Auto start/battery charge issue

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Ken2147
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I have a Carrier Model ASPAS1CCL025 (25kw) generator that a recently repired and have connected with an ATS. Initially everything was working great. Auto start, transfer, exercise mode, providing power etc...
While closing everything up a accidently pinched 2 wires (N1/N2) under a saddle clamp. These 2 wires go to a transformer (TR1) that provides 16 VAC for the battery charger and 16 VAC to the control board as the sense voltage. When this voltage goes away that tells the generator to start.
i reapired the 2 shorted wires, and replaced the 2 fuses in my transfer switch. With everything connected correctly, I have 220 VAC on the primary of the transformer, and 0 VAC on both 16 VAC secondaries. If I disconnect one leg (#225) of the secondary that sends 16 VAC to the control board, both secondaries provide 16 VAC. The wire I disconnected is direct shorted to ground. If I disconnect J2 on the control board, there is no longer a short.
What I want to ensure I am not overlooking something before I order a control board (they are way expensive).
Also, is there someone out there that repairs these control boards?
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Ken2147
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I am getting notifications that there have been responses to my question, but I cannot see the responses.
Chris
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I don't see any responses to this post other than yours (and now mine).

It's odd that if there were a direct short to ground it wouldn't have melted the wire. There are no fuses (to my knowledge) on the load side of the transformer there. Keep in mind that while a meter may beep (tone) for continuity, there are MANY things in a circuit which would show that and NOT be shorted. For example, a solenoid, indicator lamp, another transformer or coil, etc.

It almost makes me wonder if the transformer is really the culprit and when load is applied it drops to 0 volts. I would find a way to use a test lamp or something to verify that it will handle rated load before throwing a controller in it...
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Ken2147
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Chris wrote:
Mon Jun 24, 2024 8:20 am
I don't see any responses to this post other than yours (and now mine).

It's odd that if there were a direct short to ground it wouldn't have melted the wire. There are no fuses (to my knowledge) on the load side of the transformer there. Keep in mind that while a meter may beep (tone) for continuity, there are MANY things in a circuit which would show that and NOT be shorted. For example, a solenoid, indicator lamp, another transformer or coil, etc.

It almost makes me wonder if the transformer is really the culprit and when load is applied it drops to 0 volts. I would find a way to use a test lamp or something to verify that it will handle rated load before throwing a controller in it...
When I was closing everything up, and everything was working, I pinched the N1 and N2 wires from the transfer switch (2-120VAC) feeding that transformer. Blew both Fuses in the transfer switch. I found my short, repaired both wires and replaced the fuses. As soon as I place my Auto-Off-Man switch to Auto, 20 seconds later the generator starts. I replaced the transformer because I had no 26 VAC to either the control board or the battery charger. After replacing the transformer the same thing happened. I disconnected both secondaries of the transformer, and both sides are at 26 VAC. I connected the battery charger, and both sides read 26 VAC. I connected the control board side and both seconderies read 0 VAC. I disconnected wire #225, and both secondaries read 26 VAC. Wire #225 shows direct short to ground. With J2 on the control board disconnected, the short goes away. I have more than 44 years experience in electronics, so I understand that other components can show resistance to ground. Wire #225 does not go ANYWHERE else in the entire generator as far as I can see. This wire is also not grounded with the control board disconnected. This is 26 VAC input to the board to monitor utility power available, so neither leg should be 0 ohms to ground (meter set to 200 ohms range reading 0 ohms). I only asked to get another set of eyes to confirm what I'm seeing.
I sent my board off to be repaired, and the place confirmed that it can be repaired. Though, I would like to know what component gets replaced.

As far as replies to this post, I received an email stating that someone had replied to my question, but I could not see any replies. I also recieved an eamil when you replied
Chris
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They may have replied and deleted it, or replied by accident or something and removed it. I don't see anything else but the two of us here.
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Ken2147
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Chris wrote:
Tue Jun 25, 2024 9:50 am
They may have replied and deleted it, or replied by accident or something and removed it. I don't see anything else but the two of us here.
Good to go!
PhilD13
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I have seen some strange things with control transformers in equipment over the last 40 years. Some or maybe all of this you may already have done. Verify it again. Some of this will kill you (120-240v) as there will be live voltage tests so make sure you use proper safety.

Sounds like a possible back feed. Maybe even through the battery charger feed or enough stray voltage in the control wiring to make it appear you have 240v when using the meter but no actual current.

The N1/N2 feed is from the transfer switch. Disconnect both ends (transfer switch and generator). Check the ohms of the N1 and N2 at the transfer switch to ground and between them. It should be an open circuit.
Take the fuses out at the transfer switch and verify they are both actually good in the transfer switch.
Disconnect the control transformer at the generator, insert the fuses at the transfer switch and check the voltage and use a load (lamp) to check 120v to ground to verify the wiring and voltage/current are actually good from the transfer switch.

The short could have spiked the windings to the transformer. I would guess about 25 ohms on the primary but it might be less or more. So give the primary windings a sanity check that the windings are not shorted.

Take the battery charger feed off 224A/225A , connect N1 and N2 back up and see if the voltage on the transformer output appears. If not disconnect the other secondary winding and see if that cures the issue.

If the transformer does not produce any secondary voltage, go back and verify the fuses did not blow. If the fuses are good, replace the transformer it's likely bad.
Ken2147
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PhilD13 wrote:
Wed Jun 26, 2024 10:57 pm
I have seen some strange things with control transformers in equipment over the last 40 years. Some or maybe all of this you may already have done. Verify it again. Some of this will kill you (120-240v) as there will be live voltage tests so make sure you use proper safety.

Sounds like a possible back feed. Maybe even through the battery charger feed or enough stray voltage in the control wiring to make it appear you have 240v when using the meter but no actual current.

The N1/N2 feed is from the transfer switch. Disconnect both ends (transfer switch and generator). Check the ohms of the N1 and N2 at the transfer switch to ground and between them. It should be an open circuit.
Take the fuses out at the transfer switch and verify they are both actually good in the transfer switch.
Disconnect the control transformer at the generator, insert the fuses at the transfer switch and check the voltage and use a load (lamp) to check 120v to ground to verify the wiring and voltage/current are actually good from the transfer switch.

The short could have spiked the windings to the transformer. I would guess about 25 ohms on the primary but it might be less or more. So give the primary windings a sanity check that the windings are not shorted.

Take the battery charger feed off 224A/225A , connect N1 and N2 back up and see if the voltage on the transformer output appears. If not disconnect the other secondary winding and see if that cures the issue.

If the transformer does not produce any secondary voltage, go back and verify the fuses did not blow. If the fuses are good, replace the transformer it's likely bad.
I have done all of this, minus the load lamp. The wiring is all new, as was just installed a couple of days after the transfer switch was installed. Transformer has been replaced, as stated above. With battery charger disconnected, the output of the secondaries of the transfer is 0 VAC. The only way to get 26 VAC on both secondaries, is by disconnecting wire #225. With the transformer working, the fuses have to be good. I have 220 VAC across the primary of the transformer, even when both secondaries are reading 0 VAC. This is with both transformers.
As I stated earlier, everything was working. As I was tightening a strain relief clamp on my cabling, somehow, N1 and N2 were pinched and shorted to ground, blowing the fuses. Short was repaired. N1 and N1 both have 120VAC. Battery charger is working, if wire #225 is disconnected.
stefuel
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Something is not making sense here. With everything connected if 225 was really shorted, the wire would cook or the transformer would fail fairly quickly.
Is that transformer getting hot to the touch? You could try a 2-3 amp fuse between 225 and the transformer and see if it blows or set your multimeter to amps and actually see how much it is drawing. If the fuse isn't popping, i'd recheck n1 and n2. I think the line voltage feeding the transformer is dropping out. If you truly have good primary voltage and short the secondary, the transformer would get hot as a pistol
Ken2147
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stefuel wrote:
Thu Jun 27, 2024 10:46 pm
Something is not making sense here. With everything connected if 225 was really shorted, the wire would cook or the transformer would fail fairly quickly.
Is that transformer getting hot to the touch? You could try a 2-3 amp fuse between 225 and the transformer and see if it blows or set your multimeter to amps and actually see how much it is drawing. If the fuse isn't popping, i'd recheck n1 and n2. I think the line voltage feeding the transformer is dropping out. If you truly have good primary voltage and short the secondary, the transformer would get hot as a pistol
Transformer is not getting hot. With #225 connected, N1 and N2 read 220 VAC, 120 VAC each measured to ground. As you suggest, this should burn up the transformer in short order.
Also, #225 should not read a short to ground. With J2 disconnected on the control board, secondaries read 26 VAC. This is why I sent my board to be repaired.
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