Need help on R2E3 Boss 81

[sharp-shooter]

I have finally got this thing powered up with a new phase converter and have yet to get it to run. I have 2 problems that may be related to one another, or not.
1. I cannot get a file to load into the memory from the Greyco box. It keeps giving me a COMM ERROR. I have checked the connections, and the parameters, baud rate , etc.. It should light up a "activity" light on the box as it loads, but it doesn't.
2. I can't get the spindle to turn. When I turn the cw direction switch and the spindle enable button, the brake goes off, the spindle turns aprx 1/2 revolution and then quits as the brake comes on. At this point the screen reverts backs to "enable drive axis". It almost seems like something is conflicting.
Any help would be much appreciated.

[machintek]

Item 2 is probably a phase converter going into saturation. It just cannot give the motor enough power.
Not familiar with the Greco box. Are you supposed to be using port A or B?

George

[sharp-shooter]

Could you elaborate on the phase converter going into saturation? It is a 5 hp Genco, the machine is only 2 hp. I have the legs balanced the best I can @ T1-T2=242, T1-T3=260, T2--T3=264 T1-grd=121, T2-grd=119, T3-grd=233.
I wouldn't think that there would be a load on the motor, but it is in the lowest speed setting.

The Greco box is a cnc minifile. Basically a 3-1/2" floppy drive connected to B port. I realize this is obsolete technology, and I rather load straight from a laptop, but what is required for successful file downloads from a laptop?

[machintek]

I have heard this many times. The instant load of the spindle motor trying to spool up kills the power coming out of a phase converter. It may work well on a standard machine but the electronics in a CNC cannot take the instantaneous drop.
That is why Bridgeport issued a service bulletin that machines attched to a phase converter would not be warranted.

George

[sharp-shooter]

Is there a way to test to see if this is ideed happening? Is there a fix?

[Newby2]

I recently quired a 1985 R2E3 for the cost of having it removed to my home. After installing a 6.5 kw Temco convertor and a new membrane panel, the machine works quite well. I have read the threads about convertors and the unbalanced voltages. Here in northern Michigan, most of the 3 phase that is available commercially has what is known as "the wild leg", "stinger phase", and others. This can be as high as 277 volts with the other two legs around 240 volts. I see that some are checking each leg of the convertor to ground (with a reading of around 120 volts). As I see on the wiring diagrams, all the 120V used by the periphals comes from a 240 to 120 transformer and not from a single leg of the 3 phase. Also the power for the servo drives and electronics comes from a transformer drawing from 2 legs of the 3 phase.
My question is should we be concerned about the L1,L2,L3 voltages to ground? I initially powered the machine up per the manufacturers installation manual which directs to pull certain fuses, then check voltages, install a fuse and check voltages, and so on in an orderly manner. Following this proceedure, I found all the voltages read were well within the parameters specified down to the +/-5V to the heart of the system. Any comments or suggestions will be appreciated
Steve

[sharp-shooter]

I've got the power balanced well, as it had to be 208 volts. The spindle motor contactor will not stay in, and when the spindle enable is pushed, the axis drives are kicked out. The spindle will start and run as long as the contactor is held in manually. It starts good, and does not bog down or labor upon starting, which would tell me the voltage and the phases are right.
When checked with a voltmeter, the contactor is getting 21.7 v. which I assume should be enough to hold it. It almost seems like a program error or something in the memory is missing.

[Newby2]

According to the Installation manual I have, the voltage to CR1 should read 24V +/- 10%. If you calculate this out, the minimum voltage would be 21.6V
Upon starting the spindle, the L1,2,3 voltages will drop with a resulting drop of the 24V to the electronics. Also, T5 has a resistor installed to further limit the voltage to CR1 to allow it to respond more rapidly. Since you are reading 21.7V, this is barely above the recommended. Is your incoming power sufficient enough to prevent this? The voltage drop may be caused simply by to small of wire guage for the run length. I have #10 wire running to the RPC and # 6 wire from the RPC to the machine.
Steve