Can I run a 3HP table saw and a 2 HP dust collector off of one 240v 50amp circuit?

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Forum topic by noone posted 06-30-2016 08:01 PM 4463 views 0 times favorited 31 replies Add to Favorites Watch
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583 posts in 2422 days

06-30-2016 08:01 PM

“Can I run a 3HP table saw and a 2 HP dust collector SIMULTANEOUSLY off of one 240v 50amp 10 gauge circuit?”
Was wondering if this was possible and recommended?

31 replies so far

View Plain's profile


157 posts in 848 days

#1 posted 06-30-2016 08:10 PM

I thought that 240V circuits should be dedicated for one consumer only.

View firefighterontheside's profile (online now)


19096 posts in 2006 days

#2 posted 06-30-2016 08:15 PM

I think your problem will be getting 50 amps with 10g wire. Otherwise, a 50amp sub panel with two circuits, one for each tool, would be fine.

-- Bill M. "People change, walnut doesn't" by Gene.

View bonesbr549's profile


1576 posts in 3217 days

#3 posted 06-30-2016 08:28 PM

Like someone mentioned 50A cannot go with 10awg wire. Could 50A do the job probably but it might be pushing it if the saw is under load.

It’s much better to have a circuit for your DC. I have a shared 220v line for tools where I can since I would never have more than one big tool and dc going at the same time.

-- Sooner or later Liberals run out of other people's money.

View clin's profile


931 posts in 1146 days

#4 posted 06-30-2016 08:29 PM

#10 wire is limited to 30 A circuits. So if you have a 50 A breaker on a circuit using #10 wire, this breaker is the incorrect size and should be replaced with a 30 A breaker. It is an electrical hazard.

I’m not an expert on the electrical code, but those are the general requirements, though perhaps there are exceptions.

For a 50 A circuit, you need #6 wire.

Having said that, a 30 A circuit is plenty to run a total of 5 HP, ignoring startup currents for motors.

-- Clin

View Natobious's profile


49 posts in 855 days

#5 posted 06-30-2016 08:35 PM

1. For wire sizing: There are many factors involved, for instance #8 CU THHN is good for 50 amps but 8/3 Romex is not, you would need 6/3 if Romex.

Also, you cannot install any lower size receptacle on a 50-amp circuit. Do your tools have a plug to match a 50 amp receptacle? Would you want to rewire the power cables?

2. For two motors on one branch.
If both motors do not each have their own overload protection. Then absolutely don’t do it. It might run, but a short may never trip the 50A breaker or would trip it too slow.

If both motors have their own overload protection, read on.

Per NEC Article 430 in simpler terms: if you have multiple motors on the same 220V circuit they must be overload protected as stated above, and the conductor has to be sized for all motors running at the same time. So if you had an air compressor and table saw, two separate branches would be the most economical way to go because they don’t run together, however the saw and dust collector will often run together therefore there is less advantage to running separate feeds.

For sizing your specific situation, what are the FLA ratings on each of the motors and the type of conductor you will use.. Without this information it is not possible to answer your question with confidence.
However after all the math it may work out to use a 30A breaker instead; then smaller receptacles and wire.

For non general motor applications there are rules requiring dedicated lines: hot tubs, AC, Jacuzzi etc.

View WhyMe's profile


1053 posts in 1711 days

#6 posted 06-30-2016 09:10 PM

Depending on where you live and what electrical codes are adopted you may not be able to have multiple outlets on a single circuit greater than 20 amps. Usually plug connected equipment requiring 30 amps and greater need to be on dedicated circuits.

View Rentvent's profile


151 posts in 998 days

#7 posted 06-30-2016 10:14 PM

You should only need 15.6 amps total to run the two machines at 240v

5HP X 750 watts per HP = 3750 watts
Divide by 240v =15.6A

View Natobious's profile


49 posts in 855 days

#8 posted 06-30-2016 11:56 PM

I’m not hear to make anyone feel bad, or to argue, but 15.6A is just not true.
It would be close if we were talking about a small DC motor.
The Full Load Amps of a 2HP and 3HP single phase AC TEFC motor should be around 12A and 17A making the total 29A.
The nameplate on the motor will list the FLA for that specific motor at the rated voltage.

View BurlyBob's profile


5920 posts in 2415 days

#9 posted 07-01-2016 12:54 AM

Ask “Topamaxsurvivor” He’s the go to guy here for electrical issues.

View noone's profile


583 posts in 2422 days

#10 posted 07-01-2016 03:33 AM

Thanks for the responses. I should have been clearer in my initial post.

I am looking to buy a SawStop ICS 3HP table saw (230v, 13amps) and a Jet DC-1200VX-CK1 2HP (230v/8 amps) dust collector.

My panel and sub panel are full and cannot take an additional 240v circuit, so I would have to get a new panel if I need an additional 240 circuit.

There is a 50amp “General Plug” circuit (slot 22/24 on the main panel) that looks to be a pretty heavy gauge. (greater than 10 gauge for sure). The plug is directly below the main panel. The wires are all about a 1/4” thick and appear to have multiple solid core wires twisted. Not sure if this was used for welding at some point or what.

Is there anything I can do with this circuit to run the two units I am talking about above simultaneously? Or do I just need to drop down to a 1.5HP dust collector that runs off of 115v/11amps that I can put on a separate circuit?

Right click and open in new tab any of these pics to see the full pic. For some reason, this forum chops off the right side of photbucket pics.

View Harry's profile


80 posts in 1329 days

#11 posted 07-01-2016 04:23 AM

My guess is that “general plug” was a backfeed for a generator. Can that Jet collector be wired for 120?

-- Harry - Professional amateur

View noone's profile


583 posts in 2422 days

#12 posted 07-01-2016 04:28 AM

No it can’t.

Are the plug wires large enough to add a small sub panel with two 20amp 240v circuits?

View Natobious's profile


49 posts in 855 days

#13 posted 07-01-2016 04:36 AM

The 240 v sub-panel can work safely and be to NEC code. if protected by the existing 50A breaker you can add as many 20A breakers as you like in the sub-panel.

As was mentioned I think this can also work safely and be to NEC code, but all the details would need to be worked out. Replacing the 50 amp breaker with a 30 amp breaker Rewiring from breaker to the receptacle with smaller wire Replacing the 50 Amp receptacle with two 30 amp receptacles Rewire the machines for 30 Amp plugs.

View Fred Hargis's profile

Fred Hargis

5097 posts in 2643 days

#14 posted 07-01-2016 11:20 AM

What about consolidating 4 of the existing 120V circuits into 2 slots (replace the 4 breakers with 2 tandem breakers)? May not be allowed depending on authority. But that would free up room for another 240V.

-- Our village hasn't lost it's idiot, he was elected to congress.

View jonah's profile


1845 posts in 3448 days

#15 posted 07-01-2016 11:23 AM

Why on earth do you have so many 240V circuits in your panel?

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