View Full Version : Yet another rotary phase converter question

06-22-2010, 08:02 PM
Is it absolutely necessary to hard wire a phase converter to the building? I've been talking with a colleague about the phase converter for the mill I bought (he knows about electrical things and I don't) and he checked with the building inspector for the city and suddenly there's all this talk of building permits being needed to do the work. I told him I really just wanted to be able to plug it in to an existing outlet so I could still have that outlet available for my air compressor as well, so I don't understand why I'd need a building permit. This is really turning into a circus. I just want to be able to use my mill. What do you guys think?

06-22-2010, 08:32 PM
The only reason I can think of wanting to hard wire one is that they get a chance to cool down after use. The fan on mine will run when powered off until cool.

06-22-2010, 08:38 PM
In my hood the building inspector has been told he will get shot if he comes around, we do what the hell we want.

oh yea FREEDOM!

J Tiers
06-22-2010, 11:02 PM
The best policy is to wire in a dryer outlet, or upgrade one to the newer 4 wire. Just keep quiet and do it, it is minimally visible.

Then PLUG THE CONVERTER IN. if you want to be a stickler, don't fasten ANY of it to the building in any way.

As a plug-in appliance, the inspector can't say anything about it.

You may already have screwed the pooch by asking questions.

Rich Carlstedt
06-22-2010, 11:13 PM
How big is the mill motor ?
You can buy a VFD (variable Frequency Drives) that plugs into a 120 V wall outlet and will run a 3 phase 240 volt motor.
Check out this
dealers Electric
Very reputable guy


not sure of your Local code there in Urbana, but usually when inspectors hear"'3 phase" they think of hard wire applications.
You should be able to do it without, if you plan the job right


06-22-2010, 11:38 PM
i live in a rural county and regulations are pretty lax for a property owner doing his own work. my rpc(1) plugs into the wall and my machines(2) plug into it one at a time. an electrician buddy,a master, said i could pretty much do what i want but he, being a license holder, would have to do it by the book. if you must have an electrician wire in a plug for your wifes new clothes dryer out in your shop,just call her crazy and do it.

Jim Stabe
06-22-2010, 11:45 PM
Mine's plugged in and works fine

06-23-2010, 12:01 AM
You may already have screwed the pooch by asking questions.

Believe me, I didn't think for a minute that the building inspector would ever be a part of this deal. I just asked the head of the electronics department at the community college where I teach for help with it, as I am profoundly dumb when it comes to electricity. I really need to rectify that.

06-23-2010, 12:41 AM

J Tiers is exactly right. If you have a proper cord and plug on the RPC it is then considered "cord connected equipment" and it no longer falls under the inspectors purview. Now the outlet it plugs into does fall under the inspectors area, but if it is existing and large enough (amp rating and breaker size) to handle the load there is NO reason to even call the inspector. As for a RPC, to be legal and safe you only need a 3 prong outlet (2 hot 1 ground) unless the RPC requires 120 volts internally for something, then you would need the 4 prong type of outlet (2 hot 1 neutral 1 ground) assuming of course that this is a 220 volt RPC.