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Generac Generators (SEARS, etc.)

Generac under voltage shutdown


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  #1  
Old 12-07-2011, 06:16 PM
Bawb Bawb is offline
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Default Generac under voltage shutdown

I have two generacs (model 59180, 700 hours) (model 60541, 8 hours). Both will run for 5 seconds and shut down with an under voltage message. The 700 hour one I felt I may have overloaded it operating a 2 hp motor although it was not operating that motor when it quit. The 8 hour model ran fine with about a 3000 watt load and then shut down. I'm operating them through the panel/transfer switch that came with the 59180. There is no utility power here. I know it is not intended as a prime power generator. The plan was to use it a few hours a day for charging a battery bank and running a couple block heaters.

Any ideas would be appreciated. I have a good meter with frequency, amp clamp, etc but the machines won't run long enough to test much. I'm 500 miles from the nearest dealer. Also, I bought them at Costco so the dealers don't feel obligated.
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  #2  
Old 12-07-2011, 09:23 PM
DPeterik DPeterik is offline
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Default Re: Generac under voltage shutdown

I need the serial numbers of these units. Also pull off the covers to the controllers. Need the part number and revision number. The boards should be OH6680B Rev F. Will also need to check software. If it is a 8kw it should be 0J1467 Rev F. 10-20kw should be Rev C.
Can you take pics. There was an issue with some controllers having the under voltage issue. If the controllers meet the criteria this may be a warrantable issue. Let me know I may be able to help you out. These are Honeywell branded but use Nexus controllers.
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  #3  
Old 12-07-2011, 10:32 PM
Bawb Bawb is offline
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Default Re: Generac under voltage shutdown

The serial numbers are 6139038 and 6139038. I've attached pictures of the board and software tags.

The smaller unit had an issue early on where the choke plate was sticking but I managed to figure that out on my own. Both choke plates operate freely now.
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  #4  
Old 12-08-2011, 08:14 AM
DPeterik DPeterik is offline
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Default Re: Generac under voltage shutdown

You gave me the same serial number for both. 6139038 is a 10 kw Guardian with a GT530 V-twin engine. Purchased on 6-24-2011, warranty expires on 6-24-2014.
Recheck the other serial number. The first two pics, that board is the bad one. needs to be replaced with a OH6680B. Will need to check on the Honeywell board, those are programmed specific to Honeywell.
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  #5  
Old 12-08-2011, 03:34 PM
Bawb Bawb is offline
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Default Re: Generac under voltage shutdown

Whoops. Second serial number is 6659492.
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  #6  
Old 12-08-2011, 05:55 PM
DPeterik DPeterik is offline
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Default Re: Generac under voltage shutdown

Email, me at dpxholdings@msn.com. I will send you a diagnostic manual for these units. On the Honeywell you will need to perform a Fixed Excitation/Rotor Amp Draw test. The manual will take you step by step.
The other unit may be a controller replacement due to the Rev # and serial number.
I will give you more info on this when you email me.
P.S. I may not be able to reply until later tonight or tomorrow.
Thanks
Dave
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  #7  
Old 12-09-2011, 01:21 AM
Bawb Bawb is offline
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Default Re: Generac under voltage shutdown

It should be in your mailbox. Thanks.
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  #8  
Old 12-15-2011, 07:10 PM
Bawb Bawb is offline
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Default Re: Generac under voltage shutdown

Dave:

I emailed you, but am getting no reply. Maybe it got caught in your spam filter.

Bob
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Old 12-19-2011, 03:49 AM
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Default Re: Generac under voltage shutdown

This diagnostic manual, (OH9172 Rev D) does not list the 12kw model. Should I slide the 10kw back into firing position or use this manual on the 12kw that is already hooked to gas and the panel?
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Old 12-19-2011, 06:29 PM
DPeterik DPeterik is offline
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Default Re: Generac under voltage shutdown

The 12 kw and the 14 kw are the same unit. If it lists a 14 use that.
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  #11  
Old 12-28-2011, 06:46 AM
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Default Re: Generac under voltage shutdown

This report is about the results of tests done on a 12 Kw with about 7 hours total run time with a 3 Kw load.

The results of Test 4, the fixed excitation/ rotor amp draw test, were zero or residual voltage and zero current draw. This leads to test eight, resistance check of rotor circuit, all of which were open. This leads to test nine, check brushes and slip rings, the first step of which is commence major disassembly.

Looking into the prospect of major disassembly, I find that some of the wires, like the 8 ga ones coming from the gen head look and feel to be glued or melted together for about 3 inches after exiting the gen head and before entering the wire loom. It is difficult to get a good look and feel of them in their installed position.
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Old 12-28-2011, 10:44 AM
Bassplayer1985 Bassplayer1985 is online now
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Default Re: Generac under voltage shutdown

Quote:
Originally Posted by Bawb View Post
Looking into the prospect of major disassembly, I find that some of the wires, like the 8 ga ones coming from the gen head look and feel to be glued or melted together for about 3 inches after exiting the gen head and before entering the wire loom. It is difficult to get a good look and feel of them in their installed position.
I would suspect the machine was overloaded and unbalanced between the neutral. I ran into the same issue with my 7k, and the hottest wire was the neutral. Once that melted the other wires began to thermally fail. Once I got inside the panel just about every single wire had melted together.
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Old 12-29-2011, 10:20 AM
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So, after 7 hours of operation with a 3K load, one of the brushes was burned, twisted and mutilated. The other one is perfect.

Once I got it flipped over and in the light, there was nothing wrong with the wires exiting the alternator.
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  #14  
Old 12-29-2011, 03:12 PM
Bassplayer1985 Bassplayer1985 is online now
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Default Re: Generac under voltage shutdown

Wow thats a crispy bush assembly. Its def arcing.

1. My first guess is there is a short in the rotor windings.
2. Insulation near the slip rings has broken down and the brush is arcing to ground

Not sure where to go from here, a tech can troubleshoot more if the problem lies in the voltage regulator, but for it to be arcing like that suggests to me a bad connection or insulation failure.
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  #15  
Old 12-29-2011, 07:39 PM
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Default Re: Generac under voltage shutdown

Purchased on 6-24-2011, warranty expires on 6-24-2014.
If it is under warranty, I would not fool with it. That amount of heat probably damaged slip ring assembly. It may no longer be concentric, and replacing brush & holder may not fix the issue.
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  #16  
Old 12-29-2011, 08:35 PM
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Default Re: Generac under voltage shutdown

Due to the remote location, a warranty claim would involve shipping costs equal to about half the value of the gen set.
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  #17  
Old 12-29-2011, 08:46 PM
Ed Sparks Ed Sparks is offline
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Default Re: Generac under voltage shutdown

you mean generac doesn't have an authorized service center up there on the north pole???
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  #18  
Old 12-30-2011, 05:27 PM
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Default Re: Generac under voltage shutdown

>>you mean generac doesn't have an authorized service center up there on the north pole??

Clearly an oversight on their part.
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Old 12-31-2011, 12:55 PM
Bassplayer1985 Bassplayer1985 is online now
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Default Re: Generac under voltage shutdown

Looking for the pics again Bawb, I noticed that it is the inner brush thats getting cooked. When the brush holder is mounted, is there any exposure to the metal frame at all? Also is the spring firmly up against the slip rings?
Could you post the picture of the rotor end/slip ring assembly?

A shorted winding in the rotor will definitley cause this and you mentioned the rotor was open circuit. The one part that is escaping me with this conclusion is why just that one brush and not both of them being cooked?

Funny, I actually have a spare rotor here in Connecticut but its only good up to 7k watts for a Generac 7000EXL. Part# B1342G. measures 15 ohms on the rings.
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Old 01-01-2012, 09:36 PM
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Default Re: Generac under voltage shutdown

Picture of slip rings attached.
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