Strange AC unit current draw
#1
Senior Member
Thread Starter

Electrician cleaning up bad wiring, installing new ground well, happened to clamp on the Goodman unit feeders, 11a per leg while running, but 5 a on both when not running. WhAt could that be? Will check if the air handler is supplied from the compressor unit but should be on a separate breaker me thinks?
#3
Senior Member

compressor heater maybe,
should turn on when compressor is off.
not sure if it is controlled by a low temp switch or not
should turn on when compressor is off.
not sure if it is controlled by a low temp switch or not
Last edited by 99yam40; 09-30-2020 at 11:47 AM.
#6
Senior Member
#9
Senior Member
#11
Senior Member
Thread Starter

Clamp on ammeter, was not the air handler, some jackass put capacitors across the 240v feeding each compressor trying to correct phase angle.
( a common scam here that has surfaced a number of times over the years, usually coupled with a meter leg bypass to show the Huge savings.......)
AC units were replaced, installer left the caps in place, probably failed long ago. Disconnected them. phantom consumption gone.
13A @240 x 24hrs/day, x 30 days/billing period. @ $.34/Kwh.
The shit i see...........
was 5a on one unit, 8 a on the other.
( a common scam here that has surfaced a number of times over the years, usually coupled with a meter leg bypass to show the Huge savings.......)
AC units were replaced, installer left the caps in place, probably failed long ago. Disconnected them. phantom consumption gone.
13A @240 x 24hrs/day, x 30 days/billing period. @ $.34/Kwh.
The shit i see...........
was 5a on one unit, 8 a on the other.
#13
Admirals Club 

#14
Senior Member

Capacitors add reactive power. Don't really consume much power. Draw power on the rise of the sine curve, discharge on the downslope of the sine curve. Net consumption near zero except for resistive losses. Amp meters can't tell the difference between reactive power and resistive power, it's still just amps in either case. Not sure if kWh meters can tell the difference, I think they do.
#15
Admirals Club 

#18
Senior Member
#19
Senior Member
Thread Starter

DC Current is measured in line (most meters limit this to 10A max), voltage across, for AC current a clamp on around the hot or neutral indicates AC amps.
Yes, the Capacitor itself indicated 5 A current, the other one 8A, but realized that might have been reactive. Or they are bad/shot. Probably a way to figure out actual watts drawn and it is probably less than the read value.
The 5 and 8 amp reading was when the compressor was not running.
Been reading up, phase angle correction (Power factor correction) can cause issues with surges and spikes if not done right.
Power co does it to balance resistive vs.reactive on substations and transmission lines but over here it's all disconnected no doubt.
Yes, the Capacitor itself indicated 5 A current, the other one 8A, but realized that might have been reactive. Or they are bad/shot. Probably a way to figure out actual watts drawn and it is probably less than the read value.
The 5 and 8 amp reading was when the compressor was not running.
Been reading up, phase angle correction (Power factor correction) can cause issues with surges and spikes if not done right.
Power co does it to balance resistive vs.reactive on substations and transmission lines but over here it's all disconnected no doubt.
#20
Senior Member


Certainly would troubleshoot the unbalanced line. Best method for that would be hiring an experienced electrician.