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Power 120V Pump from a 240V circuit

19K views 26 replies 6 participants last post by  frenchelectrican 
#1 · (Edited)
UPDATE: Jump to post #23 to see correct schematic for EXISTING WIRING and PROPOSED WIRING CHANGE.

Hi,

I have a 120V pool pump (electric motor) that I am using to replace a 240V pump. The new pump draws 14.6 Amps maximum.

In the electrical box, there is existing wiring for 240V to the pump and there is also a neutral wire that powers a 400 Watt pool light. The hot wire to the pool light is protected by a 20 Amp circuit breaker. There is also a GFCI protecting the pool light.

-DELETED-

The new 120V pump specifies to use 12 gauge wiring for wire lengths up to 50 feet. The neutral wire from the service panel to the electrical box is 15 feet. Then it would tee to the pump (5 feet) and to the pool light (50 feet).

What is the best way to get 120V to the new pump? Should I run a new neutral, using the existing Hot wire from the 240V circuit breaker? Or do I have to run a brand new 120V circuit for this pump? Running a brand new circuit has two major drawbacks. I won't be able to use my existing 240V time switch and I won't be able to slave my pool cleaner (Polaris) booster pump timer to it. I could still wire the timer clock motors to 240V and use them. But it would be tricky to prevent the Polaris/Cleaner pump from turning on without the filter pump being on.

This is a lot to describe in words, so I will try and post a schematic of the existing wiring.

Thanks,
RoberTX
 
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#11 ·
Ahh ok before I can comment more on this one was the old pump did have two speed or not due the diagram you posted here that is wired for single speed so if you do need two speed function you will need addtional connections to order to get second speed running { I think cleaning mode will run in high speed while normal operation will run in low speed unless it is reversed as I stated.,, }

You will have to bring seperated netural for the pump motour you can NOT tap to the lighting circuit that is complety off limit for safety issue.

Note: as soon I posted I did see updated drawing so that is good however you will need two pole GFCI breaker to handle both 120 volt motour et 240 volt motour.

Merci,
Marc
 
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#12 ·
You are correct. This is a two speed pump. But the pump has a switch mounted on the back of the motor for selecting Hi / Lo speed. So only one power wire goes to the switch. The switch and wiring for the two speeds is not shown because it is part of the pump assembly.

So there are no other issues if I run a separate neutral and wire as above? The 240V 30 A circuit breaker and 12 AWG wiring is all adequate and safe? I think it should function just fine.

Any more input is greatly appreciated! I am not taking this 'amateur electrician' job lightly!

Thanks,
RoberTX
 
#17 ·
I think you should be fine as long you have proper size conductor however there is one guy he may comment little more in the moring so I will wait and see what he have to say due the codés between French and USA side is pretty simauir but slightly diffrent purpose so I will let this guy chime in the moring he will know more details if I did cover the base correct and the way I posted I used the USA side much as I can due the French Codés are stricter.

Merci,
Marc
 
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#6 ·
That kinda odd I did look up website about this pump and it did stated 240 volts and can you double check the nameplate again to make sure you see word say " VOLTS " it will stated either 120 volts or 120-240 or 240 volts.

And also what horsepower rating this pump motour is ?

Also if you are aware with modern NEC code all the pool pumps either on 120 volts or 240 volts it have to be GFCI protected.

Most pool pump I have run into genrally are wired for 240 volts when you get above 1 Horsepower rating the 3/4 HP rating can be either way.

Merci,
Marc
 
#4 · (Edited)
Existing Wiring

This is the existing wiring - 230V pump used in this installation.


The yellow DPST box is a manually controlled double-throw-single-throw switch to remove all 240V power. The power goes from the manual DPST to the timers

The 1,2,3,4 yellow boxes are the terminals for two DPST 240V time switches. When a switch is ON, LINE connections 1 and 3are connected to 2 and 4. The cleaner (Polaris) pump is slaved to the filter pump.

The top right blue shaded box is my main service panel. The left blue shaded are is an electric box that houses the two timers and wiring between the service panel and the pool equipment.
 
#5 · (Edited)
Here is what I asked about in the original post - connect one of the old 240V pump wires to neutral to supply 120V to the new pump. This would be very easy to do and it would allow me to use my existing timers and still be able to slave the cleaner pump to the first pump.

What do the experts (anyone with more experience than me) think about this? I'm definitely not sure enough about it to try it yet! Please see my concerns in the original post.



Thanks,
RoberTX
 
#7 ·
Here is what I asked about in the original post - connect one of the old 240V pump wires to neutral to supply 120V to the new pump. This would be very easy to do and it would allow me to use my existing timers and still be able to slave the cleaner pump to the first pump.

What do the experts (anyone with more experience than me) think about this? I'm definitely not sure enough about it to try it yet! Please see my concerns in the original post.



Thanks,
RoberTX
What you suggest on this one it will NOT work if you hook up in that way as you posted in the photo one thing I will say for sure you will trip the GFCI as soon the pump kick on.

Merci,
Marc
 
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#8 ·
#15 ·
Oui you can if both pump drawage do not excess 24 amps you are fine I allready out the 120 volts however need one more info on the exsting 240 volt motour how many amp or HP rating on the other motour to make sure so you can keep the exsting breaker otherwise you will have to get new GFCI breaker { this is a current code requirement }

Merci,
Marc
 
#14 ·
Oui there is other thing is that make sure you have good bonding wire that typically #6 bare copper if the old pump did have it then it will be simauir loction to rehook the bonding wire and make sure the #6 conductor is clean before you hook it up to the motour.

What conductor size you have in there now due you mention to moi the 30 amp breaker as long it is hard wired and have overload protection at the motour it is fine however if not then you will have to downsize the breaker to 20 or 25 amp depending on what the other pump motour size is and what the current drawage as well.

Merci,
Marc
 
#16 ·
The pump will be bonded.

The new two-speed Pentair pump will run at low-speed 99% of the time. High speed will only be used to prime the pump and never at the same time as the second Cleaner/Polaris pump. However I think it could run fine.

Pentair Pump is 115V 14.6 Amps on High speed , 4.7 Amps Low speed
Polaris Cleaner Pump is 230V, 12.8 Amps

The old pump was 230V 9.2 Amps and it ran with the Polaris fine.

All of the wires are 12 gauge.

Thanks again!

RoberTX
 
#18 · (Edited)
You may not run a separate neutral wire. Neutral and hot must "travel" together from the panel.

You may not use the neutral of a different branch or a different circuit.

Incidentally once you are th inking of running a separate neutral you might as well run a 12-2 or 14 =-w cable as needed for the entire power feed.

If one of the wires of the 240 volt circuit is white and you don't need 240 volts you can convert that circuit to 120 by taking the white wire off the double braker and connecting it to the neutral bus bar in the panel.

Appliances, pumps, etc. are rated for the maximum amerage circuit they may be connected to. The instructions should tell you what the circuit requirements are. You may not connect a 15 or 20 amp rated pump (it may draw much less) to a 30 amp circuit even if you have lots of other things connected to the same circuit. Instead you need a subpanel with 20 amp breakers for subcircuits to feed the 20 amp pump and other 15 or 20 amp rated things. Things with common parallel prong plugs for common 120 volt wall receptacles are 15 amp rated things. You may plug in 15 amp rated things into a 12 gauge 20 amp circuit.
 
#19 ·
You may not run a separate neutral wire. Neutral and hot must "travel" together from the panel.

You may not use the neutral of a different branch or a different circuit.
But I am suggesting running a new neutral wire from the service panel along with the 240V wires. That is how I drew it in the schematic above.

Incidentally once you are th inking of running a separate neutral you might as well run a 12-2 or 14 =-w cable as needed for the entire power feed.

If one of the wires of the 240 volt circuit is white and you don't need 240 volts you can convert that circuit to 120 by taking the white wire off the double braker and connecting it to the neutral bus bar in the panel.
The only white wire I have accessible right now is the one for the pool light. If you look at the schematic that shows my existing wiring, you will see that there are only 2 pairs wires coming into the timer box: Blue/Black with 240V and Red/White with 120V.
 
#20 ·
Allen.,

I understand you want to help the OP on this one and I did look at the oringal drawing { Post #4 } that is oringally wired for full 240 volts for both motours.

However there is a next drawing { Post #7 } and I did told the OP that drawing will not work in that fashon so he revised it to corrected one in post #9

Due that circuit for pump motours one pump is allready wired for 240 and the motour the OP is replacing is 120 volts so that why he have to make a new netural conductor for it. And I did mention to the OP when he pull new netural conductor it have to be the same size as the exsting conductor size there { There is a loophole that you can run " reduced netrual conductor size" but let not go there there is too much connries there }

I hope that clear up the confusing and I know you say keep the netural with that pump circuit however I did not get a chance to ask the OP was the pump motour hard wired or have cord with plug attachment so I will let the OP answer that question.

Merci,
Marc
 
#27 ·
I did told the OP about the netural conductor and in USA code we keep the pump seperated from the pool luminaire { this part is in the NEC codé }

I do know how strict with your pool set up in your country but I know in France it is stricter somehow what depending on how you set it up.

Merci,
Marc
 
#23 · (Edited)
This post has gotten confusing with the multiple ideas I have come up with. Please disregard above schematics and reference below:

Existing wiring with old 240V pump installed:


Timer 1 and Timer 2 are mechanical timer DPST switches. On each timer, terminals 1 and 3 are LINE. Terminals 2 and 4 are LOAD. The motor [m] for each timer switch is powered by 240V. Timer 1 is for the Filter Pump (being replaced) and Timer 2 is for the Cleaner/Polaris Pump. The Thermostat powers on the Filter Pump when the outside temperature is below 34 degrees F. The timers are wired such that the Polaris cannot be turned on without the Filter Pump being on. My goal is to modify this wiring to replace the old 240V Filter Pump with my new 120V Filter Pump while retaining the same control functions.

This is my current proposed solution for adding a neutral wire to power the new 120V Pentair Dual-Speed Pump while retaining existing control functions:


The above schematic shows the Filter Pump 120V switched by Timer 1. The 120V Filter Pump Neutral wire is hard wired to the pump (not switched). The thermostat also can apply 120V to the pump HOT lead. Note that this leaves the existing Pool Light circuit alone.

Notes:


The new two-speed Pentair pump will run at low-speed 99% of the time. High speed will only be used to prime the pump and never at the same time as the second Cleaner/Polaris pump.

Pentair Pump is 115V 14.6 Amps on High speed , 4.7 Amps Low speed
Polaris/Cleaner Pump is 230V, 12.8 Amps

The old Filter Pump was 230V 9.2 Amps and it ran with the Polaris fine.

All of the wires are 12 gauge.

The Timers are both double pole single throw (DPST) switches. Terminals 1 and 3 are LINE. Terminals 2 and 4 are LOAD.
 
#25 ·
Bob, Marc,

Thank you for your replies.

Are you both saying that it is safe/acceptable to wire the new 120V pump per my schematic in post #23? : 2 #12 wires from one double pole 30 amp circuit breaker plus one #12 neutral wire to power both the pumps?
 
#26 ·
Oui .,

You will be fine with that due there is a specal code that do address the motour useage { it will be in Art 430 et 440 } so you will have no issue with this one.

Merci,
Marc
 
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