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Kohler 12 RES Installation


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  #21  
Old 11-28-2018, 01:01:42 AM
zaphod zaphod is offline
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Default Re: Kohler 12 RES Installation

Thanks for the come back. The original fuse was a 20A/250 Volt. I stupidly replaced it with a 20 A fuse 120 V and it blew after 10 minutes. Subsequently I put the proper fuse in, cleaned out the fuse holder, and it still shuts down. I have looked at the programming manual for the 12 RES and have tried to follow it. I've gotten as far as to ascertain that the program version is 1.17, or, one digit shy of 1.18 version needed for the ADC2100 controller which updates the one I have. My unit is apparently a 12 RES 10 KW unit from 2004-2005. The controller is not the same as the 12 RES 12 KW unit.
What's odd is that when I replaced the fuse it ran for a full 10 minutes or more. Now it shuts down after 10 seconds. No surging, no odd behavior other than that. I am having trouble finding the programming instructions for the earlier controller. The "password" (3 down arrows, then 3 up arrows) doesn't seem to work for my unit. ANY suggestions? I could see the voltage readout before it shut down. High of 120, then 115, then 105 and shutdown. Bad ground? Tried it with line breakers on and off line.

Quote:
Originally Posted by Birken Vogt View Post
Is it the fuse in series with the auxiliary (regulator power) winding? 55/66 IIRC?

High resistance brushes or some other excitation problem can cause that fuse to blow, due to the regulator circuit needing higher power than normal.

Just speculation here.

[Based on extensive experience with these. This would be a rare problem but not unheard of.]
I assume it is, although I'm not familiar with the AUX power winding. The controlled has 3 fuses on the panel: two 250 V and one 120 which is in line with the starter. I've replaced the two output fuses. Last one (farthest on left) blew.
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  #22  
Old 11-28-2018, 01:55:33 AM
Birken Vogt Birken Vogt is offline
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Default Re: Kohler 12 RES Installation

What is happening when you enter the password? IIRC the decimal point needs to be moving when you do this. Read the instructions very carefully. A lot of strange little twists and turns before you get to 99 extra lives with the secret code as one of my customers said.
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  #23  
Old 11-28-2018, 10:13:53 AM
Zephyr7 Zephyr7 is offline
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Default Re: Kohler 12 RES Installation

The fuses voltage rating doesnít affect when it blows. The voltage rating is just the highest voltage the fuse is capable of blocking when it blows. Only the current (amp) rating matters in this particular application since Iím assuming 120v is a safe blocking rating for the fuse.

Basically that means that replacing the 20A/120V fuse with a 20A/250V fuse didnít really fix anything ó whatever caused the fuse to blow is something else.

With your voltage gradually dropping off as you describe, you have something interesting going on, maybe something thermally sensitive that changes as it warms up. Check brushes (easy, relatively). If itís in the regulator, I would suspect a bad capacitor somewhere. Itís probably going to take some digging to figure out whatís going on if not the brushes.

Bill
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  #24  
Old 11-28-2018, 10:56:18 AM
zaphod zaphod is offline
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Default Re: Kohler 12 RES Installation

Quote:
Originally Posted by Zephyr7 View Post
The fuses voltage rating doesn’t affect when it blows. The voltage rating is just the highest voltage the fuse is capable of blocking when it blows. Only the current (amp) rating matters in this particular application since I’m assuming 120v is a safe blocking rating for the fuse.

Basically that means that replacing the 20A/120V fuse with a 20A/250V fuse didn’t really fix anything — whatever caused the fuse to blow is something else.

With your voltage gradually dropping off as you describe, you have something interesting going on, maybe something thermally sensitive that changes as it warms up. Check brushes (easy, relatively). If it’s in the regulator, I would suspect a bad capacitor somewhere. It’s probably going to take some digging to figure out what’s going on if not the brushes.

Bill
Bill, thanks. I noted the decimal point moving when I entered the "code" I'll go back and try again. I have somewhat of an electronic background (movie industry) and can agree to a leaking capacitor causing a voltage drop. I am intrigued, however, about the brushes: are they accessible without taking the housing off? (I mean the metal box the genset is in). Could I use a spray contact cleaner on the armature, or is this a take apart and clean exercise? Wish I had some documentation. The book I downloaded is for the 12 KW and, while similar, shows different components (controller interfaces, etc...)

Addendum: the voltage drop off is rapid: within 5-10 seconds.
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  #25  
Old 11-28-2018, 12:48:17 PM
Birken Vogt Birken Vogt is offline
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Default Re: Kohler 12 RES Installation

The brushes are in the far end and you have to tear down most of the box to get to them but it is quite easy as long as you have it installed properly (not too close to other stuff). And the screws are not all rusted.

Remove roof, 4 screws. Remove right side, 2 screws by controller, 1 by battery floor, 2 on back. Remove back, 2 screws in wiring/air intake box and 2 screws on back. Remove left side/front panel. Now you are down to the air duct for the alternator, remove that and one tin cover and you are at the brushes.

The system works by getting pulses from some orange/gray/violet wires (can't remember) from the controller to the SCR pack which is mounted on the floor of the control box area. The SCR pack takes power through the fuse that is blowing (I think this is your fuse) and rectifies and regulates it and feeds DC direct to the brushes.

There is a relay PCB with some red LEDs that blink when it is battery flashing the field, etc. that will also be visible when you get the right side covers off.
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  #26  
Old 11-28-2018, 01:21:38 PM
zaphod zaphod is offline
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Default Re: Kohler 12 RES Installation

Hi Bill,

I got as far mas removing one side, then the bolts on the floor started turning without product, so I retraced. Started the unit, voltage came up to 124, the dropped off to 104 and stopped. I replaced the fuse in question with a 30 AMP SFE, and restarted it. Unit ran for 7 minutes, surging slightly (erratic fast idle) then blew the fuse. I replaced the fuse again and am waiting for it to blow again. Voltage while the fuse is good is 238-240. This time I have disconnected the unit from the ATS to see if the amperage draw is
caused by something in the house.

Fuse blew after 5 minutes with the unit disconnected from the house. I think I'm getting somewhere, I just don't know where.
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  #27  
Old 11-28-2018, 01:26:04 PM
Birken Vogt Birken Vogt is offline
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Default Re: Kohler 12 RES Installation

Can you get to the electronics in the box yet? The brush wires are in there, black and labelled FP and FN (field + & -)

Disconnect and measure their resistance is easy enough. You might also do this by removing the control panel from the front but it will be cramped.

Also, observing the relay board lights will be helpful.

I would put a meter on the FP and FN and see if they are increasing over time in a vain attempt to keep voltage up, or what.

You might also pierce them for metering where they go through the firewall in a piece of split loom but not sure about the routing.
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  #28  
Old 11-28-2018, 01:29:43 PM
Zephyr7 Zephyr7 is offline
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Default Re: Kohler 12 RES Installation

Replacing a fuse with a bigger one is dangerous. That fuse is blowing because something is wrong. Putting in a bigger fuse frequently just makes something more difficult, and more expensive, to fix break instead of the fuse.

I was originally thinking you were saying you were seeing ~120v on a 120v winding and then it would drop off to around 105v before shutting off. That would have meant it was starting out ok and then dropping. From your more recent post, it appears you were seeing ~120v on a 240v winding which means it never got up to where it should be before dropping off. That’s important info.

Check the brushes. I think your unit is popping the fuse because it’s trying to drive the field too hard because the voltage isn’t coming up. That makes me think bad brushes, or bad regulator components. In the case of brushes, the regulator is trying to drive the field through bad brushes and is probably heating the brushes up before the fuse pops. The bad brushes limit how much current actually makes it to the field so the generator output voltage never gets up to where it should be. The other possibility is the regulator is bad (or the SCR pack Birken mentioned), and it’s unable to drive the field with enough current.

Check the brushes first. Chances are good that’s where the problem is.

Bill
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  #29  
Old 11-28-2018, 01:46:59 PM
zaphod zaphod is offline
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Default Re: Kohler 12 RES Installation

It shut down again, but didn't blow the fuse this time. Now the voltage doesn't go above 51 so it's something in the voltage regulator. Hate to do it but I'm going to call in the troops. Thanks.
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  #30  
Old 11-28-2018, 02:08:21 PM
Newoldstock Newoldstock is offline
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Default Re: Kohler 12 RES Installation

I have not been following this thread and I am sorry for not being any help.

BUT zaphod beeblebrox I get it!!!!
Thats funny.
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