Intermatic Pool Timer Wiring

[mas985]

Have you inspected the impeller and diffuser? Any obstruction would cause the motor to overheat and trip the thermal sensor. Also, I don't think you ever answered my other question about pump noise. Is is screeching or whining?

[sjeffers01]

I did check it for obstruction and there wasn't anything, I am not sure about diffuser but I will check it. The pump is really quiet. No screeching or whining.

[PoolDoc]

@Pappy: pumps wired 120v but fed 240v can die fairly spectacularly . . . but they don't run for awhile and then shut off. I'm not sure I've seen a pump wired 240v and fed 120v, but I'm guessing it would just hum till it overheated.

[BigDave]

... I may have a licensed pool technician check the wiring ...

Please have a licensed electrician with pool experience look at your wiring. Pool guys are not electricians. Please.

[Pappy]

Years ago, when I did plant maintenance, I got a job at a place that had just fired a guy for sub-standard work. They had 240v chain hoists that the man had wired one leg direct, meaning one leg at the fuse box was run through the fuse and the other leg was TOTALLY unswitched. One of the supply cables got pinched and shorted the protected leg. The fuse blew, but the wire welded to the steel trusswork. The guy running the hoist had his back to the fireworks, and didn't hear anything because of the plant noise. The hoist slowed WAY down and fried after a few seconds. After that happened I got to looking at the wiring, and there was ALL kinds of stuff that he had done that way. I haven't done that kind of work in MANY years and motors have changed alot since the early 80's but it might be worth looking at.

[mas985]

In both the under-voltage and over-voltage case, an induction motor will draw excessive current so it is a matter of what fails first. Either the breaker will trip, which usually happens in most cases or the motor will heat up very quickly and trip the thermal limiter or the winding's will melt. In all cases, the motor will either not run at all or run for just a few seconds before failing. But it won't run for minutes and it won't pump water.

http://www.motorsanddrives.com/cowern/motorterms12.html