Danny, are my posts making it to you, through your server? You've not answered my question. And you're going through a lot of bother which isn't really needed.
But, did you ever do any thing simple?
I leave you to your complications.
Danny, are my posts making it to you, through your server? You've not answered my question. And you're going through a lot of bother which isn't really needed.
But, did you ever do any thing simple?
I leave you to your complications.
-- . Christopher A. Young
On 7/9/2016 6:48 PM, Danny D. wrote: ...
There's something missing here & that is the cap. As I understand it, the cap is wired in series with the start winding in order to phase shift its current and get the motor started in the right direction. Without the cap, I don't think that the motor will start.
Bob
Also, now knowing what the output terminals of the relay are, one can diagnose it directly. Its circuit follows:
--||-- cap | | v v v v | |
120
You're right.
By gathering clues, I figured out which is the neutral on the compressor and which was the always powered pin, and which was the sometimes powered pin.
Then I created a test jig and hooked it up, without a capacitor. When I powered it up, the compressor still didn't run.
Can you modify your test jig to include the cap? Wire it in series in the start wire.
It isn't always a capacitor; 'relay' and 'NTC resistor' are other start components that one might encounter.
Thank you Bob for suggesting jumping the capacitor terminals to short them out, as that gave me some additional connectivity diagnostic information when I checked continuity:
The relay has only two wires going into it, and three holes coming out.
Disconnected from power, and with the capacitor terminals shorted: a. Red power input terminal went directly to the relay top output pin b. White neutral input terminal went directly to *both* lower output pins
If I remove the short between the capacitor pins, it changes to: a. Red power input still went directly to the relay top output pin b. White neutral input still went directly to the rearward lower output pin c. White neutral input no longer innervates the forward lower output pin
Unfortunately, it appears that the relay & cap are working. Do you interpret this the same as I do?
I will make any jumper cable we need to debug this darn thing.
Since it appears (to me anyway) that both the cap and the relay are working, that leaves mainly the compressor to test (which is critical).
If my prior tests of the relay were accurate, they seem to indicate a working relay, since there is 120VAC across the two lower terminals to the upper power terminal.
I wish the motor had a marking for the Start terminal versus the Mark/Run terminal and common, but there is nothing marked I can decipher. A. POWER TERMINAL B. RUN TERMINAL (aka MARK terminal) C. START TERMINAL
So these are just my guesses for the three terminals:
Given that, is this your suggestion for wiring the cap in series:
Is that what you are suggesting I test?
Yes, I think that's right.
Except that it's standard to switch the "hot" line, not the neutral. Are you sure that the white input wires are neutral? White is the usual color for neutral, but inside an appliance they could do otherwise.
I agree
Yes. And as the parts guy advised, as soon as the motor starts, disconnect the START pin.
...
WE "got's to know": did you try it & what happened?
I apologize for missing yesterday. I had a family engagement. All the salmon is gone by now, so I have more time anyway. :)
What do you make of these results?
Given:
In both tests, the motor just hummed but did not appear to start. When I pulled what I think is the start wire neutral off, the hum didn't change.
What do you make of this? What are my options? (PS: Money is tight).
The markings on this cap are:
Can that 120VAC 12uF zap kill me? Is it safe (to the cap) to short the terminals?
On Fri, 8 Jul 2016 23:22:01 -0000 (UTC), Danny D. wrote: Here is a summary, from top to bottom of where it's at.
SUMMARY: I don't know if I tested it correctly, nor if I identified the circuit correctly, but if I both identified and tested the circuit correctly, then the compressor motor is bad.
However, maybe I made a mistake?
DETAILS:
Here is another video of the humming noise and click off the next day when the compressor was cold:
======================
In both tests, the motor just hummed but did not appear to start. When I pulled what I think is the start wire neutral off, the hum didn't change.
What do you make of these results?
On 7/11/2016 6:06 PM, Danny D. wrote: ...
Yep, that's right.
Actually, with AC, it's all the same. Functionally, that is - there is a safety difference.
You've already determined that there is continuity on the start winding, so no difference when pulling it does not indicate an open winding.
The no-difference is due to the cap-in-series which limits the start current to about 1/2 amp (its impedance is 220 ohms), while the run current is likely 6, 8, or more amps. I.e., the start current is too small to notice when it's removed.
I can't think of anything else to try. It seems pretty conclusive that the compressor is shot. Oh ... somebody said that the "Freon" line could be plugged. That could be, but diagnosing and fixing that would be just as expensive.
I suppose, for the hell of it, you could try reversing the start & run leads. Can't hurt & maybe there was a brain fart that got their identities reversed.
Bob
Nicely done.
Oh, oh, oh... Set up a video and put this on youtube. It might be a winner.
Just for the hell of it can you take an ohmmeter measurement from any of the three terminals to the case? It should show open (very high resistance). If it measures any resistance, the compressor is bad.
I hadn't thought of that. I did avoid touching the chassis. :)
Thanks for explaining that the start current is much less than the run current, so the motor "sounds" wouldn't be easily discerned.
I don't know how to test for a plugged freon line either. :(
Thanks for that idea. I just reversed the START and RUN terminals, and there was no difference. It hummed but didn't kick on.
One problem is that I can't tell what's going on from the sound, but when I hooked all the old parts back, it kicked off again as it did when I started this thread.
Sigh.
Ah, resistance. Why didn't I think of that. I'll make a test jig out of the existing wires, and put a 5K ohm resistor on it. Thanks for that idea.
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