Running high amperage machines

colu41

colu41

Joined
Dec 24, 2014
Messages
1,598
Now I'm no electrician. But I can wire some stuff and make it work. Lol
Anyways. I have my 2x72 VS grinder and my HT oven, both that I built. Grinder runs on maybe 5 amps, oven is around 18?. Are these 2 machines ok to run at the same time? Or does it all depend on my shop elec. box?

I just wanted to heat up the oven to treat a few blades while I grind a few others out.

Grinder runs on 220, oven runs on 110.
 
Depends on the feed circuit to the shop. I assume as one is 220 and the other is 110 they are on separate circuit breakers. 5 Amps is pretty low current even for a 220V machine I would expect closer to 6 and 8-10 for startup surge of course that depends on your motor. The HT oven is pulling some pretty serious current. That is why I try to run 200 when I can as it pretty much halves the current need for the unit.
None the less, if your 220V breaker is rated at about 10amps and the 110 breaker for 20-25 amps with the main breaker at 40 amps you should be fine running them all at the same time.

Wiring size also has a lot to do with this but again, I have to assume you have them on separate breakers. Code says they should be but I have seen some stuff you would not believe.
 
Yes they are absolutely on different breakers. And you're right. My grinder may run higher. Maybe 7 or 8. Whatever a 3ph 2hp would normally run at. Lol
 
OK, some basic terms. Amps and volts are different things. Wattage is what you get from the combination.
All house wiring will carry 120 or 220. the difference is the of the number of wires. Most circuits are 20 amp max. Workshop circuits for high draw machines, clothes dryers, and electric ranges may have special higher amp circuits. The normal wire gauge for a 20 amp circuits is 12 gauge. 10 gauge and even 8 gauge are needed for higher current. 220 volt motors and appliances allow higher wattage to run on smaller wires than would be possible with 110 volt circuits.

Now, your grinder does draw 5 amps ... per leg. That is the same wattage as a 110 motor drawing 10 amps. So it draws about 1100 watts. The oven draws 18 amps at 110 volts, which is about 2000 watts. The two running at the same time draw 3100 watts. If the power panel delivers 220 volts and has a 100 amp main breaker, it can handle up to 22,000 watts, so you are only using a small fraction of your capacity. If it is a 40 amp sub-feed, you are at about 40% capacity.
 
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Nothing should "fry", the only thing that should happen is you'll start kicking breakers. That's what they're made for ya know, knife makers who wire a buncha stuff together and run it at the same time!!! 😉
 
Be sure and check what else is running on those circuits. If something else is on those breakers, you could go over the rating of the breaker. I would also make sure all the breakers are labeled for what they feed. Flip the breakers one at a time and see what turns off. Have a shop light or something to plug into the outlets to see if they have power. Knowing what breakers power what, makes it much easier to trouble shoot problems and make sure you don't overload a circuit.
 
Tx Bass Tech said:
Be sure and check what else is running on those circuits. If something else is on those breakers, you could go over the rating of the breaker. I would also make sure all the breakers are labeled for what they feed. Flip the breakers one at a time and see what turns off. Have a shop light or something to plug into the outlets to see if they have power. Knowing what breakers power what, makes it much easier to trouble shoot problems and make sure you don't overload a circuit.
Click to expand...

Yes for sure. I did this before I even started building my shop. Just to see where I would have to set everything up. As of now, everything seems pretty equal with all the lines. Nothing is over powered. Thanks!
 
Great answer! Also keep in mind:
- your subfeeder circuit breaker should be sized at a minimum of 120% of your "expected load" (not your max load)
- circuit breakers for motors should be sized at a minimum of 125% of rated load.
- all 120v outlets in your shop or garage that are not dedicated to a stationary device should be GFCI protected.

Stacy E. Apelt - Bladesmith said:
OK, some basic terms. Amps and volts are different things. Wattage is what you get from the combination.
All house wiring will carry 120 or 220. the difference is the of the number of wires. Most circuits are 20 amp max. Workshop circuits for high draw machines, clothes dryers, and electric ranges may have special higher amp circuits. The normal wire gauge for a 20 amp circuits is 12 gauge. 10 gauge and even 8 gauge are needed for higher current. 220 volt motors and appliances allow higher wattage to run on smaller wires than would be possible with 110 volt circuits.

Now, your grinder does draw 5 amps ... per leg. That is the same wattage as a 110 motor drawing 10 amps. So it draws about 1100 watts. The oven draws 18 amps at 110 volts, which is about 2000 watts. The two running at the same time draw 3100 watts. If the power panel delivers 220 volts and has a 100 amp main breaker, it can handle up to 22,000 watts, so you are only using a small fraction of your capacity. If it is a 40 amp sub-feed, you are at about 40% capacity.
Click to expand...
 
adnj said:
Great answer! Also keep in mind:
- your subfeeder circuit breaker should be sized at a minimum of 120% of your "expected load" (not your max load)
- circuit breakers for motors should be sized at a minimum of 125% of rated load.
- all 120v outlets in your shop or garage that are not dedicated to a stationary device should be GFCI protected.
Click to expand...

And when not into construction , maximum load bearing on a breaker is 80%. So don't plug a 15 amp pressure washer into a 15 amp breaker.
 
All of my stationary machines are on GFCIs. I think everythings good to go. Thanks for all the help guys.
 
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