Author Topic: Is this an electrical connector, a fuse, or what?  (Read 6010 times)

index

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Re: Is this an electrical connector, a fuse, or what?
« Reply #50 on: March 09, 2023, 08:47:55 PM »
There shouldn’t be an induction blower here, it’s a heat pump. That other wiring area must be for a different model version.

Good call on not needing to call for fan, I was clearly not thinking things through. Thanks, it’s little things like that that be confusing for the poor soul on the other end of these troubleshooting blasts.

Hey, you fixed my on vs off error! Twisting together 1 and 3 bypasses everything and runs the fan as soon as you switch the power back on.
« Last Edit: March 09, 2023, 08:56:07 PM by index »

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zolotiyeruki

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Re: Is this an electrical connector, a fuse, or what?
« Reply #52 on: March 10, 2023, 08:21:28 AM »
There shouldn’t be an induction blower here, it’s a heat pump. That other wiring area must be for a different model version.

Good call on not needing to call for fan, I was clearly not thinking things through. Thanks, it’s little things like that that be confusing for the poor soul on the other end of these troubleshooting blasts.

Hey, you fixed my on vs off error! Twisting together 1 and 3 bypasses everything and runs the fan as soon as you switch the power back on.
Nice. So you know your motor and wiring are good.  The next step would be to confirm that you're getting 24VAC across the coil side of the relay.  The "click" you heard earlier would seem to indicate that you *are*, so this is just a double check.  Put back 1 and 3 where they were before, turn power on, and call for fan.  Then measure the voltage across that coil (see picture).  If you get 24V, but no blower, then the relay needs to be replaced. 

To triply make sure of the diagnosis, you can, with the same setup, measure the voltage between 1 and 3.  I would expect to see something near 240V if the relay has failed.

ATtiny85

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Re: Is this an electrical connector, a fuse, or what?
« Reply #53 on: March 10, 2023, 09:06:19 AM »
There shouldn’t be an induction blower here, it’s a heat pump. That other wiring area must be for a different model version.

Good call on not needing to call for fan, I was clearly not thinking things through. Thanks, it’s little things like that that be confusing for the poor soul on the other end of these troubleshooting blasts.

Hey, you fixed my on vs off error! Twisting together 1 and 3 bypasses everything and runs the fan as soon as you switch the power back on.
Nice. So you know your motor and wiring are good.  The next step would be to confirm that you're getting 24VAC across the coil side of the relay.  The "click" you heard earlier would seem to indicate that you *are*, so this is just a double check.  Put back 1 and 3 where they were before, turn power on, and call for fan.  Then measure the voltage across that coil (see picture).  If you get 24V, but no blower, then the relay needs to be replaced. 

To triply make sure of the diagnosis, you can, with the same setup, measure the voltage between 1 and 3.  I would expect to see something near 240V if the relay has failed.

Wrong user...we are waiting for slackmax to check in. Hopefully your steps are the next in line.

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #54 on: March 10, 2023, 09:09:10 AM »
Before I open up the control box, I want to check out voltages at the capacitor and motor. SInce I get 120 volts at the 2 wire connector, I want to hook up the downstream connector, and see what voltages I get at the end of those wires.

See attached diagram and pic of three wire connector.

Should I check by grounding the black probe and using the red probe at the wire?

Can I leave the wires connected to the capacitor while testing voltages? Can I check all 3 wires at the capacitor, while connected to it?

My thing here is that if I get 120 volts on its way to the motor, at the upstream connector, what is happening to it downstream? Where is it going? 

By the way, just to add data, I tested the 2 wires at the upstream connector, and got 120 volts on the dark blue wire, and zero volts on the red wire, in both fan on and fan off.    Does that make sense? Fan off and fan on having the same readings?

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #55 on: March 10, 2023, 09:12:09 AM »
Pic of hand drawn wire diagram near cap and motor.

zolotiyeruki

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Re: Is this an electrical connector, a fuse, or what?
« Reply #56 on: March 10, 2023, 10:28:29 AM »
Ignore testing the capacitor for now.  Its purpose is to help get the motor started turning. You can also ignore the white wire, as it doesn't connect to anything.

If you test the resistance between the dark purple wire (from the connector to the capacitor) and the black wire (from the capacitor to the motor), it should read 0 Ohms.

With power on, but fan *not* commanded, you should measure 120VAC between the black wire (motor <-> cap) and ground, and 0 VAC between that same black wire and the red (motor <-> connector) wire.  Once the fan is commanded, you should see 240VAC between that red and black wire.  This is with everything plugged in.

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #57 on: March 14, 2023, 04:01:21 PM »
Zolotiyeruki,

I wasn't sure exactly what you meant, so I went and did some testing of my own.

I have noticed something interesting.  At the 2-wire connector. Whenever I test it, by grounding the black multimeter probe, I get 120 volts at the black wire, no matter if it is 'fan off' or 'fan on'.  And I always get zero volts at the red wire, in fan on and fan off.

I think there are supposed to always be 120 volts on black wire, and zero on red unless  fan is called for, then red is supposed to have 120 and black is supposed to have  120, equaling 240 volts. Right ?     

I also jumpered R and G when thermostat was in 'fan on' and 'fan off' modes, and heard a click on and a click off when in 'fan off' mode, but the voltage never moved off zero.  ALways zero at the red wire.

Thoughts?


index

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Re: Is this an electrical connector, a fuse, or what?
« Reply #58 on: March 15, 2023, 10:48:03 AM »
Zolotiyeruki,

I wasn't sure exactly what you meant, so I went and did some testing of my own.

I have noticed something interesting.  At the 2-wire connector. Whenever I test it, by grounding the black multimeter probe, I get 120 volts at the black wire, no matter if it is 'fan off' or 'fan on'.  And I always get zero volts at the red wire, in fan on and fan off.

I think there are supposed to always be 120 volts on black wire, and zero on red unless  fan is called for, then red is supposed to have 120 and black is supposed to have  120, equaling 240 volts. Right ?     

I also jumpered R and G when thermostat was in 'fan on' and 'fan off' modes, and heard a click on and a click off when in 'fan off' mode, but the voltage never moved off zero.  ALways zero at the red wire.

Thoughts?

Have you tried twisting together 1 and 3 (red wire) from the relay yet? This takes the thermostat, transformer, and relay out of the equation and should tell your fan is good or not. If I had to guess, it sounds like something in the relay is messed up or possibly the transformer, though I don't think your thermostat will power on if the transformer is fried. 

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #59 on: March 15, 2023, 12:15:53 PM »
Zolotiyeruki,

I wasn't sure exactly what you meant, so I went and did some testing of my own.

I have noticed something interesting.  At the 2-wire connector. Whenever I test it, by grounding the black multimeter probe, I get 120 volts at the black wire, no matter if it is 'fan off' or 'fan on'.  And I always get zero volts at the red wire, in fan on and fan off.

I think there are supposed to always be 120 volts on black wire, and zero on red unless  fan is called for, then red is supposed to have 120 and black is supposed to have  120, equaling 240 volts. Right ?     

I also jumpered R and G when thermostat was in 'fan on' and 'fan off' modes, and heard a click on and a click off when in 'fan off' mode, but the voltage never moved off zero.  ALways zero at the red wire.

Thoughts?

Have you tried twisting together 1 and 3 (red wire) from the relay yet? This takes the thermostat, transformer, and relay out of the equation and should tell your fan is good or not. If I had to guess, it sounds like something in the relay is messed up or possibly the transformer, though I don't think your thermostat will power on if the transformer is fried.

I attached pics of the relay. It looks like all the wires are in the front, and they are on spade terminals. I guess I could jumper them together.  But which one is 1 and which one is 3?   

zolotiyeruki

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Re: Is this an electrical connector, a fuse, or what?
« Reply #60 on: March 15, 2023, 12:28:02 PM »
I think there are supposed to always be 120 volts on black wire, and zero on red unless  fan is called for, then red is supposed to have 120 and black is supposed to have  120, equaling 240 volts. Right ?     

I also jumpered R and G when thermostat was in 'fan on' and 'fan off' modes, and heard a click on and a click off when in 'fan off' mode, but the voltage never moved off zero.  ALways zero at the red wire.
Yes, that is correct.  The red and black both have 120VAC, and since they're 180 degrees out of phase, the difference between them is 240VAC.

The fact that you're seeing 120VAC on the black wire at the two-wire connector, and 0V on the red, tells me the voltage from the wall isn't getting past the relay.  The next step is to do as index says:
Quote
Have you tried twisting together 1 and 3 (red wire) from the relay yet? This takes the thermostat, transformer, and relay out of the equation and should tell your fan is good or not. If I had to guess, it sounds like something in the relay is messed up or possibly the transformer, though I don't think your thermostat will power on if the transformer is fried.

I attached pics of the relay. It looks like all the wires are in the front, and they are on spade terminals. I guess I could jumper them together.  But which one is 1 and which one is 3?   
The wiring diagram indicates the wire colors.  See the attached photo.  The wires connected to 1 and 3 are both red.

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #61 on: March 15, 2023, 01:35:03 PM »
Terrific! Thank you.

One of the red wires has the word 'two' on it. Not a problem? (Just means it is the second red wire, not term 2?)

Just to be sure, turn power off, then I would take the two red wires off the spade terminals, in the relay pic.

Then connect those two wires, turn power back on, in any mode (fan on or off) and if motor is good, it will come on ?     


zolotiyeruki

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Re: Is this an electrical connector, a fuse, or what?
« Reply #62 on: March 15, 2023, 01:50:18 PM »
Terrific! Thank you.

One of the red wires has the word 'two' on it. Not a problem? (Just means it is the second red wire, not term 2?)

Just to be sure, turn power off, then I would take the two red wires off the spade terminals, in the relay pic.

Then connect those two wires, turn power back on, in any mode (fan on or off) and if motor is good, it will come on ?     
My guess is the "two" corresponds to the "RD/2" in the wiring diagram, and the other wire will be "one".

And yes, your sequence of steps is correct.

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #63 on: March 21, 2023, 11:03:41 AM »
There shouldn’t be an induction blower here, it’s a heat pump. That other wiring area must be for a different model version.

Good call on not needing to call for fan, I was clearly not thinking things through. Thanks, it’s little things like that that be confusing for the poor soul on the other end of these troubleshooting blasts.

Hey, you fixed my on vs off error! Twisting together 1 and 3 bypasses everything and runs the fan as soon as you switch the power back on.
Nice. So you know your motor and wiring are good.  The next step would be to confirm that you're getting 24VAC across the coil side of the relay.  The "click" you heard earlier would seem to indicate that you *are*, so this is just a double check.  Put back 1 and 3 where they were before, turn power on, and call for fan.  Then measure the voltage across that coil (see picture).  If you get 24V, but no blower, then the relay needs to be replaced. 

To triply make sure of the diagnosis, you can, with the same setup, measure the voltage between 1 and 3.  I would expect to see something near 240V if the relay has failed.


To check voltage across the coil in the relay, I should use the multimeter probes on term A and B (green and blue) on the right side of the relay, right?

Can I just insert the probes up in the corners of the terminals A and B and make contact on the metal in there?   

This is with all the wires in their normal places.
« Last Edit: March 21, 2023, 11:09:10 AM by slackmax »

zolotiyeruki

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Re: Is this an electrical connector, a fuse, or what?
« Reply #64 on: March 21, 2023, 04:55:31 PM »
Yes, blue and green wires, and yeah, if you can shove the probes in, that should work.

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #65 on: March 23, 2023, 07:26:03 PM »
OK, I did some voltage testing of the relay with all its wires on.

With the black probe grounded I probed some of the terminals on the relay.  (see pic above)

With 'fan off' , at 6 (red) I got 120, at 9 (red) I got zero.  Also zero at A (green) and B (blue).

With 'fan on', at 6 (red)  I got zero, at 9 (red) I got 120, at Green I got 26, at Blue I got zero. 

All that was with the black probe grounded.

When I tested between  6 and 9 (no grounding) I got 8 volts in 'fan off' and 7 volts in 'fan on'.

I was expecting to see 120 volts when testing between them, since the multimeter is testing the difference between term 6 and term 9, right? 120 minus zero is 120, but I got 8 or 7.

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #66 on: March 25, 2023, 09:42:23 AM »
Update. I didn't do anything  other than jostle some wires and wiggle some connectors during testing, but now the fan WORKS !!  I'm not even going to guess what it was. I''m so happy the ****ing fan is working again.

Thanks, Zolotiyeruki, for all your help. I now know ten times as much about HVAC electronics as I did before this juggernaut, lol. 


ATtiny85

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Re: Is this an electrical connector, a fuse, or what?
« Reply #67 on: March 25, 2023, 07:05:53 PM »
Well…..great!?

Been there many times.

slackmax

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Re: Is this an electrical connector, a fuse, or what?
« Reply #68 on: March 26, 2023, 08:34:38 AM »
Well…..great!?

Been there many times.

Thanks for your help, too, ATtiny85  ! 

zolotiyeruki

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Re: Is this an electrical connector, a fuse, or what?
« Reply #69 on: March 26, 2023, 09:14:42 AM »
Well…..great!?

Been there many times.
heh, well put! Glad we were able to....help?