Ametek Thermox WDG Insitu, Руководство пользователя

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6-10 | Thermox Series 2000 WDG Insitu Analyzer
AC Power Checks
Loss/Inadequate AC Voltage
to the Sensor
Measure the AC voltage to the sensor board at terminals L1
and L2. Ensure that this voltage is sufficient. Check the mea -
surement technique used by the Volt meter (for example, RMS,
average, peak, etc.). Specifications are based on RMS mea -
surements.
Furnace Checks
Open Furnace
Disconnect power to the control unit and the sensor. With Ohm
meter, measure across Terminals “R” and “S” on the sensor
board. The resistance of the furnace should be:
32 ohms (±10%)
If the furnace resistance is not within allowable tolerances,
replace the furnace.
Loss of AC Power
to the Furnace
If the furnace drive signal is
not present:
Verify the correct line voltage at L1 and L2 of the sensor board.
With line voltage present, check the voltage at terminals R and
S on the sensor board. If voltage is present and the system is
not heating, remove power and check the furnace resistance
(see “Furnace Checks” section). If no voltage is present at ter-
minals R and S on the sensor board, check for the DC furnace
drive signal at terminals 3 (+) and 4 (-) at the sensor board.
The furnace drive is a 15 VDC pulse train, and depending on
the frequency of the pulse train, the measured voltage will be
between 5 and 15 VDC. If this furnace drive signal is present,
reset the power to the control unit and see if this solves the
problem. If this doesn’t solve the problem, replace the sensor
board.
Check the interconnecting wiring. If the interconnecting wiring is
correct, check across FURNACE and 15V COM on the control
unit wiring card for the furnace drive signal. If the signal is not
present, check fuse F1 on the wiring card. If this fuse is OK, re -
place the control unit power supply/keypad module. If this fuse
is not OK, replace the fuse (1/4 amp, 125 volts, IEC speed type
FF). Check the interconnecting wiring for short circuits before
applying power to the control unit.
Process Pressure Checks
To check that you entered the process pressure correctly, select Process Pressure from the
Setup key. Also ensure that the calibration process pressure equals normal operating process
pressure. Calibration should only be performed under these conditions for highest accuracy.
Cell Checks
If the cell fails when you first begin
to use the analyzer:
It is likely that there is a leak in the sensor plumbing
or an improper calibration gas setup, and there is not
a problem with the cell itself (see the “Leak Check”
section later in this chapter for help on how to check
for leaks; see the “Calibration/Aspirator Air Checks”
section earlier in this chapter for help on checking
your calibration gas setup).