Bard TCS22-***-003, Operation Manual

Page: 30 / 95

2100-444-003A
Page 24
Door Alarm
If Input #9,Door Alarm, is open for more than three minutes indicating an open door, a medium
priority alarm is logged in the Event list and Output 12, Shelter Alarm, is energized. The door
must be opened continuously for more than three minutes for the alarm to be logged. This is a
self clearing alarm.
4.2.6 DEHUMIDIFICATION SEQUENCE
Dehumidification Setpoint is compared to Space Humidity. If Space Humidity is above
Dehumidification Setpoint , Stage 1 cooling is enabled. Compressor and Blower of the Unit are
energized. During dehumidification Active Heating Setpoint and Active Cooling Setpoint are changed to
70
o and 72 o respectively and cannot be changed. This prevents coil freeze up during dehumidification.
If Space temperature is cooled below Active Heating Setpoint by the dehumidification, Stage 1
heating is enabled. Heater and Blower of the Unit are energized.
4.2.7 THERMAL SHOCK PROTECTION SEQUENCE
The thermal shock protection sequence protects equipment in the structure from being subjected
to rapid changes in temperature after a power outage. The thermal shock routine limits the rate of change
in the zone temperature to less than 15 degrees F per hour. This is accomplished by making incremental
changes to a temporary setpoint every 8 minutes until the desired setpoint is reached. If the room
temperature is more then 6 degrees above the setpoint the thermal shock routine is active.
4.2.8 MODEM SEQUENCE
The power to the modem will be cycled off for one minute every day at midnight.
4.2.9 POWER MANAGEMENT SEQUENCE
If Input #13, Power Sense, is closed indicating a utility power failure, a critical priority alarm is
logged in the Event list and Output 12, Shelter Alarm, is energized. All unit outputs are de-energized.
Two minutes after the alarm, Output #3, Power Transfer Switch, is energized. Three minutes after the
alarm, Lead Unit Blower and Lead Unit Economizer are energized continuously until Utility Power
Failure Alarm is cleared. The economizer modulates to maintain a 55 degree F entering air temperature.
This is a self clearing alarm.