Help Wiring 230V compressor

[NovasTaylor]

Hi folks,

I'm new to the forum here and searched for an answer but couldn't find it.

I just bought a Kobalt 60 gallon compressor and have a question about wiring.

Here are the specs:
Voltage : 230V / 1 phase
Full load amps: 16
Breaker Size : 30 Amp

Its the 230V that is throwing me off. I bought a book on household wiring and it covers 220V outlets for things like dryers and stoves. How can I get 230V? The breaker panel is in my garage (in the basement of my house) and I only need to run the wiring about 15ft to where the compressor is sitting. The breakers in the panel appear to be mostly of the 120/240 type.

Obviously I know little about wiring so I should likely through in the towel early and hire an electrician. Advice, anyone?

Tim

 

[KeukaDan]

For safety if you are not comfortable you shouldnt wire it yourself. Not that it is hard but starting with adding a new service from your box is not the place to start.

To answer your voltage question. 220V is the lower allowed value from the electric company, 240V is the high and 230V is what the target is. The same is true with 120V devices.

Hi folks,

I'm new to the forum here and searched for an answer but couldn't find it.

I just bought a Kobalt 60 gallon compressor and have a question about wiring.

Here are the specs:
Voltage : 230V / 1 phase
Full load amps: 16
Breaker Size : 30 Amp

Its the 230V that is throwing me off. I bought a book on household wiring and it covers 220V outlets for things like dryers and stoves. How can I get 230V? The breaker panel is in my garage (in the basement of my house) and I only need to run the wiring about 15ft to where the compressor is sitting. The breakers in the panel appear to be mostly of the 120/240 type.

Obviously I know little about wiring so I should likely through in the towel early and hire an electrician. Advice, anyone?

Tim

 

[Aahz]

Electrical motors typically allow 10% + or - on voltage. 230 volt + 10% is 253 volt, 230 volt - 10% is 207 volt....In essence...230 volt and 220 volt are the same. (If you are running 3 phase motors, the percentages are theoretically the same, but many electrical companies have reduced voltage to 208 volt instead of 220 volt...lower voltage means higher amps...they bill you from amperage....higher amperage means higher $$$$ for them...AND a 208 volt service will DESTROY a 230 volt motor relatively quickly.....so ALWAYS confirm the voltage with a volt meter!!!)

 

[Acebusa]

All that said, if you have an adiquate sub pannel in your shop, and enough free space to install your 30 amp breakers, this should be an easy task, I never assume that a sub pannel is wired correctly without first checking it out. you should have two power legs, and a neutral, and a ground. When running a 230v circuit you will only use the two power legs, and a ground. I always check the incoming power with my meter across the two power legs, you should be around 220-230v, + or - 10% of your motor load as stated before. If your voltage is correct, and the sub panel is correct, you just need to install your 30 amp tandom breakers, and install proper wire size to your compressor, look on the motor and make sure you do not have a duel voltage motor, if it is you should also check the wiring on the motor, diagram is usualy posted under the cover plate of the electrical cover on the motor. if it is 230v. only then this step is not needed. Proper wire size should be around 10g. depending on the length of run you will be using. It doesn't matter where you hook the two power legs into the breaker, as long as it is a tandom breaker. Just make sure the green ground wire is hooked to ground in the pannel.

 

[NovasTaylor]

Excellent advice. Thanks much. Turns out this is a much easier task than I had anticipated so I will indeed tackle it myself. I picked up a decent wiring book and your estimate of 10g wire corresponds to what I had read. The only other thing I may add to the line going to the compressor is a shut off switch.

Cheers!

Tim

 

[wilbilt]

The only other thing I may add to the line going to the compressor is a shut off switch.

According to the NEC, there should be a disconnect (shut off switch) nearby and within sight of the equipment.

A 30A disconnect as typically used for home air conditioners would be sufficient to satisfy this requirement, but many of them are of the "open the cover and pull out the jumper" variety. For use as an on-off switch, the kind with the lever on the side are superior.

 

[Senorpablo]

.. but many electrical companies have reduced voltage to 208 volt instead of 220 volt...

I believe that 208 is the common reference voltage for three phase power.

 

[KeukaDan]

I believe that 208 is the common reference voltage for three phase power.

You are correct. Without going into it to deep, a power company does not reduce power to 208V. If you get 208V that likely means that you have a circuit run from the third leg of a three phase circuit. The three phase electrical system allows for some ingenious electrical wiring to allow for the use of 120, 208 and 240. The 120 is single phase and neutral, 208 between the third leg and neutral and 240 between any two phases. The 208 is a three phase voltage and should likely never be seen in any residential applications unless you use a phase converter. three phase systems aren't even available to most residences in the united states(at least without spending big bucks)

Three phase has many beneficial features but it wont do any good to most people unless you have a phase converter. for a normal compressor you will have no trouble hooking up a new circuit as a normal residential service will only have one phase so you cant screw that up.

 

[thefairlaneman]

ITs an easy thing to wire up a 220/230 circuit. Only problem is you dont get a second chance to make a bad mistake and learn from it. Take your time, understand what you are doing BEFORE you ever attempt this type of homeowners project.

 

[W-Cummins]

You are correct. Without going into it to deep, a power company does not reduce power to 208V. If you get 208V that likely means that you have a circuit run from the third leg of a three phase circuit. The three phase electrical system allows for some ingenious electrical wiring to allow for the use of 120, 208 and 240. The 120 is single phase and neutral, 208 between the third leg and neutral and 240 between any two phases. The 208 is a three phase voltage and should likely never be seen in any residential applications unless you use a phase converter. three phase systems aren't even available to most residences in the united states(at least without spending big bucks)

Ahhh Where to start

I guess at the first question why 230V

In the US the change in voltage you see listed, in the case of SINGLE phase 220-230-240 (hot to hot) and 110-115-120 ( hot to the grounded conductor {Center tapped Transformer}) Are due to the increse in the voltage supplied by the power company. They started out at the lower and over the years raised it up to the current 120/240 "standard" voltages we see today.

So if you see motors that are listed as 220V they are older. You will still see some new motors listed as 230V but, most are now listed as 240V. The lingo dies slower though, so you still hear 220v and 230v used rather then the current 240v.

Now the above information

"Normal" 208V 3 phase power is reduced to that voltage by the power company, and it's not one leg of 3 phase to the neutral but rather between 2 of them. 208V is generated when you have a wye conected bank of 3 transformers. You get 208 volts between any 2 of the three phases. In that system you also get 120volts from any phase to the grounded conductor. Now it's possable to have 208 Volts hot to hot and not have a 3 phase system _IF_ your power company is messed up they have VERY low voltage on a normal 240 volt line . Lots of light industral, shopping centers, and larger apartment buildings are wired with a 208V wye system. It's a good way to get higher amp loads into thouse places and also provide for 3 phase power if it's needed.

So with 208V 3 phase you get 208v hot to hot and 120 hot to grounded conductor and _NO_ 240V of any type.



William...

 

[KeukaDan]

"Normal" 208V 3 phase power is reduced to that voltage by the power company, and it's not one leg of 3 phase to the neutral but rather between 2 of them. 208V is generated when you have a wye conected bank of 3 transformers. You get 208 volts between any 2 of the three phases. In that system you also get 120volts from any phase to the grounded conductor. Now it's possable to have 208 Volts hot to hot and not have a 3 phase system _IF_ your power company is messed up they have VERY low voltage on a normal 240 volt line . Lots of light industral, shopping centers, and larger apartment buildings are wired with a 208V wye system. It's a good way to get higher amp loads into thouse places and also provide for 3 phase power if it's needed.

So with 208V 3 phase you get 208v hot to hot and 120 hot to grounded conductor and _NO_ 240V of any type.

William...

Your right I reread what I wrote last night and realized I had mis stated that. I forgot that since the two sine waves created for ac power with 240V systems are 180degrees off where as with three phase they are split by 120degrees and therefore you cant realize the two 120V legs into a 240V circuit due to the ~1.73 power factor. This is why you get ~208V off from the two legs of the system

 

[thefairlaneman]

For safety if you are not comfortable you shouldnt wire it yourself. Not that it is hard but starting with adding a new service from your box is not the place to start.

To answer your voltage question. 220V is the lower allowed value from the electric company, 240V is the high and 230V is what the target is. The same is true with 120V devices.

There is wisdom is not starting off your first hands on wiring job messing with the main service panel. I saved it for last after I was 100% sure I knew what I was doing and HOW TO DO IT.............you dont get s second chance to learn with 440/660 .....