Transfer switch will not switch back to utility

Automatic/Manual transfer switch repair, wiring & troubleshooting questions
windboy14571
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Quiet Source
27 KW 1 phase
2.4 L
Model QT02724ANAN
Serial 5083645
Built 08/04/08

Transfer switch
Model RTSE200A3
Serial5105498
120/240 volts

Our generator will not switch back to utility automatically. It was noticed first when the exercise cycle ran and the switch went to generator, but not back to utility when the exercise cycle was finished. Utility power was available the entire time. I have tried some different things (from other comments) and taken some readings.

What do I need to check next or what could be the problem?

Some readings from 23 & 194
Utility power available, on utility power
194 13.3 VDC
23 5.4 VDC
194 -23 8 VDC

If you pull the 23 wire off the terminal, the contacts in the cube cycle back and forth. Fwd to the front of the panel when wire 23 removed, aft towards the back of the panel when wire 23 touches the terminal block

trip utility, gen starts, switch goes to gen
194 13.3 VC
23 1 VDC
contact in cube are fwd

close breaker to utility, gen stops, but switch does not got to utility
193 13.3 VDC
23 5.4 VDC
contacts in cube are fwd

remove wire 23 from terminal, switch goes to utility
193 13.3 VDC
23 at wire 0
23 at terminal block 13.4 VDC

touch wire 23 to terminal block
wire in contact, contacts move aft
wire not in contact, contacts move fwd

If 23 wire is off the terminal and close the utility breaker, the switch will go to utility

If gen is running and you close the utility breaker, with the 23 wire off the terminal board and before generator shut down, then you put the 23 wire on the terminal board, the switch cycles to utility and then back to generator. Gen shuts down. It does not switch to utility. Take the 23 wire off the terminal board, the switch switches to utility.
Chris
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First things first, do NOT allow the generator to continue to exercise until you fix the problem!

If the unit is running a low speed test, you could burn up the transfer switch and/or the connected loads inside!

It sounds like the 23 wire is grounded somewhere. Basically anytime the switch is seeing generator voltage, it's instantly transferring, not good.

You'll have to find out where the 23 wire has rubbed through, or been hit with something grounding it.
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windboy14571
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Thanks. Will take a look at it.
windboy14571
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Been travelling but finally got back to this.

I checked the 23 wire at the terminal in the transfer switch. (disconnected from the terminal strip) It is not grounded. (Gen in off, Gen breaker in transfer switch in off). Utility power on. Utility breaker in transfer switch on.

23 wire is not grounded if I put the Gen breaker in the transfer switch to on.

There is no voltage on the 23 wire from the generator if the gen breaker in the transfer switch is on or off. And if the generator is running or not (Gen Breaker in off when gen running).

I pulled the 23 wire off the transfer relay and the terminal for the 23 wire on the relay is grounded. Same if the gen breaker in the transfer switch is on or off. Gen not running.

With the generator running, the 23 wire off the transfer relay is open (not grounded) and the 23 wire from the generator is not grounded. There is 13.9 volts on the 23 wire from the transfer relay and no voltage on the 23 wire from the generator.

All the wires in the transfer switch and gen are tight. Nothing loose.

Is the transfer relay bad?

What else should I check?
Economacy
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Will have a look at it.
Chris
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Sorry I missed your reply the other day!

I will explain a little about how the transfer switch works and maybe that will help in the troubleshooting!

The transfer switch's 'default' position is up and into the utility position. This will ONLY occur if there is utility power present on the N1 and N2 terminals AND the 23 wire is un-grounded from the generator (or a short somewhere in the wiring is grounding it unintentionally). The 23 wire gets grounded to battery ground (-12V) when the generator tells the transfer switch to move into the standby position (generator would already be running and warmed up). Just like the utility side, generator power MUST be present for the switch to move into standby.

The 23 wire will not have voltage on it, rather it just gets pulled to ground when the generator tells the switch to move. You would see voltage on the 23 wire TO ground when the switch is in the utility position due to the 194 wire passing through the coil of the transfer relay and out onto the 23 terminal. Without the 23 wire grounded, you'd have a reference back to the 194 (+12V) through the relay.

Probably the easiest test is to have the switch in the standby position (manually move with ALL power turned off, including the generator), generator off, remove the 23 wire from the terminal, and then turn on the utility breaker. The switch should immediately jump into the utility position. If it does NOT move, then you have a transfer switch problem. Most likely the transfer relay (now included in the SACM load module), a limit switch, or the upper coil.

I hope that helps a little!
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
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windboy14571
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Back from another trip. At it again.

I checked your last.

With the 23 wire removed. It has not voltage on it regardless of switch positions, generator running or not, and gen breaker open or shut.

The resistance on the 23 wire is 2.98 Mohm regardless of switch postions also.

I do get 13.3 VDC (charger) on 194 & 23 terminal with the gen in auto or running. No voltage with the gen in off.

I put the transfer switch in standby, moved all to off and removed the 23 wire. I shut the utility breaker and the transfer switch immediately jumped to the utility position.

Tried some other things.

If i have the breakers, utility and gen, shut. The gen running. The 23 wire off the terminal. The moment I touch the 23 wire to the terminal, the transfer switch immediately goes to standby. Remove it from the terminal, and it immediately goes to utility.

Moving down the line, I removed the 23 wire from the terminal in the generator, lower box where the wires come in. The transfer switch does not go to standby with the 23 wire is connected to the terminal in the transfer switch. The wire is not grounded.

Followed the 23 wire to the J2 connector going onto the control board. Measuring at the pin in the J2, the wire is not grounded.

Took out the control board. Cleaned with contact cleaner. Don't see anything wrong on the board (burnt, grounded, discolored etc)

Back at the transfer switch

Utility on. utility power available, gen running, but breaker in the transfer switch in off, the relay clicks and moves when the 23 wire is touched to the 23 terminal. Cycles as the wire is on and off the terminal.

With the breaker shut, the moment the 23 wire is touched to the terminal, the transfer switch goes to standby, remove the wire, goes back to utility.

Is it the control board? Are there other places to check on what would be causing the problem?

R-200B controller 2008 Generac Power Systems. Assy # 0G8455E Rev G. Software 0G8650-E.S19, Rev E K1425.
windboy14571
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Also, should the generator have local ground attached to it, ie copper spike in ground to the generator chassis?

Ours does not. I read somewhere that it should.

Please advise and where should it be connected to if needed?
Chris
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There's so much going on in that last post I think maybe it's making it sound more complicated.

We've established that the 23 wire os grounded, that's a good start! What we need to know is if it's the controller grounding it or if it's the wire rubbed through somewhere or a stray strand or something.

If you take a continuity meter with the 23 removed inside the transfer switch, it should (based on what you've said here) read continuity to ground. With it still reading continuity, remove the connectors from the PCB and see if continuity goes away. If so, it's the PCB grounding it and is probably a stuck transfer relay on the PCB.

To answer your question about driving a ground rod, the answer is NO. These are considered non-separately derived systems and should not have another ground point in the system. It can cause undesirable issues...

If you post the serial number for the generator, I can see what the current PCB for it should be.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
windboy14571
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It is a model QT02724ANAN Serial 5083645.

If I remove the connector from the PCB, it is no longer grounded.

Mike
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