3020 X axis motor overtemperature.
Sheet 4 plug 2 pin-F

This error is detected through a loss of 24 volts on wire number 407 to the control

a) Check for 24 volts at terminals 400 and 407 with a voltmeter (TB1 in the power distribution panel). If there is no 24 volts, indicator-fuse 4 in the PDP may be faulty. 

b) If there is 24 volts at terminal 400 but not at terminal 407 then the error is true, or the thermistor switch in the X axis motor is faulty; go to paragraph (f).

c) If there is 24 volts at both 400 and 407 then the fault lies from terminal 407 through to Plug 2, Pin-F and the 'Digital Input Board' in the control. 

d) Switch-off the control and transpose the 'DI' boards situated in the lower rack to the left. Power-up the machine. If the fault disappears, or a different, unrelated error code shows-up, then the 'DI' board is faulty and a replacement is required. 

e) If the same error code persists switch-off the machine, remove plug 2 and check the continuity from pin-F to terminal 407. There may be a spare wire in the cable loom to utilize if wire 407 appears to be broken. If the wiring is O.K. the fault may be with the 'Watchdog' board (WD 50x) in the control or corruption of the memory. If another control is available the 'Watchdog' boards can be exchanged to test. If the memory is to be reloaded remember to punch-out programme and tool information first (although an up to date back-up tape should always be held).

f) Remove the slideway covers to gain access to the X axis motor. If the motor feels cool disconnect terminals 400 and 407 in the motor junction box and check the resistance across the two wires to the thermistor. If the resistance is high the thermistor switch is faulty and should be replaced.

g) If the motor is hot, disconnect wires A1 and A2 to the motor. With a multimeter or 'Megger' check the resistance from one of the motor wires to Earth. The reading should be in Mega-ohms for a good motor. If the reading is low (10K ohms or less) it indicates a build-up of carbon around the brush-gear, damaged brush-holders, a faulty commutator or windings. The same check can be made with the motor brushes removed. If the reading is then considerably higher than with the brushes fitted (Mega-ohms), then the commutator or windings are faulty and the motor needs repair or replacement.

h) If the motor has been removed for repair it will be necessary to check and adjust the axis reference position. Remember to datum all the axes before running a programme.