I have a question... I am a little tired of having output 3 phase cables hard wired into the phase converter. I want to wire them nicely using 3 phase breakers (which I have) and make 3 phase receptacles attached to the phase converter. One would be for the 200 A DC welding machine rated for 44 amps. Another would be for "stuff", unlikely to exceed 5-7 HP. Right now I only have a 3 HP bench grinder tat is 3 phase, but that could change as time goes on.
What I would like some help on is selecting proper receptacles. I have some cable with a "30 A 3 phase plug" (I cannot look at it at the moment), so it would be nice for the bigger receptacle to be compatible. Any suggestions? thanks
Three phase plugs, receptacles, and heavy electrical cabling are very expensive. What I did originally was to cut in six receptacles on the sides of my phase converter's enclosure box. However, later I wired the phase converter into a wiring system, and now I run my 3 phase "bus" to six points throughout my shop. These points terminate in 30A disconnect boxes. I locate 3 phase machines by one of these points and use conduit and loose wire to connect them. In my shop, I only use one machine at a time.
If you persist in using receptacles, I suggest you watch ebay until you can buy a bunch from a quality manufacturer, all the same size and spec, and standardize on that size.
I suggest you ask for what you want by NEMA Rating. - The hardware guys will know what you mean. I would suggest you use a grounding type, (4 Wire connection, 3 Phases
ground), for general safety reasons. (I am hoping that that 44A. for the welder is output if you're proposing a 30A. Cable. Its best not to limit your run time by guess). The 30A. receptacle in question is called 15-30 R and is rated for 30A. , 250V. , 3 phase. - It has 3 flat parallel, 'phase tines and one round ground tine. The 3 phase 30A. , 250V. receptacle is NEMA 11-30 R., it has three flat tines in a triangular array. For the application you propose, you might want to use locking, (twistlock), receptacles. These are rated 30 A. 480V., (no problem using a higher voltage rated set providing there's no 480 V. equipment around). the numbers are 3 Phase:L12-30R, 3 Phase grounding: L16-30R. MadDog
Get Hubbell twist-locks. Watch eBay for a while, they will turn up from time to time. What you probably want is a 4-pole, 3 phases and a safety ground. No need for the neutral for a motor application. They also come in 5-pole, if you had real 3-phase Wye service, that could include a neutral, so you could run a combination of 3-phase and 120 V single-phase loads on one 3-phase circuit. That is handy for control cabinets.
I found ONE END of some suitable twist-locks at HQ a while ago that were reasonable, the other end they wanted $48 or something like that for. So, I got the other end on eBay.
Go get a recent year catalog for receptacles that your local wholesale houses carry like Leviton, Hubbell or Pass & Seymour Legrand. There's an invaluable reference chart inside that shows the proper NEMA uses for the various devices, and the P&S book has interesting section on the various International hookups... And as a bonus, you can see if the pin configuration you want to use is available in the formats you need - Flanged Inlets and Outlets, Weatherproof, and other odd styles are not available in all pin arrangements.
If the three phase supply is a phase converter, or the utility feed is Open Delta supply with a High Leg, make sure you always wire everything with the Wild or Manufactured leg on the middle or Y leg of the X-Y-Z marked pins, so you can swap equipment around to different receptacles.
Watch your rotation connections, so they are all connected running the same way. If you don't have one, go get a rotation checker so you can easily test things while you wire them, rather than chance bumping the motor on the equipment - some things can get wrecked even if they're running backwards for only a few seconds.
If you EVER loan out any gear (or even send it out for repair) check the wiring over when you get it back before you plug it in again - some people modify the tool power cord or motor connections so it works on their system and don't put it back the way they found it, or remember to tell you about it...
And never use the wrong NEMA configuration for the voltage and amperage of the circuit in question. Even if you have to go buy the right plug and receptacle for full price (Gasp!) that's still far cheaper than blowing up a perfectly good piece of equipment.
Guys..bear in mind..and Ill deny it if you quote me... but you can run a hell of a lot more than the rated capacity through a twist lock, as long as you dont make or break the connection under load.
My various welding equipment..some of it is running on 30 amp Hubbles, even though the machine is rated for 100amps input..and Im pulling
50-60 amps actual under load. They dont even get warm.
Disconnect one under load..and its a whoooooole new ball game.
"Pax Americana is a philosophy. Hardly an empire. Making sure other people play nice and dont kill each other (and us) off in job lots is hardly empire building, particularly when you give them self determination under "play nice" rules.
Think of it as having your older brother knock the shit out of you for torturing the cat." Gunner