A/C - slow power draw increase


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Old 07-08-20, 01:37 AM
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A/C - slow power draw increase

i have a split ac unit that was moved from one location to another location.
it is specified on the unit that imput power should be 1350-1450w for cooling (6.1-6.6 A). it is on a 10A breaker, and after a few minutes the breaker pops. the power it starts at around 1300w, and after that slowly goes up, and up, and up until it trips the 10 A breaker about 15 minutes later.
it uses r410a , it has only one port for checking the pressure and filling, on the low side (is the model with capilary action). the pressure when not in use is 1.7 MPa and the outside temperature was about 30 drgrees C. and when it is runing it drops to about 0.7 MPa.
the ac was not used for about 6-7 months and after it was moved. is this normal to do so? could be over filled, the cap is going bad? is the motor going bad? the unit is about 10 years old but it wasn't used verry much.
 
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Old 07-08-20, 05:31 AM
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You only provide the voltage to the unit. The electrical circuit determines the current draw. Usually the condenser fan and compressor motor both start when the unit turns on. Motors draw approximately 10x the run current at startup (about 1 second) so the 1300 watts looks suspicious. Where did you make the measurement and what type of instrument did you use? Are you sure the compressor motor is operating?
 
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Old 07-08-20, 07:58 AM
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the voltage is 230(234 at the breaker, and about 232 at the compressor when running). and yes, in the first second or so the power is much more, then is stabilize to what i said. i mesured with a watt-meter and a amp-meter clamped on 1 live wire to reconfirm the first mesure.
could it be a simple problem like over charged? how to mesure for that ?
(yes, the compressor and the fan is running, i can both hear them working and cold air starts to flow on the inside unit when it is on)

i will call a autorized professional firm to take a look at that, but first i would like to know if it might be a simple problem like over charged with gas, or it could be that the compressor is failling, because if i suspect the compressor then i buy another unit instead of paying to fix this one because i have free install with new purchase.
 
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Old 07-08-20, 10:25 AM
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Welcome to the forums.

You should put non-US in your member bio.

it has only one port for checking the pressure and filling, on the low side
That is odd but I know some of the units over there are different than here.
If it was overcharged it should trip a high pressure switch but yours may not have one.
 
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Old 07-08-20, 04:35 PM
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i foud the service manual, it said to put a breaker of 15A not 10A, whitch is odd to me, since it says that the current is under 7A...i attatch it below part of it.

is it normal for a ac that says input power for cooling in the range 1350-1450 W and current 6.1-6.6 A to draw more than 2300W and trip a 10A breaker? (ok, i know now they say a 15A breaker should be used,but still...)
 
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Old 07-08-20, 04:43 PM
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That A/C has high and low ports.

The manufacturer sets the minimum breaker size. The operating current may rise when started and settle down after cooling. Those units don't always behave like they are supposed to.
 
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Old 07-09-20, 12:07 PM
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When an A/C starts up in a warm / hot room on a hot day, the head pressure will be high as it starts cooling off the room. The unit will draw more power until things start to cool off, including the outdoor temp.
 
 

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