3 phase Delapena Honing Machine wiring...

[stholt5233]

Trying to hook this machine up, it is 3 phase, but there are no neutral or ground wires to connect, only the 3 hot wires??  It is an older machine, it was apparently purchased about a year ago,but never hooked up.  I have 3 phase in the shop, but I am a little unfamiliar with wiring 3 phase.

I have done a fair bit of residential wiring over the years(in the States) but no 3 phase.  To my understanding, I should have at least 4 wires, 3 hot(phases) and one neutral.  I only have the 3 hot wires coming out of the machine in a little junction box on the side.  The wires are marked 1-2-3. These wires follow up to a 3 phase rotary switchfuse, from there to the control switch and motor. 

I see no ground strap or lug, or neutral wire or anything like that, other than a case grounding wire on the motor itself,so i am a bit puzzled.  You still need a neutral(ground) for this to work, right?  Am I missing something?

Cheers, thanks.

 

[roys]

Is this in your own hobby shop or is it  commercial.  If it is commercial (which it sounds like due to being 3 phase) then there is a lot more to it re legislation PUWER for example, Sidey on here is the expert on regs.

Apart from that you still need protection from short circuit and overloads. It probably doesn’t need a neutral, but difficult to say from the info supplied and without being there to see. It will need an earth fitted, probably via an earth stud on the machine..

Recommend getting in a spark to advise, and one that is use to commercial/ industrial work, but no harm you asking on the forum to get an insight, again though please get some professional help.

 

[Tony S]

You don’t always need a neutral but you do need a ground. Changing the power cord would be the logical step.

I’ve lost my copy of NFPA-NEC codes so can’t really help anymore. Contact a US forum, avoid Mike Holt’s as they will not help DIYers.

 

[roys]

Ahh I read it different Tony, I read that he was in USA but now in UK, don’t know why? My bad.

 

[stholt5233]

Thanks for the replies, to clarify a few things...I was in the States, but now live in Ireland.  The machine does not have a cord or cable coming out if it, just a small junction box on the side that has a terminal strip with wires labeled 1-2-3.  This is a commercial shop, I have a lathe and mill, both 3 phase already hooked up.

I knew I needed something to return the power back to ground, but I have looked all over this machine and with the exception of the single wire coming out of the motor case and connecting to one of the mounting bolts, there is no grounding stud anywhere to be found.  I am guessing that this possibly came out of a shop where the machines were grounded in place.   I had thought of grounding to that stud, but I am not familiar enough with 3 phase to be comfortable with just doing that.   I was hoping to get this sorted on my own...getting an electrician to show up over here is like playing the lotto.

 

[roys]

That’s a coincidence, yesterday I was getting told about the difficulty of getting a spark in Ireland

Just for your clarity the earth is required under fault conditions not for normal running, but obviously it has to be there in case a fault occurs so don’t be tempted to run it without.

Sometimes the earth stud is in the motor term box, usual is to have it external, sometimes both.

Again please try and get professional advice.

 

[Sidewinder]

I would not expect a Delapena machine to require a neutral.

 

[stholt5233]

Here is a photo link to show the motor.  You can see a wire running out of the motor casing to a mounting bolt.  Is this possibly the ground I am looking for?  Seems odd that there is no actual stud or direct wiring connection,but then again, this machine was made in the 60's I believe.

Photo

 

[Geoff1946]

Is that a rubber anti-vibration mount? If so I would suspect that the visible "earth" lead is a bonding across the mount.

I see a hole through the flange at the bottom of the junction box. Is that a through hole which would take a bolt for an earth connection terminal?