The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Hiring an electrician to put in a 240v circuit: worth it?

franken · 04-10-2015, 09:17 PM

Step one is can your service support one or more 240V feeds? What's the age of the house and main breaker rating? Next, where is the service in relation to the place where power will be delivered. That is, is the service in the garage, or as far away as possible like mine...
What do you want to run on 240V? A good compressor needs 30A and if you're far from the service, you may want to use 8AWG cable to reduce losses. Similarly w/ a 20A welder you may run 10AWG. If close use 10 and 12.
While you're pulling wire, you may want to run a dedicated 20A 120V circuit or two.
I used to be an electrician, so I understand, but not everyone does. Electricity can kill you, but we're pretty hard to kill. I seem to recall that ~100mA (.1A) can kill when run through the heart. That said, skin is about 50k resistance, so unless you grab both sides in each hand so current flows through the heart, you'll probably be more scared than dead. 240V/50k=5mA and current has to flow through 2 layers of skin so .25mA. Add sweat and all bets are off.

Bottom line is does the OP understand electricity, wiring techniques, the risks, liability, permits, inspections, etc. of doing it him/herself?

04-10-2015, 09:17 PM	#12
franken Registered User Join Date: Jun 2013 Location: Somewhere Posts: 3,160	Re: Hiring an electrician to put in a 240v circuit: worth it? Step one is can your service support one or more 240V feeds? What's the age of the house and main breaker rating? Next, where is the service in relation to the place where power will be delivered. That is, is the service in the garage, or as far away as possible like mine... What do you want to run on 240V? A good compressor needs 30A and if you're far from the service, you may want to use 8AWG cable to reduce losses. Similarly w/ a 20A welder you may run 10AWG. If close use 10 and 12. While you're pulling wire, you may want to run a dedicated 20A 120V circuit or two. I used to be an electrician, so I understand, but not everyone does. Electricity can kill you, but we're pretty hard to kill. I seem to recall that ~100mA (.1A) can kill when run through the heart. That said, skin is about 50k resistance, so unless you grab both sides in each hand so current flows through the heart, you'll probably be more scared than dead. 240V/50k=5mA and current has to flow through 2 layers of skin so .25mA. Add sweat and all bets are off. Bottom line is does the OP understand electricity, wiring techniques, the risks, liability, permits, inspections, etc. of doing it him/herself? Last edited by franken; 04-10-2015 at 09:28 PM.