Road trip..

Discussion in 'General foundry chat' started by DavidF, Mar 1, 2021.

  1. DavidF

    DavidF Administrator Staff Member Banner Member

    I should learn to stay off the internet, it only winds up costing me money. But in this case I think it was well spent.
    For some time now I have been wanting to build a investment mixing machine to save time with my casting projects. Mixing 5 lb batches is just too time consuming ( not to mention boring as hell)
    I haven't been able to find the time to build the mixer so today I just decided to push the magic button.
    Heading up to RI on Friday to pick this up...
    SmartSelect_20210301-103521_Chrome.jpg SmartSelect_20210301-210327_Chrome.jpg SmartSelect_20210301-210424_Chrome.jpg
     
  2. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    Nice! How many HP is that vacuum pump? 1 or 3 phase?

    Best,
    Kelly
     
  3. DavidF

    DavidF Administrator Staff Member Banner Member

    It's 3ph. Not 100% sure on which model vacuum pump it is, but I would bet that it is
    3 hp.
    Which leads me to the question.... if I use a vfd to run the vac pump then once it's running I should have my 3rd leg to start the smaller mixer motor???
    Going to see about getting the garage wires up soon. Might go 3ph depending on cost.
    Found a nice induction melter at fairly reasonable price that is 3ph also...
     
  4. Zapins

    Zapins Gold

    Keep us posted. I'm planning on getting 3 phase setup over the next few months and I'm interested in seeing how you do it.

    Nice wax injector. What did the damages come to?
     
  5. OMM

    OMM Silver

    In my shop I run three phase 240 V and three phase 600 V all through a rotary phase converter. I also run about five machines in my machine shop off of VFD's and two machines in my woodworking shop from a Vfd's. In the past year, I've set up over 500 VFD's in single phase shops. I can walk you through each and every phase converter and price tag, Pros and cons. No strings attached.
     
  6. OMM

    OMM Silver

    There is only a few ways to do it.
    Static phase converter
    A Vfd or variable frequency drive
    Rotary phase converter
    Phase Perfect

    I put these in order of price tag for set up.

    If you're set up $ north of three to $4000 a RPC phase converter is your best that but not by itself. Vfd's can enhance certain machines. Rotary phase converter's or RPC's are the most robust. But…

    If you have about $10,000 to spend you can go for PHASE Perfect. I do think this is a great all in one machine. But it does have its drawbacks. If it goes on the blitz it might take you two or three weeks to get parts. If you are OK with your shopping down for two or three weeks, this is something you need to weigh out.

    Back to rotary phase converter's. They are a Sherman tank. But, they waste electricity because they are spinning...... You might be wasting two or three dollars a day with them spinning in a residential property. But, you don't need to have it spinning if you're not using the machinery. These will usually run you $500-$8000 for infrastructure and connection.

    Now, if a Vfd is only hooked up to one machine generally. $200-$300 and that single machine is up and running. Yes, a little bit of wiring time is involved. But, it's not that scary if you get help.
     
  7. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I know you plan on using the VFD at 100% power, and there are so many variations and features on VFDs these days it's hard to generalize, but many require settings to a particular motor power, sense down stream load, and a million other things that may not play well with the rest of components and control circuits in the investment machine.

    I'd say buy an RPC and pull the wire in your shop for whatever number of circuits you need +2, or every 10-15 feet. When I built my shop I bought a 10HP RPC for $800. That was almost 7 years ago. Looks like they are $950 now. I bought from NAPECS because they had been around a long time and had Baldor purpose built idler motors. They are quiet compared to most RPCs and very nice for the money. Most of the 3ph equipment I have is 3HP or less. I have an 2HP Oliver 20" Dual disc sander. That thing is a huge inertial mass and about the hardest starting scenario possible. The 10HP RPC can just barely lug it up from a standing start, but I usually give the disc a couple good shoves with my hand and then it yanks it up right away. Other than starting you can pull more machines simultaneously on the RPC.

    Rotary, Static & Digital Phase Converters & Electrical Supply - NAPCES (northamericaphaseconverters.com)

    One word of caution even with RPC depending upon type, though the voltage between legs will be the same, the generated phase will most likely be a higher voltage to ground (some folks call this the "wild leg"). If you have internal control circuits in machinery that are stepped down, you just need to make sure you grab one of the other two legs for your controls.

    In addition to the RPC, I have two VFDs in my shop. One is dedicated and built into my lathe and the other is a <2HP unit that I can move between several machines. My (manual) mill is usually plugged into an RPC circuit but I installed a plug on the motor pig tail when I power it from the VFD and leave the rest on the RPC circuit. That way power feed motors and DRO remain happy. It only takes a minute to add or remove the VFD which is powered from 220vac 1ph. I think the price of single phase powered VFDs goes up rapidly after a couple HP. You get a little deeper into the HP range if the VFD is 3ph input, but again, beware if the source of 3ph is an RPC as the VFD may not like the generated leg.

    When I did my shop from scratch, it had fourteen 220vac 1ph circuits, six 3ph circuits, nineteen 120vac circuits, Ten recessed lights. I had a 200 amp service run from the curb (utility company charged $200 for that tap), a 200amp service panel, a 60 amp sub panel, a 60 amp 3ph sub panel, AC, Furnace, etc. Most all circuits were 20 amp 12ga conductor but three were 50 amp for compressor, welder, electric foundry furnace, and extra. I wrote a check for all that for $4k during construction. It's all Romex behind drywall with receptacles. -Best money I ever spent.

    Electrical Service and 10HP Phase Inverter.JPG

    Hope that helps.

    Best,
    Kelly
     
  8. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    One thing I forgot to mention, VFDs can produce a lot of noise, both radiated and conducted. If you plan on using one with any other shop equipment with a micro-P or displays that are not filtered and hardened, they can pose problems.....ask me how I know!

    Best,
    K
     
  9. DavidF

    DavidF Administrator Staff Member Banner Member

    Another reason I'm not an electrician. Lol
    Well I have to get it home first, then I'll sort it out.
     
  10. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I edited the cost for all that. I had to go back and look at the check. Initially it looked like I paid $3200 and $4k but they had originally quoted $3200 and upcharged $800 for the six 3ph circuits and subpanel for a total of $4k.....that was a no-brainer.

    Best,
    K
     
  11. Tobho Mott

    Tobho Mott Gold Banner Member

    Cool new toys! Drive safe.

    Jeff
     
    DavidF likes this.
  12. Does getting three phase connected to your house cost a lot in the USA?.
     
  13. DavidF

    DavidF Administrator Staff Member Banner Member

    Depends on how close the 3ph power is to you.
    Most areas do not have it available or if it is it could be miles away.
     
  14. OMM

    OMM Silver

    Kelly, very nice set up.

    I too went with North American rotary phase converter's. I have the 5 hp. I just bought the panel. I had a couple 5 hp motors.

    53840DBE-C027-4108-8934-9D2D66FAE466.jpeg

    Yes you do have to identify the wild leg and when it goes into the machine do you have to make sure that the coils on the motor starters are receiving the natural legs.
     
  15. Zapins

    Zapins Gold

    What's the benefit of using Americans rotary phase converters over one of the cheap $100 ebay vfds?

    Seems like you could skip a huge amount of setup and cost to just get that?
     
  16. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    That looks nice OMM. What do you use for a pony motor?

    Best,
    Kelly
     
    OMM likes this.
  17. OMM

    OMM Silver

    Thanks, but your set up trumps mine ten-fold. A pony motor is a motor that gets the idler motor up to speed for phase conversion. Neither you or I have this.

    I also have a 20 hp rotary phase converter that is on a portable cart. It is an automatic start and does not have a pony motor. The 20 hp RPC I built from scratch.

    Yes, I do run a 5 hp RPC and a 20 hp RPC in my shop. The 5 hp is powered off 240 V single phase 40 A. The 20 hp (which is home made) is powered off 240 V single phase 60 A. The 5 hp RPC has 6 kVA transformer and the 20 hp RPC has a 15 kVA transformer.

    I only use auto transformers to step up the voltages as the breakers I use to power the units are ground fault. Ground fault breaker's prevent wild leg amps going back to the Ground. This is a must if you're running a rotary phase converter to have a ground fault breaker feeding the RPC.

    Kelly, what kind of breaker are you feeding your RPC? It should be a ground fault.



    [​IMG]
     
    Last edited: Mar 2, 2021
  18. Petee716

    Petee716 Gold Banner Member

    The bigger boys with lots of bigger toys can explain it more in-depth than I can but I think for guys like you and I with one or two 3ph machines, we're are better off fitting them with VFDs. Whether to buy them off eBay or from a domestic vendor will get you different answers, but unless there's a number of machines involved VFD seems to be the way to go.

    Pete
     
    Jason likes this.
  19. Al2O3

    Al2O3 Administrator Staff Member Banner Member

    I thought it may have been built into the Baldor converter but I take it there are start capacitors in the control box? I really don't know squat about RPC design. I remember 7 years ago doing some reading and then discovered the difference between (me) building and buying a was maybe a couple hundred bucks and I wrote the check. In your video, are there 3 banks of caps? Start + 2 phase balance? Is that how the NAPCES units are arranged. I don't think I ever even had the lid off the control panel. It's has never given me a problem other than trying to start the Oliver disc sander. If I just spin that up to 30-60 rpm with my hand it takes it all in stride. That was why I went 10HP......and IIRC, they were running a promotion at the time that knocked the price down $100.
    I don't know I'll have to check, but from memory I don't think so. The electrician that did all the shop electrical work installed the RPC. The only GFI circuits I know of are all the 120vac utility receptacles. I had to remove one of those for my lathe because I couldn't run the VFD with it installed.

    The only thing I did for the RPC install was build the steel frame to mount the idler motor. I toyed with mounting it 15 feet away on the garage side of the wall where my air compressor resides but it wasn't worth it. It's rubber isolated and although there is a low hum, most machinery I would operate with it is louder. I am glad my compressor is not in the same room with me!

    Best,
    Kelly
     
  20. OMM

    OMM Silver

    Rotary phase converter's (or RPC's) are for the guys that are thinking that they will have more than 6-8 three phase machines in their shop. I personally have eight machines. My investment with a 5 hp RPC unit and all the wiring and plug receptacles with transformer ran me over $2000 with my own labour.

    Kelly, the main reason why am running ground fault breaker is because I'm stepping up my voltages to 600 V through a auto transformer. It's not so important for you, But it could be. Because you have a separate service to your garage shop, this makes it less important. Indirectly you have two different services. In my situation I do not. If I have a fault to ground on my 600 V legs, this could leak to all my ground circuits in my home. There is a big difference when working with 240 V equipment to 600 V equipment. On everything after my 600 V transformer I have to make sure all wiring, receptacles and fuses are properly rated.
     

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