220v Electrical Question

[larrystephens]

I have a Powermatic 3520 and a single outlet and a single extension cord with a junction box on the end that goes to the powermatic. I also have a 220v forced fan heater with the exact plug, but obviously cannot run both at the same time and it's cold out there.

Can I just get another junction box and outlet and daisy chain it to the extension cord to operate the heater or will I hurt something.

 

[Edgar]

Electrically, that will certainly work. However, you need to make sure that your circuit has adequate capacity to power the lathe & heater at the same time.

Keep in mind that there is always some resistance (& therefore slight heat generation and power loss at each splice). It might not be significant, but it is important to make proper connections to do it safely. You also will need to be sure to use properly sized wire for a safe connection.

Your setup may or may not meet local codes (if you have to be concerned about such things). I live in the county, so as long as I'm satisfied that my wiring is safe & meets NEA standards, that's all I have to worry about.

 

[SteveG]

I am not an electrician and thus not able to give "certified" advice on house wiring. I can share general knowledge. It is doable to have two outlets on a single extension circuit. If two pieces of equipment running at the same exceeded the rating of the circuit, you have a potential hazard. If you rely on yourself to selectively avoid running both items at the same time, you would be OK, but only if you remembered to do that 100% of the time. The problem is that you might forget to run only one at a time. An example would be a heater that cycles on and off may kick on while you are running the other item, resulting in an overload. So this would not be a good practice; it is advisable and prudent to have individual circuits that are rated for the intended load. I repeat that I am not an authority in this field, and you must make your own decision on how to proceed.

 

[maxwell_smart007]

I'd be especially leery with a jury-rigged 220v setup. 220v is way more dangerous than 120, and the possibility of loose connections, etc, would have me very leery about your proposed setup. Is the wiring sufficient to allow another 220v circuit rated to power your tools? These are questions that a qualified electrician can answer.

Electricity is dangerous - for safety and insurance, you shouldn't be messing around with it. Hire an electrician to set up a safe and permanent extra outlet that you can be sure is both legal and SAFE.

 

[BJohn]

I agree with Steve, I to am not an expert but you are better off with a separate circuit for the heater. Adding onto the current circuit may draw to much current for either the breaker or the gauge wire in the circuit. Hopefully the circuit breaker that is installed can handle the current draw do not put a larger breaker in, the wire may get to hot and start a fire.

I just went through that issue I used a 115v space heater last week because my wall mounted heat pump which is on it's own 220v circuit went out. Well I went to eat lunch and came back smelled the burnt plastic smell and the outlet and the plug was black. GOT WAY TO HOT. Those elctric space heaters draw a lot of current.

Replaced the start capacitor in heat pump last night all is good now.

 

[H2O]

220 circuits are normally ran as dedicated circuits for the intended equipment. That is why there is a single outlet. Trying to run two sources of load, will overload the circuit. You won't find a range and a dryer on the same circuit, for this very reason.
Either have a dedicated line ran for the heater, or switch between the heater and the lathe, provided the start and run amps don't exceed the current breaker amps.
220 is not more dangerous than 110. More people are killed by 110 than 220, because 110 will contract your muscles and lock you to the line and 220 will push you away provided you are hit by both legs. Otherwise, if you get hit by one leg, you are still only at 110.
Either way, it isn't fun to be hit by either one. I have the shirt to prove it.

 

[Smitty37]

It is possible but if the circuit breaker and wiring are properly sized for your lathe you will probably trip the breaker constantly if you try to run both at the same time. If you increase the breaker size neither piece of equipment or the wiring will be properly protected. I wouldn't do it.

 

[KenV]

Larry

Add the amperages together and compare to the breaker. The amps for a 2 hp motor on a Powermatic is about 7 1/2 amps.

The heater could be lots more.

I have my 2 hp lathe on a 20 amp circuit with 1 hp bandsaw.

Big heater, probably will need to talk to the local electrician.

 

[Magicbob]

amps plus amps will give you total load. If the heater does not list amps but shows watts divide watts by 120 to get amps.
Then check the breaker, if it is bigger, you then need to check wire size to make sure it will handle total amps

 

[TimS124]

Why not get another 220v circuit installed? I just did that in my garage...took the electrician an hour and the price was very reasonable.

 

[Smitty37]

I have a Powermatic 3520 and a single outlet and a single extension cord with a junction box on the end that goes to the powermatic. I also have a 220v forced fan heater with the exact plug, but obviously cannot run both at the same time and it's cold out there.

Can I just get another junction box and outlet and daisy chain it to the extension cord to operate the heater or will I hurt something.

How many watts is the heater? What is it's current draw. The current draw of your powermatic is around 7 amps. Look in your User's manual and it will probably give you a chart on the wire size needed in the extension cord based on the total amps drawn (by both units) and the length of the extension cord. You can do what you want IF you don't exceed 20 amps (assuming a 20 amp breaker) AND you meet the wire size requirement and DO NOT exceed the recommended extension cord length. A 2000 watt 220v heater will draw about 10 amps so you would have a total current draw of around 17 amps. A 20 Amp Circuit can handle that if you have the correct power cord....
I still wouldn't do it.

 

[plantman]

I'll pass on this one !! To many "if's" involved !! But I will say, plugging and unplugging a 220 volt outlet repeatedly can lead to some hair raising moments. You must also consider start up amperage of your lathe. If cold and tight it may draw 2 or 3 times the rated running amperage on start up. This amperage surge is usually taken care of by the built in time delay in your breakers, but if overloaded for to long of time, will trip the breaker. Wire size of the extension cord would be my big worry. Check your local code as many have restrictions on extension cords, and require CFCI protection on them. Jim S

 

[wyone]

I am a Master Electrician and I have concerns. My thought without seeing it is that the receptacle you are using is a 20 amp 230 volt and the cord is probably #12 conductors. The load on your motor as indicated by others who have posted is probably around 7.5 amps. I am again guessing about the size of your heater. I am imagining it is probably either a 3000 watt or 4000 watt heater. If it is a 3000 watt that would make the amperage around 12.5 amps and around 16.67 for a 4000 watt. I would not share that circuit with a lathe in either case. Additionally, I would be very hesitant to use any heater on an extension cord. There is a difference with the amount of energy used by a heater compared to a motor load. When we figure a heater load we calculate it as being a continuous load, which causes us to apply an additional factor of 25% on the load. Now if you have something different than a 20 amp receptacle and circuit, say for example a 50 amp welder circuit that someone has made an adapter cord for (and hopefully installed the correct breaker for the adapter) then I would suggest converting the welder plug to a small panel and then you could have two separate circuits.

Long and short... hard to give great advice based on the information provided, but I would be very cautious about it. I do agree with the plugging and unplugging of a 240 volt load causing issues as well. We take for granted that it is made to disconnect, while in fact most higher amperage plugs are designed to be disconnected without being energized, and certainly not with any load of any sort turned on.

 

[maxwell_smart007]

Wyone, I've been unplugging my DC to turn it off, as i can't reach the motor switch...I didn't know that! Should I have a switch installed? I was thinking of buying a Leviton 30Amp 240v DPST switch for the 15A circuit...

 

[plantman]

Wyone, I've been unplugging my DC to turn it off, as i can't reach the motor switch...I didn't know that! Should I have a switch installed? I was thinking of buying a Leviton 30Amp 240v DPST switch for the 15A circuit...

Yes !! The DP ( double pole ) ST ( single throw ) switch is a much safer way to disconnect 220 volts under power. The switch itself contains the arc internally so there is no chance of contact. Any time that an extension cord is used on higher voltage/amperage it should have a twist lock plug and matching outlet to keep it from coming apart. Also since 220 has no white/return wire, make sure you have a copper ground wire going back to your main panel. Jim S

 

[maxwell_smart007]

Wyone, I've been unplugging my DC to turn it off, as i can't reach the motor switch...I didn't know that! Should I have a switch installed? I was thinking of buying a Leviton 30Amp 240v DPST switch for the 15A circuit...

Yes !! The DP ( double pole ) ST ( single throw ) switch is a much safer way to disconnect 220 volts under power. The switch itself contains the arc internally so there is no chance of contact. Any time that an extension cord is used on higher voltage/amperage it should have a twist lock plug and matching outlet to keep it from coming apart. Also since 220 has no white/return wire, make sure you have a copper ground wire going back to your main panel. Jim S

In Canada, everything has to be grounded, and we have to use metal boxes - so no issues there!

 

[Smitty37]

Wyone, I've been unplugging my DC to turn it off, as i can't reach the motor switch...I didn't know that! Should I have a switch installed? I was thinking of buying a Leviton 30Amp 240v DPST switch for the 15A circuit...

Yes !! The DP ( double pole ) ST ( single throw ) switch is a much safer way to disconnect 220 volts under power. The switch itself contains the arc internally so there is no chance of contact. Any time that an extension cord is used on higher voltage/amperage it should have a twist lock plug and matching outlet to keep it from coming apart. Also since 220 has no white/return wire, make sure you have a copper ground wire going back to your main panel. Jim S

True enough - I have 3 220 breakers and the Dryer is the only one that even has a plug and you can't reach that one without moving the dryer. The stove and AC are hardwired.

In my old farm house the dryer had a plug which I installed (not reachable without moving the dryer) but the stove and well pump were hard wired, the well pump had a DP/ST switch. But to remove power from the stove you had to throw the breaker.

Pulling the plug is not a good way to remove power from 220 tools.