Safety Features - Bosch LV009 Installation And Maintenance Manual

LV Heat Pump Series
Safety features includes the following:
• High pressure switch located in the refrigerant
discharge line and wired across the HPC terminals
on the complete UPM board
• Low pressure switch located in the unit suction line
and wired across terminals LPC1 and LPC2 on the
complete UPM Board
• Complete UPM board dry contacts are normally
open (NO).
• Water side freeze protection sensor, mounted close
to condensing water coil, monitors refrigerant
temperature between condensing water coil and
thermal expansion valve. If temperature drops
below or remains at freeze limit trip for 30 seconds,
the controller will shut down the compressor and
enter a soft lockout condition. The default freeze
°
limit trip is 26 F, however this can be changed to
°
15 F by cutting the R30 or Freeze1 resistor located
on top of DIP switch SW1. For resistor location. If
unit is employing a fresh water system (no anti-
freeze protection), it is extremely important to have
the Freeze 1 R30 resistor set to 26
down the unit at the appropriate leaving water
temperature and protect heat pump from freezing if
a freeze sensor is included.
• Evaporator freeze sensor, mounted between the
thermal expansion device and the evaporator,
monitors refrigerant temperature between the
evaporator coil and thermal expansion valve. If
temperature drops below or remains at freeze limit
trip for 30 seconds, the controller will shutdown the
compressor and enter into a soft lockout condition.
The default freeze limit trip is 26
• The condensate overflow protection sensor is
located in the drain pan of the unit and connected to
the COND terminal on the complete UPM board.
Figure # 11 Water side Freeze Protection Sensor
NOTICE: If unit is employing a fresh water
system (no anti-freeze protection), it is
extremely important to have the Freeze1
R30 resistor set to 26
shutdown the unit at the appropriate
leaving-water temperature and protect your
heat pump from freezing if a freeze sensor is
included.
LV Heat Pump Series
°
F in order to shut
°
F See Figure # 10
°
F in order to
Figure # 12
The UPM Board includes the following features:
• ANTI-SHORT CYCLE TIMER: 5 minute delay on
break timer to prevent compressor short cycling.
• RANDOM START: Each controller has a unique
random start delay ranging from 270 to 300 seconds
on initial power up to reduce the chance of multiple
units simultaneously starting at the same time after
power up or after a power interruption, thus
avoiding creating large electrical spike.
• LOW PRESSURE BYPASS TIMER: If the compressor
is running and the low pressure switch opens, the
controller will keep the compressor ON for 120
seconds. After 2 minutes if the low pressure switch
remains open, the controllers will shutdown the
compressor and enter a soft lockout. The
compressor will not be energized until the low
pressure switch closes and the anti-short cycle time
delay expires. if the low pressure switch opens 2-4
times in 1 hour, the unit will enter a hard lockout
power to the unit would need to be reset.
• BROWNOUT/SURGE/POWER INTERRUPTION: 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 on the dip switch setting for "ALARM". If it is
set to "CONST", a constant signal will be produced
to indicate a fault and the unit requires inspection to
determine the type of fault. If is set to "PULSE", a
pulse signal is produced and a fault code is detected
by a remote device indicating the fault. See LED
fault indication for blink code explanation. The
remote device must have a malfunction detection
capability when the UPM board is set to "PULSE".
Installation | 13
8 733 905 683 (2016/09)