Megger TTR310 - Troubleshooting

Service
AVTMTTR310 Rev 8 May 2016
115
Troubleshooting
The Troubleshooting Guide, Table 7-1, is arranged to help you evaluate the
reasons for TTR310 test set malfunction. The table lists possible test set
malfunctions which may be encountered during operation and lists possible
causes. Electronic circuit repairs should not be attempted in the field. Refer to
Repair section. Refer to Section 8 for a list of spare parts.
Table 7-1. Troubleshooting Guide
MALFUNCTION POSSIBLE CAUSE
Display stays blank after POWER switch is turned
on.
 No service power.
 Defective line cord.
 Defective fuse(s).
 CONTRAST potentiometer not adjusted.
 Defective display or electronics.
Error message:
ANALOG OFFSET VOLTAGE HIGH
and/or
ANALOG GAIN OUT OF TOLERANCE
appears after self-test is complete.
Out of tolerance condition(s) in measurement
circuit.
Red TEST VOLTAGE ON lamp does not light on
start of testing.
 Defective lamp.
 EMERGENCY TEST OFF switch is not
released.
 Problem in measuring circuit.
One of the following messages appear on the test
result screen.
 CHECK CONNECTIONS
 PHASE A (or B, or C) EXCITATION
CURRENT TOO HIGH;
 TURNS RATIO TOO LOW, <0.8; or
PHASE A (or B, or C) TURNS RATIO
TOO HIGH;
 CHECK PHASE A (or B, or C)
CONNECTIONS, REVERSED;
 CHECK PHASE A (or B, or C)
POLARITY
 Abnormal operating condition.
 Incorrect setting of TRANSFORMER TYPE in
the quick test setup or the full test setup 1
menus.
 Incorrect connection of leads.
 Defective test leads.
 Incorrect marking of a transformer.
 Problem in test specimen.
 Problem in measuring circuit.
RATIO and/or Iexc (mA) readings erratic.
 Defective test leads (open circuit, poor
connection).
 Severe abnormal transient in service power.
 Problem in test specimen (poor connection).
 Problem in measuring circuit.
Cannot obtain printout when printer is connected.
 Printer power not turned on.
 Printer battery discharged.
 Problem in measuring circuitry.