# How would one determine the amperage...

### Help Support Homebrew Talk:

#### JayInJersey

##### Well-Known Member
How would one determine the amperage of their home Dryer outlet?

Assuming the idiots who initially setup my house didn't label anything...or if they did, in the 28 years since they did it fell off or became unreadable.

It's one of those standard three-prong jobbies...(too tired to look up the Nema number)

#### Catt22

##### Well-Known Member
Check the circuit breaker that it's hooked up to. Usually it will be a 30 amp breaker.

#### FreebootersBrewing

##### Well-Known Member
It depends on your load. Ohm's Law states that Current = Power(watts)/Voltage.

So if your dryer outlet is 240 volts and you're using a 1200 watt heating element then:

I = 1200/240
= 5 Amps

So your element is going to draw 5 Amps. The same element would draw 10 Amps on a 120V circuit.

#### lschiavo

##### This space for rent.
I have never seen a dryer that wasn't 30A. But do check the breaker and try to verify 10 guage wire.

#### Bobby_M

##### Vendor and Brewer
It depends on your load. Ohm's Law states that Current = Power(watts)/Voltage.

So if your dryer outlet is 240 volts and you're using a 1200 watt heating element then:

I = 1200/240
= 5 Amps

So your element is going to draw 5 Amps. The same element would draw 10 Amps on a 120V circuit.

I think he's asking what the circuit is rated for, not how to determine current draw.

I would check the breaker that is feeding it and then verify the cable is capable of handling it.

#### FreebootersBrewing

##### Well-Known Member
I think he's asking what the circuit is rated for, not how to determine current draw.

I would check the breaker that is feeding it and then verify the cable is capable of handling it.

Yeah I realized that after I typed it. But it doesn't hurt to know how to figure out how much you can hook up to any given circuit.

#### Marsdude

##### Well-Known Member
Cat22 is correct, it will likely be 30 amp. You could test this by finding flipping the 30 amp breaker(s) and checking if you have power at your dryer outlet.

#### evanmars

##### EAC Wannabe
It depends on your load. Ohm's Law states that Current = Power(watts)/Voltage.

So if your dryer outlet is 240 volts and you're using a 1200 watt heating element then:

I = 1200/240
= 5 Amps

So your element is going to draw 5 Amps. The same element would draw 10 Amps on a 120V circuit.

The resistance of an element is constant at different voltages, not the wattage.

Ohms = Watts/Volts squared
1200/57600 = 48 ohms

Amps = Volts / ohms
120/48 = 2.5 amps

The same element would draw 2.5 amps

#### illin8

##### Well-Known Member
Dryers are usually 30 amps on 240v...the plug is usually a NEMA 10-30.

Cross check yours here.

I'd also...(1) determine what type/size wire feeds the outlet; and (2) trace it back to the box and verify the breaker it's hooked up to. It's easy to do and will give you peace of mind that it's wired properly as well.

OP
OP

#### JayInJersey

##### Well-Known Member
Cool I'll try the breaker (which is also not labeled...that I get to thank my late father for as he saw it fit to remove the labels in there with the intent of redoing them for "neatness") I don't expect there will be too many 30a breakers in there.

Maybe this and the stove right?

As for the wire...well the Dryer cord is the standard 3 prong gray dryer cord...the flat kind like HD sells as their 3Prong Universal 30a one.

#### willynilly

##### Banned
Are you going to need a neutral for anything 120VAC in your rig? If so, you will need to wire up a 4 prong outlet.

#### illin8

##### Well-Known Member
Don't be surprised if the stove is a 40amp, 4-wire. Dryers are typically 3-wire (non-grounding).

#### willynilly

##### Banned
New homes are now wired for 4 prong dryer outlets, to my knowledge that is now code.

#### lazybean

##### Well-Known Member
Dryers are usually 30 amps on 240v...the plug is usually a NEMA 10-30.

Cross check yours here.

I'd also...(1) determine what type/size wire feeds the outlet; and (2) trace it back to the box and verify the breaker it's hooked up to. It's easy to do and will give you peace of mind that it's wired properly as well.

Real good advise to check the wire type/size. It can save you later.

#### Marsdude

##### Well-Known Member
The stove should have a higher amperage breaker, at least 40 amp.

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