220 vs. 110v SWG

[PFlynn]

I've noticed that at least one of the SWG systems is 220v. I'm going to assume that it's being imported from Austrailia.
I see the need to rework my power as an avoidable expense.

Is there any reason why you would need 220v to generate chlorine?

[donaldm823]

I've noticed that at least one of the SWG systems is 220v. I'm going to assume that it's being imported from Austrailia.
I see the need to rework my power as an avoidable expense.

Is there any reason why you would need 220v to generate chlorine?

I think you will find that all of them are 220v since most use 220v to power their pool pumps (lots cheaper). But also, most SWGs, give you the option to rewire via jumpers at a terminal on the SWG to convert to 110v

[tonyl]

I think you will find that all of them are 220v since most use 220v to power their pool pumps (lots cheaper). But also, most SWGs, give you the option to rewire via jumpers at a terminal on the SWG to convert to 110v

Don's right about most people using 220V but actually, it's not cheaper.
P(watts) = E(voltage)X I (amps). By doubling the voltage the amperage draw is halved, but the watts will be constant whether 220 or 110.

The cost is the same.

[donaldm823]

Don's right about most people using 220V but actually, it's not cheaper.
P(watts) = E(voltage)X I (amps). By doubling the voltage the amperage draw is halved, but the watts will be constant whether 220 or 110.

The cost is the same.

Disagree that the cost is the same! 220v pumps are usually more efficient (and cheaper to run) since the motor amps are less which means less heat is generated in the motor windings-also the starting amps are much less. Heat is wasted electricity. There is a noticeable difference with 220v pumps running cooler and they are more efficient. The new Pentair permanent magnet motors are even more efficient based on the motive power method used in the motor's permanent magnet rotor. Ever wonder why your AC, clothes dryer or oven is always at 220v???

When you start using 1hp pumps or larger, that little bit of heat and lower motor efficiency results in higher electric bills and I am not talking chump change, but tens of dollars per month, especially up in the north where residential kwh are in the $0.15 kwh range with a pool pump running 10-12 hr per day, 30days a month.

[JohnT]

Power is power, and there is no significant difference in efficiency between a 220 and 110 motor. The savings is in the wiring. 220 can use substantially smaller wire than a 110 motor of the same power, so you can save serious money on the run to the motor.

[Poconos]

Don is right. Heat is wasted electricity. As for efficiency it all depends on the I**R (current squared X Resistance) = Watts or heat. You can play games by cutting the wire size for 240 vs 120 wire runs and this can negate any I**R savings but the one-time cost of the wire run will be less. However using a lower resistance run for a 240 application will reduce the recurring cost of wasted heat. Another reason for using 240 on residential high current devices is to balance the load on the legs from the pole transformer.
Al

[mas985]

I also agree that a pump operating at 240v has better efficiency than one running at 120v but I don't think it is that significant. The losses in the wires feeding the pump are not that significant either.

Let's assume that the wiring is 12 awg and that the run from the electrical box to the pump is 25 feet. 12 AWG wire has about 1.6 ohms/1000 feet of run. So for 25 feet, that is about .04 ohms.

Say you had a pump that could be run at 120v @ 16 amps or 240v @ 8 amps. The loss in the feed wire would be 10 watts @ 120v or 2.5 watts @ 240v. But if you compare it to what the pump is drawing at 1.92 kw, that is only 1/2% @ 120v or 1/8% @ 240v. Not a lot different compared to the pump itself. Even the pump generally will run less than a few percent more efficient @ 240v. You could probably make up the difference by running your pump a few minutes less each day.

A SWG would probably have the same % power loss but they run less than 200 watts so the absolute loss would be much less.

The difference between the two is fairly minor but having said that I would still always go with 240v if the cost of equipment is not that much different and easily available.