Replies

1. 
   mikeinohio | Dec 14, 2020 10:13pm | #1

   >>If the motor draws 10 amps at 220v, won’t it force the transformer to pull twice the amperage at 110v? <<

   Yes it will pull (at least) twice the amps.

   >>using 2 110v outlets and wiring them into a single 220 receptacle<<

   This is legit. The trick is that the two 120v receptacles must be on different circuit breakers back at the main panel *AND* those circuit breakers must also be on opposite hot legs within the panel *AND* they must be on lightly used circuits that can support the extra amps you need to use for the DC.

   >>My REAL question is: short of installing a new panel in my garage and wiring in proper 220 voltage receptacles, how do I get 220 to my shop to run a 2HP DC?<<

   I don't know of a way other than a generator.

   MikeInOhio

1. 
   Rayflection | Dec 14, 2020 10:33pm | #2

   Thanks for the quick response, Mike.
   By "legit" do you mean that it works electrically, or that it also is common practice, meets code, etc?

1. 
   esch5995 | Dec 14, 2020 10:43pm | #5

   It could work but is not up to code

2. 
   esch5995 | Dec 14, 2020 10:40pm | #3

   While you probably need to speak to an electrician I will give you a head start based on my 30 years in home improvement.

   First I'll address the YouTube video. Beware of what you see on YouTube! Electrical power enters our homes in the US on 2 wires as 240v which each get connected to a separate lug within our panel boxes. These bars alternate inside the panels in such a way that every other slot connects to a different pole. Single Pole Breakers only contact one pole and provide 120v. Double pole breakers, the wide ones, contact both poles and provide 240v. To be able to achieve 240v from 2 120v outlets you would need to know that they were on different poles inside the panel box, theoretically possible but not likely in your garage unless it has multiple circuits(2 adjacent single pole breakers will always be on separate poles). Even if you have or can arrange(by moving breakers) to have 2 circuits on different poles you still would have other challenges and safety issues. Most 120v circuits are wired use 14 ga. or 12 ga. wire which can handle 15A/20A respectively. Voltage has no bearing on wire size only current flow or amperage and yes most tools will draw half as much amperage at 240v as at 120v so as long as your dust collector draws less than the wires rated maximum you would be fine, but don't take it for granted know the wire size along the entire path. You don't want the wire becoming the weak link in the circuit, that's how electrical fires get started. That brings up another consideration, in the event of something going wrong and a fire would occur you could find yourself facing a denial of claim by your insurance company for a flagrant electrical code violation.

   Now to another sticky issue. If you would have an overcurrent situation arise and you used two independent single pole breakers one could theoretically trip while the other stayed live creating a potentially dangerous situation or possibly tool damaging. Some breaker manufacturers do offer bridges which mechanically connect the handles of 2 single pole breakers effectively making them a 240v double pole breaker.

   The final problem I could see with this "solution" is that you will still be at best limited to 15A/20A of draw including the dust collector this leaves very little room for what ever tool you want to connect the dust collector to. The likelihood of running a tablesaw or planer along with your dust collector on a single 20A breaker are not good.

   As for the transformer idea I don't believe they are designed to handle the high startup currents tools. Like dust collectors require but I could be wrong.

   That's a lot of typing so I'm going to ice my thumbs. Good luck

1. 
   Rayflection | Dec 15, 2020 12:55am | #6

   This is exactly why I posted here: on YouTube you might learn what you CAN do, but I wanted to know if I SHOULD do it.
   Thanks for the write up. It all makes sense.

3. 
   mikeinohio | Dec 14, 2020 10:41pm | #4

   By legit, I mean that it works electrically.

   But if your garage is an unattached outbuilding, it's unlikely that your garage can meet the conditions listed for two separate circuits on opposite hot legs.

   If the garage is attached then maybe......

1. 
   john_c2 | Dec 15, 2020 02:37am | #8

   Yes. If there is only 120 going into the garage, there is no combination of any two outlets in there that can get to 240.

   But it was a really, really, really bad idea to begin with.

   To the OP: You REALLY, REALLY, REALLY don't know enough about electricity to be messing with it. Be safe. Hire an electrician to run a new line to the shop, or just get a 120 volt dust collector. I have a 120v Jet vortex with a canister filter. It does an amazing job. I very much doubt the one you want is much better, and even if it were, it isn't worth burning down your shop.

4. 
   Rayflection | Dec 15, 2020 12:56am | #7

   Thanks Mike.

1. 
   esch5995 | Dec 15, 2020 08:53am | #11

   Rayflection

   I still think you are going to need to add a circuit or 2 to your garage. Any 120v dust collector is going to push a 20A breaker to its limit because of the high startup current they require. If your garage only has one circuit, hopefully 20A not 15A. You won't be able to run any of the other tools while the dust collector is on.

   You may be able to do some of the work yourself and just hire an electrician to make the connection to your panel and certify your work. A small 6-8 (keep in mind 240v breakers need 2 slots, so a 6 slot box would allow for 2 240v Circuits plus 1 for outlets and one for lights.)slot panel doesn't cost much. This could be powered by a 60-70A breaker in the main panel. If you did all the labor and time consuming work like burying the cable and making basic cable runs the electrician wouldn't cost too much. Whatever you do plan for future expansion don't do just enough for today or you could find yourself in this position again.

5. 
   rob_ss | Dec 15, 2020 03:05am | #9

   I'm lucky enough to live where everything is 240V.
   Never understood the 110 thing...

   As usual, what @john_C2 said...

   Not myself being an electrician, but like @esch5959 experienced in home improvement and home electrics...

   There is, for interest only, ONE more way you can do this. You CAN in theory at least use two 110V lines on the same pole. Whether you SHOULD is another matter, but here is how it is done:

   In most garage circumstances, you will have a single wire feeding the garage. This means you can't create 220V from the power board in the garage. However, if the single wire feeding the installation is beefy enough, you can either use a higher current breaker in the garage or connect the output of two breakers together. This would allow you to draw more current off the two breakers to feed your 220V transformer. The two need to be the same phase, but that will always be the case in the situation described.

   It means you have two wires trailing to two plugs and then your transformer, and of course as was mentioned earlier you need to be careful of overcurrent - that protection needs to be on the 220V side.

   By the time you have done this, having a proper 220V installation done by an electrician is starting to look more appealing than it was before...

   Anyway, you should be able to draw the 15A required for a 2HP device from a single 110 phase nyet? 1.5Kw/110V = a shade less than 15A... I can draw 20A at 240V on 2.5mm cable...

6. 
   gulfstar | Dec 15, 2020 08:43am | #10

   Short of installing a new panel and assuming there is one breaker slot available in your panel you could add a 20 amp/120V circuit breaker dedicated to the 120v outlet for your dust collector and use the transformer to step up the voltage.

1. 
   Rob_Sp | Dec 15, 2020 11:43am | #13

   It's not clear if he has an existing panel in the garage. If he does and it has an open slot he can use a slimline breaker for a 220v circuit. If full, he can replace two standard breakers with a 110v slimline and free a slot for his 220v circuit. Assuming his panel is compatible. An electrician could easily advise regarding this.

   
1. 
   gulfstar | Dec 15, 2020 12:25pm | #14

   What I am suggesting does not involve 240V being brought in.

2. 
   esch5995 | Dec 15, 2020 08:25pm | #16

   While it doesn't apply to the OP's problem just FYI that breaker you posted is a Square D QO tandem breaker, which while it does provide 2 breakers in a single slot they are both on the same pole so there would be no way to connect them to provide a 240V circuit

7. 
   Deleted | Dec 15, 2020 09:36am | #12

   “[Deleted]”

8. 
   user-7053772 | Dec 15, 2020 12:51pm | #15

   Power = Voltage x Current. So a 10 amp load at 220 v (2200W) will draw 20 amps at 110 volts. On top of that, you have to factor in power lost in the transformer - at least 10% but more likely closer to 20% so 22 - 24 amps. Get a 220V line installed (or buy a 110V dust collector) would be the safest option.