Thread: Clarifying 3ph Motor connections

Some interesting reading on SWER
PB Report: Indicative Costs for Replacing SWER Lines - Energy and Earth Resources

When One Wire Is Enough | Archive content from TDWorld

Originally Posted by cba_melbourne

Some interesting reading on SWER
PB Report: Indicative Costs for Replacing SWER Lines - Energy and Earth Resources

When One Wire Is Enough | Archive content from TDWorld

I found the PB Report interesting. There are many similarities between the UK and OZ.

Thanks for the links.

Thanks for those links Chris. Some clarification found there. We have been close to the mark. 12.7Kv for the main line as it is the phase to ground voltage for 22Kv 3ph. Simple.

Reminds me that I spoke to the electrician at work about 240v input VFD's. He knows about them, but has never had anything to do with them. One question he asked was regarding the voltage. If 240v is fed in, then is 240v fed out per phase, which would be equal to 415v between phases. I had a bit of a think and realised that it would be 240volts between phases and a lesser voltage from a phase to earth. I hope I am correct in this.

Dean

Originally Posted by Oldneweng

One question he asked was regarding the voltage. If 240v is fed in, then is 240v fed out per phase, which would be equal to 415v between phases. I had a bit of a think and realised that it would be 240volts between phases and a lesser voltage from a phase to earth. I hope I am correct in this.

Dean

240/1.732 = 140V to ground. ( 1.732 is the square root of 3 )

Ray

Originally Posted by RayG

240/1.732 = 140V to ground. ( 1.732 is the square root of 3 )

Ray

Thanks Ray. This forum is a never ending learning experience.

Dean

I finally found my leftover cable. Have maybe 2m of 12awg in few pieces and maybe a metre of 16awg 200. You can have it if its of any use. It 200 degree rated silicon sheathed.

Neil

Originally Posted by gallegos

I finally found my leftover cable. Have maybe 2m of 12awg in few pieces and maybe a metre of 16awg 200. You can have it if its of any use. It 200 degree rated silicon sheathed.

Neil

Hang on to it for the moment Neil. I will keep it in mind and let you know if I need it. I am not going to do much of anything for the next 3 months or so. Vintage started today, quietly but will ramp up over the next week or so. 8 hours of confined space training today so I am completely brain dead. That was about 6 hours longer than was required for our situation, in my opinion and I will forget most of the details. I have been doing this for 16 years now. 6 am start in the morning and knock off when the work is finished.

Dean

The holding on to stuff bit i have down pat.. I just struggle when it comes time to find it again.

8 hours confined space training... thats impressive. I wouldnt have thought any organisation outside of bhp or rio tinto could pad it out that long.

Originally Posted by gallegos

The holding on to stuff bit i have down pat.. I just struggle when it comes time to find it again.

8 hours confined space training... thats impressive. I wouldnt have thought any organisation outside of bhp or rio tinto could pad it out that long.

CSR (Confined Space Rescue) is one of the most technical of all the rescue disciplines. You can spend half the day just studying Oh&S act, regs and other associated legislative requirements. One day doesn't seem to bad. Sounds like fun to me!

Slightly OT sorry

Simon

Originally Posted by gallegos

The holding on to stuff bit i have down pat.. I just struggle when it comes time to find it again.

8 hours confined space training... thats impressive. I wouldnt have thought any organisation outside of bhp or rio tinto could pad it out that long.

That statement is so damned close to the truth. I can tell you I really struggled to stay awake. Did I take much in? I hope so, but I have my doubts. When are these people, from our HR, Govt Dept's (Never) and training providers going to realise that data overload is not conducive to retention. We don't need stuff that is totally irrelevant to our worksite.

Dean

Originally Posted by simonl

CSR (Confined Space Rescue) is one of the most technical of all the rescue disciplines. You can spend half the day just studying Oh&S act, regs and other associated legislative requirements. One day doesn't seem to bad. Sounds like fun to me!

Slightly OT sorry

Simon

Sounds like fun to me!

I worry about you, Simon.

However, it wasn't "CSR (Confined Space Rescue)". Rescue was touched on, but only in terms of the prior to entry assessment. It was a full day of the "Oh&S act, regs and other associated legislative requirements." of just the "Entry" process. We have a team to conduct rescues.

Dean

Originally Posted by Oldneweng

I worry about you, Simon.

That's just what my wife says!

I figured that industry training would have a different angle to emergency response training. Yes, as part of your entry permit for CS you must have a self rescue plan in place. Working in CS is certainly an interesting occupation. Of course, many people have worked in CS and probably not realised it due to ignorance!

Simon

Back on track again. I have decided to reassemble the motor, connect it in Delta mode as per the diagram inside the motor connection box lid, and hook it up to the vsd temporarily to see what happens.

I went looking for some 3ph cable today. I did find a length long enough to do what I want. It is only 1.27mm² per conductor. I have checked this via a couple of online calculators and using a length of 2m, it seems to be acceptable. Does anyone disagree with this. I am using a total current of 25A which I think is quite generous. The vsd has a total of 23A. This is just a bench (floor) test. Should I clamp the motor down. I do not intend to run it at max speed.

Would it be better to obtain some larger gauge cable in the long run? If I mounted the vsd on the lathe I could use individual wires inside conduit.

Dean

The motor is back together. I have connected the vsd temporarily. It is working and even in the right direction. The speed ramps up and down. It seems almost normal to me.

The only issue is that at 50Hz the motor does not seem to be running at anything like normal speed. Can anyone make any suggestions or comments regarding this matter. One thing that was a bit of a concern, was the default frequency. When first turned on, it showed 400Hz.

Maybe I should have just connected the motor up from the beginning, but I did learn a lot along the way.

Dean

What is your setting on PD004?

Stuart