Pump Timer Wiring

[codyt]

I've come across a used intermatic timer, model ET279C, that I want to use on my pool timer and possible new salt water chlorine generator. My pump is currently set up for 240 volts and wired with a simple disconnect switch. Which wires connect to which terminals on the timer? From what I can tell, the timer has to be wired with 120V for the timer power on terminals 1 & 2. Where do I connect the red and black pump and red and black supply wires? I can't figure it out from the manual diagrams. Also, I don't see anything in the manual about setting the timer for 120V vs 240V, is this automatic, or part of how it's wired to the pump?

Link to manual:
http://www.intermatic.com/~/media/Intermatic/Documentation/Obsolete/ET279.ashx

Thanks for any guidance and help you can provide.

 

[JohnT]

The switches in that timer are programmed independently, and I don't like seeing single pole switches used in 220 circuits. You'd have to use both switches in that timer to switch both legs of your pump power, and then you'd have to programm them both to come on at the same time to suit me. That doesn't leave you a switch for your SWCG. But I may be pickier than other people. To wire it, you'd use Line 1 and Line 2 for your red and black supply wires, and then connect the pump red and black to the two loads.

To power the timer itself, you'll need to run a separate 120V line unless you have a 4-wire 240 circuit, in which case you can tap 120 from your supply there....but again, I don't like doing that. I prefer having the 240 separate so you can throw the breaker to work on the pump without shutting your timer down

 

[hoosierrun]

I concur with John T. The switch you have was really never designed to switch a 220 V pump. If you wired it as such, load 1 would be for 1 wire of your pump and load 2 for the other wire of the pump (usually a pump has red and black wires for the 220 service). Then, each of the load switches would need to be programmed to turn on and turn off exactly the same time. You would have no additional contacts or switches to operate any additional equipment. The line contacts are the ones that go back to your breaker panel or disconnect switch. There should be a ground bonding screw or lug to tie the green ground wires to. Of course, for the switch you have, the timer clock requires 120VAC which you would get from 1 wire of the 220 legs (doesn't matter which one) and ground.

I would personally buy a 220 volt timer with 2 DPST sets of contacts. Then you can operate the pump with one double pole set of contacts and use the other to either operate 120 volt (by using one contact) or 220 volt (use both contacts) equipment. A 220 volt timer assures that both load contacts open and close simultaneously which provides a clean disconnect or reconnect of power to the motor. (never depend on a timer to disconnect power to equipment when you are working on it. Always open a disconnect switch).

 

[codyt]

Thanks for your responses. Looks like I'll try to find a different timer then.