Table of Contents
Advertisement
AC Power Checks
Furnace Checks
Verify the correct line voltage at
J4 Pins 1 and 4 of the backplane
board.
If voltage is present but system is
not heating:
If the furnace drive signal is not
present:
Cell Checks
If the cell fails when you first begin
to use the analyzer, it is probably
a leak in the inlet sample line or
an improper calibration gas setup,
and not a problem with the cell
itself.
Loss / Inadequate AC Voltage to the Sensor
Measure the AC voltage to the backplane board at J4 Pins 1
and 4. Ensure that this voltage is sufficient.
Check the measurement technique used by the volt meter (for
example, RMS, average, peak, etc.). Specifications are based
on RMS measurements.
Open Furnace
Disconnect power to the analyzer. With an Ohm meter, mea-
sure across TB1 Pins 1 and 2 (both labeled AC on connec-
tion) on the backplane board. The resistance of the furnace
should be 42.75 and 47.25 at room temperature. Add 5% if
the furnace is still hot.
If the furnace resistance is not within allowable tolerances, replace
the furnace.
Loss of AC Power to the Furnace
With line voltage present, check the voltage at terminal TB1
Pins 1 and 2 on the backplane board. (The voltage at termi-
nals TB1 Pins 1 and 2 will be either on or pulsating on and
off.)
Disconnect power and check the furnace resistance. If no
voltage is present at terminal TB1 Pins 1 and 2 on the back-
plane board, check for the DC furnace drive signal at the top
of resistor R4 and the anode side (side opposite the stripe) of
diode D1 on the backplane board.. The furnace drive is a 15
VDC pulse train and depending on the duty cycle of the pulse
train, the measured voltage will be between 4 and 15 VDC.
If this furnace signal is present and you have no voltage at terminal
TB1 Pins 1 and 2, replace the backplane board.
Replace the display module.
If your analyzer doesn't respond properly to the calibration
gas, then it may be a problem with the cell. Before replacing
the cell, put the analyzer through a primary calibration. If this
does not work, check the following:
•Are the gases at proper flow rate and pressure?
•Is there a leak or plugged plumbing in the inlet sample line?
•Is the cell is hot enough?
If this does not solve the problem, replace the cell and run another
primary calibration and a regular calibration after the primary
calibration.
Maintenance and Troubleshooting
|
6-7
Advertisement
Table of Contents
