On Oct 13, 12:55*am, " wrote:
I recently added some new, heavier-duty equipment to my garage
woodshop and am now finding that I'm tripping the breakers more often.
There are two circuits in the garage, both 15 amps. The new tools are
rated as high as 20 amps and trip the breakers under loads (no
surprise there). If I upgrade, should I just take these circuits on up
to 30 amps? Is this as simple as merely installing new breakers, or
will it likely require some rewiring? I don't plan on trying to do
this myself, but I would like to get a feel for what's involved and
how much it might cost. The house was built in 1978. I'll be calling
the electricians this week in any case.

Thanks.

Lynn Willis
Indianapolis

No.
Only if the wiring is of suitable size.
15 amps for #14AWG
20 amps for #12AWG
30 amps for #10AWG
The circuit breaker is there to protect the wiring as well as against
something faulty plugged in. Also your insurance company might not
honour your insurance policy if something happened! Putting in
breakers that are too big might SEEM TO WORK but is unsafe and not in
accordance with electrical code; and is the equivalent of people
putting a penny in place of a blown fuse. Lots of fires that way!
Also as some have mentioned if it is long run from the circuit breaker
box to the tool location, like 50 to 100 feet say. There might be
enough voltage drop on low gauge wiring (like #14AWG) to slow the
start-up of the tools and cause them to take too many amps for a
moment!
But trying to use a 20 amp tool on a 15 amp circuit doesn't make any
more sense than trying to put 7 people in a four seater car! Also not
using more than one tool at a time????
We have #10AWG 115/230 (3 wire plus ground) for a wiring distance of
less than 25 feet, to a sub panel in our workshop. It is fed from a 30
amp double pole breaker. The sub panel has 20 amp fuses to #12AWG
wiring to 115 and 230 volt outlets; because we have a few tools and a
couple of soldering irons that operate on 230 volts. Only time we have
occasionally 'blown' anything is when we have stalled a 230 volt bench
saw; and not always then. The sub panel is also a means of switching
off 'everything' in the workshop (except a row of lights on another
circuit) before leaving that room.
Please be careful.