rather than run two new lines for two new pieces of equipment, i would
like to run just one line and share the new outlet given that i would
never need to use the two pieces of equipment at the same time.
one of the pieces of equipment i want to hook up is rated as 1p, 240v,
47a and came with a 6-50 plug. the other piece of equipment is rated
as 1p, 230v, 28a and came with a 6-30 plug.
my plan is to run a dedicated 50a line which would accommodate the 47a
(6-50 plug) piece of equipment. i then want to change the 28a piece of
equipment's plug from 6-30 to 6-50 so that it will also fit into the
new 6-50 outlet.
would this create a hazard and/or damage my 28a piece of equipment?
The nominal answer is no, there would be no harm, because the power
drawn is determined by the appliance, not the circuit breaker. However,
some equipment may not be adequately protected against overload or fault
if it depends on the circuit breaker for overcurrent protection. Check
whether the smaller equipment has built-in overload and overcurrent
If you want to be a bit more sophisticated, install a small sub-panel
with one circuit of each rating at the location of the equipment.
In reality you will be running a dedicated 60A line, since you have to
run # 6 wire, which is rated for 60 amps. You can't run #8 wire because
that is rated for only 40 amps.
Keep in mind the 28A equipment might need a different breaker for
protection. Consult with the manufacturer. What kind of equipment are
we talking about?
Please correct me if I'm wrong but are not the breakers meant to
protect the wiring from the breaker to the load? Any load device
protection provided by the breaker is just by accident?
Load & circuits do tend to be balanced but isn't that mostly a cost
consideration not safety?
Kind of silly to run a 60 amp 220v circuit when a 30 will do?
How often do we plug a 1 or 2 amp appliance into a 20 amp breaker, no
load protection here.
Did you read the original message, or just the title? (I'm not being
sarcastic; the original message was posted several days ago.) He wants
to install a 50A outlet and switch back and forth between plugging a 50A
or a 30A appliance into it.
The biggest problem I see is the contacts in the outlet might wear out
from all the plugging and unplugging. Then they would overheat someday
when the higher load was plugged in.
I'd either run a seperate circuit for each, or (if maybe I didn't have
enough extra spaces in my panel) run a 50A or 60A branch circuit with
both a 50A outlet and a 30A outlet (30A devices are rated 50A.) Protect
the 30A appliance by installing a fused disconnect or switch just before
the 30A outlet. A switch for disconnecting large equipment in case of a
fire without having to pull the plug is a good thing anyway.
He might also look at the very specific tap rule for installing an
electric oven and electric cooktop on the same circuit -- it doesn't
<i>literally</i> apply here, but...
Bob (no relation)
You're correct, I didn't read the OP very carefully.
I missed the plug / unplug idea, which isn't great but does prevent
Switching the load would guarantee not over loading the breaker but his
best bet is two separate circuits.
Having both loads plugged to separate outlets feed by the same circuit
would allow a potential overload condition.
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