29
SECTION NINE — SERVICESECTION NINE — SERVICE
SECTION NINE — SERVICESECTION NINE — SERVICE
SECTION NINE — SERVICE
INFORMAINFORMA
INFORMAINFORMA
INFORMA
TIONTION
TIONTION
TION
9.19.1
9.19.1
9.1
INTRODUCTIONINTRODUCTION
INTRODUCTIONINTRODUCTION
INTRODUCTION
This section of the manual is intended for those who
wish to perform their own troubleshooting and repair.
Persons attempting to perform the drive service de-
scribed in this section should have a strong background
in power electronics, experience in using test equip-
ment, and a good understanding of analog and digital
control circuitry. Graham Company offers service
schools to show you how to troubleshoot and repair this
drive. Contract the Graham Service Department for
service assistance.
9.29.2
9.29.2
9.2
DESCRIPTION OF OPERATIONDESCRIPTION OF OPERATION
DESCRIPTION OF OPERATIONDESCRIPTION OF OPERATION
DESCRIPTION OF OPERATION
The drive consists of two main sections, the power
section and the control section.
The first part of the power section is the input SCR
bridge. It converts the incoming three phase AC to a
regulated DC voltage.
The second part of the power section is the conduction/
commutation switching circuit. This circuit directs the
regulated DC to the inverter.
The third part of the power section is the inverter. The
inverter directs the regulated DC to the correct phases
of the motor for the proper time period.
The control board contains the circuitry required to
interface the power section with the low voltage control
chip board. It also provides the interface between the
customer inputs and the control chip board. The control
board is the large square printed circuit board located
under the clear plexiglass cover.
The control chip board contains the control logic cir-
cuitry, customer selection switches, customer and fac-
tory adjustment potentiometers and LED indicators.
9.39.3
9.39.3
9.3
TROUBLESHOOTINGTROUBLESHOOTING
TROUBLESHOOTINGTROUBLESHOOTING
TROUBLESHOOTING
The procedures outlined here are intended to assist in
locating and correcting a problem in a standard drive.
Power circuit measurements should only be made by
qualified technicians.
DANGER
!
EYE PROTECTION IS REQUIREDEYE PROTECTION IS REQUIRED
EYE PROTECTION IS REQUIREDEYE PROTECTION IS REQUIRED
EYE PROTECTION IS REQUIRED
ANY TIME THAT THE ENCLOSUREANY TIME THAT THE ENCLOSURE
ANY TIME THAT THE ENCLOSUREANY TIME THAT THE ENCLOSURE
ANY TIME THAT THE ENCLOSURE
IS OPEN.IS OPEN.
IS OPEN.IS OPEN.
IS OPEN.
EXTREME CAUTION MUST BE USEDEXTREME CAUTION MUST BE USED
EXTREME CAUTION MUST BE USEDEXTREME CAUTION MUST BE USED
EXTREME CAUTION MUST BE USED
WHENEVER POWER IS APPLIEDWHENEVER POWER IS APPLIED
WHENEVER POWER IS APPLIEDWHENEVER POWER IS APPLIED
WHENEVER POWER IS APPLIED
AND THE ENCLOSURE IS OPEN.AND THE ENCLOSURE IS OPEN.
AND THE ENCLOSURE IS OPEN.AND THE ENCLOSURE IS OPEN.
AND THE ENCLOSURE IS OPEN.
ANYONE WORKING ON THE DRIVEANYONE WORKING ON THE DRIVE
ANYONE WORKING ON THE DRIVEANYONE WORKING ON THE DRIVE
ANYONE WORKING ON THE DRIVE
WILL BE EXPOSED TO HIGH VOLT-WILL BE EXPOSED TO HIGH VOLT-
WILL BE EXPOSED TO HIGH VOLT-WILL BE EXPOSED TO HIGH VOLT-
WILL BE EXPOSED TO HIGH VOLT-
AGE. ALWAYS REMOVE POWERAGE. ALWAYS REMOVE POWER
AGE. ALWAYS REMOVE POWERAGE. ALWAYS REMOVE POWER
AGE. ALWAYS REMOVE POWER
WHEN SERVICING THE COMPO-WHEN SERVICING THE COMPO-
WHEN SERVICING THE COMPO-WHEN SERVICING THE COMPO-
WHEN SERVICING THE COMPO-
NENTS OF THE DRIVE. WAIT UN-NENTS OF THE DRIVE. WAIT UN-
NENTS OF THE DRIVE. WAIT UN-NENTS OF THE DRIVE. WAIT UN-
NENTS OF THE DRIVE. WAIT UN-
TIL THE “BUS POWER” AND “COM-TIL THE “BUS POWER” AND “COM-
TIL THE “BUS POWER” AND “COM-TIL THE “BUS POWER” AND “COM-
TIL THE “BUS POWER” AND “COM-
MUTATION POWER SUPPLY” LEDSMUTATION POWER SUPPLY” LEDS
MUTATION POWER SUPPLY” LEDSMUTATION POWER SUPPLY” LEDS
MUTATION POWER SUPPLY” LEDS
HAVE EXTINGUISHED.HAVE EXTINGUISHED.
HAVE EXTINGUISHED.HAVE EXTINGUISHED.
HAVE EXTINGUISHED.
THEN MEASURE FOR VOLTAGETHEN MEASURE FOR VOLTAGE
THEN MEASURE FOR VOLTAGETHEN MEASURE FOR VOLTAGE
THEN MEASURE FOR VOLTAGE
FROM J2-9 TO J5-20 ON THE CON-FROM J2-9 TO J5-20 ON THE CON-
FROM J2-9 TO J5-20 ON THE CON-FROM J2-9 TO J5-20 ON THE CON-
FROM J2-9 TO J5-20 ON THE CON-
TROL BOARD USING A VOLTME-TROL BOARD USING A VOLTME-
TROL BOARD USING A VOLTME-TROL BOARD USING A VOLTME-
TROL BOARD USING A VOLTME-
TER SET ON THE 100 V DC SCALE.TER SET ON THE 100 V DC SCALE.
TER SET ON THE 100 V DC SCALE.TER SET ON THE 100 V DC SCALE.
TER SET ON THE 100 V DC SCALE.
ALLOW THIS VOLTAGE TO DROPALLOW THIS VOLTAGE TO DROP
ALLOW THIS VOLTAGE TO DROPALLOW THIS VOLTAGE TO DROP
ALLOW THIS VOLTAGE TO DROP
TO ZERO BEFORE WORKING ONTO ZERO BEFORE WORKING ON
TO ZERO BEFORE WORKING ONTO ZERO BEFORE WORKING ON
TO ZERO BEFORE WORKING ON
THE DRIVE.THE DRIVE.
THE DRIVE.THE DRIVE.
THE DRIVE.
All power circuit voltages are floating at a very high
potential with respect to ground and require isolated or
floating test equipment. Control signal voltages are
referenced to ground through a 1,000 ohm resistor.
If a problem is isolated to a calibration setting, refer to
the internal adjustments section of this manual before
attempting any changes.
Some steps in these instructions use conditions set up
in previous steps. Therefore, any time power is inter-
rupted or controls are changed, care must be taken to
repeat the specified set-up.
It is recommended that a complete checkout of the
Main Control Board be made or a known good Main
Control Board be installed whenever problems recur or
components continue to fail. A log of all service should
be maintained. The following information should be
included.
1. Date and time of failure
2. Description of symptoms
3. Operating conditions
4. What component failed
5. Other conditions occurring at the same
time which may be related
6. Service performed
7. Who performed the service
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General