Edgetech 2000 Series - Preliminary Checks and Fault Isolation

Symptoms
Corrective Action
Instrument is
completely inoperative
with no LEDs lit.
Check the 120/240 voh PC card for proper position for input AC voltage
being used If the fuse is good, check for line voltage across the AC
terminals.
Line voltage and fuses
are good, but still no
indication of
equipment operation.
Unplug the power cord and slide the clear plastic door to the left to check the
AC voltage select card and fuse. Check that the cables connecting to the
PWB are intact.
Replaced fuse blows
when power is turned
on again.
Check that the proper fuse is being used. The fuse value should have a
2-amp rating for 120 VAC operation and a l-amp rating for 240 VAC
operation. Both fuses should be rated 250V, 3 AG, Slo-Blo.
CONTROL indicator
is too far left or too far
right daring the time
the ABC indicator is
on steady.
This indication can occur if the Sensor is not plugged in, if the Sensor has
been changed, or if the Sensor mirror sur:W:e is very dirty.A dirty mirror
causes the CONTROL indicator to indicate more to the left. Adjustment of
BALANCE potentiometer RS2 can usually bring this indication back. to
center scale if a new Sensor has been attached. Cleaning a dirty Sensor mirror
has a similar effect.
Control indicator and
dew point temperature
output do not settle out
to a steady reading.
First check that the dew poiut sample flowing through the Sensor is under a
constant pressure and does not vuy, and that there are no plmnbing leaks. If
thes e inputs to the Seusor check out, then either the GAIN or
COMPENSATION control may be set too high, or the sample flow rate may
be too high.
Sluggish response to
changes in dew point.
TIDCKNESS setting may be too high or GAIN setting may be too low .
Dew point reading is
always too high.
THICKNESS setting is too low or GAIN settingis too low.
When operating at
high Sensor ambient
temperatures near
+IOOOC , the instrument
indicates ambient
temperature rather
than dew point
temperature.
If the Sensor base temperature has been allowed to exceed+ 1 OSOC, the
thermostat in the Sensor will open, preventing the mirror from cooling to the
dew point The mirror temperature will now rise to ambient. Reduce the
Sensor temperature to +800C or below to reset the Sensor thermostat
Model2000 Series DewPrime
Dew Point Hygrometers
----------Troubleshooting and Repair---------
Table 6-1. Troubleshootin g clw1: preliminary ehecks.
.
6-2