Bosch SM Split CS Series Installation, Operation And Maintenance Manual page 18

18 | Safety Devices and the UPM Controller
to R, the board must be manually powered off
and powered back on to exit the hard lock out.
•
BROWNOUT/SURGE/POWER
INTERRUPTION PROTECTION: The brownout
protection in the UPM board will shut down the
compressor if the incoming power falls below
18 VAC. The compressor will remain OFF until
the voltage is above 18 VAC and ANTI-SHORT
CYCLE TIMER (300 seconds) times out. The
unit will not go into a hard lockout.
• MALFUNCTION OUTPUT: Alarm output is
Normally Open (NO) dry contact. If pulse is
selected the alarm output will be pulsed. The
fault output will depend on the dip switch
setting for "ALARM." If it is set to "CONST," a
constant signal will be produced to indicate a
fault has occurred and the unit requires
inspection to determine the type of fault. If it is
set to "PULSE," a pulse signal is produced and
a fault code is detected by a remote device
indicating the fault. For blink code explanation,
see Table #15 on page #31. The remote device
must have a malfunction detection capability
when the UPM board is set to "PULSE."
If 24 VAC output is needed, R must be wired
to ALR-COM terminal; 24 VAC will be
available to the ALR-OUT terminal when the
unit is in the alarm condition.
• TEST DIP SWITCH: A test dip switch is
provided to reduce all time delays settings to
10 seconds during troubleshooting or
verification of unit operation.
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 30°F (sensor number 1);
however, this can be changed to 15°F by
cutting the R24 resistor located on top of the
DIP switch SW1. Since Freeze Sensor 2 is
dedicated to monitor the load side coil it is
recommended to leave the factory default
setting on the board. The UPM controller will
constantly monitor the refrigerant temperature
with the sensor mounted close to the
condensing water coil between the thermal
expansion valve and water coil. If temperature
8733825873 (2020/05)
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
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 Fig. 7. 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.
• INTELLIGENT RESET: If a fault condition is
initiated, the five-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. A single condensate overflow
fault will cause the unit to go into a hard
lockout immediately, and will require 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."
The blower motor will remain active during
a lockout condition.
Subject to change without prior notice
SM Split CS Series Heat Pump
SM Split CS Series Heat Pump