Interesting dilemma (one for the sparkies who hang out here)

[Fishy Jim]

It's actually ironic joe, I give you the mental space you give me - not much.

Why would I want 3 phase? Are you really that dense?

I have a 4hp lathe coming in less than two days.

[joebass]

ARE YOU DENSE? I SAID why not hardwire, I didnt say anything about three phase. I have been in alot of industrial settings and not one had plugs on their machine tools. You dont need disconnects either.

[Fishy Jim]

I already said why not hardwire. READ.

[joebass]

Yeah it doesn't make any sense. I said you don't need disconnects. You really wonder why people don't like you don't you. Why not ask Franz? I'm sure he would know.

[joebass]

What kind of plug you gonna use for that syncrowave?

[MAC702]

14-50's are NOT twist locks once again you have NO idea what you are talking about. ...

I thought he said he was thinking about using the NEMA 14-50 because he didn't want to use twistlocks, and now he's also seen that there are also straight-blade designs for three-phase, but they are expensive because they aren't used very often.

I would try an eBay or Google search for them, though. I buy most of my breakers and odd receptacles online and usually pay MUCH less than Grainger or even local wholesale houses in the US.

[Fishy Jim]

Mac, the 3ph stuff online is still 3x the cost of the single phase. I could deal with it if the plugs were expensive (only need two at the moment), and the outlets were cheaper, but I'm putting in 5 or 6 outlets and that ends up being 300 when you factor in a $40 plug and $35 outlets.


Now my original question remains - does the inspector have any grounds to tell me to change it if its not charged or connected to the houses electrical service? After all, it's an orphan without the phase converter in the loop. Might as well be speaker wires.

As for the plugs on my 220v stuff - they're all 6-50P's. 3 conductor grounded. I've been using those with no trouble and it has been mentioned (on this forum I believe) that the ampacity requirement of the plug can be de-rated based on the duty cycle of the machine - so the 6-50's are completely legit even though the welder needs a 100A breaker. Yeah, I'm clueless huh?

[Steve]

OK, a little story. We use 440 3p NEMA twist locks for our welders cause we do move them around to different places. The up front guys got a 440 single phase welder and used 440 3p plugs to get it going. So naturally when they plugged it into our 3p outlets all kinds of booms were heard as the fuses blew. Had they used the correct NEMA plugs for 440 single phase, they would not have been able to plug into our 3p outlets and averted the catastrophe. Nema has all kinds of plugs for all kinds of different voltages for a reason. So you can't plug the wrong thing into the wrong outlet. I'm sure there is one for your purpose.

[joebass]

Why if you are running new electric would you NOT wire up the syncro so you wont pop the breaker running higher amps? Maybe you dont need to go full bore making kitty beds for the new shop?

Nevermind just reread your post. See I can admit when I'm wrong. I still had to ask about the kitty bed though since you keep deleting my posts on tbt.

[Steve]

Since it is electrical wiring, and it will be connected when you put the converter in, then I as an inspector would require everything to be honky dory and conform to the standards set forth in the codes. Myself? I like everything cold to the touch at its rated capacity. If a welder requires 100 amps, then it gets wired for 100 amps. The welder gets all it needs and everything stays cool to the touch. Electrical fires start with heat.

[Fishy Jim]

Steve, I'm wiring my service for 100A to the syncro's outlet. The only thing not actually rated for 100A is the plug and socket. Given the huge margin of safety nema has for receptacles, there is no risk of anything getting remotely warm. After all, the sync's only capable of drawing 85A though a 100A breaker and the plug/socket's are rated for 150% of rated load for a number of minutes making and breaking contact prior to getting hot (I'd have to look up the actual test scenario), so that means it's capable of being abused at 75A for a long time prior to thermally reacting.

I ran 4ga on all three poles for the sync, but I still only have a 60A breaker in it and I have had it wide open at 310A before without tripping it. I'd say that's being safe.


I do fully understand the point for the different plug types for the different service types and configurations. What I disapprove of is how it drastically inflates the cost of my already expensive as he11 electrical system. I have over $1500 in wire in the system as it stands. Granted, that includes the new 2ga drops down the mast to the service mains coming into the shop, and then the 80' run of 4-3nm to feed the house from the new main panel, but it still makes the wallet a lot lighter.

There are NO 4 conductor outlets in my shop which aren't going to be 3ph. That is the protection against blowing things up. If I label all the outlets, there should be no issues with what connectors are implemented as long as they are of sufficient capacity to handle the load. I realize, If this were an OSHA shop things would be different.

I'm going to try and call the inspector tomorrow. I'm not quite ready for my rough in, but I'm be darn close.

Joe, why don't you go make another hammer rack or something. I don't even care what you say about me. You mean nothing in my life.

[Portable Welder]

I'd like to mention on my 250 amp synchrowave, I had some electrical problems years ago with it popping the breaker.

When the electrician came in he told me to max my machine out while he checked my amp draw off 230volts, The amp draw turned out to be 110 amps
which was a hare more than the machine said it draws.

I ended up having to use a 3PH plug, twist lock Russell stohl if I remember correctly and just not using the 3rd leg.
That plug was about $275.00 for the male female.

As far as phase converters go, If you want to run multiple machines and dont want a static phase converter, I made a phase converter out of an old
7-1/2HP Y- Wound motor, ounce you get the motor spinning, it will run off 2-110v legs of power and the 3rd leg spits out the 3rd leg of power.

I use to use a little 110v motor with a vee belt to get the 3 Ph motor spinning, then just un plug the small motor.

I had this in my old shop for 8 years to run a big pedistall grinder and my drill press.

My phase converter was a poormans phase converter, a pain in the but to use every time I needed to drill a hole but it worked at the time.

[Fishy Jim]

I have all the capacitors and relays to do the phase converter without a pony motor. I am not buying one pre-made.

[MAC702]

Sorry, Jim, but I just can't give you my blessing to not use the proper devices. I know they are expensive.

That also means I'm not telling you not to do it your way. But if you do, PLEASE label the receptacles in some permanent way to clearly identify them as 3-phase and being used for something other than their design.

[weld-tek]

Sorry, Jim, but I just can't give you my blessing to not use the proper devices. I know they are expensive.

That also means I'm not telling you not to do it your way. But if you do, PLEASE label the receptacles in some permanent way to clearly identify them as 3-phase and being used for something other than their design.

good post mac,thats how people get hurt or killed,trying to cut corners or not knowing what they are doing.then they get mad when the cant get blessings.