Help! A/C only works when below 100°
Hopefully someone can help me diagnose… Cooking here in Lone Pine CA at 105° this afternoon. I know the cycles / behavior of this Dometic Brisk 2 Air conditioning unit (15k btu), so I think can art...
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Thanks for all the responses.
I have tried to follow up on everyones suggestions… other than calling out a tech for an intermittent issue, or just replacing the unit. :)
Voltage is above 110v when fan/comp are operating.
Current spike is about 4 amps for fan motor then settles at 2ish amps, and spiking about 26 amps for herm comp settling at 14ish amps from what my clamp on can catch. So running about 16.5a in the upper 90°’s here (within factory specs).
Fairly clean coils from visual inspection (better than my 4 ton at the house).
No ice buildup.
I had been looking everywhere for a replacement Positive thermal coefficient resistor (wsx-7) as suggested, but it was out of stock everywhere (dometic called it a motor starter, but said it had been discontinued). I finally found a coleman hard start kit with a capacitor that included the same PTCR wsx-7 replacement I was looking for at a parts house in Reno. It had a cap rated at 43-53 Mfd. vs my original cap that was rated 43-52 MFD, so I didnt swap it out just yet as my current ratings were still ok for now (IIRC, one Mfd higher on replacement specs is not an issue, so I will save it as a backup for now). I swapped out the PTCR and its running normal for now.
Now just need a few days over 100° to see if we got this fixed. FWIW I saved the old “thermistor” for further testing if I can find a diagnostic procedure for it…
I have tried to follow up on everyones suggestions… other than calling out a tech for an intermittent issue, or just replacing the unit. :)
Voltage is above 110v when fan/comp are operating.
Current spike is about 4 amps for fan motor then settles at 2ish amps, and spiking about 26 amps for herm comp settling at 14ish amps from what my clamp on can catch. So running about 16.5a in the upper 90°’s here (within factory specs).
Fairly clean coils from visual inspection (better than my 4 ton at the house).
No ice buildup.
I had been looking everywhere for a replacement Positive thermal coefficient resistor (wsx-7) as suggested, but it was out of stock everywhere (dometic called it a motor starter, but said it had been discontinued). I finally found a coleman hard start kit with a capacitor that included the same PTCR wsx-7 replacement I was looking for at a parts house in Reno. It had a cap rated at 43-53 Mfd. vs my original cap that was rated 43-52 MFD, so I didnt swap it out just yet as my current ratings were still ok for now (IIRC, one Mfd higher on replacement specs is not an issue, so I will save it as a backup for now). I swapped out the PTCR and its running normal for now.
Now just need a few days over 100° to see if we got this fixed. FWIW I saved the old “thermistor” for further testing if I can find a diagnostic procedure for it…
