Delta RAS 33-893 - LVC question

[Don Buck]

Just picked up a Delta 33-893 3 phase 12" RAS with LVC starter from a local high school shop phase out. The school states the saw was working when taken out. There was no way to test the saw but I only have $100 invested. The model plate clearly states that it is a Delta 1991 vintage 33-893 (see attached) but the Delta web site doesn't show a manual or parts for this model but it looks nearly identical to the 2007 manual 33-890 thru 33-892 (with "old style" motor). I did find a manual on OWWM that was listed as a 33-893 and upon downloading it is a 1983 manual for a Rockwell 12" RAS (very similar). My saw has no Rockwell markings.

My question concerns the voltage for the saw. It (LVC) is set up for 200 volts. The motor plate (attached) only lists voltage for 200 volts and the Rockwell manual lists information on converting the LVC to higher voltage (switching 1 wire - see attachment). The newer Delta manual has no mention of converting the voltage but another Sawmill Creek contributor sent me a link for a 2004 Delta LVC manual (same conversion). The LVC unit on my saw is identical to the 2004 manual.

My questions
#1 : Assuming the motor is okay, should I expect the motor to work at 230v 3 phase if I corretly change the LVC from 200v to 230v? I have 3 phase via a 5 hp rotory converter.

#2: The LVC manual states that I may have to change the heater elements in the overload block. However, I would need to know the full load current at 230 volts to calculate the proper heater element. Is it likely that the change from 200v to 230v will require different heater elements? I can use a Delta chart to determine the proper heater if I could determine the full current load for 230v.

Any help or suggestions are greatly appreciated.

Don

[Chip Lindley]

No help Guys? Ok, I'll jump in!

Don, understand that the transformer in the LVC inputs the line voltage (thus the different voltage taps) and outputs 24v to the starter's contactor coil through the momentary pushbuttons. (thus LVC--Low Voltage control)

A 200v 3ph motor can only be run on 200v. A step-down transformer will have to be used to reduce 230v line voltage to 200v before it enters the motor. I am sure somebody here can steer you toward an affordable transformer to make that nice, but unusable RAS a keeper.

Otherwise, you will have to keep your eye out for a single-phase or 230v 3ph motor from a saw being parted out. I have read of using a 230v input VFD with a 200v motor, to vary it's cycles-per-second up to around 73, and give 200v output. I've only read--not done!

[Mike Heidrick]

Chip is right on. The LVC change only affects the LVC. Motor will have to support the voltage that is selected on the LVC. This is so you can use the same LVC on more than one motor option for the saw. You should be able to find a new motor on ebay. The 890 series motors are in more demand though than the larger Delta saw.

I thought the heaters and their part numbers were listed on the inside cover of the lvc (if you have that). Once you get a 230V motor you can size the heaters. Delta can give you any new sub part numbers you might need from changes in models.