Need help on wiring a 220 v switch

[luvrbus]

Guys, I am on the outside on this so I need a little help from you electrical people.
Here is the problem and the question when we get ready for a trip I have to go to the panel to turn the hot water heater off is there any way I can wire a wall mounted switch to turn the heater off or does it have to be a breaker  


thanks

[Chuck Newman]

Clifford,

Are you talking the HWH in your house or in the bus?  On the presumption you're talking the house HWH, the NEC only specifies no more than one device per circuit on any circuit 30 amp or more.  Typically the HWH is left on 24/7 in most cases, and those with cabins, etc. open the circuit breaker when leaving for extended down time.

If you leave on a regular basis and don't want to use the CB, try:

http://www.onestopshopcatalog.com/d321n.html

or

http://www.acehardwareoutlet.com/%28bi2ivq455p1a2cfwho0eqya5%29/ProductDetails.aspx?SKU=34822

or

http://electrical.hardwarestore.com/14-51-safety-switches/30-amp-fusible-type1-654851.aspx?utm_source=nextag&utm_medium=cpc&utm_term=654851&utm_campaign=nextag

You could wire the switch into the 240 vac line feeding the HWH at any point.  It  won't require "within view" as required for motor control contactors.

Also some utilities offer programmable controllers for electric HWH's.  The degree of user control will vary.

Chuck

[DebDav]

Most wall switches are 120 VAC.  Saying that, you could wire 2 switches - one for each hot leg.  This would be inconvenient and also would not meet code.  Instead, wire a switch to activate a double pole relay that has contacts big enough to work with your water heater.  If you buy a switch that has an integral pilot light, you would know when the water heater is active.

[Chuck Newman]

DebDav hit the nail on the head.  I was wearing my code hat.  Now with my usual hat, the remote relay is the best idea.   Have used them several times in homes and will have them control all AC and DC lighting in the bus.

The advantages are small 12 vdc switches of various configurations with small 20 AWG wire from switch to relay.  No large 30 amp wall switch boxes.  The dual pole single pole relay of a minimum 30 amp contact rating and 12 vdc coil, can be located in a convenient location as noted.  Small wire, small holes, easy run to the control switch.  A $3.00 toggle switch would do.

Mount the relay in a metal box with NMC (or conduit) clamps/connectors at a location where you can easily break the 240 vac line to the HWH, probably NMC cable.  Be sure to ground the box with the cable's ground.  Some construction required.

Or just purchase one of the above boxes, cut and reconnect the cable to the internal switch, an your off and running.

Chuck

[kyle4501]

If you wanted to go the relay route with a pilot light switch, get a relay with a 120v coil, & you won't need a low voltage power supply . . . .
http://www.grainger.com/Grainger/items/5Z546

Of course you'll need to put this stuff inside a 'proper' electrical enclosure.

However, a simpler solution may be more cost effective - provided it meets code (I can't think of why it wouldn't) - just a little more 10ga wire & a simple double pole 220V/ 30A switch.

http://www.grainger.com/Grainger/items/2WEU3

A standard switch box is usually much cheaper than all the stuff involved with the relay.




Hope this project works out well for you.

[Sean]

Clifford,

You can certainly use a relay as Dave and Chuck have suggested, but there is no need to get that complicated unless you need to put the switch someplace far away from the existing circuit.

277-volt, 20-amp, double-pole switches that look just like normal wall switches, fit the same boxes, and take standard cover plates are available for exactly this type of application from all the major suppliers.  Here's one from Leviton:
http://www.leviton.com/OA_HTML/ibeCCtpItmDspRte.jsp?sitex=10021:22372:US&item=399

These are generally commercial-grade items and you may have to go to a real electrical supply house to find one, rather than, say, Home Depot.

The idea here is that both hot wires must be switched together (and, of course, the ground wires must run continuously with the hots).  But if you can mount the switch in close proximity to the heater or anywhere near the existing circuit, this is probably the easiest way to go.  It is almost certainly the cheapest.

-Sean
http://OurOdyssey.BlogSpot.com

[Dreamscape]

Clifford,

If it's the house, simply wire a 240v 30amp non fused disconnect switch/box in the garage between HWH and panel. Any box store should have one, if not check you local supplier. Get a Square D, I think they are the best quality. You can put a lock on that if you want to.

Paul

[luvrbus]

Thanks guys the double pole 220v switch was what I was looking for.
I love the simple way   


good luck