Can I put in a 220 toggle switch?

[mpire]

I have a nice 10 guage wire going to my hot water heater, and I think that since its sitting nicely in the corner of the garage it would be the perfect place to put the compressor.

The compressor is a 220 60 gallon unit. Nothing too crazy.

Anyways, its not going to be easy to run a new wire because I have no attic access. The breaker box is on the other side of the door from the compressor.

Anyways, back to the point of the story...

I want to take the wire going to the hot water heater and toggle it back and forth between the compressor and the hot water heater.

So is there a box out there that I can get to do this or do I have to come up with something on my own?

Any ideas?

 

[Fast Orange]

This is one of my pet peeves with this or any other shop oriented message board.Everyone can go out and get a nice compressor,welder,etc,spending a fair amount of cash to get it,and then tries to shortcut on the proper way to hook it up.If you can save up the cash to get the tool,save a bit longer to do a decent hook up.If the compressor is meant to be hard wired to a dedicated circuit,why is it so hard to decide to do it right?While there are no NEC codes that prohibit hooking up a compressor/hot water heater this way,it certainly is M-I-C-K-E-Y M-O-U-S-E ,isn't it? Instead of cobbling up some half-fast transfer switch that may or may not be adequate or safe ,spend the money and do it right-either learn the proper way to do it or get a competent electrician to do it for you.The house and family you save will be your own.

 

[LoneGunman]

A regular toggle switch is not going to handle the amperage. If you must do it this way the better way to do it would be to use a contactor with a 120V coil, the toggle switch will energize and deenergize the coil which will switch your loads. How many amps does the compressor draw before you do anything?

 

[mrb]

yes you can do that, you need a double pole double throw switch. P&S p/n 1228 is what you want. 30a (or 2hp motor) rating. Costs about $60. Leviton has one too but they just resell the P&S. This switch is like an oversized lightswitch.

If your motor HP is higher, you will need a double throw safety switch but those arent cheap - around $150. Another option is SQD has a little breaker panel with a mechanical interlock for generator transfer. You could use that with two 30a breakers in it to feed each item. I think that panel is around $100.

 

[Charles (in GA)]

You could, a double pole, double throw switch of the appropriate amperage rating (and motor rated also) would do what you want to do.

First time you get in the middle of a shower and realize that you forgot to switch the power back to the water heater, and it gets cold on you, you will be wishing you had a dedicated compressor circuit. I tend to agree with Fast Orange. There is a way to get the wire there, even if it means conduit on the surface from one point to another.

You don't say what amperage your compressor motor is, that is very important to this discussion.

Charles

 

[mrb]

This is one of my pet peeves with this or any other shop oriented message board.Everyone can go out and get a nice compressor,welder,etc,spending a fair amount of cash to get it,and then tries to shortcut on the proper way to hook it up.If you can save up the cash to get the tool,save a bit longer to do a decent hook up.If the compressor is meant to be hard wired to a dedicated circuit,why is it so hard to decide to do it right?While there are no NEC codes that prohibit hooking up a compressor/hot water heater this way,it certainly is M-I-C-K-E-Y M-O-U-S-E ,isn't it? Instead of cobbling up some half-fast transfer switch that may or may not be adequate or safe ,spend the money and do it right-either learn the proper way to do it or get a competent electrician to do it for you.The house and family you save will be your own.

if this is done properly, its not mickey mouse at all, and actually may be safer if he is on the verge of overloading his subpanel. after looking at the costs to do this properly though, i think most people would just go run the circuit.

 

[Torque1st]

Do it right. Run new wiring for the compressor.

 

[Mike in Ohio]

Instead of a switch just put in in a dryer or range plug of the proper size for your heater and compressor. Then you just unplug one and plug in the other. I did this for the welder and compressor over at my dads house, that way the compressor can't come on while welding. His subpanel in the garage is pretty small and I didn't want them both running at the same time. If you have room and enough power in the panel it would be better to run a dedicated line though.
Good luck,
Mike

 

[nissan_crawler]

Uggg, I would use conduit. Why is there no attic access? That doesn't seem right.

You WILL forget to switch it over, and you will end up with cold water and somebody's going to be pissed when they're lathered up and figure it out. This is assuming you're not overloading things.

 

[Fast Orange]

Cost for average 2p30a breaker-$15
Cost for 30' 10/2 Romex-$10
Surface mount 30a dryer recepticle-$12
3 Wire dryer cord/plug-$10
Total- $47-add in a connector and staples-call it $50
Add in about $10 to patch drywall if needed-total-$60
Spending a week on the couch AND listening to the griping after your wife gets the cold shower-PRICELESS
CASE CLOSED

 

[Steve in Mi]

Only if the #10 wire will safely handle the compressor load you could do as Mike suggest but with one addition. Install a disconnect ahead of the plug so that you are not plugging in either the hot water heater or the compressor under power. Always disconnect, switch off the power, before transferring from one load to the other. Maybe one day you will get a cold shower - then you will probably run a separate circuit.

Instead of a switch just put in in a dryer or range plug of the proper size for your heater and compressor. Then you just unplug one and plug in the other. I did this for the welder and compressor over at my dads house, that way the compressor can't come on while welding. His subpanel in the garage is pretty small and I didn't want them both running at the same time. If you have room and enough power in the panel it would be better to run a dedicated line though.
Good luck,
Mike

Example of disconnect;
http://cgi.ebay.com/SQUARE-D-H221N-...3286.c0.m14&_trkparms=66:2|65:1|39:1|240:1318

 

[mpire]

Wow, I am one who does everything overkill, so "doing it right" isn't something I am trying to avoid.

At the moment, the breaker box is full, as in no more room for anything.

The breaker box is about 10 feet if that from the compressor, but its on a block wall and when the wires are in concrete it makes it hard to get in there and modify it. Also, there is the second floor of my house on top of the garage, so there is no access unless I just start cutting holes in the sheetrock, and I have no intention of trying to match the popcorn on the ceiling.

So... Since its a concrete floor, and solid filled concrete block walls, I don't have alot of options other than running conduit, but there is a doorway in between the compressor and the panel.

 

[mpire]

Here is a pic of the garage...

The compressor base is built to the right of the hot water heater.

The compressor is a Kobalt 60 gallon unit.

11.5 scfm @ 40psi
10.2 scfm @ 90psi
135 psi max
3 hp
230v/15 amp

 

[LoneGunman]

Here is a pic of the garage...

The compressor base is built to the right of the hot water heater.

The compressor is a Kobalt 60 gallon unit.

11.5 scfm @ 40psi
10.2 scfm @ 90psi
135 psi max
3 hp
230v/15 amp

If you can, install 2 tandem breakers which will free up two spots. Mount a 1900 box above the panel, fish a wire from the panel to the back of the 1900 box then pipe out of the 1900 box to the compressor. From the picture you posted an electrician should be able to do it in two hours.

 

[VHF]

A lot of RVs, including motorhomes costing hundreds of thousands of dollars, have a toggle switch to choose between powering the electric hot water heater and the microwave. Seems like that is making intelligent use of the (limited) service that is available.

There is nothing wrong with mpire's proposed setup, as long as the toggle switch and wiring is sized correctly and the installation demonstrates good workmanship. (However, a sloppy install with Romex in an "exposed location" would qualify for the "Mickey Mouse" moniker!)

I can think of a couple ways to share the circuit and still avoid the cold shower scenario--both involve using a 240V DPDT contactor rated at at least 30A. When the contactor coil is deenergized, the N.C. contacts would power the water heater; when energized, the N.O. contacts would power the compressor.

(1.) Use a mechanical timer switch to control the contactor. When you want to use the compressor, you just wind the timer based on anticipated work time (ex: 2 hours) which energizes the contactor, thus sending power to the compressor. When the time is up, power is automaticly restored to the water heater.

(2.) Rewire the compressor so the pressure switch on the compressor controls the contactor. The N.O. contacts would feed the motor directly. That way the compressor can run whenever it wants, and the hot water heater has power any time the compressor is not operating. You might add a toggle switch (standard SPST light switch would work fine as it is only controlling the coil current) in series with the pressure switch to have a means to switch the compressor off when not in use. Air whenever you need it and no cold showers!

 

[mrb]

it is important to make sure any switch or contactor used is rated for the HP of the compressor, not just the 30 amps. For example, all the 30a DPDT (and the 40a ones for that matter) are only rated for 2HP, and the OP stated his compressor is 3HP.

 

[Fast Orange]

The Gunman hit the target-that's the best way to handle this one.He's outlined a solution that is the simplest,most cost efficient and safe.If I were to put a rough estimate of the cost together,a good electrician would charge between $200-$300 to do the hookup.

 

[shopnut]

Hardwiring a dedicated line is certainly the best solution.

HOWEVER - An alternative to this is using a high-amp timer with Normally Open and Normally Closed contacts (at least two of each). You wire the WH to the normally closed contacts as the "default" condition and the compressor gets wired to the normally open contacts. You buy extra "trips" that screw to the timer wheel so it switches back to "default" many times a day (maybe every two or four hours). Don't attach any trips that switch the compressor on.

When you want to use the compressor just manually switch it from the default position. You may have to switch it back on several times if you are working for a while. Later, if you forget to switch it back to the water heater, it will automatically do it at the next timed "trip" to default. If you look, you can find used these timers for about $40 or new ones for $120.

 

[mpire]

I gave up on this project pretty much. The laundry room is right behind the compressor wall, so I ended up just running an extension off of that using conduit. It works great, and the dryer hookup is more than enough power.

I don't run them both at the same time.

 

[sberry]

We can assume the dryer goes back to the main service panel? A word of caution as is in another thread, range and dryer recepts are not the same as grounding type recepts used on equipment such as welders or compressors.

 

[1Garageman]

Cost for average 2p30a breaker-$15
Cost for 30' 10/2 Romex-$10
Surface mount 30a dryer recepticle-$12
3 Wire dryer cord/plug-$10
Total- $47-add in a connector and staples-call it $50
Add in about $10 to patch drywall if needed-total-$60
Spending a week on the couch AND listening to the griping after your wife gets the cold shower-PRICELESS
CASE CLOSED

That sums it up!!! Good job "Fast Orange"

 

[Aceman]

We can assume the dryer goes back to the main service panel? A word of caution as is in another thread, range and dryer recepts are not the same as grounding type recepts used on equipment such as welders or compressors.

If your talking the old crows foot style then I agree.
The newer styles are grounded, but with an extra slot for the neutral.

 

[Falcon67]

it is important to make sure any switch or contactor used is rated for the HP of the compressor, not just the 30 amps. For example, all the 30a DPDT (and the 40a ones for that matter) are only rated for 2HP, and the OP stated his compressor is 3HP.

The Leviton switch I use for my compressor off is rated at 20 amps. No HP rating on it anywhere. It's well over the 125% rating of the motor, so I don't really see a problem with it.

 

[mrb]

The Leviton switch I use for my compressor off is rated at 20 amps. No HP rating on it anywhere. It's well over the 125% rating of the motor, so I don't really see a problem with it.

A switch used for a motor is supposed to be HP rated, the ones that arent eventually burn up.

 

[Falcon67]

A switch used for a motor is supposed to be HP rated, the ones that arent eventually burn up.

Then I'll start hunting a HP rated replacement. You would think that current is current and I understand about start surge - you'd think the contacts would handle a decent load since it is a switch rated to energize "instant on" load of 20A. It certainly looks more robust (less cheezy?) than the 20A/3HP rated on/off switch I got from Grizzly. Chances of the compressor starting with switch on are pretty rare - it's a leave the shop/power off deal and not a start/run control. I could replace it with a 30A easily and I'd think that would cover even the surge current from a bitty 220V 3.2HP compressor. I'll google around and see what I can find - none of the big home stores have anything. I should check at TSC - they sell motors, maybe they sell rated switches too.