+- Woodnet Forums (https://forums.woodnet.net)
+-- Thread: HVAC hard start (/showthread.php?tid=7377690)
HVAC hard start - meackerman - 01-15-2025
had my heater maintenance done today, they found that the outdoor unit an American Standard Gold series heat pump was drawing 134amps on startup when it should be pulling a little over 100.
They suggested a hard start be installed.
After they left, I got to thinking if its drawing that much over what it should be, isn't that indicative of some other problem? A hard start is just masking that issue?
or is a hard start the thing to do?
it seems to work just fine.
RE: HVAC hard start - crokett™ - 01-15-2025
what did they mean by hard start? have you seen my thread? is it the same thing? if so did they suggest a specific kit?
RE: HVAC hard start - meackerman - 01-15-2025
(01-15-2025, 04:54 PM)crokett™ Wrote: what did they mean by hard start? have you seen my thread? is it the same thing? if so did they suggest a specific kit?
hard start I think its a capacitor that takes the load? as opposed to a soft start that's used with generators.
I'm not exactly sure the difference between the two.
RE: HVAC hard start - blackhat - 01-15-2025
A hard start is essentially a big start capacitor and a relay to drop it out of circuit. It will increase the torque to get the compressor turning. They do solve a few issues and can extend the life of a compressor. If the unit starts fine now I don’t see the need. I have never used one as a precaution. I use them to get a few more years out of a system that has some issues.
RE: HVAC hard start - crokett™ - 01-16-2025
(01-15-2025, 06:21 PM)meackerman Wrote: hard start I think its a capacitor that takes the load? as opposed to a soft start that's used with generators.
I'm not exactly sure the difference between the two.
Ah. my assumption was that pretty much all compressors have a start cap.
RE: HVAC hard start - blackhat - 01-16-2025
Most compressors in residential HVAC units are PSC, permanent split capacitor, motors. They essentially only have a run capacitor and are low start torque motors. Hence the high inrush current on start up. A hard start kit converts it to a cap start, cap run hybrid with a higher start torque.
RE: HVAC hard start - meackerman - 01-17-2025
so am I correct that the higher than expected amp draw on startup indicates some problem?
RE: HVAC hard start - blackhat - 01-17-2025
Maybe. That’s a reading that I could duplicate just by being impatient and not allowing the system to equalize pressure between cycles. Tossing that number out without context is meaningless. Honestly, I wouldn’t sweat it without other indications of problems.
RE: HVAC hard start - meackerman - 01-18-2025
Thanks.
every time I get the annual service they always want to upsell me something.
after I had a new system installed at my previous place, the company's tech came out to do the annual service and tried to upsell me stuff...to which I replied some like...if my brand new system needs that, why didn't my salesman say anything about it? Do I need to call him and complain? The tech shutup pretty fast.