ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
Shout Box
Recent Posts
Furnace igniter leaking noise to stereo
by Haligan. 05/21/18 03:28 PM
480 Delta
by ghost307. 05/21/18 10:38 AM
turning down possible problem customer
by HotLine1. 05/21/18 07:53 AM
electircal ageing test on IPC
by HotLine1. 05/14/18 09:42 AM
What estimating software do you recommend?
by wattsittoyou. 05/14/18 06:28 AM
New in the Gallery:
Plug terminals
Housebilding DIY wiring
Who's Online Now
0 registered members (), 25 guests, and 10 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
back up generators #69960
09/26/06 02:12 PM
09/26/06 02:12 PM
J
jersey  Offline OP
Member
Joined: Feb 2005
Posts: 13
Hopatcong N.J. 07843
I am installing a 35 kw generator to backup a 70 amp 3 phase sub panel. My question is if the building has a delta high leg service, will this effect the generator?

Work Gear for Electricians and the Trades
Re: back up generators #69961
09/26/06 02:34 PM
09/26/06 02:34 PM
L
LarryC  Offline
Member
Joined: Jul 2004
Posts: 783
Winchester, NH, US
ASSume voltage is 120/240 center tapped delta.

What are the loads on the sub panel? All single phase, all 3 phase, or mixed? If mixed, can the generator supply them, or are you going to use a transformer? Remember the issues with SDS and grounding through transfer switches.

Re: back up generators #69962
09/26/06 03:27 PM
09/26/06 03:27 PM
J
jersey  Offline OP
Member
Joined: Feb 2005
Posts: 13
Hopatcong N.J. 07843
With the 3-3 phase refridgerator units and single phase 240v water pump each leg was drawing around 31 amps apiece. Thera are other small loads.

Re: back up generators #69963
09/26/06 03:34 PM
09/26/06 03:34 PM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Can you get a generator that will supply 120/240 3 phase 4 wire?
Don


Don(resqcapt19)
Re: back up generators #69964
09/29/06 10:06 AM
09/29/06 10:06 AM
J
jersey  Offline OP
Member
Joined: Feb 2005
Posts: 13
Hopatcong N.J. 07843
the guardian type. They make 3 phase generators

Re: back up generators #69965
09/29/06 10:33 AM
09/29/06 10:33 AM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
jersy,
Quote
the guardian type. They make 3 phase generators

They are all 3 phase wye connected units. That is not the same as a 3 phase delta system with a high leg. I have never seen a generator that could be connected 3 phase delta with a high leg. I have only seen that configeration on transformers.
Don


Don(resqcapt19)
Re: back up generators #69966
09/29/06 01:40 PM
09/29/06 01:40 PM
L
LarryC  Offline
Member
Joined: Jul 2004
Posts: 783
Winchester, NH, US
When I repaired generators many years ago, the small gennys on reefer trucks were 3 phase 240 delta. I don't know if they where available in anything larger than 5 or 10 KW.

If the Guardian you are talking about has a 12 lead alternator, you could rewire it for 120/240 delta with a high leg. I would check with the factory about the maximum unbalanced load.

Larry

Re: back up generators #69967
09/30/06 10:11 AM
09/30/06 10:11 AM
R
resqcapt19  Offline
Member
Joined: Nov 2000
Posts: 2,148
IL
Larry,
Quote
If the Guardian you are talking about has a 12 lead alternator, you could rewire it for 120/240 delta with a high leg.

I didn't look at all of the wiring diagrams, but on the ones that I did look at, the center of the wye was an internal connection.
Don


Don(resqcapt19)
Re: back up generators #69968
10/05/06 10:52 AM
10/05/06 10:52 AM
J
jersey  Offline OP
Member
Joined: Feb 2005
Posts: 13
Hopatcong N.J. 07843
Just talked to guardian . There 3 phase units not compatible with a delta system. I have a meat packing plant that needs emergency back-up . Power always goes out they dont want there meat to go bad. Is ther an other way to go?

Re: back up generators #69969
10/05/06 11:04 AM
10/05/06 11:04 AM
J
jersey  Offline OP
Member
Joined: Feb 2005
Posts: 13
Hopatcong N.J. 07843
one more question , Why would it matter if the back-up generator Was a wye ? The equipment would work 3 phase, delta or wye connected

Page 1 of 2 1 2

Featured:

2017 Master Electrician Exam Preparation Combos
2017 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
Tom
Tom
Shinnston, WV USA
Posts: 1,044
Joined: January 2001
Show All Member Profiles 
Top Posters(30 Days)
twh 12
Popular Topics(Views)
246,857 Are you busy
184,210 Re: Forum
173,451 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.6.1
(Release build 20180101)
Page Time: 0.034s Queries: 15 (0.006s) Memory: 1.0215 MB (Peak: 1.1985 MB) Zlib enabled. Server Time: 2018-05-22 04:00:04 UTC