ATS Will Not Transfer Back To Utility

[Sam Moore]

I don't know how this post got in front of mine, because it wasn't there when I did my last post, but anyhoo, yes its basically the same switch as in my link, but its a much clearer diagram. I do believe it is the two wires got swapped accidentally. This would cause the switch to work on utility fail, but once transfered, it can't switch back because the other hot is open. I would check those connections first. If it's not there, check for voltage output on J1 to ground. Should be 120 volts at that point if the controller is calling for the transfer back to normal. The CT's are just for load shed purposes, so they should have nothing to do with the transfer.

I believe youre on to something...I will check those two wires as soon as I go back

 

[steve66]

It looks like there is a 5 minute minimum generator runtime, with a 10 sec. deley before retransfer.

Are you sure you waited 5 min and 10 sec. for the ATS to transfer back to utility??? Did you actally time it with a clock?

 

[hillbilly1]

It looks like there is a 5 minute minimum generator runtime, with a 10 sec. deley before retransfer.

Are you sure you waited 5 min and 10 sec. for the ATS to transfer back to utility??? Did you actally time it with a clock?

The Op stated that it would stay on generator power until it ran out of fuel even though utility was present. If the two wires I described in an earlier post are swapped, the generator will crank and transfer to generator, but because it is inadvertantly breaking the voltage sense circuit to the generator, it still thinks the utility is dead and continues to run. And with the miswire also opens the circuit to the utility solenoid, causing it not to transfer back to the prefered source, hence the failure to transfer back.

 

[steve66]

The Op stated that it would stay on generator power until it ran out of fuel even though utility was present. If the two wires I described in an earlier post are swapped, the generator will crank and transfer to generator, but because it is inadvertantly breaking the voltage sense circuit to the generator, it still thinks the utility is dead and continues to run. And with the miswire also opens the circuit to the utility solenoid, causing it not to transfer back to the prefered source, hence the failure to transfer back.

Good point, I forgot he said it ran until the generator ran out of fuel. I knew it was a slim chance the OP just didn't wait long enough (for the retransfer), but I thought I would throw that out there just in case.

 

[Sam Moore]

Good point, I forgot he said it ran until the generator ran out of fuel. I knew it was a slim chance the OP just didn't wait long enough (for the retransfer), but I thought I would throw that out there just in case.

I actually didnt let it run until fuel ran out, but I did let it run for about 25 min.s while I was on the phone with a sales rep...pretty sure it would continue to run until tank was empty.

 

[ATSman]

Off on a Tangent

Off on a Tangent

Ok, I'm at wits end with an ATS that I'm trouble shooting...

-Briggs and Stratton 200 Amp ATS with Service Disconnect and AC Control Module
connected to a 12 kw B & S Generator

- Utility power fails and switchs to gen and all is well, problem is Utility returns and ATS will not switch back to Utility. Control board LEDs indicate that both utility and gen power is present. Once Utility is restored the only way it will transfer back is shut Gen breaker of and it will switch back to Utility, other wise it will run Gen until fuel runs out

History- I got involved after a surge hit ATS and this started...I replaced control board and transfering mechanism (solenoids and all) due to obvious burn marks on both...only parts left were fuses and breakers and ct's...generator and 240 volt sensing circuit check out fine
I also installed a surge suppressor to help prevent future attacks from mother nature and the poco

What am I missing???

Guys,
Everyone is missing the one key point in the OP: "Once Utility is restored the only way it will transfer back is shut Gen breaker off and it will switch back to Utility"
This statement proves that it is not a wiring error in the solenoid circuit as Hillbilly is alluding to. Furthermore if Sam is waiting long enough for the return timer to run
out then( and all ATS's are designed to immediately transfer back to a good normal source if the generator dies or is disconnected) I go back to my suggestion of raising the frequency (speed) of gen to 60.2HZ. This seems to be a simple adjustment and would quickly rule out whether the ATS has the IM feature.
Or, what am I missing here!!!:[/B]

 

[mkgrady]

This same thing happened to me.

This same thing happened to me.

When I had a similar problem someone on this board suggested that these B&S units have a poor connector at the generator. Because I some of my testing indicated bad parts, I didn't belive it. I troubleshot it to death, replaced numerous parts that I was sure were bad and I was wrong. I finallay went to the generator and found a multiwire connector that connects about 14 small gauge control wires to the control board. Once I changed the connector (B&S sells a kit for this) it ran normally.

What was frustrating is that there wasn't enough of a wiring diagram that I could use to see if there was a bad connection. I just changed the connector and prayed but it worked.

 

[badabing]

Guys,
Everyone is missing the one key point in the OP: "Once Utility is restored the only way it will transfer back is shut Gen breaker off and it will switch back to Utility"
This statement proves that it is not a wiring error in the solenoid circuit as Hillbilly is alluding to. Furthermore if Sam is waiting long enough for the return timer to run
out then( and all ATS's are designed to immediately transfer back to a good normal source if the generator dies or is disconnected) I go back to my suggestion of raising the frequency (speed) of gen to 60.2HZ. This seems to be a simple adjustment and would quickly rule out whether the ATS has the IM feature.
Or, what am I missing here!!!:[/B]

Oh am I glad I found this thread. My facility actually has the problem that's being discussed here - 1 of our ATS is not transferring back to utility after the generator is shut down. Had techs out to troubleshoot (and it actually didn't work while he was there, thankfully!) and he diagnosed replacing the transfer switch itself, believing something was bad within it (don't remember exactly what he said).
Anyways he was only able to get it to transfer back to utility after removing several protective guards by the manual transfer switch and pushing some other lever in or something (Couldn't see what he was doing)and using the manual reset, he was able to reset it. Just using the manual lever itself wasn't releasing it to utility power.
When they return to replace the guts at a cost of $7k, I wonder if I should have them do what has been suggested here to this problem - shut breaker off to generator and see if it will reset to utility power, and increase frequency? We have 2 ATS at our facility fed off 1 generator, both load tested monthly, and run weekly. Our problem just occurred 2 weeks ago, and we're still waiting for the parts. This is the worst time of year for this to break down for us as well - lots of rain and wind this month and we loose power around this time each year.

 

[Electric-Light]

I would look for a toggle switch or a software command that tells the ATS to behave one way or to behave the other way.

And even if it isn't user selectable, if the ATS comes in multiple models, its possible that they share the same control board and different functions are implemented by firmware switches that are not published as user accessible, which can also hold other things such as calibration constants.

Sometimes control boards have off-limits factory use only connectors. Some use the same communication port as the user, but configuration parameters are not meant for end-user.

Surges do cause firmware corruption and may require sending back a module or the unit to factory service center. It happened to our photocopier after an outage. Would copy fine, but won't scan from computer. A board had to be sent back to factory for firmware re-flash. They didn't replace anything. $100 later, everything was back to normal.

 

[hillbilly1]

Unless it has an in sync transfer mode, increasing the frequency will not make it transfer back to utility. This is a cheap version transfer switch, and all it's looking for is voltage within it's specified parameters, if the incoming voltage meets it's spec's, then it will transfer.

 

[LarryFine]

... if the incoming voltage meets it's spec's, then it will transfer.

And, if it doesn't?

 

[hillbilly1]

And, if it doesn't?

That's why they call it troubleshooting!:grin: