Temporary emergency feeder
- Thread starter anbm
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- Location
- Placerville, CA, USA
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- Retired PV System Designer
It needs to be protected from damage, but not necessarily buried.
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publicgood
Senior Member
- Location
- WI, USA
Concur. For less than 600V, this commonly done with camlock style cable. Example:
http://www.steadypower.com/categories.php?category=Power-Cords-and-Cables/Camlock-Power-Cables
Protected from damage does not mean just physical such as guarding at pinches, but also from moisture by means of crates to raise the connection points if needed. Also arrangement of cables ABC ABC to prevent heating, etc.
publicgood
Senior Member
- Location
- WI, USA
Interesting. Have not heard this. Looking forward to input on the subject. Brings up a Q: is this an emergency standby genset or a life safety genset?
I agree. 590.3(C) allows temporary power and lighting during emergency's but 590.2(A) does not give any relief from article 700 and 590.2(B) would require approval of the installation.
We have run some pretty elaborate temporary emergency systems to meet the requirement.
Roger
Because it is used for emergency genset or in general the cables not accessible to public.
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
I don't think anything to do with an emergency generator should be accessible to the casual passer by.
But I also think this would be covered by some of the general prohibitions found in article 110.
Life Safety would be an article 517 system, Emergency could be an article 517 or an article 700 system, and Standby (meaning Optional) would be a 700.2 system, the OP says it's for an emergency system.
If it is an optional standby system the rules would be a lot more lax.
Roger
I believe anbm's past posts have often referred to hospitals.
So I was assuming this is a hospital generator, and that it probably supplies a mix of emergency, critical, and life safety loads.
I agree the rules would be a lot more lax for an optional generator. Are those cam-lock cables that Carnivals frequently just run across the ground, and everyone walks over them? If it's an optional generator, I don't think it would be much different.
Yes, hospital with (3) branches of ATS fed out of a main emergency panel located inside the building.
It will be a cost saving if we can run conduits overhead but I doubt it complies with either NEC 517, 700 articles
for emergency feeders.
Thank you.
publicgood
Senior Member
- Location
- WI, USA
Yes.
publicgood
Senior Member
- Location
- WI, USA
I'm glad you brought our attention to 590. Good add to the topic - one that I will look to more often now.
For our instance, new to the code in 2017 is 700.3(F) [typically accepted forward code cycle interpretation if jurisdiction is in an earlier code cycle]. This requires a temporary connection means, but does not outline anything beyond the need to have a connection point. I'd go so far as to say the code realizes an emergency condition does not warrant more then an electrically safe, not necessarily hardened, installation for a temporary installation needed to substitute emergency power.
Even still, if the AHJ required further, what kind of precautions must be made? 700 does not dictate type of wire/cable. The only item I see possibly is 1-hr rating a run for the occupancy conditions in 700.12.
The wiring methods are still covered elsewhere in the code.
I'd say if your installation met wiring requirements covered elsewhere in the code you would be fine.
Once again, 590 does not give any relief to the requirements of 700.10.
Now that the OP has clarified this is in a hospital 517.30(C)(3) ( 517.31(C)(3) in the 2017) could / would come into play.
Roger
publicgood
Senior Member
- Location
- WI, USA
I do not see anything in 700.10 that would require cam lock cables to have anything special in a temporary installation.
Valid point - thanks.
517.30C sure sounds like overkill for a temporary installation that may only be in place a few hours. I really never thought of that as being a requirement for a temp. installation.
I wonder if the AHJ could approve an installation without the conduit based on 590(B)?
See 700.10(C), (D)(1),(2), and(3)
If the cam lock installation followed those requirements all would be fine.
In reality I agree that a temporary method should be allowed but, the AHJ could certainly require a fully compatible article 700 installation since there is no written exception.
Roger
I guess it would be up to the AHJ but in the hospitals I normally work in even temporary dust partitions must be built to a full UL recognized wall assembly and must be properly rated down to fire retardant framing members and backing if using wood.
Roger
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