Phase converter wont run my shear

[H80N]

Okay, The shear is rated for 1/4" x 10' its a 1989 manufacture date, The wires are all properly sized, I checked amp draw as I stall out the motor and its pulling 67-68 amps, the pump is spinning the right way. and its stalling out with max pressure at 2000 psi.

I have a high end electrician coming out to verify everything, I don't want to call American rotary until my electrician can verify everything.

I talked to the pump manufacturer and they can drop my pump down from 16 GPM to 11 gpm which will allow me to get the psi that I need.

I haven't gaped the blades yet but since it will still cut a limited amount of 1/4" plate before it stalls the plate edge seems good based on the 1/4" x 12 accurshear I use at my buddies shop.

Im not sure if I can change the rake but since I cant make more than 2000 psi I doubt that rake is the issue.

Yes all the hold downs seem to work good.

I hope Ive answered all the questions.

Sounds like you are dealing with the troubleshooting in a logical & methodical fashion... and on the right track...

PLS keep us posted...

[Tryagn5]

does the motor stall.....

Ok, im clear except when the pump only makes 2000 psi is the electrical motor stalling and not building speed? If so then you clearly have a hp issue at the motor, if the motor does not stall then i woild be looking at the hydraulic pump, relief valve, and cylinders. Also if you do replace the hydraulic pump you can use a 2 stage pump, hi gpm at low pressure, hi pressure low gpm at high pressure.
Kevin

[dulle1999]

That's what i was wondering if he wasn't getting the rpms high enough with the converter. With a converter you typically lose 1/3 the rated horse, might be lugging and not able to build the correct pressure. Is a used VFD an option. You can buy one that is single phase input and puts out 3 phase. I will keep thinking on this one.

[Dobermann]

First of all, I doubt that a VFD is a solution for this problem. I've never seen a 20 HP capacity VFD that can run from a single phase input. Just sayin'

But I think we need to back up. What size is the single phase wire running to power the RPC? And how long is the run? What is the single phase input voltage at the converter when you're trying for maximum pump pressure? Yeah, I know, it's tough to run those sorts of measurements without 6 hands and 4 feet.

This problems sounds more like a power supply issue than a bad pump or bad machine. Running a 20 HP 3 phase machine off a single phase line is very difficult due to the inefficiencies of the 3 phase converter PLUS the problems with power factor on motors that large run off single phase current. (Power factor is part of the efficiency equation. The motors represent a large inductive load and as such, current is not in phase with voltage so for a given POWER level, the current input will be higher than you'd figure from just horsepower and voltage.)

Your "high end" electrician should be able to figure this out for you!

[Synchroman]

First of all, I doubt that a VFD is a solution for this problem. I've never seen a 20 HP capacity VFD that can run from a single phase input. Just sayin'

But I think we need to back up. What size is the single phase wire running to power the RPC? And how long is the run? What is the single phase input voltage at the converter when you're trying for maximum pump pressure? Yeah, I know, it's tough to run those sorts of measurements without 6 hands and 4 feet.

This problems sounds more like a power supply issue than a bad pump or bad machine. Running a 20 HP 3 phase machine off a single phase line is very difficult due to the inefficiencies of the 3 phase converter PLUS the problems with power factor on motors that large run off single phase current. (Power factor is part of the efficiency equation. The motors represent a large inductive load and as such, current is not in phase with voltage so for a given POWER level, the current input will be higher than you'd figure from just horsepower and voltage.)

Your "high end" electrician should be able to figure this out for you!

I agree that it's a power issue. Those two motors will put over 120 amps together with an even larger starting load. He would need a dedicated 200 amp line to make the combination work properly. Sounds like big $$$$$.

[Tryagn5]

gpm psi....

I agree that it's a power issue. Those two motors will put over 120 amps together with an even larger starting load. He would need a dedicated 200 amp line to make the combination work properly. Sounds like big $$$$$.

I would really like to know the gpm and pressure required to run this shear, then it would be easy to calculate the hp and power needed to acheive it. In a previous post i commented on my reasons for not buying a press brake...power...i could not find the ability to power it.

[dulle1999]

What I was getting at was he needs 20 horse to power the 19 gpm pump. With the converter, he has roughly 13 horse, not enough. He will either have to downsize the pump, which will slow the shear considerably, upsize the motor, which will probably require a different converter, or get true 3 phase, which I was hoping they made a VFD that size.

[Tryagn5]

What I was getting at was he needs 20 horse to power the 19 gpm pump. With the converter, he has roughly 13 horse, not enough. He will either have to downsize the pump, which will slow the shear considerably, upsize the motor, which will probably require a different converter, or get true 3 phase, which I was hoping they made a VFD that size.

Depending on the amount of use i would be looking into a aux hyd power unit to run the shear. I know when i was quoted 3 phase power it was 50k to get it. 25hp gas motor and pump is a lot cheaper....if its not going to run all day.
Kevin

[snowbird]

From a guy that doesn't know much... not enough HP for psi/gpm .

I have seen on production log spliters with small hp motors the use of a flywheel.

Does that pump can be belt driven at a lower rpm and produce the required pressure?

Just my .02

good luck.

edit: not knowing for how long the high pressure and high gpm are to be maintained, my suggestion might be worthless.

[Portable Welder]

To answer some questions: Yes the motor is stalling at the point where I make the 2000 psi and it wont go anymore.

Im told the pump is a 16 GPM pump and the manufacturer of the pump said they can modify my pump down to 11 gpm for about $ 550.00 .

The meter I used to check amp draw is new to me and is the first time I have used it, with that being said, the meter showed a spiked amp draw on all 3 legs of about 67 amps as the motor would stall.
( There is a chance that maybe I didn't have the meter set correctly )

The phase converter generator from Baldor appears to have been specifically made for a phase converter application ( There is not a shaft sticking out the end ).

So at this point I'm waiting for the electrician.

Someone also asked about wire size. I had a electrician wire this ( Not the technical electrician that I am currently waiting for) We followed the recommended wire size from American Rotary. My 200 amp service feeding the shop required 140' cable from the transformer on the pole to the shop. ( That is also figuring the cable going out of the ground and up the pole and out of the ground into the panel.
The shear and phase converter are not more than 12' from the main electrical panel in the shop, The actual wire length is probably 30' at the most.

[Tryagn5]

pump...

To answer some questions: Yes the motor is stalling at the point where I make the 2000 psi and it wont go anymore.

Im told the pump is a 16 GPM pump and the manufacturer of the pump said they can modify my pump down to 11 gpm for about $ 550.00 .

The meter I used to check amp draw is new to me and is the first time I have used it, with that being said, the meter showed a spiked amp draw on all 3 legs of about 67 amps as the motor would stall.
( There is a chance that maybe I didn't have the meter set correctly )

The phase converter generator from Baldor appears to have been specifically made for a phase converter application ( There is not a shaft sticking out the end ).

So at this point I'm waiting for the electrician.

Someone also asked about wire size. I had a electrician wire this ( Not the technical electrician that I am currently waiting for) We followed the recommended wire size from American Rotary. My 200 amp service feeding the shop required 140' cable from the transformer on the pole to the shop. ( That is also figuring the cable going out of the ground and up the pole and out of the ground into the panel.
The shear and phase converter are not more than 12' from the main electrical panel in the shop, The actual wire length is probably 30' at the most.

I would be very interested in what the pump manufactor is going to do to that pump. When we are talking pump are we talking the entire power assembly? Ie pump and electrical motor assembly....depending on the design of the pump it willbe very difficult to change, but very easy to resize the pump. I would look into a 2 stage design pump, it will give you high cycle speed and pressure when needed.
Kevin

[Portable Welder]

Tryagn5, No its just the pump ( Some type of ring they said ) I'm not sure if a vane pump can be set up dual stage.

Thanks for the mention of the 2 stage pump, if I find that the 11 gpm pump is too slow then I will look into a gear pump verses the vane pump.

[Country Metals]

Can you shear a full length piece of 3/16", 1/8"?
This will determine that your problem is the pump/electric as the machine works fine. This will also see if there is stuttering in the cylinders from a partial blockage or possibly a partially broken pump.

Since the motor stalls or fails to produce, and you don't have reliable electric source. Rent a generator for a day. Yes that's more money, but it will completely isolate the pump and for sure guarantee the electric is the problem.

Also, did you check to see if that is the correct motor for the machine? Used equipment might not have the original components.

[Tryagn5]

Tryagn5, No its just the pump ( Some type of ring they said ) I'm not sure if a vane pump can be set up dual stage.

Thanks for the mention of the 2 stage pump, if I find that the 11 gpm pump is too slow then I will look into a gear pump verses the vane pump.

Going to be difficult to go from a vane pump to gear pump.. normally different valve...ie closed center to open center. However vane pumps are easy to change displacement on.
kevin

[Portable Welder]

Country metals, I am positive that its the right motor, When looking at new ones from the manufacturer as well as used ones they both call out for a 20 hp motor.
I'm going to wait for my electrician to check and validate as to whether the phase converter is putting out proper power.

Today we were shearing 1-1/2" #6 expanded metal, tomorrow I will be shearing full sheets of 10 ga. that are 10' which is full length, I don't anticipate any problems with the 10 ga., however the shear did not like 3/16" diamond plate x 6' across.