Furnace Checks; Cell Checks - Ametek Dycor CG1100 Series User Manual

Furnace Checks

Furnace Checks
Verify the correct DC voltage at
TB3, Pins 1 and 2 of the analog
board.
If voltage is present but system is
not heating:
If furnace drive signal is not pres-
ent:

Cell Checks

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.
Open Furnace
Disconnect power to the analyzer. Disconnect plug TB6 and,
with an ohm meter, measure the resistance across TB6,
Pins 1 and 2 on the analog board. The resistance of the fur-
nace should be between 12 and 13 ohms at room tempera-
ture. Add 5% if the furnace is still hot.
If the furnace resistance is not within allowable tolerances, replace
the furnace.
Loss of DC Power to the Furnace
with Dc voltage present, check the voltage at terminals TB6
Pins 1 and 2 on the analog board. (The voltage at terminals
TB6, Pins 1 and 2 will be either on (+24 Volts) or pulsating
on and off.)
Disconnect power and check the furnace resistance. if no
voltage is present at terminals TB6, Pins 1 and 2 on the ana-
log board, check for the Dc furnace drive signal at terminals
P1, Pins 20 and 8 at the analog board. The furnace drive is
a +5 VDc pulse train and depending on the duty cycle of the
pulse train, the measured voltage will be between 3.5 and 5
VDc. If this furnace signal is present and you have no voltage at
terminals TB6, Pins 1 and 2, replace the analog board.
Replace the Mcu board.
If your analyzer doesn't respond properly to the calibration
gas, then it may be a problem with the cell. check the fol-
lowing:
•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 a regular
calibration.
Maintenance and Troubleshooting | 6-5