Hansen Technologies HSC4H-N10K Specifications, Applications, Service Instructions & Parts page 16

TROUBLESHOOTING GAS MONITORS
Symptom: No lights displayed on panel.
Cause:
1. Power failure. Check incoming line.
2. Tripped circuit breaker or blown fuse on electrical
supply.
3. Unit warming up. It takes 3-5 minutes after power
is switched on.
Symptom: Red light is on, but no alarm condition is
active. (i.e. No horn or no relay operation after 3 minutes).
Cause:
1. Check to be sure the horn has not been
deactivated by Key switch.
2. Possible wiring or sensor fault. Check wiring and
connections for continuity.
3. Check calibration for proper alarm levels.
A100g
JULY 2017
TROUBLESHOOTING GAS SENSORS
Symptom: Sensor green light is off.
Cause:
1. Possible wiring fault between controller and
sensor. Check power supply to Controller. Check
connections between the controller and the
sensor. Check wires are connected to the proper
number terminal.
2. Sensor possibly damaged. Check by installing
another sensor to confirm sensor fault.
Symptom: Output from sensor is 2mA (for 4-20mA
output). Output from sensor is 0 V or .5V (for 0-10, 0-5,
1-10, 1-5 output signals).
Cause:
1. Sensing element has failed or is disconnected
from printed circuit board. Check wiring and
sensor element for proper installation.
2. Electronics do not match replacement sensing
element (250 PPM only). Check electronic revision
identification label on the circuit board located
inside the enclosure. See Special Element
Replacement section on page 24.
Sensing Element Type
Semi-conductor sensor
Electrochemical sensor
above 250 PPM
Electrochemical sensor
for 250 PPM or below
Infrared sensor
Symptom: Zero fluctuations without the presence of
target gas.
Cause:
The sensitivity characteristics of the sensing element
can be altered by changes in atmospheric temperature
and humidity.
1. Following a change in temperature/humidity
allow 2-3 hours for the sensor to stabilize. Small
changes of +/-1% or less should be considered
normal and know further action is required.
16
Electronic Revision
Identification Label
1000-5501.1
1000-5503.1
1000-5504.1
1000-5508.1
TABLE 6