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Help adding 120V irrigation controller to 240V pump circuit

Help adding 120V irrigation controller to 240V pump circuit

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  #1  
Old 02-15-15, 09:04 PM
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Help adding 120V irrigation controller to 240V pump circuit

I think my problem will be fairly easy to solve if I can describe it adequately. To that end, I have included a schematic and some photographs. I have a multimeter and can report back. Any help will be appreciated.

I have a 240V pool pump controlled by a WH40 intermatic timer. I would like to add a 120V always on irrigation controller near the pump . Rather than run another wire from the breaker box, I was hoping I could use a 120V wire from the pool pump.

My current setup is as shown in the picture. The pool pump only works when both the 120V switch and the WH40 timer are on.

I have a multimeter. And took these measurements that confuse me

1. When the 120V switch is off but the timer switch is on. I get 120V between each hot wire and neutral and 0V between hot wires.

2. When the 120V switch if on and the timer is on. I get 120 V between each hot wire and neutral and 240V between hot wires.

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  #2  
Old 02-15-15, 09:30 PM
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Your diagram does not show 120 volts to the timer. It only shows two hots. Or is there a neutral you failed to include in the diagram?
 
  #3  
Old 02-15-15, 09:34 PM
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I see two hot red wires (240v) and two load black wires. The timer motor is 240v.
You don't have a neutral there and cannot tap 120vac from that timer.
 
  #4  
Old 02-16-15, 08:18 AM
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Thanks PJmax and Ray2047 for your replies. That is very helpful!

You are right, I do not have a neutral wire going to the Timer. I have included a pictures of my set-up, you can see how close things are so I can add a wire from the breaker box if necessary. But I am not sure that would help, as wires from the 120 V switch to the pump are under concrete for about 5 feet.

What then confuses me is that, before going to the pump the wires from the 120 V switch then go to a nearby plug receptacle. The receptacle (see pic) looks to all intents and purposes like a 120V 4 outlet receptacle. It has never worked properly ( I measured 60V with the switch on and the timer off and 90V with both on). Is this an error? Because there are only 3 wires coming to this plug receptacle, the two hots and a ground.

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  #5  
Old 02-16-15, 08:54 AM
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The quad receptacle wiring needs to be removed and replaced with compliant wiring methods. The box shown is for indoor use only. The yellow NM cable is also for indoor use only and no cable connector was used. The metal box is not bonded to ground.

The receptacles should be GFI protected if they are not already protected.
 
  #6  
Old 02-16-15, 09:54 AM
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You need a 2 pole switch going to that pump,switching one leg is quite dangerous.
Geo
 
  #7  
Old 02-16-15, 10:00 AM
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I cringe when I see something like that receptacle box. The only way possible to ever get 120v from it would have been to use the ground as neutral
 
  #8  
Old 02-16-15, 10:38 AM
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Thanks for the replies guys, I think I now understand what has happened. This house is always full of surprises

There was originally a 240V running underground (and under concrete) to the pump. At some point, something must have happened to that connection because it does not register anything on the multimeter anymore. So instead of fixing that, our heroes have left the mess I now have...

The receptacle is within 5 ft of the breaker box and yes, the ground is being used as neutral...

So I am going to
1. Remove the receptacle and bring that box to compliance as suggested by pcboss.

2. Switch to a 2pole switch... thanks Geochurchi

3. Give up on the sprinkler controller for now

Thanks guys.
 
  #9  
Old 02-20-15, 09:36 PM
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So, I just received my sprinkler controller, it was already ordered before I discovered the trouble I would have.

It comes with a 120V AC to 24V, 300mA AC adapter that feeds the controller. Seeing that I only have a 240V supply, will it be possible to just replace the adapter with a 240V to 24V AC adapter. Does anyone know where I can find such an adapter, I've been looking on Amazon and no luck.

I can find 240V to 120V step down transformers but am reading on a couple of threads here that might not be a good way to go. Though I am not sure why?

Is there a problem with that route to get 120V from 240V, I see a Rockstone Transformer that seems highly rated and looks like it might work. My only concern is that it will have to be on 24/7.

Again, thanks for your time.
 
  #10  
Old 02-20-15, 09:57 PM
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The top three are on eBay and the bottom two are on amazon. Many A/C units use this type of transformer so you can also check with an HVAC supply store too. I would anticipate fusing the transformer. I would put a 1A fuse in the 240v line to protect the transformer and your controller.


Transformer Primary 120 208 240 Vac Secondary 24 Vac VA 40 SXT105 | eBay

Tyco 4600 213C02AB48 Transformer 230V 265VAC 20VA Out 24VAC Class 2 Guaranteed | eBay

Edwards 598Y Transformer 240VAC to 8 16 24 Vac 30VA New | eBay

Amazon.com - Furnace Control Transformer 40VA 24V coil Mars 50203 - Isolation Transformers

Amazon.com: Jard Magnetics 4031FK 40va,120/208/240 Primary VAC, 24 Secondary VAC Transformer: Electronics
 
  #11  
Old 02-21-15, 05:50 AM
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Is there a mfg.on the transformer that came with the controller?may be you could contact them and see what they offer.
Just a thought
Geo
 
  #12  
Old 02-21-15, 10:37 AM
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Thanks for that PJmax, thats great. I had the word adapter in my search and all it was turning up was AC/DC. Thanks for the fuse tip as well. My controller has a fuse so I think I should be okay on that. I should be all good to go!

I actually talked to Orbit the manufacturer about a 240V adapter... no go! thanks Geo, we had the same thot!
 
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