53
General Description:
The six (6) channels accept independent RTD (Resistive Temperature Device) inputs (spare channels have a 100
ohm [100
Ω
] 5% tolerance resistors installed) and there is an individual set point for each channel. In operation,
the scan rate between channels is four (4) to six (6) seconds, and the display will have the temperature measured
by the individual RTD’s. A “
red
” L.E.D. indicates an alarm condition; in the event of an alarm, scanning is halted
and the “ALARM” relay de-energizes until the manual reset button is depressed.
IMPORTANT
: If a hi-limit alarm occurs, check that a hi-temperature has not occurred. If no, correct
the condition and test.
IMPORTANT
:
DO NOT
TROUBLESHOOT THE SHLC (Sprinkler High Limit Controller)
UNLESS THE WATER VALVE TO THE SPRINKLER IS CLOSED.
SHLC will cause:
•
The sprinkler water valve to open.
•
The entire dryer to power down.
•
The “SPRINKLER RESET” button on the main panel to light.
• With the dryer control voltage “ON,” not executing a drying cycle, one
should be
able to adjust the
temperature settings on any of the hi-limit controllers and cause their respective “
GREEN
” L.E.D.’s (light
emitting diodes) to cycle “ON” and “OFF.”
• If their corresponding L.E.D.’s (light emitting diodes)
do not
cycle, check their respective:
• temperature sensors (RTD’s [Resistive Temperature Device])
• power connections
• electrical circuits (refer to the ADS-464 main electrical wiring diagram)
• If the previous items are “OK,” replace the hi-limit controller.
6. “HI-TEMP FAULT” Message
PLC MESSAGE “HI-TEMP FAULT”
a.
PROBABLE CAUSES;
1. Airflow
2. Hi-limit temperature controllers (channel 1 and channel 2)
3. RTD 1 and 2
4. Fuse 10
b.
POSSIBLE SOLUTIONS;
1. For airflow problems refer to
D. External Supply Connections - 4. exhaust air ducting
.
2. An illuminated red indicator on the HI-LIMIT TEMP CONTROLLER indicates that the hi-limit
control relay is in “ALARM” and in internal relay is “OPEN.”
