Generators and Electric Motors
[Home] - [HELP] - [Forums] - [Groups] - [Classified Ads] - [Subscribe] - [Books] - [Sponsors] -

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

Notices

Generators & Electric Motors General Discussion Antique Generators and Old Electric Motors: Questions and answers about restoring and showing old power generation systems.

Generators & Electric Motors General Discussion

Marathon Magnamax 300kw reconnect


this thread has 7 replies and has been viewed 271 times

Reply
 
Thread Tools Display Modes
  #1  
Old 08-26-2019, 08:50:28 PM
J.B. Castagnos J.B. Castagnos is offline
Registered-III
 
Join Date: Nov 2004
Location: South Louisiana USA
Posts: 2,719
Thanks: 927
Thanked 3,565 Times in 1,116 Posts
Default Marathon Magnamax 300kw reconnect

I have a Marathon 300kw generator, tag on the enclosure says 480 volts. The tag on the generator is hard to read but it looks like 277/480 volts. The business that's interested in it is fed by high voltage, 480? to a transformer then to a transfer switch. I was wondering if the machine could be wired to feed the transfer switch. I took the cover off the generator and there are 12 leads coming out, I didn't read them all but it looks like they are tagged 1 through 12, no L or T. The machine was rebuilt, don't know if this is rebuilders tags or factory. Should they just get a 300 KW transformer, a 480V transfer switch to go before the existing transformer, or try to reconnect it? If reconnected does the voltage regulator automatic sense the correct voltage or would it have to be addressed?
Reply With Quote
Sponsored Links
  #2  
Old 08-26-2019, 09:59:46 PM
Birken Vogt Birken Vogt is offline
Email NOT Working
 
Join Date: Sep 2009
Location: Penn Valley, California, USA
Posts: 2,665
Thanks: 2
Thanked 938 Times in 653 Posts
Default Re: Marathon Magnamax 300kw reconnect

Just reconnect it for the voltage the transfer switch runs at. If the info is not inside the generator box then a call to Marathon should get it. It will require minor adjustment after reconnection but not much else.
Reply With Quote
The Following User Says Thank You to Birken Vogt For This Post:
  #3  
Old 08-27-2019, 05:43:54 PM
scottie scottie is offline
Registered-II
 
Join Date: Oct 2006
Location: on. can.
Posts: 37
Thanks: 0
Thanked 13 Times in 8 Posts
Default Re: Marathon Magnamax 300kw reconnect

All the reconnect info and diagrams are available on the Marathon website
Reply With Quote
The Following User Says Thank You to scottie For This Post:
  #4  
Old 08-27-2019, 06:47:48 PM
J.B. Castagnos J.B. Castagnos is offline
Registered-III
 
Join Date: Nov 2004
Location: South Louisiana USA
Posts: 2,719
Thanks: 927
Thanked 3,565 Times in 1,116 Posts
Default Re: Marathon Magnamax 300kw reconnect

Thanks Birken and Scottie, I looked at the web site, talked to Marathon, very helpful. I was wondering how the regulator would adapt, Mike at Marathon explained that the regulator see's 240 in the center of the 480 configuration, will see the voltage at the line on 208, will have to be lowered.This is new to me but I really enjoy doing it and learning.
Reply With Quote
  #5  
Old 08-28-2019, 12:49:49 AM
pegasuspinto pegasuspinto is offline
Registered-III
 
Join Date: Oct 2006
Location: Floyd, AR, USA
Posts: 2,966
Thanks: 339
Thanked 1,421 Times in 925 Posts
Default Re: Marathon Magnamax 300kw reconnect

One 'bad' news is now you will need a new ~1200 amp breaker, and those are NOT cheap. You'll also need more copper between the gen and ATS. Are you sure you can't reconfigure the ATS? How many amps is the ATS?
Reply With Quote
The Following User Says Thank You to pegasuspinto For This Post:
  #6  
Old 08-28-2019, 04:53:11 AM
J.B. Castagnos J.B. Castagnos is offline
Registered-III
 
Join Date: Nov 2004
Location: South Louisiana USA
Posts: 2,719
Thanks: 927
Thanked 3,565 Times in 1,116 Posts
Default Re: Marathon Magnamax 300kw reconnect

I would have liked to see them buy a 300kva transformer, I see them offered for $2-3000 used. It may work out OK though, the unit is oversized for the transfer switch building, about 15 feet of cable needed here. I think the generator has a 600 amp breaker, will have to check. If this will be enough to supply the switch they may be able to add two 200 amp breakers to supply an office and a laundromat, these are within 100 feet.
Reply With Quote
  #7  
Old 08-28-2019, 01:12:32 PM
pegasuspinto pegasuspinto is offline
Registered-III
 
Join Date: Oct 2006
Location: Floyd, AR, USA
Posts: 2,966
Thanks: 339
Thanked 1,421 Times in 925 Posts
Default Re: Marathon Magnamax 300kw reconnect

i DO NOT recommend hooking a transformer directly to the output of a generator, such that it has to start and stop directly connected. They make all kinds of ugly noises when you do that.

If you're going to have other feeds to more ATS at 208 volts, best to reconfigure now.
Reply With Quote
The Following User Says Thank You to pegasuspinto For This Post:
  #8  
Old 08-28-2019, 01:46:28 PM
J.B. Castagnos J.B. Castagnos is offline
Registered-III
 
Join Date: Nov 2004
Location: South Louisiana USA
Posts: 2,719
Thanks: 927
Thanked 3,565 Times in 1,116 Posts
Default Re: Marathon Magnamax 300kw reconnect

All of the transfer switches will be manual.
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

Similar Threads Chosen at Random
Thread Thread Starter F o r u m Replies Last Post
300kw - scrap? trukinbear Onan Generators 47 01-23-2019 01:04:51 AM
Delco AC Model Y1-4907 M2 300Kw Burningoil Generators & Electric Motors General Discussion 2 01-11-2014 12:43:43 AM
Reconnect Question Cruiser Onan Generators 3 12-03-2010 12:52:56 AM
Marathon generators Roger Hayenga Generators & Electric Motors General Discussion 1 02-09-2003 10:41:58 PM


Use "Ctrl" mouse wheel to change screen size.
All times are GMT -4. The time now is 04:08:17 PM.

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 - 2019 by Harry Matthews P.O. Box 5612 - Sarasota, FL 34277