Power mains question: wire gauge

Conduit is mentioned in the leadoff post by OP. The cost of putting in conduit almost completely swamps the wire gauge issue.

?-)

Of course not. Michael is being silly with his suggestion of running #6 wire for the compressor. I thought I'd join in. For anything I've done, 1/2" Type-L copper is fine. That's probably what I'll use again but it's getting rather pricey.

Agreed, sorta. PVC isn't too bad, though. This whole thing has gotten absurd.

Those who are always wrong, are certainly stupid, AlwaysWrong.

Protectionism at work:-

Best regards, Spehro Pefhany

Unbelievable. With the housing market in the tank and commodities through the roof, what the housing market really needs *more* help from UncleS.

You're just helpless.

it's a tough call as to what sucks more, mexi-narco pipes, chinese copper plated lead or the government meddling.

inrush current that should be plenty to kick the motor in. It could even be better to have more drop to reduce stresses on the motor

massive inrush current that should be plenty to kick the motor in. It could even be better to have more drop to reduce stresses on the motor

Do you know what brownouts do to motors?

Really? S.E.D having an absurd conversation? What's your point?

Rick

You guys are all pretty ridiculous calling each other names and such, but at least you know how to trim a post. Thanks. It makes it easier to get through this crap.

Rick

(or

Then

it,

in the NEC code. An AWG 13 should be fine if the US code resemble the European in anyway. On a side note, conductor sizes are not defined according to inrush currents, but steady-state currents...

Not always. You can learn about it, drop is the issue as often as ampacity in longer runs.

?-)

That's the best idea I've heard yet.

Sadly, he had already located the compressor, installed the air lines, hooked it up before calling me to wire it. He placed it right next to the main air-user, the mechanic's bays. (It's an auto repair shop.)

Dave (OP)

Not

below

lugs.

It depends on several variables, including motor size, motor winding class, number of phases, design of motor start system, and some other things. Very small motors may start at 2x FLA, some very large (full voltage start) motors may require 20 to 30 x FLA.

?-)

massive inrush current that should be plenty to kick the motor in. It could even be better to have more drop to reduce stresses on the motor

Yes. The important point is if the torque produced during startup is higher than the load torque. (would be nice if the OP can supply us with a dataheet)

But, you seem to be worried about low voltage (only 3% drop in voltage during the 15A inrush current as JF calculated). How would you then handle low mains voltage (nominal - 6%) that could occur indefinitely?

Regards

Klaus

reduced mechanical stress, but increased thermal stress.

and if it doesn't start it's toast.