TM 10-6665-297-13&P
3-3.1
WARNING CIRCUIT ADJUSTMENT (continued)
4.
Turn screw adjustment of WARN potentiometer (R26 for CD800/830 Systems; R48, labeled
W, for CD802/832 Systems) fully counter-clockwise until warning relay K1 energizes and
WARN light comes on (after two-second delay past trigger point).
5.
Push and hold down RESET button and turn WARN potentiometer slowly clockwise until
WARN light goes off. (Time delay circuit does not operate as light goes out and relay de-
energizes.)
6.
Turn screw adjustment of ZERO potentiometer R24 until WARN light goes on, signifying an
energized warning relay. Note per-cent L. E. L. indication at this point.
7.
Repeat steps 2 through 5 for fine adjustment of warning relay trigger point.
8.
Using ZERO control, rezero indicating meter after confirming that detector is sampling gas-
free air.
NOTE: If adjustments do not result in setting warning reponse level at the desired percent L. E. L.
meter reading, refer to TROUBLESHOOTING procedures in Section 4.
3-3.2
ALARM CIRCUIT ADJUSTMENT. Adjust alarm circuit to operate at the voltage level representing a
specified percent L. E.L. gas-air mixture as follows:
NOTE:
If FAIL light comes on during adjustment operations, wait 45 seconds after FAIL light
goes out so that time delay circuit will not interfere with continuing adjustments.
1.
To impress an alarm-level triggering signal on the alarm circuit, turn ZERO potentiometer
adjustment screw slowly clockwise until alarm relay K2 energizes and ALARM light goes on
(circuit card extender circuitry prevents operation of external alarm devices). A two-second
time delay occurs before light goes on and relay operates after trigger signal begins.
2.
If ALARM light goes on at a meter percent L. E. L. reading lower or higher than desired, turn
screw adjustment of ZERO potentio-meter to obtain a meter reading 2 or 3 percent below the
desired point.
3.
Press RESET button to de-energize alarm relay.
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