Time delay neutral on Generac ATS question

[Timothy918]

Good evening. I'm in the process of setting up my Generac automatic transfer switch with a Mebay DC62D controller and a Generac 17500 watt generator.
The only thing I'm using from the cabinet is the ATS and the time delay resistor. I have a DPDT 120v relay for TR and a DPDT adjustable timer relay for TD.
When the ATS is on the generator side TR relay is energized.
My question is when and for how long does the TD relay energize when switching back to utility? I've included the Generac print and a picture of the ATS.
Thanks for any help. Tim
https://1drv.ms/i/s!AmM4Y-aIUTqryFm7XtiFHb-zr6jt?e=VILLcn
https://1drv.ms/i/s!AmM4Y-aIUTqryFo5_5r7sLpcDlOm?e=ygg8fw

 

[Birken Vogt]

It stays energized however long you want it to. Typically 10-60 seconds or something like that. It is not a necessary component. If you leave it out, the transfer switch will transfer quickly like a normal switch. Why do you want it?

 

[Timothy918]

It stays energized however long you want it to. Typically 10-60 seconds or something like that. It is not a necessary component. If you leave it out, the transfer switch will transfer quickly like a normal switch. Why do you want it?

Because I'm not using the inphase monitor. I was commissioning and testing without the time delay and the ats went from generator to utility and I think it was out of phase and the inrush tripped the breaker on the generator and it burned up the Mebay controller and the main board on my refrigerator.

 

[qcroanoke]

Because I'm not using the inphase monitor. I was commissioning and testing without the time delay and the ats went from generator to utility and I think it was out of phase and the inrush tripped the breaker on the generator and it burned up the Mebay controller and the main board on my refrigerator.

I know I've seen where a time delay neutral was recommended for motor loads so they would have time to spin down and stop before it transfered to either source. But if you're single phase I don't see where an inphase monitor would matter. And I thought inPhase monitors were used when paralleling generators.

 

[Timothy918]

I know I've seen where a time delay neutral was recommended for motor loads so they would have time to spin down and stop before it transfered to either source. But if you're single phase I don't see where an inphase monitor would matter. And I thought inPhase monitors were used when paralleling generators.

I read that inverter type refrigerators don't like the inrush if the phases aren't within 20 degrees or less of each other. So I figured it would be better to use a time delay neutral and let the house power down for a minute or two before transferring back to utility. power.

 

[Birken Vogt]

I know what you are saying, this area is thick with generators and many use the same transfer switch mechanism you posted. But I know of none that have any delay enabled.

The manufacturers just crank them out by the thousands and I always figured if there was real danger of damaging equipment by switching out of phase they would have put the effort into it.

I have seen AC compressors start running backwards but "they say" the thermal trip will stop them and when it resets they will be running the right direction.

I do enable inphase monitor where it exists, but nobody else seems to know or care.

 

[Timothy918]

Unfortunately I don't have the inphase monitor anymore. When I bought the cabinet I gutted it and kept the transfer switch and the 250 ohm 100 watt resistor. I got a smaller nema 12x box from work and put the Mebay controller and the transfer switch in it with a din rail for the relays and terminal blocks.

Do you have any thoughts or theories on why the main board on my refrigerator and the Mebay controller burned up when I transferred from generator to utility? The only thing I can think of is the phases weren't aligned when it transferred and the inrush killed them.

 

[qcroanoke]

Unfortunately I don't have the inphase monitor anymore. When I bought the cabinet I gutted it and kept the transfer switch and the 250 ohm 100 watt resistor. I got a smaller nema 12x box from work and put the Mebay controller and the transfer switch in it with a din rail for the relays and terminal blocks.

Do you have any thoughts or theories on why the main board on my refrigerator and the Mebay controller burned up when I transferred from generator to utility? The only thing I can think of is the phases weren't aligned when it transferred and the inrush killed them.

Was this your first attempt at a transfer to generator and a transfer back to utility after you put all this back together?

 

[Timothy918]

Was this your first attempt at a transfer to generator and a transfer back to utility after you put all this back together?

Yes. I shut utility off. Controller started generator then ats transfered to generator.
Re-energized utility and controller transferred ats back to utility. When it transferred the main breaker on generator tripped and the Mebay controller started smoking. Later that evening the wife noticed refrigerator wasn't cooling. Luckily it's under warranty. Repairman replaced main control board. One of the large capacitors released it's smoke.

 

[qcroanoke]

Yes. I shut utility off. Controller started generator then ats transfered to generator.
Re-energized utility and controller transferred ats back to utility. When it transferred the main breaker on generator tripped and the Mebay controller started smoking. Later that evening the wife noticed refrigerator wasn't cooling. Luckily it's under warranty. Repairman replaced main control board. One of the large capacitors released it's smoke.

It sounds like you're bucking phases somehow. But I wouldn't have any idea in what to tell you to look for. There are several Generac guru's on here. Maybe they'll see your post and chime in.

 

[Timothy918]

It sounds like you're bucking phases somehow. But I wouldn't have any idea in what to tell you to look for. There are several Generac guru's on here. Maybe they'll see your post and chime in.

Thank you for the help.

 

[Barbqranch]

I don't know if it is true with modern refrigerators, but long ago I dealt w/ ice makers that if you tried to start them after a very brief shutdown, they would kick out the overload because it couldn't overcome the back pressure when trying to start. Had to give it a little time for the high side pressure to go down.

 

[Timothy918]

I've read about that. I assume newer units have a restart delay on power loss. Not sure if it pertains to an inverter type refrigerator.

 

[Birken Vogt]

I just can't see how it could bother an inverter refrigerator at all. Best case it randomly happens in phase and nothing goes wrong. Worst case it happens opposite phase and now the diodes that were conducting just have to conduct a little bit longer. The capacitors are not going to know any different.

 

[hillbilly1]

Since this is single phase, and a new install, I would check the generator neutral. If the neutral bond was removed, it may not have been tightened back down. The only time I’ve ever had a surge on a single phase system, was when one of our guys pushed the generator feed into conduit, and found the neutral was shorter than the rest of the wires, so it was still taped up and not terminated.

 

[qcroanoke]

I just can't see how it could bother an inverter refrigerator at all. Best case it randomly happens in phase and nothing goes wrong. Worst case it happens opposite phase and now the diodes that were conducting just have to conduct a little bit longer. The capacitors are not going to know any different.

But it also tripped the generator breaker and burnt up the generator control board on retransfer. What caused that?

 

[Timothy918]

But it also tripped the generator breaker and burnt up the generator control board. What caused that?

Correction it didn't burn up the generator control board. It burned up the transfer switch controller. The generator still generates power. I've used it a few times since the failure. I just manually transfered power to the generator and when I go back to utility I shut the breaker off at the generator then transfer back to utility.

 

[Timothy918]

Since this is single phase, and a new install, I would check the generator neutral. If the neutral bond was removed, it may not have been tightened back down. The only time I’ve ever had a surge on a single phase system, was when one of our guys pushed the generator feed into conduit, and found the neutral was shorter than the rest of the wires, so it was still taped up and not terminated.

I don't think I've lost my neutral. I've used the generator a few times since the failure. Just transfered manually.
Presently I have the neutrals separate on the transfer switch when I'm on utility the generator neutral is open. When I'm on generator the utility neutral is open. Is that how it should be wired or should both neutrals be tied together and not switched?

 

[qcroanoke]

I don't think I've lost my neutral. I've used the generator a few times since the failure. Just transfered manually.
Presently I have the neutrals separate on the transfer switch when I'm on utility the generator neutral is open. When I'm on generator the utility neutral is open. Is that how it should be wired or should both neutrals be tied together and not switched?

Are you switching the neutrals?If you are you need to bond neutral to ground in both sources.

 

[hillbilly1]

I don't think I've lost my neutral. I've used the generator a few times since the failure. Just transfered manually.
Presently I have the neutrals separate on the transfer switch when I'm on utility the generator neutral is open. When I'm on generator the utility neutral is open. Is that how it should be wired or should both neutrals be tied together and not switched?

Is the neutral bonded at the generator? If you are switching the neutral, it should be.