Pool pump timer


Old 05-29-01, 05:42 AM
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I'm trying to install a mechanical timer for my pool pump but am having a problem with the wiring. The pump is wired on a 240V double pole circuit but it's wired with standard 12/2 cable (so no neutral). In order to wire the timer it appears that I need a neutral to wire the 120V timer inside. Can I use the ground wire in place of the neutral for this? Being a novice to eletrical wiring, I'm wondering if the ground is acting as the neutral at the pump. Should this wiring (at some point) be upgraded to use 12/3 cable?

Thanks for your help.
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Old 05-29-01, 09:52 AM
Join Date: Sep 2000
Location: Fayetteville, NY, USA
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Without knowing the motor horsepower I can't speak definitively. But if you want more circuits than just the one for the motor, I would install a pool-rated load center (sub-panel). Then the timer gets its own circuit breaker and the motor gets its own. You should run new cable. If your motor is 1 HP or less you could run 10/3-w/ground cable to the new sub-panel off a 30 amp/2-pole breaker in the main panel. If your motor is 1 HP, install a 30 amp/2-pole breaker in the new sub-panel too.

When running new cable to a pool, the ground conductor must be insulated, not bare as you whould find in regular "Romex". There are other rules in the NEC which apply specifically to pool electrical circuits and wiring. Because of safety you might be well advised to hire an electrician who will do this work under a permit and have it inspected. You really can't be too careful where water and electricity are in close proximity to each other.

Good luck.

Old 05-29-01, 04:10 PM
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Your timer must be 20 amp rated. Your pump motor has two hot wires. Break the two hot wires and run them through the two switch contacts controlled by the timer motor. Run a second power source to that timer and power the timer motor only from that second 120 volt power source. The pump circuit would not be in contact with the timer motor power circuit. Remember no other loads are allowed on that pool pump motor circuit. Absolutely do not use that bare wire as a white wire for the timer motor.

Old 05-29-01, 07:22 PM
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Could you not get a timer with a 240v clock motor and use your existing circuit for the pump motor to also power the timer instead of going through the time and expense to do otherwise.Any thoughts on this Wg?I've seen this done many times.
Old 05-29-01, 09:06 PM
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Somewhere in the NEC it required the pool's underwater light and the pool's circulating pump to be direct to the panel source with only a switch or gfi in those circuits. Now I can't find that requirement. Somewhere it changed but can't remember when it changed or I just am not looking in the right place. If this rule exists then that timer motor would not be allowed on with the pump circuit. However, I can't find the rule if it existed.

Gettin old I guess

Old 05-30-01, 04:16 AM
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I think your memory is correct. There is something somewhere about an uninterrupted path from the panel to the pump. I don't know whether or not a timer qualifies as a switch.
Old 05-30-01, 11:37 AM
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If someone can find that rule again for me requiring dedicated power from the main panel on a pool pump or underwater light fixture with only the GFI and switch allowed in that circuit I would appreciate it. I lost that rule. I think it ran away from me and hid elsewhere in the NEC.

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