Relay setup for 220v Vacuum pump

[Daniel J]

Hi-
I'm not sure this is the right forum so if it's not I'd appreciate a mod moving it.

Ok, so I need to hook up a vacuum pump with a vacuum controller. Basically, the pump is 220V and the controller is 110.
Here's the pump
http://surpluscenter.com/item.asp?UID=2006042022305301&item=4-1540&catname=
Here's the relay I plan on using
http://www.joewoodworker.com/catalog/product_info.php?cPath=60_36&products_id=513&osCsid=527dae0d9d106697eac7fe9b19c80719
Here's the pump controller
http://www.joewoodworker.com/catalog/product_info.php?cPath=60_36&products_id=58&osCsid=527dae0d9d106697eac7fe9b19c80719
The recommended setup can be seen here http://www.joewoodworker.com/veneering/pumpsys-wiring.htm under situation #4 at the bottom of the page. Setup #4 needs a 220V plug and a 110V plug. I really don't want to hook it up to two different outlets. So, can someone help me out with a wiring diagram where I only need to use a 220V outlet?

Thanks,
Dan

[suemarkp]

You have a couple of options. First, I don't think you even need the relay. The controller you chose has a rating of 15 amps. With motors I wouldn't push that and would limit myself to about half of that (7 amps or less). The vacuum motor you chose only draws 1.5 amps. Is the controller electric or mechanical -- it appears to be just a vacuum switch? If that is the case, then it doesn't require any power and you'll only need 240V for the vacuum pump. If the controller only switch one wire, then you should consider a double pole switch to totally remove power from the pump when you don't want to use it. Otherwise, realize that to totally safe the circuit you'll have to unplug it if you have one wire that is always hot on the vacuum pump.

If you still need 120V and 240V, then find a 120/240V receptacle rated for 15A and the plug that mates with it. Typically, you'll only find these in "twist lock" configuration. The plug and receptacle will have 4 prongs -- hot, hot, neutral, and ground. You'll get 240V from hot to hot, and 120V for either hot to neutral (pick either hot wire to use for the 120V source). Use the ground to bond metal items like the pump frame.

Put this on a 15A circuit using a 15A double pole circuit breaker and use 14-3 cable (black, red, white, bare NM cable also known as Romex).

[Daniel J]

Wow, I was really hoping for something simple, because I am not taking down the walls ever again :wink: I thought about a transformer but it's $50 and I'm trying to do this as cheap as possible.

Well, if that's the only way to do it then I guess I'll just stick with two plugs. oh well.

Thanks,
Dan

[suemarkp]

Don't use the relay and I think your 120V problems go away. You'll still need a 240V circuit though, but you can easily change a dedicated 120V circuit to a 240V one. To get both 120/240, you need an additional wire.

[Daniel J]

Well, I need the relay to control the pump because I don't want it running continuously. You're right, the pump could handle it, but I'd prefer to not have to deal with it. Speaking of continuous running, I'd like to add a switch to the setup. Referring to the diagram I posted the link to above http://www.joewoodworker.com/veneering/pumpsys-wiring.htm (under situation #4) I think that putting a switch on the hot line (colored blue) would allow me to shut off the vacuum controller which would stop the 220v power to the pump.

Am I right? Adding a switch to the blue wire would be like adding a secondary vacuum controller - it would stop 110v from reaching the relay which would stop the 220v from flowing (right?).

Thank you,
Dan

[suemarkp]

If you want a manual switch to stop the vacuum pump, it could be put in any ONE of these places:

The purple from the receptacle to the relay
The orange from the receptacle to the relay
The green from the relay to the pump
The blue from the relay to the pump
The blue from the 120V power to the vacuum controller
The red from the vacuum controller to the relay

The disadvantage of the first four is that your relay would be left energized all the time which is a waste of power.

I'm not so sure you still understand the functions of all the components. The relay is doing two things:
* Allowing a pump larger than what the vacuum switch can handle (this is its main purpose).
* Disconnecting both power lines from the pump which makes it qualify as a motor disconnect (but breaking either 220V power wire will stop the pump).

The vacuum switch you mentioned has plenty of amp capacity for the small vacuum pump you want to use. The vacuum switch will stop the motor whenever vacuum has been satisfied. If you want a manual shutoff for the vacuum pump, then either unplug it, or use a manual switch in its power cord. A double pole switch would be safer (breaks both lines), but you only have to break one power wire to stop the pump.

I also don't believe that drawing #4 is correct in one detail. The vacuum pump most likely does not need a neutral wire. It needs a ground, and I believe they mislabeled it neutral. What I think you want is a modification of Situation 2. You're just using 240V instead of 120V. You can wire it exactly like situation 2 if you want and it should work (just use a 240V plug and a 240V pump).