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Kohler 12 RES Installation

zaphod

Registered
New guy here: just bought a Kohler 12 RES to replace a Winco 8 KW standby. Not worked on gensets before. I have 3 wires coming off the ATS marked G1,2 and 3 and 4 wires coming off the geneet marked L0 L1 L2 and Ground. One wire in each set is wrapped white L0 and G2. This wire was budled to ground on the original Winco. The ground from the Kohler is wrapped green. L0 is neutral.
What connects to what? Mystified. Cheers, Zaphod
 

LWB250

Registered
Re: Kohler 12 RES installation

If you don't know, hire an electrician. This is not something someone can advise on via the web.

Really.
 

Zephyr7

Registered
It’s odd that you’d have three control wires coming from the ATS. Normally you’d just have two, which is why it’s commonly referred to as “two wire start”.

The heavier four leads are phases, neutral, and ground. These carry the power.

Now for the serious stuff: aside from the extra control lead, the power side is really basic 101 level stuff for both the labeling and the color codes. If you don’t immediately recognize what you’re looking at, you really should hire someone qualified to do the installation for you. You can cause a lot of damage if you wire something incorrectly, and worse, you can create a very dangerous situation that could potentially kill someone.

Bill
 

reid070

Registered
It’s odd that you’d have three control wires coming from the ATS. Normally you’d just have two, which is why it’s commonly referred to as “two wire start

Bill
It’s sounds to me like he is using the ATS that was hooked up to his old generator, and it used 3 wire start.

Steve
 

LWB250

Registered
Being a Winco it's highly likely that if it didn't have the integrated contactor style ATS they used with their sets at that time it's a Zenith or Westinghouse ATS and is set up for 3 wire start.

I'm not familiar with Kohler's current line of controls, but they've done two wire start for almost a century, so I doubt very much that new unit is going to accommodate 3 wire start.

Again, the potential for damage or even injury is quite high here. Hire a professional and shift the risk to them.

Dan
 

zaphod

Registered
Yeah.
Anyway: thanks for the replies. Apparently it's L1 - G1 etc... and the ground is redundant as it's coupled to field in the genset. I thought it was a pretty simple question.
Zaphod
 

LWB250

Registered
Yeah.
Anyway: thanks for the replies. Apparently it's L1 - G1 etc... and the ground is redundant as it's coupled to field in the genset. I thought it was a pretty simple question.
Zaphod
In context it might be, but anyone in this business with half a brain and experience isn't going to address the issue without more specific information and/or a photograph.

Not to mention you made your lack of experience known, which was also a red flag to steer clear.

Too many of us have been burned by a well meaning suggestion or direction that seemed obvious or simple to us, only to have the user damage equipment or get hurt. Then it's suddenly all our fault. Not a good situation to be in.
 

zaphod

Registered
Well, I have enough egg on me to make an omelette. It turns out the Winco ATS is a low voltage start and the one I need is a Kohler RDT series high voltage start so $1000 later its in. Now to change the overspeed sensor which I understand is a bear.
 

Mark Dieckmann

Registered
Umm....The Kohler 2 wire start control is 12volt DC / battery voltage. Not exactly what I would call high voltage. The RDT should be fine and will require two wires connected to terminals 3&4 in the switch and generator to operate. Good luck
 

zaphod

Registered
so it's the other way around: Winco is high voltage and Kohler is low. Anyway throwing a grand at it worked for this phase. Now to attack the speed sensor.

so it's the other way around: Winco is high voltage and Kohler is low. Anyway throwing a grand at it worked for this phase. Now to attack the speed sensor.
Oh yeah, he had to put in a 120V line to power the on board battery charger; the WINCO unit had it built in the ATS.
 

Mark Dieckmann

Registered
so it's the other way around: Winco is high voltage and Kohler is low. Anyway throwing a grand at it worked for this phase. Now to attack the speed sensor.


Oh yeah, he had to put in a 120V line to power the on board battery charger; the WINCO unit had it built in the ATS.
That makes sense.
 

zaphod

Registered
so I have a bad speed sensor, the gen defaults to OS immediately on startup. I bought the new sensor, and learned the original is located under the unit. I cut away a bit of the plastic fan shroud and located the flywheel next to the inspection port and mounted the new sensor to the back cover. I get resistance but no signal voltage. I'm using a 0.48 paper shim (installation says to shim between 0.31 and 0.71 ") any ideas? Sensor has resistance, just no signal on cranking. Shouldn't it generate around 3.5 volts AC?
Cheers,
Zaphod
 

zaphod

Registered
so I have a bad speed sensor, the gen defaults to OS immediately on startup. I bought the new sensor, and learned the original is located under the unit. I cut away a bit of the plastic fan shroud and located the flywheel next to the inspection port and mounted the new sensor to the back cover. I get resistance but no signal voltage. I'm using a 0.48 paper shim (installation says to shim between 0.31 and 0.71 ") any ideas? Sensor has resistance, just no signal on cranking. Shouldn't it generate around 3.5 volts AC?
Cheers,
Zaphod
Further to my previous post: Found my problem, fairly easily solved. The service guy who came out here (supremely un-motivated) told me the sensor "counts teeth" So I assumed there were magnetic plates inside the flywheel around the perimeter. I should have just discounted the guy as an idiot. Rotated the flywheel until I saw the mag block, measured the distance to mid mag block from the shroud backing plate (29.87 mm or 3 cm including midpoint mark on the sensor) fabricated a block from a piece of pine, drilled and tapped the backing plate and mounted the sensor so I can get at it from below the oil cooler. No one can tell me Kohler couldn't have done it this way to begin with, alright: maybe they would have used aluminum instead of pine, but the repair works, is adjustable and in my hostile climate a welcome respite from service calls at $90 per hour including travel. Booyah!
 

Zephyr7

Registered
Magnetic pickup speed sensors do “count teeth”, and they don’t need any magnet on the flywheel to work. Mag pickups sense the variation in metal distance between the sensor and the teeth as they go by (the top of a tooth is a shorter distance than to the bottoms of the gap between adjacent teeth.

The overspeed condition is usually sensed by something other than the mag pickup. By using a seperate sensor, overspeed conditions caused by a failed mag pickup can be detected.

I’d advise against using wood to make mounting brackets on a genset. Metal would be much better, steel or aluminum. If you need something easier to work, try a piece of acetal (also known as Delrin). It’s a very durable plastic but still easier to work than metal. I wouldn’t trust wood to work long term anywhere tight tolerances are needed.

Bill
 
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zaphod

Registered
Redesigned my system, using a Ford crankshaft sensor, I put inside a modified 1/2 ID plumbing fitting and attached to the shroud plate with a metal bracket. I shimmed it at 048" and it fired right up. The sensor is now under the oil cooler, readily available. Not too pretty but very practical.

Oh yeah: total cost: $21.25.
Cheers,
Zaphod
 

Zephyr7

Registered
Just make absolutely sure your setup is solid. If the sensor pops off and gets wound around a shaft you’ll be having a very bad day. Loose sensors will make for erratic speed too which can cause all kinds of problems for electrical equipment.

Be careful. Kludges have a way of coming back to haunt you later.

I’m not sure why you’re so concerned with replacing a mag pickup anyway. They are very reliable and rarely fail.

Bill
 

zaphod

Registered
Just make absolutely sure your setup is solid. If the sensor pops off and gets wound around a shaft you’ll be having a very bad day. Loose sensors will make for erratic speed too which can cause all kinds of problems for electrical equipment.

Be careful. Kludges have a way of coming back to haunt you later.

I’m not sure why you’re so concerned with replacing a mag pickup anyway. They are very reliable and rarely fail.

Bill
Hi,
Because the unit wouldn't run at all without it. I can't get a straight answer from Kohler here and replacing the speed sensor solved my problem.
Now I have an under-voltage problem After running perfectly, the set now shuts down after 10 seconds with UU code for under voltage. I found a blown fuse, replaced it, and the set ran for about 10 minutes, then blew the fuse. Now with proper fuses in place, it still shuts off and gives me the UU code. Any ideas?
Cheers,
Zaphod:shrug:
 

Zephyr7

Registered
What voltage is it actually producing while running? If it puts out correct voltage, but shuts down on under voltage, then your undervoltage trip is set too high and needs to be lowered. If it’s putting out low voltage, then I’d guess the regulator needs adjustment or may even have failed.

A blown fuse makes me suspect wiring issues or something in a winding, but let’s hope for now it was either a too-small fuse, or a fluke. A bad regulator trying to go full field could have popped a fuse too.

Bill
 
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Birken Vogt

Email NOT Working
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.]
 
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