Swamp cooler motor won't start (MasterCool)


  #1  
Old 04-09-19, 07:34 PM
A
Member
Thread Starter
Join Date: Dec 2017
Location: USA
Posts: 4
Received 0 Votes on 0 Posts
Question Swamp cooler motor won't start (MasterCool)

This is a 230v 2 speed electric motor in a roof mounted swamp cooler with thermostat inside the house. The wall controls are OFF-COOL-VENT and FAN LOW-HI.

I did some maintenance, oiled the motor ports, adjusted the belt. When I turned it on LOW/COOL the motor would come on then off, on then off, and repeat this in about 2 second intervals. It would never come up to normal speed so I quickly shut it down. The day earlier the cooler ran great.

So I loosened the belt a bit and the motor would start. When the motor starts it twists slightly in its rubber end clamps due to the torque, then after about 2 seconds it twists again like its changing gears. I've read that some evap motors start out in HI and then switch down to LOW,. This might be what I'm seeing. I tested it 4 times using the internal plug for the motor, not by using the thermostats OFF/COOL. Motor worked OK so I sealed up the cooler and got off the roof.

Several hours later when I turned on COOL/LOW the motor doesn't come on at all, no fan. Even on VENT the motor doesn't come on, which is usually instant. The water is pumping so I know unit is getting power. I am beyond frustrated.
 
  #2  
Old 04-10-19, 12:47 PM
A
Member
Thread Starter
Join Date: Dec 2017
Location: USA
Posts: 4
Received 0 Votes on 0 Posts
I found the problem. One of the winding wires inside the motor had been cut. I cleaned off the coating, soldered them together, coated with liquid electrical tape, cleaned then lubed the motor with Krytox. It's working great again. I dropped the tiny plastic oil hole plug and thought it fell into the cooler's water tank. I guess it fell inside the motor and impacted the wire.
 
  #3  
Old 04-10-19, 03:58 PM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 62,057
Received 1,505 Votes on 1,393 Posts
Good job.
You were lucky you were able to spot that problem. Typically a winding breaks where it can't be seen.
 
 

Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: