Condenser Fan Motors

[Valhallan]

Recently went to a service call.

Complaint was that the temperature rose for a short time in a server room. served by a Roof top unit. then it returned to normal. i checked the unit over and found nothing wrong.

I found the thermostat needed recalibrating. and thought that was it.

our service manager got called out to the site again and found the condenser fan motor was failing.

I shook the shaft when i was there and felt no side to side motion. and i checked the amps. all OK. Contactor fine. fan cycling control good working order.

What other checks should i have done on the condenser fan motor?

[chemi-cool]

If the fan motor is OK, i would check whatever starts it, any kind of pressure control.
could be a faulty contact.

[lowcool]

have come across a similar scenario,found that run capacitor mfd value was down after seeing the current draw and the blade stalling in a good northerly wind

[NoNickName]

Yeah, the capacitor is the most probable cause.

[sedgy]

hi , did you spin the shaft , was it spinning freely < is there any oil or greece points? what where the running amps? on most small fan motors its difficult to take a reading I have seen when the amps have to be taken on a new live cable by wrapping it 10 times around the amp meter prongs to give a true reading. all the best , sedgy