General; Cooling And Heating Modes; Upm Safety Features - Bosch SV007 Installation, Operation And Maintenance Manual

Revised 08/14

General

SV series heat pumps are designed to be
controlled by a standard 1 heat / 1 cool heat pump
thermostat. The heat pump control circuit
operates on 24 VAC control voltage regardless of
the unit supply voltage. If direct digital control is
required then the heat pump needs to be supplied
with a DDC control option.
Fan operation is controlled by the "G" terminal on
the heat pump thermostat terminal block. When
"G" is energized the unit fan motor will start
operating. For heat pumps with PSC motors, the
fan will immediately ramp up to 100% air flow. For
heat pumps with constant torque ECM motors, the
fan will ramp up to 100% air flow over a 30 second
period. For heat pumps with constant air flow ECM
motors the fan will ramp up to 70% air flow over a
30 second period if there is no call for compressor
operation ("Y"). If there is a call for compressor
operation along with a call for fan operation, then
the fan will ramp to 100% air flow.
Compressor operation is controlled by the "Y"
terminal on the heat pump thermostat terminal
block. When "Y" is energized, a signal to start the
compressor is sent to the Unit Protection Module
(UPM). The UPM checks a number of safety
features before then starting the compressor. If
any of the safety features connected to the UPM is
in a fault condition, the UPM will not start the
compressor and will flash a fault code on the red
status LED indicating the nature of the fault.
Additionally the UPM will delay compressor
operation randomly on initial start up (random
start delay) and will prevent the compressor from
restarting with less than 5 minutes of off time (anti
short cycle delay). Once all faults are cleared and
the time delays are satisfied, the UPM will energize
the compressor. The compressor will operate as
long as the thermostat calls for "Y" and there are
no faults. Refer to the troubleshooting chart for
fault diagnostics.

Cooling and Heating Modes

SV series heat pumps operate in cooling with the
reversing valve energized. When the "O" terminal is
energized, the heat pump will be in the cooling
mode, however, will not be actively cooling until
the "Y" and "G" terminals are also energized. If the
"Y" and "G" terminals are energized without the
"O" terminal, then the heat pump will operate in
the heating mode.
SV Heat Pump Series

UPM Safety Features

1
2
3
4
5
17
15
7
Figure # 10
[1] Board Power Indicator
[2] UPM Status LED Indicator
[3] Water Coil Freeze Protection Temperature
Selection
[4] Air Coil Freeze Protection Temperature
Selection
[5] UPM Board Settings
[6] Water Coil Freeze Connection
[7] Air Coil Freeze Connection
[8] LED Unit Display Connection
[9] 24VAC Power Input
[10] Compressor Contact Output
[11] High Pressure Switch Connection
[12] Call for Compressor Y1
[13] Low Pressure Switch Connection
[14] 24VAC Power Common
[15] Condensate Overflow Sensor
[16] Dry Contact
[17] UPM Ground Standoff
If the unit is being connected to a thermostat
with a malfunction light, this connection is made
at the unit malfunction output or relay.
If the thermostat is provided with a malfunction
light powered off of the common (C) side of the
transformer, a jumper between "R" and "COM"
terminal of "ALR" contacts must be made.
Unit Controls - UPM | 15
11
13 12
9 10
8 733 914 818 (2014/08)