Intermatic Pool Timer Wiring

[PoolDoc]

If you know how to do so, check the voltage while the pump is running.

OR, engage the multimeter with the pump OFF, and then have someone turn it ON while you are watching the voltage. It shouldn't drop more than 3% -- 4 volts at 120; 7 volts at 240.

It's harder to check for a short across the windings; you can check resistance, but unless you know the 'good' value, it may not tell you much.

Do you have an ammeter? (Amp-meter)

. . . I'm going to ask Mark to take a look; he understands electric motors better than I.

[mas985]

I doubt it is the winding's. Winding's are usually shorted or opened on failure so the motor will trip a break or won't run at all.

If the pump is turned on but after a few minutes shuts off on it's own, then it is likely the thermal limiter switch tripping. This is caused by overheating in the motor which in turn is usually caused by bad bearings in the motor or even a problem with the impeller. Under voltage and over voltage can cause the problem as well but that is pretty rare. If you are comfortable checking the motor voltage, you should probably do that first just to make sure.

Is the motor loud when running?

How old is the motor?

[sjeffers01]

I found instructions for testing a pool pump with a multi-meter at Inyo Pools website. I will test the pool pump this afternoon. Testing to check for a short across the windings sounds too complicated for me and way beyond my skill level. I don't have an amp-meter. If I have to replace my Pentair 3/4 HP Whisperflo single speed motor, can I buy a 3/4 two speed motor instead? Is the quality of an OEM motor equal to Pentair's replacement motors? I think the pool pump is at least a few years old. I have to see if there is a date on the pump and will update thread if its older.

[mas985]

Yes you can replace your current motor with a two speed. Is your pump the WF-3 or the WF-23?

Pentair does not make motors, they usually use a branded A.O.Smith now branded as Century motors on their pumps which are also sold aftermarket.

[PoolDoc]

The 2 speed motors are pretty expensive. Since you have a small pool, if your motor is shot, you might be better off getting a 2-speed above ground pump:
Hayward SP15922S Power-Flo Matrix 2-Speed


Here's a link for replacement motors:
http://www.a1poolparts.com/-strse-Mo...Categories.bok

[sjeffers01]

I agree that buying a new pump is better than paying for a new 2 sp motor. It costs more than a new pump to replace the motor because I would have to buy some other parts to install it. I checked out the Hayward SP15922S and it is 1 Hp. The Pentair Whisperflo pump I have is 3/4 HP and it is too big for my 8190 gal pool. Would a 1 HP be ok or should I look for a 3/4 HP 2 speed pump?

[mas985]

Actually, the Whisperflo is a larger pump than the Matrix. You can't always go by label HP when sizing a pump, you have to compare head curves for a true measure of a pump's power. For example, on typical AG pool setup, the Whisperflo will deliver about 53 GPM but the Matrix will deliver only 50 GPM.

[PoolDoc]

What he said.

You could use a smaller pump, but as far as I know, an above-ground 3/4 HP with 2 speeds is not available.

[sjeffers01]

You are correct about the 2 speed 3/4 HP for above ground pools but they are available for in-ground pools. I bought a used above ground pool that came with an in-ground Pentair Whisperflo 3/4 HP (WFE-3 single speed) pump.

[sjeffers01]

I looked at the wires coming from the pump and they are thinner than the wires that I used to supply power. I have a GFCI outlet and added a 15A 125V three pronged plug to supply power to the Intermatic Pool timer and pump. If you look at the first or second page of this post you can see a picture of the wiring for the Intermatic. The wires from the pump are blue, blue, and white. The blue wire has 12 AWG and the wires that supply the power to the timer are for 15 amps 125V and are thicker. Would the smaller wire coming from the pool pump cause the overheating problem?