Static phase converter wiring assist needed...

[Novadon]

Brand new "Gear Head" here, who is only semi-smart on electrical issues and needing guidance.

I have a Stewart Warner (Alemite Div) STROBE WHEEL BALANCER that is currently wired for 220 3Ph. I only have SINGLE phase 220V available in my shop. The unit consists of a roll around cart with a 7.5 HP motor w/drum (for contact spinning the tire on the vehicle), a strobe light and vibe pickup module.

I have researched the use of Phase Converters and a Static unit (designed for low torque, non reversing and infrequent staring) will fit the bill even with the related loss of 1/3 HP potential IMO.

My concern is this...I assume that the attached strobe and vibe contact portions of the balancer work off a 110V (or are stepped down less ?) leg of the existing wiring set-up.

Can I simply add / wire-in a wall mounted phase converter without regard to the strobe and pick-up as currently installed for 3 phase?

Pictures of this unit can be viewed at

http://community.webshots.com/user/maxturbo

Album title "Strobe Balancer".

I do not have a manual for the balancer. I may be able to locate a schematic (motor wiring at least) if I remove some of the covers. I can also provide additional pics as needed.

TIA...Don

 

[OperaHouse]

I'm not a big fan of static phase converters when you get over 1 hp. That looks like a pretty small motor for 7.5 HP, though I just worked on a commercial washer with a 7.5 and that was pretty small. If you use a VFD, don't connect anything electronic to it. The pulses will destroy it. Isolate your power to the other circuit. Frankly, if this is a 7.5 I would scrap the motor. You can't undersize an inverter. Try getting a 2 hp to do the job with a little more time for ramp up. You can get a 2 hp inverter for $100 on eBay.

 

[itsmoked]

I'm with OperaHouse, Stick a 2HP on there and run it with a VFD. Isolate the electronics stuff.

Or..... Stick a 2HP single phase on there.

BTW: That static unit you are refering to sez infrequent starting? I have used this type of balancer and if I recall you start and stop these things may be 6-10 times in the process of doing one wheel. And while its in motion.

If you use a VFD you will want to avoid EVER turning it off and on while it's spinning.. Somebody correct me on this.

This may suggest a single phase makes more sense.

Also if you keep that 7.5 HP motor you will need to feed it about 30Amps in single phase, 230V!

 

[Novadon]

Thanks guys. I'll try and respond to some of your points thus far...
"I'm not a big fan of static phase converters when you get over 1 hp. That looks like a pretty small motor for 7.5 HP"

She's 7.5 per name plate data! FWIW, I've been using a Static Phase Converter (Heavy Duty from MSC) on my 5HP Bridgeport mill daily for about six years.
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" Stick a 2HP on there and run it with a VFD."

Uh, what's a VDF?
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"BTW: That static unit you are referring to sez infrequent starting? I have used this type of balancer and if I recall you start and stop these things may be 6-10 times in the process of doing one wheel. And while its in motion."

I guess it's all a matter of technique. I've watched a local fellow balance my truck tires and he simply leaves the motor running as he starts and stops the TIRE during the operation. You make a valid point though.
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"Also if you keep that 7.5 HP motor you will need to feed it about 30Amps in single phase, 230V!"

THAT is the easy part as I have 5 welder and air compressor 30 AMP receptacles currently wired up around the shop.
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"Isolate the electronics stuff."

I'm not sue how to do that. Can you explain?
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"Or..... Stick a 2HP single phase on there"

I can do that. The shaft diameter will probably be a lot smaller, but I CAN adapt easily enough.
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I was looking for an easy way out, but thus far it's not looking that way. LOL

 

[itsmoked]

Hmmm.. Nice NOVA by the way ..Actually VERY nice.

Okay power not a problem. Check!

You cannot run the electronics with inverter power.
Cuz you're talking maybe 20% chance they will work.
20% chance they won't. 60% chance they'll be distroyed.

Bad odds those.

So you can either figure out how to separate the electronics from the motor and feed them straight 220V, which if you are in the US is actually probably 240V.

Then run the the existing motor with your converter.

Or you can change the motor to a 2HP single phase and the electronics can stay connected.

Or you get a rotating converter that makes smooth 3ph.

You might consider this option since your shop is riddled with 3ph loads.. Just get a whopping big rotoary phase converter and have true three phase power.

Other hair brained ideas. I don't about you, but I pay $0.267 a KW-HR. I would "think" about a 3ph generator that runs off of natural gas. I could run one for far less then what I pay for my electricity and just run it when 3ph is needed or the utility is dead .

 

[OperaHouse]

You'd think 7.5 HP would mean something. That industrial washer motor nameplate also said 4.6A at 240V. That must be Instantanious Momentary Peak On a Good Day HP. I think having another 5HP motor running as a phase converter would be a good idea if you got the space and the power. Then you just have to make sure that the other stuff on the cart is powered by the two wires that are powered by the main line and not the generated third phase.

 

[Novadon]

I think I'll go the replacement single phase motor route then.

Do ya'll think 2 HP is big enough?

Is bigger O.K. (3-5 HP) if I can find a "deal" and keep the physical frame size similar to the 7.5 HP motor currently installed?

I think that the onboard "switch" may contain overload protection of some sort. It is sort of a "breaker" looking style of switch. I need to look inside and perhaps post a pic too.

I'll need to make sure that the electronics side (sensor and strobe portion) get safely hooked up, huh.

Thanks for the complement on my Nova. It's my baby. Bought her brand new, my 1st new car

 

[itsmoked]

Novadon;

Yes 2HP is big enough. Remember that 7HP is to cover all bases in a commercial shop. That's including those cement truck front tires with the mondo cast iron break drums inside. And in a "time is money" shop. If you just take it easy 2HP would be fine. But absolutely go ahead get the most HP that will fit. I'm betting 2HP may be it tho.

Remember this type of balancer always leaves that disturbing slicked area on the tire.

Yeah post a pic when you get to that point. And yes you will need to make sure the electronics get their happy power.

Did you note opera's comment? You can use a motor to make adequate 3PH power that would allow you leave the balancer alone.

 

[Novadon]

"Did you note opera's comment? You can use a motor to make adequate 3PH power that would allow you leave the balancer alone."

Caught that. In other words a stand alone additional motor, right? I think that I'll just invest in a single phase motor in the 3-5 HP range (for the pucker factor) and mount it in place of the 7.5. I'll keep ya' posted as this thing plays out.

Thanks,

Don