Buying A Hard Start Capacitor Help - DIY Chatroom

D1G1T4L3CH0 · 10-17-2008, 08:41 PM

I have been looking into getting a Hard Start Capacitor since I was told I needed one. The compressor just buzzes every 30 seconds or less and never turns on to make the air cold. The compressor does start up and run rarely and even right after the new fan motor was put in the compressor was working great for a long time. Everything else seems to work properly. A lot has been changed out on this central AC unit. It is very old. I got some information from the unit and the parts inside. The parts are not all original. I need a recommendation on a hard start capacitor as to which one will work and be the best choice for my situation. I want a safe one too. I was looking at the Supco SPP8E but am unsure if that will work or would be overkill. Anyhow, there is some info below.

AC Unit: Coleman Suncutter (Sorry no model information.)
Capacitor (Top): Aerovox
(This one was recently replaced when a new fan motor was put in.)
Z23 P4407Y
7.5uf
440v
60Hz
Protected P10000 AFC
123 8 80-197
SH 8704
Capacitor (Bottom): ShiZuki
WME-RS
40.0 MFD +10%
370 VAC
60Hz
Protected 10000 APC
NO PCB's-SH
1499-472
SPEAROL 8930 USA
Motor: Emerson
(This is the new fan motor.)
Model KA55HXSMR-1861
HP 1/3
Volt 208-230
60Hz
Amp 2.1
PH 1
RPM 1075

Thanks.

biggles · 10-17-2008, 10:01 PM

when the unit cucyles off that time is spent within the unit to equalize the pressures for the next cycle.when it is running the pressures ther might be 60PSI/240PSI during a hot day when it cycles off the pressures will balance off to at least 100PSI/200PSI or even 150PSI/150PSI for a balanced start.the hard start is a way/ to go to boost the windings to overcome that unbalanced pressures .....but your pushing the insulation on the windings and might result in a compressor burn out especially on an older unit like that.the million dollar question is if you shut the unit down for say 10 minutes does it restart like when you did the fan...the safer fix here is to install a time delay relay on 1 wire on the 24v side into the condenser from the house.set it for 5 minutes(pressure balancing time) and on the next cycle it will start..are you running a digital stat there or mercury bulbs react quicker to temp changes with no built in time delays.check out www.grainger.com part # 4E233 they welcome over the counter sales to DIYrs you should have around you
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D1G1T4L3CH0 · 10-17-2008, 10:30 PM

Quote:

Originally Posted by biggles

when the unit cucyles off that time is spent within the unit to equalize the pressures for the next cycle.when it is running the pressures ther might be 60PSI/240PSI during a hot day when it cycles off the pressures will balance off to at least 100PSI/200PSI or even 150PSI/150PSI for a balanced start.the hard start is a way/ to go to boost the windings to overcome that unbalanced pressures .....but your pushing the insulation on the windings and might result in a compressor burn out especially on an older unit like that.the million dollar question is if you shut the unit down for say 10 minutes does it restart like when you did the fan...the safer fix here is to install a time delay relay on 1 wire on the 24v side into the condenser from the house.set it for 5 minutes(pressure balancing time) and on the next cycle it will start..are you running a digital stat there or mercury bulbs react quicker to temp changes with no built in time delays.check out www.grainger.com part # 4E233 they welcome over the counter sales to DIYrs you should have around you
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Thanks for your quick reply. I'm not sure I completely understood your reply but I think you may have misunderstood my post. I mean to say that the compressor does not turn on and hasn't been for about a week. It used to turn on and sometimes go out for a day and not come on. It makes a buzzing noise every 30 seconds that is definitely coming from the compressor and the air does not get cold. I know the sound to look for when the compressor turns on also and it's just not coming on but keeps trying about every 30 seconds. Also note that I was informed by a contractor to get a Hard Start Capacitor. I got one free but taking a further look under the cap revealed it was wet inside and the cap easily came out with pieces moving around inside unattached. So I won't be using that one. It's a digital thermostat.

biggles · 10-17-2008, 10:42 PM

sorry about that ......

if it doesn't restart in a day from a the first call that is a starting problem,might want to eyeball that contactor for the compressor might be arc'd,and causing (the hard start

) and tripping the overoad thats your 30 seconds on/off cycle your hearing..maybe a contactor change will give you a truer amp draw on start and not trip the OL.......i am trying my best to keep you away from that Hard Start kit... becuase you will be going for a new compressor/or entire condenser change out in the future. when the compressor "NUKES OUT" it burns the freon and contaminates the entire system.if the unit doesn't have a crank case heater that could also cause the overloading..you can get awrap around one and tie it into the top of the compressor contactor