MSA Chillgard RT Instruction Manual page 87

TROUBLE DESCRIPTION
Thermostat sensor Controls
failed optical bench
inside
temperature
Sensor temperature Checks for
range failed temperature
range of 45
to 90 °C
Humidity sensor failed Checks H 2 O 1. Return to MSA for service.
sensor output
Infrared source failed Checks the I 1. Return to MSA for service
of source
assembly
Photo synchro failed Checks the
chopper for
operation
PA IR sensor failed Checks the
sensor
microphone
for output
Memory protect Checks
checksum
External reset failed Checks the
external
reset button
Display failure Display
commu-
nications
Audio alarm failure Audio alarm
SOLUTION
1. Replacement of optical bench
requires MSA service
1. Replacement requires MSA service.
1. Return to MSA for service.
1. Return to MSA for service.
1. Return to MSA for service.
1. If not used, check for jumper between RST
minus and RST plus on J16.
2. If used, verify switch is wired normally closed.
1. Check RS485 connector on J15,
terminals 1 and 2.
2. Check for broken or cracked display.
3. Remove rear panel cover and check cables
between the display and the display board.
1. Check output terminals 6 and 7 on J17.
2. Check for faulty horn buzzer.
5-5