Megger SR-98, Instruction Manual

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a. See Alarm Descriptions.
b. If no current through the Resistor Bank, check resistor using an
Ohmmeter.
c. Check test leads for broken conductors.
3. Removal of Chassis from Enclosure:
To remove the chassis,
a. Disconnect the power cord from the unit.
b. Carefully remove the four- (4) screws located on the front panel, two
on each side.
c. Turn the unit on to back side, and slide the unit from the enclosure.
Digital Display /Timer Section
Basic troubleshooting is as follows:
1. No display when the SR-98 is energized:
Power supply failure, defective display IC's, defective components on
printed circuit board, loose cable connection between power supply and
printed circuit board. See “No Power” above for corrective action.
2. Weak or defective display:
Contrast needs to be adjusted, see Power Up screen to adjust. Poor
supply voltage, defective display, or defective components on display
board. See ‘No Power’ above for corrective action.
3. Timer will not Start or Stop counting. Check the Start/Stop modes for
proper selection. Check that the Timer Latches are properly set. If the
Timer will not stop when using the
CURR X
(Current Actuate) mode,
check to make sure the Timer Start Latch is OFF. If the Timer will not
Start when Initiating the output, check to make sure the Timer Start is set
to the
INIT
(Initiate) position.
4. Counting errors:
AC applied or removed Start/Stop signals can create, what appears to be
poor repeatability, an inaccuracy or a malfunction in the Timer. The lower
the voltage level, the more serious the "error" will be. What appears to be
an error, however, is actually a variation in the point on the sine wave at
which the voltage is great enough to cause the gate circuit to operate. If
the circuit used for the timing test has a low AC voltage, and the point at
which the contact in the test circuit opens or closes, is at or close to zero
on the sine wave, the period of time before the voltage level will be high
enough to trigger the gate circuit can be as much as 4 milliseconds. The
total timing variation can be as much as 8 milliseconds. The shorter the
duration of the timing test, the more significant the variation becomes.
Therefore, if small timing variations would present a problem, it is
recommended that an AC voltage of 115 volts or above or a DC voltage
be used for voltage applied/removed test selections.