GE motor running very hot
GE motor running very hot
(OP)
I have a small ge moter in a packedge heat pump that is running 190 F. This is the third moter in this unit. Its a 230 volt single phase condensor fan moter. checked and double checked every conection. Amp draw is 3.7 and the name plate rates the RLA at 4.8. This seems way to hot. Also GE has a company that is making some of there small motors like this. Has any one seen any corolation between that and motor quality going down. I was having a problem with a head presure controll and a over heating fan motor and the guy from ICM told me GE is crap and to buy AO Smith. Not in those words of course. All my whole salers cary GE though. Input?





RE: GE motor running very hot
RE: GE motor running very hot
RE: GE motor running very hot
The number of blades will impact airflow and
It is important to match a fan blade to a motor’s horsepower and speed. Do not replace a 1,100-rpm motor with a 1,725-rpm motor using the same fan blade, as the increased speed can cause the motor to overload.
RE: GE motor running very hot
RE: GE motor running very hot
That said, the symptoms reported suggest the system may be slightly overcharged, or the condenser has become clogged with grass clippings, or has lost some fin area to corrosion, or ... is crap.
[ My current system is out of commission because the borderline magical government recommended high efficiency variable speed evaporator fan motor died and nobody sells a replacement for less than twenty percent over the price of an entire air handler, but that's a different rant. ]
Over the years I've screwed around with condenser fan motors on patched- together systems, which I squeezed a few more years out of by using a somewhat stronger than stock condenser fan motor, with a low- pitch four- blade fan, and a motor- sized fan mounted on the same shaft. Your A/C parts wholesaler has those small fans with big hubs hung on the wall right behind the counter; he sells a lot of them.
Mike Halloran
Pembroke Pines, FL, USA
RE: GE motor running very hot
RE: GE motor running very hot
.85*220*3.7=691 watts
If its efficiency is 60 % (typical) then you have to dissipate
.40*691*3.41 BTUH=943 BTUH thru the surface of the motor. GE should show you what that airflow will yield for a thermal coefficient coupled with the delta T (motor to air temp you measure)to estimate the motor temperature.
Note that the temperature rise across the condenser should not be greater than 20 degrees, since that might signal poor airflow and consequently a poorer thermal coefficient.
RE: GE motor running very hot
RE: GE motor running very hot
But I think try a class F motor next time she goes, increasing the winding design temp from 130 to 155degC (266 to 311degF), on a 40degC (104degF) ambient basis. The extra 25degC might go a long way - the rule of thumb was 10degC reduction will double the insulation life.
Surface temps can normally be 80-100degC (176 to 212degF) according to a quick web search that turned up sites I can only confidently reference as 'folk lore':
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