Generators and Motors
[Home] - [HELP] - [Forums] - [Library] - [Photo Gallery] - [Groups] - [Classified Ads] - [Subscribe] - [Links] - [Books] - [Sponsors] -

Go Back   SmokStak > SmokStak® Vintage Electrical Equipment > Generators & Electric Motors General Discussion > Onan Generators
Forgot Password? Join Us!

Notices

Onan Generators Restoring, operating and maintaining vintage Onan generators.

Onan Generators

Onan 12.5JC Sorting it Out


this thread has 77 replies and has been viewed 2707 times

Reply
 
Thread Tools Display Modes
  #41  
Old 02-10-2018, 10:21:35 AM
consolenut consolenut is offline
Registered-I
 
Join Date: Oct 2017
Location: Bristol, Tennessee / Broken Arrow, Oklahoma
Posts: 362
Thanks: 15
Thanked 109 Times in 75 Posts
Default Re: Onan 12.5JC Sorting it Out

Correction that was a typo. I got L0 to the lug in the bottom of the box. That connection was at 127 volts.

But yes I will double check the numbers

When I started re-configuring I assumed L0 was the neutral. But it now seems the lug in the bottom of the wiring box is the Neutral/Ground. Am I missing something? I posted a small portion of the configuration drawing. I referenced it versus the schematic on the cover of the unit.
Reply With Quote
Sponsored Links
  #42  
Old 02-10-2018, 10:50:07 AM
Wayne 440 Wayne 440 is offline
Registered-III
 
Join Date: Nov 2004
Location: Kentucky
Posts: 6,390
Thanks: 389
Thanked 5,417 Times in 2,608 Posts
Default Re: Onan 12.5JC Sorting it Out

lets start over here- please list the voltages you have

L1 to L2

L1 to L0

L2 to L0

If it is correctly wired, L1 to L2 will be twice the voltage of the latter measurements. L0 is the neutral, and grounding same should not affect the measurements above.
Reply With Quote
  #43  
Old 02-10-2018, 11:18:34 AM
consolenut consolenut is offline
Registered-I
 
Join Date: Oct 2017
Location: Bristol, Tennessee / Broken Arrow, Oklahoma
Posts: 362
Thanks: 15
Thanked 109 Times in 75 Posts
Default Re: Onan 12.5JC Sorting it Out

L1 + L2 is 240 volts

Ill check the voltages between L1 & L0 and the same with L2 & L0.....those connections if wired correctly should be 120V each? Correct?

So my first thought was correct. L1 + L2 are my hots. And L0 goes to the neutral Bar in my 70 amp panel.
Reply With Quote
  #44  
Old 02-10-2018, 11:53:02 AM
Wayne 440 Wayne 440 is offline
Registered-III
 
Join Date: Nov 2004
Location: Kentucky
Posts: 6,390
Thanks: 389
Thanked 5,417 Times in 2,608 Posts
Default Re: Onan 12.5JC Sorting it Out

here you go
Attached Thumbnails
Click image for larger version

Name:	double delta.png
Views:	31
Size:	77.1 KB
ID:	302786  
Reply With Quote
The Following User Says Thank You to Wayne 440 For This Post:
  #45  
Old 02-10-2018, 12:03:02 PM
EnginePat EnginePat is offline
Subscriber
 
Join Date: Aug 2011
Location: Connecticut
Posts: 721
Thanks: 485
Thanked 259 Times in 157 Posts
Default Re: Onan 12.5JC Sorting it Out

Reconnection diagram
Attached Thumbnails
Click image for larger version

Name:	ReconnectionDiagram.jpg
Views:	25
Size:	98.1 KB
ID:	302787  
__________________
Pat
5GO 3/RA
7.5 jb's x4
6.0 DJE X 1
Reply With Quote
The Following User Says Thank You to EnginePat For This Post:
  #46  
Old 02-10-2018, 12:12:01 PM
consolenut consolenut is offline
Registered-I
 
Join Date: Oct 2017
Location: Bristol, Tennessee / Broken Arrow, Oklahoma
Posts: 362
Thanks: 15
Thanked 109 Times in 75 Posts
Default Re: Onan 12.5JC Sorting it Out

I used this page from the manual. My voltage code is 18 and i used double delta. I think im on same page.
Attached Thumbnails
Click image for larger version

Name:	Screenshot_Lightning_20180208-212404.jpg
Views:	77
Size:	115.0 KB
ID:	302788  
Reply With Quote
  #47  
Old 02-10-2018, 01:46:16 PM
armandh armandh is offline
Sponsor
 
Join Date: Aug 2006
Location: Suburban St. Louis, Missouri
Posts: 2,983
Thanks: 257
Thanked 784 Times in 611 Posts
Default Re: Onan 12.5JC Sorting it Out

seems to be 120/208Y with all the leads flipped from the drawing.

double delta can be the standard connection or one of 11 other ways

the standard connections will save much confusion later
__________________
.
by using this free advise, you, your heirs, etc
absolve, save, and hold harmless the advisor.
CAVEAT EMPTOR
YMMV
Reply With Quote
  #48  
Old 02-10-2018, 02:06:19 PM
consolenut consolenut is offline
Registered-I
 
Join Date: Oct 2017
Location: Bristol, Tennessee / Broken Arrow, Oklahoma
Posts: 362
Thanks: 15
Thanked 109 Times in 75 Posts
Default Re: Onan 12.5JC Sorting it Out

So which drawing are you referring to armandh
Reply With Quote
  #49  
Old 02-10-2018, 02:29:08 PM
consolenut consolenut is offline
Registered-I
 
Join Date: Oct 2017
Location: Bristol, Tennessee / Broken Arrow, Oklahoma
Posts: 362
Thanks: 15
Thanked 109 Times in 75 Posts
Default Re: Onan 12.5JC Sorting it Out

Hmm after reviewing a few things in the drawings it mentions v1-V4. After looking at everything. The jumpers appear to me to be v1-v2. Did i miss something pic attached
Attached Thumbnails
Click image for larger version

Name:	IMG_20180209_091458.jpg
Views:	39
Size:	141.0 KB
ID:	302806  
Reply With Quote
  #50  
Old 02-10-2018, 07:38:48 PM
zuhnc zuhnc is offline
Registered-I
 
Join Date: Nov 2013
Location: Norfolk, Virginia
Posts: 194
Thanks: 3
Thanked 162 Times in 86 Posts
Default Re: Onan 12.5JC Sorting it Out

V4 is the COMMON. Jumper is from V4 to any of the other three, per diagram. V1-V2 is incorrect. zuhnc
Reply With Quote
Reply

Bookmarks


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

F o r u m Jump


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 09:08:01 AM.

Smokstak and Enginads site search!


All use is subject to our TERMS OF SERVICE
SMOKSTAK® is a Registered Trade Mark - A Community of Antique Engine Enthusiasts
Copyright © 2000 - 2016 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277