can use or should I just accept it and let the fire marshal worry about it? I don't think that's the best option because it implies that the NEC accepts a situation that I would deem as unsafe.
I look forward to your wisdom, as usual.
Heinz R.
 
I can't speak for other areas but here our fire department has what they call a "pre-plan" and I have several buildings in town with a similar set-up (buildings with multiple services). When I have a building as such I involve the fire marshal so he can denote the location of the service disconnects and to make sure that the required identification from 230.2(E) is worded in a manner that is acceptable to him.

It would be nice to have all the service disconnects grouped in one location although sometimes, as in a very large facitlity, this is just not feasible.

My only advice would be to be proactive and involve the fire department in the early stages of the project.

Pete
 
Thanks for your advice, I will do just that. I've worked with this particular Fire Marshal before and he's pretty good. It just struck me as odd that I couldn't find an NEC requirement that asks to group service discos pretty much the same as it does for feeders or branch circuits. I know that it can be difficult, read expensive, to group service disconnects but not to do that also exacts a cost - att particularly the wrong time.
Thanks again.
Heinz R.
 
Although anything is possible, from a practical standpoint, with large installations it would be cost prohibitive to group all disconnects.
If you are dealing with 480 or 208 volt systems, the added costs to size the conductors taking voltage drop into account if that was a requirement could be astronomical. A second method would be to switch the higher voltages supplying the service transformer, but that would likewise be at considerable expense.
 
Augie47
A somewhat different question. I also cannot find anything in the NEC that requires that a service disco be on the outside of the building, Am I wrong?
Heinz R.
 
230.70(A)(1) says this:

(1) Readily Accessible Location. The service disconnecting
means shall be installed at a readily accessible location
either outside of a building or structure or inside nearest the
point of entrance of the service conductors.

See 230.6 for what is still considered outside a building.
 
Last edited:
Status
Not open for further replies.
Top