[Lex Computer & Tech Group/LCTG] refrig

[Ken Pogran]

John,

My guess is that the problem is with the refrigerator compressor motor 
or its supporting components.  Motors such as these draw far more than 
the usual current as they start; once they are at running speed, the 
current draw decreases to normal. (It's why your lights might dim a 
little bit when your central A/C kicks on, for example.)

Also, some  motors are "capacitor-start", using a capacitor to give the 
motor an extra "kick."  There's usually a centrifugal switch that takes 
the capacitor out of the circuit once the motor is up to speed.

If a motor never gets up to speed, it will continue to draw too much 
current and overload the circuit; eventually the breaker will trip (how 
fast depends on the degree of overload; it's not like a fuse that blows 
instantly).

The motor might not get up to speed because

  * The capacitor has gone bad (open or shorted)
  * The motor winding has failed in some way
  * The motor shaft has seized due to failure of bearing lubrication (my
    Mech. E. dad explained to me that so-called "oilite" bearings—made
    of sintered bronze—are impregnated with oil under pressure at
    manufacture.  They last a long time with no attention but eventually
    lose their lubrication, resulting in great friction. He had his own
    trick for extending the life of a motor by temporarily re-lubing
    such a bearing. Even a ball bearing will eventually fail as the
    grease it is initially lubricated with eventually dries out.)
  * The refrigerator's compressor, driven by the motor, has seized,
    probably for similar reasons.

Or, if the centrifugal switch fails, the motor might be running at full 
speed but the capacitor may still be in the circuit, continuing to draw 
excessive current.

Ken Pogran

P.S.  I trust you know that to reset a tripped breaker, you first move 
it to the OFF position and then to the ON position.

John P. Rudy via LCTG wrote on 8/26/24 11:14 AM:
>
> The extra refrig (with a freezer compartment) is in the garage and 
> both it and the separate freezer go to the same outlet box.
>
> 3 days ago the refrig stopped being cold but the light was on so there 
> was power. I didn’t look at the breaker then.
>
> I removed everything from the refrig/freezer and set the dial from6 to 
> 9 and left for the weekend.  When I returned last night everything was 
> cold.
>
> This morning it was warm and the light was off.  One breaker was in 
> the middle and I tried to reset it to the left but it wouldn’t hold.  
> I connected the refrig to another circuit and then returned to the 
> breaker and this time it did reset.  I returned to the refrig and 
> cleaned the coils.  I haven’t pulled it out to try to find the fan.  
> Then the refrig stopped again.
>
> I returned to the circuit breaker and was able to reset it.  That 
> worked for 20 minutes and then it flipped.  I reset it again and all 
> has been fine for a half hour.  I’ll check it again in an hour
>
> No water and no damage to the cord.
>
> The first time the refrig stopped and the light was on the separate 
> freezer was working. When the breaker flipped, both stopped (of course)
>
> It is an aged Amana refrig
>
> *From:*Steve Isenberg <smisenberg at gmail.com>
> *Sent:* Monday, August 26, 2024 10:56 AM
> *To:* John P. Rudy <jjrudy1 at comcast.net>
> *Cc:* Lex Computer Group <lctg at lists.toku.us>
> *Subject:* Re: [Lex Computer & Tech Group/LCTG] refrig
>
> 1. What changed between (when it was working and not tripping the 
> circuit breaker) and (now when circuit breaker trips)?
>
> 2. Does the breaker trip as soon as you plug in the refrigerator or 
> reset the circuit breaker?
>
> 3. Has it been exposed to water (e.g., flooded basement)?
>
> 4. Could the power cord be damaged? (rodents might chew on it)
>
> For #1 I'm wondering if you moved it to a new spot or plugged 
> something else in on the same circuit, and then the problem started.
>
> For #2 if it happens immediately when you plug it in or reset the 
> breaker, this would make me think there might be a short in the 
> refrigerator (which leads to #1, when did this start?)
>
> On Mon, Aug 26, 2024 at 10:48 AM John P. Rudy via LCTG 
> <lctg at lists.toku.us <mailto:lctg at lists.toku.us>> wrote:
>
>     I have an old refrigerator.  The circuit breaker has tripped 3
>     times today.  Any suggestions?
>
>     I know I can buy a new refrigerator
>
>     John
>
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