timer switch for 2 240v motors

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Old 11-29-17, 09:18 PM
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timer switch for 2 240v motors

I have a septic system hat has 2 blowers that run on 2hp electric motors that are powered by a double breaker each. Right now they have a switch where you can only have one on at a time, but still each one has its own 240v breaker. The septic company that came out is quoting $600 to install a timer but I see outdoor 240v timers for around $50 and I called my electrician and he said he would charge between 50-100 to install them. That is my first obvious option but it would mean he would have to install 2 timers and there isn't much space unless someone her know of a timer that can run 2 240v loads.
Other option would be redo the system a little, put one timer switch after 1 of the breakers and a different kind of switch to feed the 2 motors but still only 1 motor at a time but both motors connected to the same breaker but I do not know if that find of a switch exists or if there is a code that says you can not do that.
Just trying to see if anyone has any ideas on how to do this simpler/cheaper before I order the timers, also is there any difference really between the $50 timers from the hardware store and the intermatics that are like $200.
 
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Old 11-29-17, 09:25 PM
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That must be a very involved switch to select two motors on two circuits.
We really should see what that looks like. How-to-insert-pictures

Why would they wire it to two breakers if only one can be on at a time ?
A better longer lasting timer will cost more.
 
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Old 11-30-17, 11:05 AM
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I will take pictures today and post them
 
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Old 12-01-17, 07:35 AM
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HI, what size are the motors,do they have controller,is 1 pump always running, have you considered an alternating relay ?
Geo.
 
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Old 12-01-17, 11:03 PM
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Alright sorry, I guess the specs and thing the septic guy said were wrong, motors are 3 hp(checked myself) and they both can be on at the same time and its just a switch before them but they are not supposed to be on at the same time. I am posting a picture(if it works) and I am seeing that it is a lot easier then he tried to make it sound. I am thinking just have him replace the switches with timers if they fit in that space and replace the seal on the outside box.
 
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Old 12-02-17, 04:57 AM
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There are 4 pole 7 day (instead of 24 hour) timers out there, but they tend to be rather expensive compared to
2 - two pole timers you would need.

The $50 timer you find in the local store may only be a single pole timer which is why they cost less. This timer is $50 but is a single pole, single throw. https://www.homedepot.com/p/Intermat...xoCTrkQAvD_BwE You need a double pole single throw. You also might need a 240 volt model as you might not have a neutral available.
 
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Old 12-02-17, 05:45 AM
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Hi, those switches have motor Overload protection (heaters) which must remain unless the pump motors have internal protection.
Geo
 
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Old 12-03-17, 03:37 PM
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So of I buy https://www.homedepot.com/p/Intermat...RD89/203569316 would that work, I can just switch it out at HD but do not want to have the wrong one when the electrician is here since its like a hr drive back and forth. So if the switches have to be there does the timer go before or after the switch or does it not matter?
 
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Old 12-03-17, 04:01 PM
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It appears to me that that timer should work, one for each motor, so you will need two timers. Timers can go before the circuit breakers, or between the circuit breakers and the motor overload protection. How it is wired will depend on what is before the circuit breakers.
 
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Old 12-04-17, 06:09 AM
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I think I would put the timer between the switches and breakers,because if someone shut a switch off you would loose power to the timer.
Will these timers be mounted out of the weather?
Geo
 
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Old 12-05-17, 09:13 PM
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The odd thing to me is that each one has its own breaker in the control panel then in a pvc conduit underground then to another breaker in the box in the picture, kinda seems redundant to have a breaker then wire then another breaker. I am thinking of having him install the timers in between the one breaker and the other in the box. They would be installed a little bit out of the weather but as you see that box it still has some moisture so it rusted, there is a fiberglass cover that goes over the whole thing.
 
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Old 12-05-17, 11:49 PM
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Yes..... it may seem redundant but it must be protected at the source.... the panel.... so that the entire system including the wiring is protected. The breakers at the motors are for servicing. The pushbutton switches are not considered a positive disconnect method for servicing.

Non fused disconnects could probably have been used at the motors for servicing.
 
 

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