220 to 110

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  #1  
Old 06-26-05, 08:21 AM
Holeybuckets
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220 to 110

First time user.

I'm replacing a irrigation controller and pump start relay. The 3 wires out of the main electrical box are black (hot), white(also hot), and copper. 220 correct?

The transformer for the irrigation controller is 110; it has a black, white, and green.

1. Without installing a new breaker, how would I wire this up?


Problem 2.

The lawn pump motor has a pump start relay. The motor is rated for 110/230. It has a black, white and copper wire. Previously, the start relay was tied into the transformer input wires.

2. Can the pump run with 110 or 220?
3. How would I wire up the pump start relay.

Thanks,

Bob
 
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  #2  
Old 06-26-05, 08:30 AM
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Originally Posted by Holeybuckets
First time user.

I'm replacing a irrigation controller and pump start relay. The 3 wires out of the main electrical box are black (hot), white(also hot), and copper. 220 correct?

The transformer for the irrigation controller is 110; it has a black, white, and green.

1. Without installing a new breaker, how would I wire this up?
Bob,

Are you 100% sure the 3 wires you say are coming from the main electrical panel are BOTH hot lines? Have you placed a voltmeter on the white and ground to read 120V ( nominal )...or are you assuming it is 240v ( nominal )...also in your panel are the black and white wires to this pump feed on a double pole breaker in the panel????

These are important questions to which may nor maynot keep you from burning up the pump itself.

As to wiring up the relay....It should have a wiring diagram on it or you should contact the irrigation company that installed it because if you installed it the unit should have come with installation manuals.

If the pump itself says 120/240 V ( nominal ) on it it could be either but if the transformer says 110V then it should NOT be connected to 240V ( nominal )....as usually it pulls less amps in the 240V ( nominal ) setup than the 120v ( nominal ) set up. The repay itself should have markings on it for either L1 and L2 or L1 and Common terminal...

Can you describe the RELAY terminals in more details....?
 
  #3  
Old 06-26-05, 08:57 AM
Holeybuckets
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Follow up response

I tested the voltage again using a multimeter and the ground wire as you specified. Both wires are hot ~110. At the breaker panel, it's a double breaker with a white and black going to separate poles.

I initially wired up the transformer per the provided instructions. However, the instructions assume a 110 power source (I also incorrectly assumed the power was 110). Mine is 220 (I believe). This caused the transformer to hum and smoke (power was shut off immediately).

If the pump can live with 110 then I can wire up the start relay easily enough. The relay is similar to that found on a outdoor AC unit. It has power input and output with a 24volt wire to draw the contacts closed. The 24v power source in this case is the irrigation controller, assuming I can get the transformer to work.

1. If I remove the white wire form one of the breaker poles that should bump the power down to 110 correct?

2. Where should I reattach the white wire in the breaker box? To the grounding block with the copper wires?

Thanks for your quick response!
 
  #4  
Old 06-26-05, 09:05 AM
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Originally Posted by Holeybuckets

1. If I remove the white wire form one of the breaker poles that should bump the power down to 110 correct?

2. Where should I reattach the white wire in the breaker box? To the grounding block with the copper wires?
Question # 1- Yes, it will not actually BUMP anything down but will only use the 120v ( nominal ) from the black feed. However, I would replace the 2 pole breaker with a single pole one...

Question # 2 - Since you are converting the circuit to a 120V ( nominal ) circuit then yes you need to take the WHITE wire in the circuit to the neutral terminal bar ( which should have whites and bare copper wires terminated on it unless you have a SUB-Panel in which will have a seperate panel for neutrals ( whites ) and one for grounds ( Bare )...otherwise in a normal main panel they are both on the same grounding bar.

As for the relay and pump issue.....smoke and buzzing is not good...lol....Now it is more clear in your second posting.....I thought the system may be 120v ( nominal ) or 110 as you stated....and was concerned you would put 220V or 240V ( nominal ) on it and burn it up which is why I asked....
 
  #5  
Old 06-26-05, 09:15 AM
Holeybuckets
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Follow up

In the breaker box I do see where whites and bare copper are attached to the same block. I'll disconnect the white and run it over there.

I'll try this configuration first and see if I can get everything working. If all goes well, I'll change it over to a single breaker later.

Mega thanks for your help!



Cheers,

Bob
 
  #6  
Old 06-26-05, 05:40 PM
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Before you go too far, you need to determine if the existing wire can supply the necessary current for this unit. Operating at 120 instead of 240 means that more current is likely needed.

Check the power requirements. If the wire is appropriate for the load then buy the appropriate sized 120 volt breaker and install it.
 
  #7  
Old 06-26-05, 11:02 PM
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In addition to Racraft's last comments, if your wire can handle the load and you decide to run the pump at 120 volts, you will probably need to change some wires at the pump motor. Look for a wiring diagram on the pump motor that shows how to wire it.

Have you checked to see if you can get a 240volt transfomer for you irragation controller? This would make your job much simpler.
 
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