Adding a timer to my old setup. Do I set it to DPST or SPST for my pump?

[caliskier]

Hi,

Just a little ignorant here about how to wire the new ET1125CR. I don't think I need guidance on actually how to wire it...yet. I think I will be ok there. It came with the diagrams I need, but it gives options based on weather or not i am using the timer to power something that is DPST or SPST. DPST (double pole single throw) SPST (Single pole single throw). My pump is listed in my signature, its 1.5hp, i do not think it is variable speed, or 2 speed, I would not know how to tell. I turn it on, it moves water. I just need to know, do I go DPST or SPST, and if I have not given enough info, I can get it for you all.

Thanks,

 

[caliskier]

Hi,

Just a little ignorant here about how to wire the new ET1125CR. I don't think I need guidance on actually how to wire it...yet. I think I will be ok there. It came with the diagrams I need, but it gives options based on weather or not i am using the timer to power something that is DPST or SPST. DPST (double pole single throw) SPST (Single pole single throw). My pump is listed in my signature, its 1.5hp, i do not think it is variable speed, or 2 speed, I would not know how to tell. I turn it on, it moves water. I just need to know, do I go DPST or SPST, and if I have not given enough info, I can get it for you all.

Thanks,

Here are photos of my pump if it helps...

 

[morzh]

I would prefer DPST so both sides get open when it is Off. Not sure what codes require.

 

[caliskier]

Oh, ok, when you say "prefer", it sounds like it will work both ways? I can hook it up either way, no issue there. Just want to do whatever is safest. I am only hooking up one motor.

Also, the timer gives me four possible voltage selections to set the timer to... 120V, 208V, 240V, 277V. The label says 208-230/115 at 60hz. So, should I set the timer to 208V or 240V? Thanks again...

 

[Thimble]

If your pump is wired for 220, I would think the DPST is your only option...110 volts on each of 2 hot legs. If it is wired for 110, the SPST would be what you want.

Check your pump breaker. It should be either a single breaker (SPST) or 2 breakers ganged together to operate as 1 (DPST). Wire your timer and pump the same way.

 

[caliskier]

If your pump is wired for 220, I would think the DPST is your only option...110 volts on each of 2 hot legs. If it is wired for 110, the SPST would be what you want.

Check your pump breaker. It should be either a single breaker (SPST) or 2 breakers ganged together to operate as 1 (DPST). Wire your timer and pump the same way.

OHHHHHHHHHHHH! That clarifies it for me, yes it is on a 220V breaker. That is where the Dual Pole comes from in DPST? right?

 

[JamesW]

240 volts uses a DPST (double pole single throw) switch.

 

[morzh]

220V only could be DpSt as there are two boys. 110V can be either one but as Thimble noticed wire it the way the breaker is.

 

[caliskier]

Thanks all for the clarification... ok so DPST wiring, understood... but what about the setting on the box, 208V or 240V? the load it 208 to 230 at 60Hz but the incoming voltage is 240 from the breaker.

 

[Thimble]

Should probably be 240 v. That is the standard for single phase wiring, which is common household wiring. 208 is the standard for 3 phase wiring, which is usually industrial.

If you aren't completely sure, call your power company and ask them if your service is single or 3 phase, or get an electrician to check.

 

[Kiss4aFrog]

Set it for 240.

3 phase isn't anything they'd run to a home unless it was specifically used as a small business with a large electrical machine as nothing in a normal home can use 3 phase. I haven't seen any 3 phase pool pump motors for a residential pool.

 

[mgarf33]

It can be set either way, it's not necessary to break both legs of a 240v power source to a load device.

With that said, I would also suggest to wire it in the 240V DPST SIM application, if you are only powering one device (pump).

If you wished to add another device to run simultaneously SIM, or independently IND, you could hard wire one leg of the 240 power source directly to each device. Then use the 2 separate load terminals to break the other leg to each device.
I would not suggest using different voltages to the load devices though.

If you wish to replace the pump with a 2 speed in the future, you can also use this controller set in the SPDT application.

The voltage switch setting is to let the control board know which transformer leg to use in order to power the controller.
You will need to install the jumpers to power the controller from the 240V power source.

If you don't fully comprehend the instructions, I would strongly suggest having a professional electrician, or HVAC technician connect the equipment.
It just may save you some money, or life.
It only takes one electrocution to relieve you from your worries permanently!