Rotary Phase Converter Tech

[bgaidan]

I guess if I wanted to be stupid, I could kill the main and clamp a pair of jumper cables to the main bus and then to the converter's lugs.

 

[cj3a]

I got the dam meter to work with the phone.

 

[cj3a]

Hooked to the single phase feed with a 100amp breaker. The 357 amp reading is true the others are from me figuring out how to get the meter to log to the phone.

 

[bgaidan]

Hooked to the single phase feed with a 100amp breaker. The 357 amp reading is true the others are from me figuring out how to get the meter to log to the phone.

Wait, what exactly is the setup there? Is that an RPC? Or how is the motor wired?

 

[cj3a]

200amp single phase panel feeding a 100amp three phase panel.

 

[bgaidan]

How? Where's the 3rd leg coming from?

 

[cj3a]

American rotary 40hp to generate the third leg

 

[bgaidan]

OK, that's the missing detail. I was really confused for a minute!


That makes me feel better if you're running that on a 100a breaker. Local junk shop has a 125a breaker for my panel on ebay. Just offered them $25 picked up tomorrow. They usually take my offers so I should be able to go grab it in the morning.


Assuming that's an AD-40, they actually list it as a minimum 125a breaker. That's the AR model that I was comparing mine to. What's strange is the American is rated for 20/40 hp and mine's rated for 20/60.

These are the specs for mine (assuming the current model is the same as my older one)

Makes me wonder if mine's maybe a 50hp or something and just shittier build quality than American so they derate the lower end.

 

[bgaidan]

Update:

Due to concurrent threads here and in GCC, things are happening.


From someone else's suggestion I realized that when I was trying to spin it up with the VFD, all the caps were still wired in, which probably mean the VFD was trying to charge the caps and spin up the motor, resulting in an insta-trip.

I pulled all the caps out of the equation and now the VFD can spin it up, somewhat. It still overcurrents when it gets to about 19Hz, but tha's to be expected when you're spinning a 40hp motor with a 10hp VFD. It at least confirms that the motor is good.

Guess I could try putting just the start caps in to it now and leaving the run/balancing caps out and see if it'll start off 220v.

Hopefully gonna pick up that 125a breaker tomorrow and then rig up a someone proper feed to it. And maybe even go grab a multimeter that can test caps just so I can make sure none of them are shot and causing problems.

 

[aczlan]

::Confused:: Why are you using a VFD on a RPC? Just to test the motor part?

Aaron Z

 

[bgaidan]

::Confused:: Why are you using a VFD on a RPC? Just to test the motor part?

Aaron Z

Correct. Before sinking any more money in to a potentially unusable motor, at at least tells me if it'll spin up or not. Gonna go pick up a breaker today and see what it does with 125a feeding it.

 

[bgaidan]

Correct. Before sinking any more money in to a potentially unusable motor, at at least tells me if it'll spin up or not. Gonna go pick up a breaker today and see what it does with 125a feeding it.

Alright, so I got an appropriately sized breaker and fed her some beans......and only get some questionable humming out of it.

I pulled the start caps off and I'm getting readings all over the place. They're supposed to be 400uf but I'm getting anything from 200 to 600. Gonna just order 6 new 400's and go from there.


In other news, I found this load center at one of my surplus places today for $200. Decent deal. Could have use a much smaller one, but who knows when I'd find a deal on it.

This should help date it

And couldn't help myself. Walked away with a whole pile of random bandsaw blades. I'll get to test out the blade welder on the "new" Do-All and 1" ones should be good for the horizontal.

Even got a nice Jacobs 16n for $20.

 

[Duc]

Alright, so I got an appropriately sized breaker and fed her some beans......and only get some questionable humming out of it.

I pulled the start caps off and I'm getting readings all over the place. They're supposed to be 400uf but I'm getting anything from 200 to 600. Gonna just order 6 new 400's and go from there.


In other news, I found this load center at one of my surplus places today for $200. Decent deal. Could have use a much smaller one, but who knows when I'd find a deal on it.

This should help date it

And couldn't help myself. Walked away with a whole pile of random bandsaw blades. I'll get to test out the blade welder on the "new" Do-All and 1" ones should be good for the horizontal.

Even got a nice Jacobs 16n for $20.

At what point would you be further ahead to buy a new RPC? LOL

That panel can be filled up quick with different pieces of equipment but also you can run non-3phase equipment off it. 3 breakers per machine can fill it up quick.

 

[bgaidan]

At what point would you be further ahead to buy a new RPC? LOL

That panel can be filled up quick with different pieces of equipment but also you can run non-3phase equipment off it. 3 breakers per machine can fill it up quick.

I could replace every component in that cabinet and still be about $2k ahead of an American Rotary.

 

[bgaidan]

At what point would you be further ahead to buy a new RPC? LOL

That panel can be filled up quick with different pieces of equipment but also you can run non-3phase equipment off it. 3 breakers per machine can fill it up quick.

Fuck you.



After replacing the caps in the big RPC, this happened:

If you've never had the pleasure of six 400uf caps blowing off in rapid succession in a relatively small space, I don't suggest you try it.

Still not entirely sure what went wrong. The caps were spec'd per the old ones. I installed them, threw the breaker and it just hummed. I was going to run over and see if I could give the motor shaft a jump start and it spinning, but before I could get there they started blowing off.

I got pissed and called up Southern Phase Converters and ordered a 30hp model. He has listings on ebay but I called him and he was was probably $4-500 cheaper over the phone. Delivered in like 4 days.

I was a little disappointed because he drop shipped the motor and then sent me the built panel separately and it didn't come with any wiring to connect the two. Not sure if that's normal for a "detached" RPC, but I wasn't expecting it. Luckily I had some 4/8 SO cable, which I swore when i checked was big enough for the load, but when I looked again for a sanity check, it may be undersized. I'll watch the load on it and probably eventually swap it out for solid #4 if I can find a deal on some used/scrap. Eventually I plan to build a little doghouse off the back of the shop, directly behind where I have it setup now and house the RPC motor and my compressor there, so I'll need to run wire to that any way.


30hp RPC motor

And here's the giant code violation that I ended up with:

I ran a 125a breaker off the main panel (right) to the 3p panel I picked up, using #2 copper. From there I'm feeding the RPC panel with an 80a breaker, per their design, using #4 copper. The 8/4 SO cable goes down to the idler motor and the generated leg is back-fed through the 80a breaker to power the the 3rd bus in the 3p panel. I'm then running 8/4 SO from a 60a breaker (need to order a 30a) to the Fadal. The Fadal has it's own 30a fuses on the incoming line so other than the 60a being a little big for the 8/4 SO, I'm not worried about the machine.

Other than needed to order a couple properly sized breakers, I'm fairly happy with how this turned out. I'm not too worried about the breaker or wire size right now as it'll be a bit before I actually put any real load on the system.


Feel free to critique my work.



I still need to tidy up a couple circuits in the main panel. This fucking cover has been off since I moved in 2.5 years ago. I fucking hate how the PO had the incoming wires run.

 

[bgaidan]

The good news is, the Fadal is alive.

I was able to raise the head to remove the transport blocking and counterweight support bar and then cold start it and home it. Managed to figure out how to load the tool changer last night and only crashed the spindle in to the changer once.


Gonna get the mill leveled hopefully tomorrow and start learning how to run it. Fortunately it came with the operation and training manuals. The training manual is actually really good and should get my running pretty quickly.

 

[aczlan]

That sounds quite exciting, I have my 10 horse RPC running, need to add a couple of fuses for the control wiring, secure the caps and idiot proof the controls.
Quick picture of the instrumentation:

Left to Right:

• Incoming A-B phase volts and A phase amps
• Outgoing A-B volts and A phase amps
• Outgoing B-C volts and B phase amps
• Outgoing A-C phase volts and C phase amps

The only reason why I have incoming volts/amps is that my control wiring is 240 volt and another volt/amp meter was about the same price as a 240V panel light (to show that power was on and ready to start).

I have a couple of 12 volt coil relays that I will use to run the start relay and the contactor (that way it can have "remote start/stop" and only have low voltage wiring leaving the RPC).

Aaron Z

 

[bgaidan]

That sounds quite exciting, I have my 10 horse RPC running, need to add a couple of fuses for the control wiring, secure the caps and idiot proof the controls.
Quick picture of the instrumentation:

Left to Right:

• Incoming A-B phase volts and A phase amps
• Outgoing A-B volts and A phase amps
• Outgoing B-C volts and B phase amps
• Outgoing A-C phase volts and C phase amps

The only reason why I have incoming volts/amps is that my control wiring is 240 volt and another volt/amp meter was about the same price as a 240V panel light (to show that power was on and ready to start).

I have a couple of 12 volt coil relays that I will use to run the start relay and the contactor (that way it can have "remote start/stop" and only have low voltage wiring leaving the RPC).

Aaron Z

I have those same v/a meters that I plan to add to this panel. I didn't get one for incoming power, but I probably will.

But one thing I'm realizing, the way Southern builds these panels, I'll always show about 15 amps on legs 1 and two when the motor is idling and then only show load on the wild leg when I'm actually running something.


This one has a simple NO switch so I can swap it out with a remote switch whenever I get around to it. I could make it low voltage if I wanted to, but I don't see the need here. I'll probably just use simple 12 hour timer like I have on my air compressor and stick it near the door. That way I can fire it up and it can run for a full day, but will eventually shut of if I forget to kill it when I leave.

 

[aczlan]

But one thing I'm realizing, the way Southern builds these panels, I'll always show about 15 amps on legs 1 and two when the motor is idling and then only show load on the wild leg when I'm actually running something.

Why would that be? How do they have their wiring run?
I have my two hots come in, go through the contactor and overload, then to the idler and the outlet to connect something into.
I put my CTs just before the outlet, so they only show outgoing amperage.
Or does yours not route A/B phase power through the RPC contactors?
The way mine is set up, if the overload trips it shuts down all outgoing power, that way I don't try to run on two legs of the three phase.


Aaron Z

 

[bgaidan]

Why would that be? How do they have their wiring run?
I have my two hots come in, go through the contactor and overload, then to the idler and the outlet to connect something into.
I put my CTs just before the outlet, so they only show outgoing amperage.
Or does yours not route A/B phase power through the RPC contactors?
The way mine is set up, if the overload trips it shuts down all outgoing power, that way I don't try to run on two legs of the three phase.


Aaron Z

I actually called the guy asking about it when the panel showed up. I can see the benefits of doing it either way and understand why he has it like this, but i'm still not sure if I like it.

You can see what's happening better here:

Single phase power in to the left two main busses on the right panel. Upper breaker sends those two phase out to the "in" side of the RPC panel's contactor. Throw the switch and the RPC starts up and the 3rd phase is back fed through the contactor, to the breaker and powers up the 3rd phase bus on the breaker panel.

The negative to this, like you pointed out, is that the two primary phases stay hot whether the RPC is running or not.


The positive - if the full load is running through the contactor, you're limited by the amp rating of that contactor. Fine under "normal" use, but after looking in the specs on the CNC lathe, the RPC may be a bit undersized. My backup plan is to fire up the 10hp Monarch and let it idle to generate some extra reserve load capacity. In that case, the monarch would also be back feeding the panel and I'd be limited by the 125a single phase breaker feeding the 3p panel and not the 80a breaker to/from the RPC. If that makes any sense.....

An alternative could be to add another bigger contactor in the RPC panel for the back feed.


I'm a little curious how American Rotary does there. I could have sworn Duc told me he burned up something in his Fadal because he tried running it without the RPC powered up....which would imply it's still getting power on the two main phases without the RPC spinning.

 

[GLTHFJ60]

My American rotary adx 10 allows the two main phases through when it's off. Convenient for lights on those circuits.

 

[bgaidan]

My American rotary ad 10 allows the two main phases through when it's off. Convenient for lights on those circuits.

That's what I was thinking most of them did. For something like the mill, I believe the controls are all in the first two phases so you can power it up but it will fault out if you try to move any axis or the spindle if the RPC isn't running.

 

[Duc]

Fuck you.





30hp RPC motor

Been there done that. Sometimes you spend more money trying to go cheap then buying what you need the first time. Rarely does cheap work out for me anymroe.

That's what I was thinking most of them did. For something like the mill, I believe the controls are all in the first two phases so you can power it up but it will fault out if you try to move any axis or the spindle if the RPC isn't running.

I believe only the spindle motor uses all 3 phases while the motors use the 2 phases and card rack only uses 1.

 

[cj3a]

I believe only the spindle motor uses all 3 phases while the motors use the 2 phases and card rack only uses 1.

I believe this is how you want it done.

 

[bgaidan]

Been there done that. Sometimes you spend more money trying to go cheap then buying what you need the first time. Rarely does cheap work out for me anymroe.






I believe only the spindle motor uses all 3 phases while the motors use the 2 phases and card rack only uses 1.

That jives with what the manual states about single phase operation:

The Fadal VMC line is designed for three phase input power. However, threephase power is not always available. If this is the case, Fadal offers a singlephase input power option. All Fadal machines are capable of operating on single-phase line input. The torque ratings will be at 60% of the published performance. The rapid traverse rate is reduced to not more than 700 IPM for machines with higher speed capability. This is because as the DC bus capacitors are drained and the bus voltage drops, the single-phase input can not recharge the capacitors as fast as the three-phase. Lower bus voltage equals lower speed and more current. Single-phase requires 73% more current to maintain the same performance (square root of 3). The main limitation is the spindle drive. It will not draw more than its rated current. The current rise is steeper in single-phase and will therefore trip sooner. Fadal does not recommend single-phase power for the High torque or the 6535, 6030 and 8030 machines and cannot be used with VHT. This option can be ordered on a new machine and can be installed in the field. Some wiring changes are also necessary. Please see the single-phase transformer charts and wiring instructions.



But, I did find today that you can't power the machine up without the 3rd leg present when it's wired for 3 phase. I can hear the transformer humming when I throw the knife switch and some of the fans in the cabinet kick on, but it won't engage the contactor when I press the green button.

 

[Duc]

This points to the computer cards being on the fake leg which is bad. I will have to look at the drawings tomorrow to see which lug the cards are on.

 

[bgaidan]

This points to the computer cards being on the fake leg which is bad. I will have to look at the drawings tomorrow to see which lug the cards are on.

Everything I read said to put the wild leg on L3, which is what I did.

But, so far without any heavy load on it, my PRC is surprisingly well balanced. Like 242-241-243v

 

[cj7jeep81]

When you get your Fadal running, let me know if you have any questions. I've been running mine for a couple years now, and very happy with it. I've been powering it off a 10hp RPC since I got it, and other than not being able to use any other equipment while its running, I've had 0 issues (I also make sure not to push it too hard). Did pick up a 15hp lathe though, and the 10hp RPC says FU when I try to start it. So will be looking for a 25 or so horse converter now.

 

[bgaidan]

When you get your Fadal running, let me know if you have any questions. I've been running mine for a couple years now, and very happy with it. I've been powering it off a 10hp RPC since I got it, and other than not being able to use any other equipment while its running, I've had 0 issues (I also make sure not to push it too hard). Did pick up a 15hp lathe though, and the 10hp RPC says FU when I try to start it. So will be looking for a 25 or so horse converter now.

Depending how you have it wired (i.e.: a breaker panel after the RPC) you could spin up another 10hp or so idler with the RPC, as in start the RPC then use it to start another 10hp motor and you'd probably be able to run the 15hp off of those.

There's a chance that the 30hp won't be enough to run the Mazak but I'm hoping that if I let the 10hp Monarch idle it'll give me that little extra capacity.

 

[cj7jeep81]

Depending how you have it wired (i.e.: a breaker panel after the RPC) you could spin up another 10hp or so idler with the RPC, as in start the RPC then use it to start another 10hp motor and you'd probably be able to run the 15hp off of those.

There's a chance that the 30hp won't be enough to run the Mazak but I'm hoping that if I let the 10hp Monarch idle it'll give me that little extra capacity.

I've tried that, unfortunately it trips the single phase 50 amp breaker feeding the phase converter, or must be getting low voltage and the contactor drops out.