220Volt vs. 240Volt ???

[pisces]

I'm putting an electric heater into the garage (see post by Pisces a few ones back), it says it must be a direct wired 240Volt circuit. I already have a 240(I think) outlet in the garage that is not being used, I am wanting to remove that outlet and connect directly to those wires. My question is that when I checked the breaker box in the basement for that outlet, it is named "220 outlet". Is this the same, is it 240V? Will it suffice for my heater?

[eurolarva]

Typically the equipment you are trying to wire will have a tolerence both plus and minus for what the voltage needs to be. I would measure the voltage coming out of the box. If it is 220 or less you will probably have to buy a buck booster transformer to bring the voltage up the the needed 240 volts. When a machine requires 240 and you are supplying only 210 to 220 your current will go up and can cause problems internally. When voltage drops at work we loose the ballasts on our flourscent bulbs and small circuit fuses on our folders.

[sparkyaber]

These are nominal voltages. like 110/220, is really 120/240 99 percent of the time. My opinion is that most equipent needs at least 110 or 220 depeding on the device.

With that being said, that is what the nameplate says on it. Enough people over time have seen these nameplates, and just renamed 120/240 voltages in a dwelling, 110/220. Again, just my opinion. In your house, I would put 100 bones that you have 120/240 give or take a few volts.

You never mentioned the current rating on the breaker for that recepticle. The wires have to be rated for the current draw for the heater. For instance, if it was a 30 amp recepticle, it should/would have #10's going to it. If your heater needs 50 amps, you will need #6's.

Hope this helped.

[pisces]

Thanks.Yea, the heater needs 30 amps and the breaker is marked 30 amp, so #10 wire it is.

[pisces]

Hey, how about I just put a small multi-tester on it and measure the voltage at the existing recepticle?

[JohnMickish]

Usually things will tollerate a 10% difference in voltage on either side of what it's rated for. In your case, I'd be willing to bet that the resistive elements in the heater will tollerate much more than that. Like Sparky said, it's just a nominal voltage (ie: common slang). Some people say 110, some say 115 and some say 120, it pretty much means the same thing unless you are working with some electronic equipment, where you better know exactly what you are working with. Again like Sparky said, unless you have some weird NSP situation where you have two legs of a three phase system running to your house it's a very safe bet to say that you have 120/240 volts.

[pisces]

Hey Mnfishinguy, thanks. Okay, you all have convinced me that my Voltage is okay. Now, next question regarding connections: I have 4-wire coming from my panel, but the instructions for the heater only talk about connecting 3-wire. There is a power terminal block with a terminal for the black wire, a terminal for the white wire, and chassis screw for the ground. What about the other hot wire, the red one?

I see your avitar looks like an electrical worker union symbol, and I do realize that you guys get paid to do these things, but I have everything I need literally five feet away from where I need it, and It would really hurt to pay someone 100 bones or whatever just to come out and twist a few wires together. I have wired remodeling type projects before, just no experience with 240V. Any help is appreciated.

[sparkyaber]

If it is a 240v heater you will not need the white wire coming from the house- it is the neutral. The black and the red will give you the 240 volts you need. Again, only if everything is hooked up with industry standards. Check which colors are on the breaker, and use those. I could explain the reasons for having a 10/3 at that outlet, but it would get technical, and take awhile. You would only need a 10/2 for this installation, but look at it this way, you have a spare wire.

[JohnMickish]

Exactly what Sparky says. If you have a black and red wire on the breaker (which is what it should be) then that is what you use.

[pisces]

It looks like my last post was lost in the redo, but I responded with a thank you to the guys who took the time to offer assistance. I completed the install as instructed and it works great. thanks again. Mike