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Bulletin 1335 22, 28 & 36 Amp Troubleshooting Guide
Bulletin 1335 22, 28 & 36 Amp
Troubleshooting Guide
Diagnostic LED Display
Power ON
-
Indicates input power is connected when illuminated
.
Overload Protection
-
When constantly illuminated, indicates an over current
condition exceeded (60) seconds
-
Momentarily illuminated whenever circuit is
activated
.
Under Voltage Protection
-
When illuminated, indicates that the Drive has tripped
OFF due to an input voltage that is less than 414 volts for a 460V Drive, 373 volts
for a 415V Drive, or 342 volts for a 380V Drive
.
Over Voltage Protection
-
When illuminated, indicates that the Drive has tripped
OFF due to the bus voltage exceeding 760V DC
.
A Phase Protection Trip
-
When illuminated, indicates either:

An Overload Condition Greater Than 180%

A Shorted A Phase Output Transistor

Section A of the Driver Board is Malfunctioning
B Phase Protection Trip
-
When illuminated, indicates either:

An Overload Condition Greater Than 180%

A Shorted B Phase Output Transistor

Section B of the Driver Board is Malfunctioning
C Phase Protection Trip
-
When illuminated, indicates either:

An Overload Condition Greater Than 180%

A Shorted C Phase Output Transistor

Section C of the Driver Board is Malfunctioning
Drive Over Temperature Protection Trip
-
When illuminated, indicates that the
heatsink temperature of the Drive has exceeded the maximum safe operating limit
.
Output Ground Fault Protection Trip Indication
-
When illuminated, indicates that the Drive circuitry has shorted to GROUND
.
DS1
-
Located on Bus Indicator Board A41
-
When illuminated, indicates that the bus
potential is in excess of 42V DC
.
Troubleshooting Procedures
IMPORTANT:
Drive Fault Trips
.
Before resetting any fault trip, refer to the following troubleshooting procedures to isolate and
correct the fault
. WARNING:
Hazardous voltage levels exist on some printed circuit boards and Drive components
.
If diagnostic LED(s) PROT
.
A,
PROT
.
B, or PROT
.
C are lit, hazardous voltages can be present at the output terminals even though the STOP push-
button has been depressed
.
If neon light DS1 on Bus Indicator Board A41 is lit, hazardous voltages are present in the
Drive cabinet
.
To guard against personal injury when boards or wires are being disconnected or reconnected, or fuses
are being replaced, always remove power to the Drive at the disconnect device, wait (60} seconds, and ensure that DS1
is not lit before servicing
.
CAUTION:
To Guard Against Equipment Damage When Troubleshooting the Drive, Before Pressing the START Push-button
Always Ensure: That the Speed Pot or speed reference is set to MINIMUM
.
That the AUTO/OFF/MAN Switch (if
present), is in the proper position
.
That the DRIVE/OFF/BYPASS Switch (if present), is in the proper position
.
That the
motor is uncoupled from its mechanical load
.
IMPORTANT:
ESD Precautions
.
ESD (Electrostatic Discharge) generated by static electricity can damage the CMOS devices on
various Drive boards
.
To guard against this type of damage, it is recommended that when circuit boards are
removed or installed the following precautions be observed
.

Wear a wrist type grounding strap that is grounded to the Drive chassis
.

DO NOT remove the new circuit board from its conductive wrapper unless a ground strap is worn
.

When removing any circuit board from the Drive, immediately place it in conductive packing material
.
Symptom 1:
Drive does not start
.
Amber POWER ON LED is not illuminated
.
DIAGNOSTIC PROCEDURE:
Check for possible loss of input line voltage by measuring line voltage between L1, L2 and L3
.
If any voltage is not present check the
AC line source for an open or missing phase
.
If voltage is present, measure voltage across input line fuses 1FU, 2FU, and 3FU
.
Measure voltage across input primary fuse 4FU at transformer 1T
.
A voltage reading across any of these fuses indicates an open
condition
.
Before replacing blown fuses complete STEPS 1
-
4
.
STEP 1
-
Remove input power to the Drive
.
Before proceeding, wait (60) seconds
.
The Bus Indicator neon light on Bus Indicator
Board A41 should not be lit
.
Use a DC voltmeter to verify that the DC bus is fully discharged
.
Start with the voltmeter on
its highest scale (x1000) and range downward to the lowest voltmeter scale
.
STEP 2
-
For 22 & 28 Amp Drives, with an ohmmeter set on the x1 scale, check Rectifier Assembly 1REC as follows:
OHMMETER
READING
+
LEAD
-
LEAD
GREEN (1REC
+
)
ORANGE (1REC
-
ACl)
Infinite
GREEN (1REC
+
)
GRAY (1REC
-
AC2)
Infinite
GREEN (1REC
+
)
YELLOW (1REC
-
AC3)
Infinite
ORANGE (1REC
-
AC1)
WHITE (1REC
-
)
Infinite
GRAY (1REC
-
AC2)
WHITE (1REC
-
)
Infinite
YELLOW (1REC
-
AC3)
WHITE (lREC
-
)
Infinite
If any of the above readings are not as shown, replace Rectifier Assembly 1REC
.
STEP 3
-
For 36 Amp Drives, with an ohmmeter set on the x1 scale, check Rectifier Assembly 1REC, 2REC, 3REC as follows:
OHMMETER
READING
+
LEAD
-
LEAD
BLACK (1REC
+
)
ORANGE (1REC
-
ACl)
Infinite
BLACK (1REC
+
)
YELLOW (2REC
-
AC2)
Infinite
BLACK (1REC
+
)
GREEN (3REC
-
AC3)
Infinite ORANGE (1REC
-
AC1)
WHITE (1REC
-
)
Infinite
YELLOW (2REC
-
AC2)
WHITE (1REC
-
)
Infinite
GREEN (3REC
-
AC3)
WHITE (1REC
-
)
Infinite
If any of the above readings are not as shown, replace Rectifier Assembly 1REC, 2REC, 3REC
.
IMPORTANT:
When replacing the Rectifier Assembly clean all surfaces
.
Apply a thin layer of thermal grease (Dow Corning 340)
to the back of the assembly
.
Torque mounting screws to 17
-
26 in
-
lbs max
.
STEP 4
-
With the ohmmeter set on the x100 scale, check Bus Capacitors 2C1, 3C1, 2C2, & 3C2 for a shorted condition as follows
.
Remove the capacitor support block and (
+
) POSITIVE bus bars
.
Connect the (
+
) POSITIVE lead of the ohmmeter to
the (
+
) POSITIVE terminal of the capacitor
.
Connect the (
-
) NEGATIVE lead of the ohmmeter to the (
-
) NEGATIVE
capacitor bus bar
.
The ohmmeter should immediately read low, then slowly increase to approximately 20k .
A sustained
low reading indicates a shorted capacitor that requires replacement
.
After completing STEPS 1
-
4, replace blown fuses and reapply input power
.
Symptom 2:
Drive does not start
.
Amber POWER ON LED is illuminated
.
No red fault LEDs are illuminated
.
DIAGNOSTIC PROCEDURE:
Check for line out condition at fuse 3FU by measuring the AC line voltage from L3 to either L1 or L2
.
If any voltage is not present,
check the AC line source for an open or missing phase
.
If voltage is present, measure voltage across 3FU
.
A voltage across 3FU
indicates that it is open and must be replaced
.
Before replacing 3FU, perform STEPS 1
-
4 in Symptom 1, then the following eleven
steps
.
STEP 1
-
Check precharge circuit fuse 5FU for an open condition
.
STEP 2
-
With input power to the Drive removed at the disconnect device, check that all jumpers on Modulator Logic Board A1 are
in their proper position, particularly the VCO/EXT
-
C jumper and the IFB/XFB jumper
.
STEP 3
-
With input power to the Drive removed at the disconnect device, check installed options, particularly those with
AUTO/MAN or AUTO/OFF/MANUAL selection (both local and remote)
.
Depending upon the options installed the
maximum speed pot adjustment R25 or the minimum speed pot adjustment R26 may be ineffective
.

If option N, N4 or G4 is installed, ensure that: The AUTO/MAN switch on the card is set to the MAN mode
.
A 1k ,
2W, linear taper speed pot has been properly connected to Terminal Block 1TB between terminals 14,15 & 16
.

If option T16, T17 or T18 is installed, check for continuity across the Motor Overload Relay contact circuit, terminals
10 & 11 at Terminal Block 1TB
.
STEP 4
-
Check for an open speed pot at Terminal Block 1TB
.
Measure the voltage at Terminal Block 1TB between terminals 14 &
16
.
There should be 3
.
2V DC
.
If voltage is 12V DC, the speed pot may be open or there may be an open wire between the
speed pot and terminals 14, 15 & 16
.
Check for an inoperative speed pot by turning the pot from 0 to 100%
.
The voltage
between terminals 15 & 16 should vary from 0 to 3
.
2V DC
.
Replace or correct as required
.
STEP 5
-
Check the voltage between terminals 9 & 11 at Terminal Block 1TB
.

If standard START/STOP configuration is used, there should be 90V AC between terminals 9 & 11
.
If not, the
START/STOP circuit is open
.
Check the START/STOP circuit connections to 1TB
.

If field installed 2
-
wire, 90V AC, RUN/STOP control is used, there should be 90V AC between terminals 9 & 11
.
If
not, the RUN/STOP circuit is open
.
Ensure that the circuit has been installed as specified
.
If field installed 2
-
wire, 120V AC, RUN/STOP control is used, there should be 120V AC between terminals 9 & 11
.
If not, the RUN/STOP circuit is open Ensure that the circuit has been installed as specified
.
STEP 6
-
Measure the output voltages in the secondary circuits of Transformer 1T
.
The following voltages should be present at
Power Supply Board A6
.
molex connector J602 between pins 4 & 1 14V AC
molex connector J602 between pins 2 & 1 14V AC
molex connector J602 between pins 5 & 6 15V AC
The following voltage should be present at terminal block 1TB
.
between terminals 1 & 11 90V AC
If any one voltage is absent, remove input power and check all connections to 1T
.
If all connections are correct, replace
Transformer 1T
.
ST