Wiring up a 30HP rotary phase converter

[Willie B]

Parallel conductors are fussy. Get length a little out of balance, or a connection a little less than perfect, one conductor sized for half the load gets more than its capacity. Rules for parallel conductors are restrictive.

[ferrret3238]

If that's the nameplate on the HTP it looks like its single phase or three phase. Do you need the phase converter to run it up to maximum amps? I'd try it on single before I spent a lot on a rotary unless I needed the rotary for something else too.

[danielplace]

If that's the nameplate on the HTP it looks like its single phase or three phase. Do you need the phase converter to run it up to maximum amps? I'd try it on single before I spent a lot on a rotary unless I needed the rotary for something else too.

I believe the top end is limited to 350 as the spec's seem to suggest when running on single phase input. I think he has been using it on single phase for a bit. He must know if that is really how it is by now.

[Oscar]

If that's the nameplate on the HTP it looks like its single phase or three phase. Do you need the phase converter to run it up to maximum amps? I'd try it on single before I spent a lot on a rotary unless I needed the rotary for something else too.

Trust me, it's been "tried". Even before I bought it I already knew what the deal was. It is indeed limited to 350A until you have a capable 3-ph supply to feed it.

[Willie B]

Trust me, it's been "tried". Even before I bought it I already knew what the deal was. It is indeed limited to 350A until you have a capable 3-ph supply to feed it.

I'm surprised, The Dynasty output doesn't change 200 to 600, single or three phase.

[Oscar]

I'm surprised, The Dynasty output doesn't change 200 to 600, single or three phase.

Why would you be surprised? It's a completely different welder, from a completely different company, with a completely different power supply.

[bigd250]

I'm surprised, The Dynasty output doesn't change 200 to 600, single or three phase.

You are incorrect. A dynasty 400 only gets 300 amps single phase and an 800 only gets 500. It's the same with a miller xmt.

[danielplace]

You are incorrect. A dynasty 400 only gets 300 amps single phase and an 800 only gets 500. It's the same with a miller xmt.

Specs seem to suggest otherwise. 5-400 on single phase for a 400.



The XMT 400 and 800 ?? do they even exist.

XMT 350/450 are the current models.

On a XMT 350 the amp on single or 3 phase are 425 amp according to specs.



The 400 ONLY runs on 3 phase but puts out 600 amp.

[Oscar]

Specs seem to suggest otherwise. 5-400 on single phase for a 400.

Spec sheet has a typo. I checked each and every single manual on the Miller website manual search page for the Dynasty 400. They all point to 300A as the 1-Φ amperage limit.

From the manual (actually in all the manuals):







The HTP Invertig 400 has more balls whether in 1-Φ (50 more amps & +15% duty cycle), or in 3-Φ (+10% more duty cycle) than the Dynasty 400. So much for the amperage not changing, eh Willie?

[danielplace]

Spec sheet has a typo. I checked each and every single manual on the Miller website manual search page for the Dynasty 400. They all point to 300A as the 1-Φ amperage limit.

From the manual (actually in all the manuals):


The HTP Invertig 400 has more balls whether in 1-Φ (50 more amps & +15% duty cycle), or in 3-Φ (+10% more duty cycle) than the Dynasty 400. So much for the amperage not changing, eh Willie?

The duty cycle charts often don't show the with the amps maxed out though. I thought I had heard they were less on single phase before it was posted here then 2 places showed specs at full amp.

Duty cycle chart doesn't read all the way out. At 400 it is only 10% duty on single phase. They don't want that number shown everywhere but there are charts showing it at 400 on single. They stop at 20% most often.

[Oscar]

The duty cycle charts often don't show the with the amps maxed out though. I thought I had heard they were less on single phase before it was posted here then 2 places showed specs at full amp.

I suppose you could be right, but then why doesn't the manual show the same info as the spec sheet brochure (aka: the 400A output on single phase) in the first portion of the pic I posted, from the manual? I was simply going by what the manual specifies and inferring from there. I mean, how hard would it have been to draw that little line going "up" from (20,300) to (X,400) (from right to left) if it was indeed capable of supplying 400A at some duty cycle lower than 20% ?I suppose we would need to find someone with a Dynasty 400 to set us straight then....

[danielplace]

I agree but they may not want you seeing 400 amp welder at only 10% set at that 400 amp.

Ya it don't matter. Just killing time until you make installation progress on the RPC for yours.

[Willie B]

You are incorrect. A dynasty 400 only gets 300 amps single phase and an 800 only gets 500. It's the same with a miller xmt.

I guess I should have said my Dynasty, I have no knowledge of some other models.

[Oscar]

I agree but they may not want you seeing 400 amp welder at only 10% set at that 400 amp.

Ya it don't matter. Just killing time until you make installation progress on the RPC for yours.

Assuming it could even get there on 1-Φ!

RPC was scheduled for yesterday but no dice. Perhaps Monday.

[Oscar]

I ordered an Eaton 3-pole breaker box and an Eaton 40A 3-pole breaker to be installed between the RPC and the welder(s). I'm just going to use that as a means of OCPD and as means of disconnect. I know, I know, not ideal nor code, but it will be fine for me.

[danielplace]

I ordered an Eaton 3-pole breaker box and an Eaton 40A 3-pole breaker to be installed between the RPC and the welder(s). I'm just going to use that as a means of OCPD and as means of disconnect. I know, I know, not ideal nor code, but it will be fine for me.

That is good. Now your setup to run something in future easily. It was the way to go.

#6's would be a good size to feed panel then 3 #8 and a #10 ground to the welder outlet unless you are hardwiring the cord straight to the breaker then obviously whatever it has now is good if they ran a 4 conductor cord on it already I hope. For a SJ type cord It needs to be 4 conductor for the 3 legs and the ground.

It is perfectly legal to use your breaker if you want to shut things off. Switching on and off with little or no load whatsoever it would last a long time most likely.

Today if getting a inspection if you puts lights and things you obviously need to shut off they must have a switch or a switch duty rated circuit breaker. Commercial warehouses many electricians and the plans even used to show the breakers being the only shut off for lights back in the day before they enforced the switch duty rating. Now you will usually see switches for them as the switch duty breakers often either are not available for a all panels or just pricey and the switch is cheaper.

[Oscar]

I do plan to have a couple outlets for the 3-Φ power as I do plan to get a 3-Φ mill sometime in the future; that way I can leave them connected. I'm still debating the final set-up because I do not want to have a fixed location install for the RPC. I end up moving things around a lot.

[Oscar]

She's a big momma.

[Insaneride]

Looks good from here.

Oscar, you have some nice tools. Way overkill but the skies the limit.

I do have a question for you. Can you show a pic of your compressor setup? I thought you had a safety net around it. It should be in the safety forum or compressor forum imo. If that was your setup please and thank you show us.

[Oscar]

Looks good from here.

Oscar, you have some nice tools. Way overkill but the skies the limit.

I do have a question for you. Can you show a pic of your compressor setup? I thought you had a safety net around it. It should be in the safety forum or compressor forum imo. If that was your setup please and thank you show us.

Thanks. As for my compressor, nope that wasn't me. Mine is out in the backyard, about 100ft from the garage, under a small roof to protect from rain.

[scsmith42]

Oscar,
The 30 hp phase converter is good for 15 hp of load.

I would size the input at near full rating.

#1's from panel to the converter A and B single phase inputs and 100 amp breaker.

From A, B and C from converter panel to the idler you would use #8s.

Then from your A and B inputs and the C coming back from idler you feed your 3 phase panel with #4's.

>>>> NEVER use the A and B for the idler for anything else but converter panel to the idler ONLY.

If not using a panel to split up loads or set your self up for future then just run what your powering with only the size wire it requires. Be sure to provide proper over current protection as soon as you leave the phase converter. Smart to have some way to kill power at the machine too if the panel or disconnect is far from the phase converter.

Daniel, according to the tag on his RPC (shown in post #43), the FLA is 71 at 230VAC. Wouldn't he need to run #4 from his RPC panel to the idler, instead of #8? Even with 90 degree C insulation, a #8 is only rated at 55A.

[TraditionalToolworks]

Thanks. As for my compressor, nope that wasn't me. Mine is out in the backyard, about 100ft from the garage, under a small roof to protect from rain.

When I clicked on that video I realized why you have it 100 ft from your garage, which I'm guessing is where your shop is...

That is one loud compressor! I wonder if you can get it 200 ft away?

[Oscar]

When I clicked on that video I realized why you have it 100 ft from your garage, which I'm guessing is where your shop is...

That is one loud compressor! I wonder if you can get it 200 ft away?

It's actually ultra-quiet. The cell phone recording makes it sound a lot louder than it actually is. It has a whisper box that really quiets the intake sound down a lot. Plus the box with the mag starter rattles a bit. I need to secure it better than the stock set-up allows for. That's what the loud tapping sound is. The background "whishhhhhhh" is all the sound the compressor actually makes. I really should fix that tomorrow, lol.

[Oscar]

So looking at the motor wiring, it looks like the wires get connected to each other in three-sets-of-four:







The question is: Is there a quick-n-easy way to do so with the 1/4" hole lugs that are already on there? using a short 1/4" bolt/nut does not sit right with me even with isolating it from the case, because you never know.

[scsmith42]

So looking at the motor wiring, it looks like the wires get connected to each other in three-sets-of-four:







The question is: Is there a quick-n-easy way to do so with the 1/4" hole lugs that are already on there? using a short 1/4" bolt/nut does not sit right with me even with isolating it from the case, because you never know.

Correct re the three sets of four for 230VAC.

Typically you would bolt all of the lugs together, wrap with a single layer of high grade electrical tape (Scott 33 or 88), then wrap about 5/16" thick with rubber splicing tape (3M Temflex or equivalent), and then finish off with electrical tape on the outside.

The reason for the electrical tape first is because the rubber splicing tape can be quite sticky, and if you ever have to take the connection apart it can be a real pain to remove the sticky splicing tape from the connectors. With a first layer of 88, you can cut through all of the tape with a knife and peel it back from the connection, and save yourself several minutes of clean up time.

In addition to bolted lugs, the other standard way of joining the wires is using a split bolt, taped up similar to what I wrote above. In your instance I would personally use the existing lugs and bolt them.