Help troubleshoot wiring issue on Harig 618 surface grinder

Hey guys.

So I wired up a North America RPC and ran it to my machine, and the machine powers on fine and wheel/spindle seems to operate fine. But my oil sump pump at the base of the column isn't pumping oil onto the ways and lead screws so I'm trying to diagnose what the issue could be.



First thing I did was check the voltage on the supplying plug w/ the machine turned on, I am getting 140v on one of the legs. The other one seems dead. I was assuming that this was a 115v pump but after pulling off the cover I found it's supposed to be 220v so this is probably the issue.




I started tracing the power from the original 3 phase input power. Here is the board and wiring schematic:







What I traced the issue to seems to be the transformer (T-1) directly after the input power fuses. H1 and H2 are the input power and I'm getting about 245v between both of them total. When I check the output power side X3 and X1 I'm only getting 140v between them. What is weird is when I check the individual terminals on X3 or X1 and put the other lead on the ground it's only measuring about 7-8v each. So I don't understand how individucally it can be 7-8v but together it can be 140v - go figure. Maybe it's my power meter?

Anyway, do you think the transformer is the issue?

I'm a bit lost. I don't see X3 on T1 transformer (on the diagram). Do you mean X1 and X2?

X2 is grounded through a fuse, so it should be 0 volts between X2 and the ground, and the equal voltage (120V?) between X1 and either ground or X2.

Is the SPINDLE light on? When it's on, the MTR-5 (lube) motor should be on too (and if either of them is ON, it means the T-2 and 4,5 and 7 fuses are OK.

MTR-5 is fed off the secondary coil of T-1. So if the secondary produces 120V, that what the motor is designed for. The SPINDLE bulb should be rated for the same voltage. So if the bulb is 120V and the motor is 220V, I'd suspect that the motor was added later and should be wired differently.

Is the POWER ON light on when you turn on the machine? If so, the T1 transformer and its two fuses are fine, and you can check the voltage rating on this bulb. Again, if it's not 220V, the 220V lube pump shown on the photo is not original and should be replaced or rewired.

MichaelP said:

I'm a bit lost. I don't see X3 on T1 transformer (on the diagram). Do you mean X1 and X2?

X2 is grounded through a fuse, so it should be 0 volts between X2 and the ground, and the equal voltage (120V?) between X1 and either ground or X2.

Is the SPINDLE light on? When it's on, the MTR-5 (lube) motor should be on too (and if either of them is ON, it means the T-2 and 4,5 and 7 fuses are OK.

MTR-5 is fed off the secondary coil of T-1. So if the secondary produces 120V, that what the motor is designed for. The SPINDLE bulb should be rated for the same voltage. So if the bulb is 120V and the motor is 220V, I'd suspect that the motor was added later and should be wired differently.

Is the POWER ON light on when you turn on the machine? If so, the T1 transformer and its two fuses are fine, and you can check the voltage rating on this bulb. Again, if it's not 220V, the 220V lube pump shown on the photo is not original and should be replaced or rewired.

Click to expand...

Sorry if I was confusing... here's a zoomed in shot of the transformer plate. It has an X3 terminal that one of the wires was connected to which is what I originally checked. just a bit ago I moved that wire to X2 based upon the diagram so now I'm getting about 115v between the two (X2 and X1) which is more reasonable.

Thanks for the input on X2, I didn't know how to read the diagram fully. But it's weird because my meter is not picking up X1 individually when I check that with the regular ground that goes back to the breaker panel.

Anyway,when I turn on the spindle the spindle kicks on and seems to run fine, not sure about the light I'll have to check I didn't know it had to be rated at 220v. But yeah, the issue is that when I turn on the spindle and check the input power to the lube pump I'm just getting one of the lines being hot (115v), so the motor won't run since it's 220v.

I guess what I don't understand is the need for the T-1 transformer if the lube pumps is 220v then what is the point of running the 2 lines (H1 and H2 which come directly from L1 and L2) when they should just connect to the lube pump with each leg being 115v or so - so I'm wondering if it's like you say and was replaced at some point.

let me go check the bulbs...

Ok just checked and the spindle on light comes on, but the main power light does not. It looks like it's 120v from what I can read on it.

There's only 2 terminals that are connected to a wire, and the numbers are 16 and 10. I did a continuity check with the machine off (between both terminals) and its connected.... Not sure if I should pull it out and physically check?

If the SPINDLE bulb comes on and is 115V, it means the same 115V get connected to the lube motor (if everything is connected as on the diagram, of course). You can easily trace if the pump is connected as on the diagram. Or simply check if you have 115V on the pump motor contacts when the SPINDLE light is on.

With all probability, the lube pump was rewired (connected differently, not as on the diagram) UNLESS they just shove the 220V pump in place of a 120V, and it never worked.

As for the POWER light, the bulb must be burnt (or wiring/connections are defective).