I currently have a Frigidaire Model FRA105CV1 10000 BTU AC Unit. Recently, when it's been very hot outside, I've noticed that this unit struggles around 5 minutes of cooling, until the compressor putters off, and the fan comes on.

I've currently got it hooked up to a power monitor, and here's my results: (Harper here: added VA and PF. VA is calculated as V x A. W is watts indicated by power monitor. PF is calculated Power Factor, aka W/VA. This may expose limitations in the power monitor's ability to measure amps or watts. I'm sure voltage is spot on, though.

Time Volts Amps VA (calc.) W (meas.) PF
0min (fan only) 118.8 1.156 137.33 138.2 101%
0min (Start cooling) 113 9.166 1035.8 995 96%
0:30 110.4 10.736 1185.2 1139.2 96%
1:00 109.1 11.547 1259.8 1225.9 97%
1:30 108.5 12.149 1318.16 911 69%
1:45 108.5 12.447 1350.5 526.7 39%
2:00 108.5 12.601 1367.2 614.1 45%
2:30 108.5 12.955 1405.6 1652.4 117%
3:00 107.3 13.364 1434.0 1935.5 134%
3:30 107.3 13.542 1453.1 1820 125%
4:00 107.3 13.800 1480.7 1688.7 114%
4:30 106.8 14.185 1515.0 1712 113%
5:00 106.8 14.305 1527.8 1593.4 104%
6:00 106.2 14.980 1590.9 1066.7 67%
6:30 105.7 15.024 1588.0 1121 71%
7:30 105.5 15.482 1633.4 2783 170%

(At ~ 7:45 it began to putter out, and fan came on)

As far as I can tell, it max power draw according to the specs should be 8amps. It's pulling well above that, and then it just kicks out. Is my house wiring bad, where it can't draw the voltage it needs? Is the power grid struggling? Does the AC need repair? IDK where to begin troubleshooting. Some days, it's fine and can run for hours. Some other days (Usually hot ones), this happens.

  • 1
    what do you mean by "struggles"?
    – user253751
    Jul 21, 2022 at 5:03
  • @user253751 It starts making like a puttering noise, and then just shuts off. Referring to the power grid, I'm wondering if they're having trouble keeping up with the demand.
    – Blue
    Jul 21, 2022 at 16:02

2 Answers 2


10,000 BTU/hr is about 3kW. So only your last reading comes close to the power rating of the air conditioner. But assuming that is the output cooling rating, and if it has a SEER rating of ~3, then it should be pulling about 1kW from the wall.

Also, at 105 VAC, your voltage looks too low. That may be due to wires that are not sized properly, or that are too long.

You say it is rated "8 amps," but the sheet I found on it said it pulled 15 amps. Also, your table seems amiss… the last entry says it's drawing 15.482 amps at 105.5 volts, which would be 1633 watts, not the 2783 shown in your table. The spec sheet says it pulls 925 watts, so there's a lot of strange data going on here, including inconsistencies in the manufacturer's data!

If it is actually pulling over 15 amps for an hour (as shown), it should be tripping a circuit breaker. Are you sure your ammeter is reading correctly?

Are there other things on the same circuit? Like a fridge or something? That may explain the voltage going up and down.

Is it physically clean, inside and out? It needs to push air though both the condenser (outside) and the evaporator (inside). If either of those is getting clogged with lint, dust, or perhaps insect debris, then you'll have problems. Check the accessible filter on the inside. If you have access to the outside, check that, too. But be aware that the internal surfaces could be clogged, as well.

So, to summarize:

  • Give it a good inspection for clogged filters, cleaning as necessary.

  • If you can get the housing off, check the internals for debris and clogging, as well, and clean as necessary.

  • See if there's anything else on the circuit you are plugged in, as you're pushing what I assume is a 15 amp circuit pretty hard, and it's causing the voltage to sag.

  • Try running it from a short and thick extension cord from a different outlet, and see if your power monitor shows more like 120 VAC from there. I'd use a cord with #12 wire of 25 feet or less.

  • If all that fails, you might need to have it serviced. It could need its refrigerant re-charged.

My bet is on dirty or clogged airflow through the condenser (outside) or evaporator (inside) or both.

  • Sounds about right, except that I believe the "time" column is in elapsed Minutes:Seconds, not time of day.
    – FreeMan
    Jul 21, 2022 at 12:19
  • It's possible for a device to be drawing 15.482 A at 105.5 V but still only be using 925 W (if the power factor is less than 1). It can't be drawing 2783 W though, so something is definitely off there!
    – psmears
    Jul 21, 2022 at 14:10
  • 1
    You might want to have the power co. check the voltage at the meter. If you have a smart meter, you can check it yourself. The power co could have some low voltage on really hot days
    – JACK
    Jul 21, 2022 at 15:26
  • Yeah, it's Min:Secs. All night last night, my AC ran at about ~13amps, and had no issues. Around 10am this morning, it started puttering out again. Right now, it just climbs to about 15 amps before the compressor just gives up and shuts off.
    – Blue
    Jul 21, 2022 at 16:01
  • 1
    @Harper-ReinstateMonica, I guess you don't normally read past the first sentence, then. I always like to lead with something the original poster can identify with — start by NOT making them wrong. Jul 26, 2022 at 6:01

The interesting figure is the "Volts" number.*

Starting the A/C compressor results in immediate voltage drop, and then voltage decays further over several minutes.

Now, let's think it through. My first reaction was "ten extension cords out to a shed", but that would not explain the voltage declining over time. Also, I have faith that you would have mentioned a freakish edge condition like that.

This suggests to me several things, and we'll need to move through the list to cross them off.

Lost hot or neutral wire on the whole service

First, go to your main panel and shut off all 240V loads (double-wide or handle-tied breakers). Is the A/C circuit now stone dead? If yes, you lost a hot wire coming from the utility. 95% of the time this is the utility's fault, and they fix it for free, just call and report an outage.

Second, grab a space heater, kettle or other large 1200W+ resistive load (you want to use a resistive load for this, don't use the A/C). Turn it on, and check voltage at outlets all over the house. We're fishing for some going down with the A/C outlet but others going UP in equal measure. For instance if they are normally 118-121V, and some are measuring 109V (10V low) while others measure 129V (10V high, that's it! That is a Lost Neutral - it's the same deal as a Lost Hot, the power company needs to fix it.

Lost Neutrals are insidious, because everything seems to work - most devices will tolerate a 10-20V drop somewhat. People can have Lost Neutral problems for months and not realize it, until you have that one problem appliance that doesn't tolerate it.

Bad connections in the circuit

Most circuits are wired as a "daisy chain". Hot/neutral/ground come from the panel to receptacle 1, then from there to receptacle 2, then to a switch, then to another receptacle, etc. etc. That is a lot of connections to potentially fail, remembering that current flows in loops - so the neutral connections matter equally since they are the return loop.

A bad connection will cause voltage drop, and localized heating at the bad connection due to series arcing or resistive heating. This heat will tend to affect the connection, often making it worse. The heat takes a few minutes to develop, so it corresponds well to what you are seeing.

If you can identify all the outlets, switches, lamps etc. in the circuit, feel them all with your hand and see if any are unusually warm. Of course if the sun is beating on an outside wall and the socket is embedded in that wall with its junction box punching through the insulation, "warmer" will be natural. Anyway if you find it that easily, you win!

The most overlooked place in the whole system is the neutral bar at the service panel.

Backstab (jab in tiny hole in back of socket) connections are notorious for failing. And they are impossible to inspect. Most of us eliminate them "on sight".

The way to fix a bad connection is NOT to torque the screw gud-n-tite. You must disassemble the connection, inspect both wire and terminal for pitting or burning or soot, clean all that up, and reassemble or replace (sockets are $3, watch the tabs).

Science has shown that the torque of a screw or clamp connection really matters, even on the small stuff where it was largely ignored. It's also shown that pro electricians can't muscle-set the correct torque any better than their spouses can! (like within 1% of "too loose" vs "in spec" vs "too tight"). As a result, NEC 2014 required the use of torque screwdrivers for anything that specifies a torque, and UL started requiring things to specify torques. Electricians are not happy about this, but the science is not with the idea of "gud-n-tite is enough".

While one might argue that backstabs don't require a torque screwdriver, I'd argue side screws can be inspected.

* Obviously there are issues with the other figures, since the measured volts and amps calculates to a VA (volt-amps aka the whole sinewave the power company must deliver). And at times that is exceeded by the watts figure (the part of the sinewave the unit actually uses), giving a Power Factor well in excess of 1.00! Heat pumps can do over-unity, but not THAT way! LOL!

  • I do have one beefy 25 ft extension cord which plugs into the wall in the other room (To keep it off the circuit with my PC). It should be rated for 20 amps, and the cord doesn't feel anywhere near hot
    – Blue
    Jul 22, 2022 at 6:16
  • The biggest thing for me, is during the day the AC couldn't really keep up. It climbed to about 15 amps and then shut off, just like my post. Around 10pm local time, I put it back on and it never climbed over 14.1amps, and has been running continuously with no issues (Time is 2:20am now). Here is the current draw: imgur.com/a/UuSucy9. It's on full cool, and fan set on high (No auto adjustments due to temp)
    – Blue
    Jul 22, 2022 at 6:24
  • @Blue Expected behaviour from an AC that "can't keep up" is it makes cold air like usual but the house gets warmer because the AC isn't making enough cold air. Anything else is a fault.
    – user253751
    Jul 22, 2022 at 10:40
  • @Blue Do not run the A/C on degraded voltage. Use resistive heat loads (e.g. space heater) for testing. I seriously doubt one large appliance grade extension cord that isn't getting warm, is a player (unless it's cheap Chinese and really has #22 wires in there? LOL) You can positively cross it off by checking voltage at each end of the cord. You might also check your neighborhood power - could just be system overloads, this heat wave has been the largest electrical load in history. Jul 22, 2022 at 16:40

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