I'm checking out a M28KSR that looks like it has had some major rewiring done to it.

All the jumpers that are normally on terminals 4-14 of the cabinet terminal blocks have been removed.  There were two, 4 conductor, external cables connected to the cabinet terminal block, all unterminated, except for a 2k power resistor (loop current limiter) connected across  C10-C11.

I see no designator on the LESU and the color codes of the cable from the LESU to to c5 - c14 do not match the colors I see on 2874WD (or any others).  The LESU has what looks like a Line Shunt Relay, a 120VDC power supply (with monitor jack), a Motor-Stop relay and an 120VAC input panel ( lamp switch & fuses). See picture enclosed.

Can anyone identify this LESU?

I tried to remove the LESU by removing the big screws.  The LESU was loose, but would not come out, apparently because of the front panel power switch extension mechanism.  I expected it to disengage when I lifted up the LESU, but it did not.  Is there something in the switch extension mechanism that has to be removed/released?


Thanks,

Duncan
K2OEQ