Bosch SSB85 User Manual

6720866940 (2017/11) US SSB
18 | Parameters description
Par.22: Baseline Outdoor Temp.
Denes the maximum outdoor temperature to calculate the minimum
supply temperature for CH
Par.23: Min Supply Temp.
Sets the minimum supply temperature of the boiler.
Par.24: Max Supply Temp.
Sets the maximum supply temperature of the boiler.
Par.25: Warm Wheather Shutdown
When the outdoor temperature rises above Warm_Weather_Shutdown,
the call for heat is blocked and the pumps stop
Par. 26/27 Boost function
The outdoor reset boost function increases the CH_Setpoint by a
prescribed increment (Boost_Temperature_Incr) if a call for heat
continues beyond the pre-set time limit (Boost_time_Delay). CH_
Setpoint increases again if the call for heat still is not satised in another
time increment.
CH_Mode=2 Request for Heat with Outdoor Sensor only.
For this mode an outdoor sensor has to be connected. The CH_Setpoint
is calculated in the same way as described for CH_Mode 1. However
the demand does not depend on the room thermostat (terminals 11 &
12) input but on the outdoor temperature and the outdoor reset setpoint.
When the outdoor temperature is below this weather setpoint (settable)
CH demand is created. During the night an input signal from an external
clock can lower the CH_Setpoint. When the room thermostat input
closes CH_Setpoint will be decreased with Night_Setback_Temp. The
room thermostat input does not inuence the CH demand directly.
Par.28: Night Setback Temp.
Sets the decrease in supply temperature when the room thermostat is
closed.
Par.29: Weather Setpoint
Denes the outside temperature below which the CH is active.
CH_Mode=3 Permanent Call for Heat.
For this mode the CH mode should be set to 3 and no outdoor sensor
is needed. The supply temperature is kept constantly at the setpoint
temperature. When the room thermostat contact closes CH_Setpoint will
be decreased by the value of Night_Setback_Temp.
CH_Mode=4 CH request with analogue input control of Temperature.
Available only with an additional 0-10V device.
CH_Mode=5 CH Request with analogue input control of Power.
Available only with an additional 0-10V device.
6.2 Domestic Hot Water
Par.35 DHW_Mode
Mode=0 No Domestic Hot Water
Mode=1 External DHW tank with temperature probe.
In this Mode (1) DHW is produced by heating a domestic indirect tank.
Either a DHW pump or 3-way valve can be used to switch to DHW mode.
The DHW temperature in the tank is measured with a sensor T_Store
and set with parameter DHW_Store_Setpoint. When this sensor
drops below “DHW_Store_Setpoint–DHW_Store_Hyst_Down” the
control detects a demand for the store and starts the general and DHW
pump. If the supply temperature T_Supply is below “DHW_Store_
Setpoint+DHW_Store_Supply_Extra–DHW_Supp_Hyst_Down” the
burner is started as well (DHW_Request). The burner stops when the
supply temperature rises above “DHW_Store_Setpoint+DHW_Store_
Supply_Extra+DHW_Supp_Hyst_Up”. The demand for the tank is
ended when the tank-sensor rises above “DHW_Store_Setpoint+DHW_
Store_Hyst_Up”. The pump continues DHW_Post_Pump_Period.
Example (°F):
DHW Store Setpoint = 120
DHW Store Hyst Down = 5
DHW Store Supply Extra = 54
DHW Store Hyst UP = 2
Both boiler pump and DHW pump “ON” when tank sensor measures = 115
Burner “ON” when boiler supply sensor measures less than = 169
Burner “OFF” when boiler supply sensor measures less than = 176
Par.48 DHW Setpoint
Set the requested setpoint for the domestic hot water.
DHW Priority Setting
Standard DHW demand has priority over CH demand but the priority
period is limited up to CH_DHW_Switching_Time. The priority timer
starts when both CH and DHW demand are present. After the CH_DHW_
Switching_Time is achieved, the control will switch from DHW to CH
operation. CH has priority now for a maximum period of CH_DHW_
Switching_Time.
Par.42 DHW Priority
Different DHW Priority types can be chosen
Mode=0
When parameter DHW_Priority is set to 0 (TIME), DHW has priority to
CH during CH_DHW_Switching_Time.
Mode=1
When parameter DHW_Priority is set to 1 (OFF), CH always has priority
to DHW
Mode=2
When parameter DHW_Priority is set to 2 (ON), DHW always has priority
to CH
Default the DHW_Priority is set to 0.
Store warm hold function
Because of the presence of the store sensor (T_Store) the control
can detect demand for holding the store warm. If T_Store drops below
“DHW_Store_Setpoint-DHW_Store_Hold_Warm” the burner starts
at minimum power. The burner stops if T_Store is higher than “DHW_
Store_Setpoint+DHW_Store_Hyst_Up”.

Bosch SSB85 Specifications

General

Brand	Bosch
Model	SSB85
Category	Boiler
Language	English