Bosch Greensource CDi TW Series Installation, Operation And Maintenance Manual page 21

Greensource CDi Series TW Model
NOTICE: Operation of unit in test mode can
lead to accelerated wear and premature
failure of components. The "TEST" switch
must be set back to "NO" after
troubleshooting/servicing.
• FREEZE SENSOR: The default setting for the
freeze limit trip is 26°F; however, this can be
changed to 15°F by cutting the R17 and R77
resistors located on top of the DIP switch SW1.
The UPM II controller will constantly monitor
the refrigerant temperature with the sensor
mounted close to the water coils between the
thermal expansion valve and water coil. If
temperature drops below or remains at the
freeze-limit trip for 30 seconds, the controller
will shut the compressor down and enter into
a soft-lockout condition. Both the status LED
and the Alarm contact will be active. The LED
will flash (3 times) the code associated with
this alarm condition. If this alarm occurs 2
times (or 4 if Dip switch is set to 4) within an
hour the UPM II controller will enter into a
hard-lockout condition. It will constantly
monitor the refrigerant temperature with the
sensor mounted close to the evaporator
between the thermal expansion valve and
evaporator coil as shown in Table 12. If
temperature drops below or remains at the
freeze limit trip for 30 seconds, the controller
will shut the compressor down and enter into
a soft-lockout condition. Both the status LED
and the Alarm contact will be active. The LED
will flash 6 times the code associated with this
alarm condition. If this alarm occurs 2 times (or
4 if Dip switch is set to 4) within an hour the
controller will enter into a hard-lockout
condition.
NOTICE: The freeze sensor will not guard
against the loss of water. A flow switch is
recommended to prevent unit from running
if water flow is lost or reduced.
Greensource CDi Series TW Model
Safety Devices and the UPM II Controller | 21
• INTELLIGENT RESET: If a fault condition is
initiated, the 5-minute delay on break time
period is initiated and the unit will restart after
these delays expire. 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 (depending 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.
• 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 shutting off unit power at the circuit
breaker when the "RESET" dip switch is set to
"R."
Subject to change without prior notice
8733954853 (2020/04)