Powermatic - Follow up up electical question

[John Van Domelen]

Just realized today (after a nights sleep) that I have 220 service to the kitchen that is not being used.

There used to be an induction cook top, it broke and it was replaced by a gas unit - totally unused line now.

I would just have to extend the circuit 6 feet to get to the attached garage wall to put in a junction box, plug. It is 220 30 amp line.

Is there a problem with the breaker being 30 amp - will this allow the Powermatic to suck more juice under load than the inverter or moter can handle?

If this would be just a breaker swap - I'll do this myself and save a second mortgage.

Thanxs -- John

 

[Steve Worcester]

I don't even play an electrician on tv, but if you use too large of wire or too large of breaker, it will not pop the breaker before you need to and may lead to overheating of the motor/inverter. I don't know exactly what the amount of extar overhead is allowable.

What you may be better off doing is removing the 30 amp, put in a 50amp and go off to a sub panel for the shop. You can't really just add 6 feet to the existing cicuit.

 

[John Van Domelen]

You can't really just add 6 feet to the existing cicuit.

Why not?

Am hesitant to spend a great deal of money at this location - we purchased 3/4 acre close to TMC where I work and will be building new in 2-4 years.

Also: s/w Powermatic - just found out the 30 amps is plenty - 3520 only pulls 6 amps running.

 

[webturner]

The existing wires running to your kitchen will limit that circuit to 30amps. Do not change the breaker to 50 amps and use the existing wire. Under most conditions, you will need 10 gauge for a 30 amp circuit. If it was me and I was on a tight budget I would run 10 gauge wire from the kitchen to your shop. Make that the input of a 30 amp sub panel. Put a 15 or 20 amp breaker in the sub panel for the 3520. Then you have a few extra circuits you can add for future 220V tools (dust collector, vacuum pump etc.)

 

[GA Darling]

jovan,
There should be a plate on the motor that tells what the max amp draw is of the motor. What your concerned with here is amp draw at start up. My bet is if the motor only draws 6 amps running then it will only draw about 8 amps at start up. A 10 amp double breaker is what you would need. As far as adding on to the wiring goes, most electricians will tell you not to do this. A splice will cause resistance. Resistance causes heat build up thus the possibility of a fire. However, if you do it make sure you make the connection in a junction box and all connections are well taped to prevent arcing also lable it 220v. It will work as a temporary connection. Myself, I would pull new wire instead of making a splice it would be safer.

GA Darling

 

[Gerry Meekins]

Go for it..

Jovan,

I say go for it. The breaker’s job is to protect the circuit’s wiring from overheating or short circuits. Breakers do not protect the appliance (Lathe).
I have my 3520 on a 20amp circuit with #12 wiring. A 30amp breaker in my area calls for #10 wire. Also, breakers do not protect equipment from surges, for that you will need to unplug the Lathe after you use it or use a disconnect switch.

You may want to hire a local electrician if you have any question about safe
electrical work practices..

 

[Brodie Brickey]

When I ran the 220 lines in my garage, I went a little overkill.

8 guage
30 amp circuit
30 amp locking sockets.

I only had the electrician come out and hook everything up to a new sub panel and run the connection (about 15 feet) to the main panel.

Even if I was running really heavy draw old iron, I won't have a problem with the circuits installed. The breaker protects the wiring in the wall from being overstressed by limiting everything to 30 amps. If the wiring is rated for 30 amps your all set. The wiring is where your worries are. If a breaker fails, it pops, if the wiring fails it can burn.

If you will be selling your place in a couple years, keep your receipts and treat it as an enhancement/remodel against your profit on the house. Even if a woodworker doesn't buy your house, someone who likes to shade tree mechanic on the weekends will certainly appreciate a well run 220 line in the garage for a compressor or maybe a dryer.

 

[Paul Engle]

I agree with Brodie, no splice and use a larger rated wire than the breaker. I ran 200 amps to sub breaker , one for my dc and one for my ts. I used 004 to the sub and 10g for the lines out to the dc and ts, I have my lathe on 110 for now as I need to run another box and wire for it , but it all comes off the sub panel so I can modify add with out a lot of grief .on 110 it pulls 15amp but on 220 each leg only draws 6 to 7 or so . and i use dual blade disconnect for the main , in case of storm stuff , one does em all.and magnetic swithches yea they are $ but sure can save a finger ,and a motor if the power is goin off and on not too mention that expensive HF you'r about to finish cut on...or LOYL's bowl .....and don't forget to grnd all the stands to the system grnd....

 

[Richard Baker]

John,
Webturner has it right. Hate to be a wet blanket, but it sounds like you really need a professional electrician on site, at least to be sure you are doing it safely. There's way too much to lose if you are not certain of what you are doing. Just a thought.