Carrier AQUAZONE 50PSH, Installation, Start-Up And Service Instructions Manual

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During this period the fault LED will indicate the cause of the
fault. If the fault condition still exists or occurs 2 or 4 times (de -
pending on 2 or 4 setting for LOCKOUT DIP switch) before 60
minutes, the unit will go into a hard lockout and requires a manual
lockout reset. A single condensate overflow fault will cause the
unit to go into a hard lockout immediately, and will require a man -
ual lockout reset.
Lockout Reset
A hard lockout can be reset by turning the unit thermostat off and
then back on when the RESET DIP switch is set to "Y" or by shut -
ting off unit power at the circuit breaker when the RESET DIP
switch is set to "R".
Selectable Alarm Mode
The UPM board can be configured to have either a constant or
pulse signal. If constant (CONT) is selected the UPM will provide
a closed contact at the alarm output until the alarm is cleared. If
pulsed (PULSE) is selected the UPM will sequence the alarm con -
tact with the fault LED flashes.
Test Mode (TEST)
In test mode the ASC and Random Start time delays are reduced
(5 seconds and 10 seconds respectively), and serve no function to
the end user equipment. The alarm and display relays also pulse
for both soft and hard lockout conditions, and are both cleared
through a manual reset.
UPM Sequence of Operations
Figure 39 shows the UPM sequence of operations.
Freeze Protection Sensors
The control system employs 2 nominal 10,000 ohm thermistors
(FP1 and FP2) that are used for freeze protection. Be sure FP1 is
located in the discharge fluid and FP2 is located in the air dis -
charge. See Fig. 46.
Fig. 46 — FP1 and FP2 Thermistor Location
Suction
Compressor
Discharge
COAX
Expansion
Valve
FP2 FP1
Liquid
Line
Water In Water Out
Condensate
Overflow
(CO)
Air Coil
Freeze
Protection
Water Coil
Freeze
Protection
(°F)
(°F)
Air
Coil
Airflow Airflow
LEGEND
COAX — Coaxial Heat Exchanger
Airflow
Refrigerant Liquid Line Flow