Rockwell Automation FlexPak Plus NRG DC Drive - Manual (Page 23)

22
TABLE 5.A - TROUBLESHOOTING SUGGESTIONS FOR THE COMPLETE CONTROLLER (Continued)
Symptom Probable Cause Recommended Procedures
8. Drive motor does
not run with M
contactor picked
up. Potentiometer
properly operatĆ
ing.
Continue this
symptom on next
page.
No output from Power
Cubes, 45Ć47.
V Examine armature wiring. First, open the power disconnect switch.
V Check armature wiring for loose connections.
V Turn aĆc power on again.
V Connect a voltĆohmmeter to terminals 47 and 45 on TB.
V Place the START/STOP switch in the START position.
V Increase the speed reference by turning the SPEED dial in the direction of 10.
V The reading across 47 and 45, it may be 0 to 240 VDC for 230 VAC controllers. It
should be 0 to 500 for 460 VAC controllers,
V If no reading is obtained across 47 and 45, it may be necessary to replace the Power
Cubes and/or the Regulator Module, digital driver module. In order to determine
which, read on.
Regulator module
suspected because
no output reading at
45Ć47.
V Test the regulator module for output to digital driver module (PREF).
V Turn power off! Open main disconnect.
V Connect a VOM, careful not to short pins together to terminals 280 (PREF) & 57 (OV)
on the regulator module.
V Restore power to controller.
V Place the start/stop switch in start position.
V Turn the speed pot to full on position.
V Voltage on VOM should be +5 volts.
V If this reading cannot be obtained replace regulator module.
Digital driver module
suspected because
no output reading at
45Ć47.
V Test the digital driver for firing pulses. (Note: Make sure above test on regulator
module has been completed first.)
V Turn power off. Open main disconnect.
V Loosen regulator/digital drive module assembly (four screws in each corner. So that
access to digital driver module on back side of assembly is possible. (Refer to Figure
5,7.)
V Connect scope common to Pin 57 on regulator module.
V Connect scope probe to resistor on primary side of pulse transformer located at 7A or
Digital Driver Board (Refer to Figure 5.4.)
V Restore power to controller.
V Place the start/stop switch in start position.
V Turn SPEED POT to full on position.
V A firing pulse waveform (+11.2V) should be seen at this point. If pulse is measured
continue this test from beginning but connect scope across the following resistors to
look at other five firing pulses. (14A,10A,11A,13A, 8A).
V If these readings cannot be obtained, replace digital drive module.
Power cubes susĆ
pected because no
output reading at
45Ć47.
V Establish that power cube is receiving pulse inputs from digital drive module. (Refer to
above previous test.)
V If power cubes are receiving pulses, yet no reading across 45Ć47, determine that the
contacts on M are closing.
V Replace drive motor wiring with light bulbs (2 light bulbs for 240 volt, 4 light bulbs for
500 volt armatures, series connection.)
V Run drive and look at waveform across light bulbs. (Should be six pulse/16.7 MSEC)
If pulse is missing indicates bad power cube.
V Check individual power cubes.
V Connect scope across 51 & 47 on terminal strip look to see if SCR is switching if not
replace power cube.
V Repeat for 51 & 45, 52 & 47, 52 & 45, 53 8 47 & 53 & 45 if necessary.
9. Remote Operator
Control Station
functions not opĆ
erating.
Malfunctioning
switches.
V Check START/STOP switch, but first remove aĆc line power at main disconnect.
V Connect ohmmeter to terminal 32 on the Remote Operator Adapter.
V Touch probe to terminal 38 on the Remote Operator Adapter,
V Place switch in the START (closed) position.
V If the switch is properly functioning, a short will be seen on the meter.
V Check the STOP function. Place the RUN/JOG switch in the RUN position. Connect
the ohmmeter to terminals 32 and 35. Place the switch in the STOP position, which
should open it if it is functioning correctly. If there is a short, it will be seen on the
meter. If there is no short, the circuit is opened, and the switch is functioning correctly.
V Using similar techniques, test the RUN/JOG switch in the RUN position at terminals 32
and 35. When the switch is in the RUNposition. a short should be read.
DANGER
THE PROCEDURE DESCRIBED HERE IS PERFORMED WITH
LIVE AĆC VOLTAGE APPLIED TO THE CONTROLLER. USE ONLY
ONE HAND TO APPLY VOM LEADS/PROBES. KEEP YOUR
OTHER HAND BEHIND YOU AT ALL TIMES. DO NOT HOLD ONTO
THE CONTROLLER FOR SUPPORT. PERSONAL INJURY MAY
RESULT IF THESE PRECAUTIONS ARE NOT TAKEN.