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Bosch Buderus SSB255 | SSB399 | SSB512 Boilers
Control Operations Guide
03.2018
|
Bosch Thermotechnology Corp.
Data subject to change
9 Cascade Quick Set-Up
The power switch must be turned “OFF” on all boilers before beginning set-up of the
cascade.
1.
Identify which boiler in the Cascade group of boilers will be the Managing
boiler. The Managing boiler will have all temperature sensors (System
Supply, DHW and Outdoor Air) wired to its control panel. In most control
scenarios the Managing boiler will also be the single point of communication
from the Building Management System (BMS) to the Cascade group of
boilers.
2.
Switch “OFF” the S4 switch on all boilers except the Managing boiler. The
S4 switch is “OFF” when it is in the down position. See Figure 8 for locating
the S4 switch on the control board.
3.
Using 18/2 wire, connect all of the boilers in the cascade using the low
voltage contacts #1 and #2 on each boilers control board. Note the polarity.
4.
Turn the power on to the Managing boiler only:
a. Press “
Menu
”
“
Settings
”
”
Boiler Settings
”
b. Using the Arrow Key pad enter the passcode “0300” to enter the
service level of the control.
5.
Scroll to each of the following parameters and adjust the default values to
the following values:
Parameter #1 – Central Heating Mode - Set CH Mode based upon
desired control method.
—
CH Mode = “0” Setpoint control of the boiler using dry
contacts (TT)
—
CH Mode = “1” Outdoor Reset using ON/OFF control of the
boiler using dry contacts (TT)
—
CH Mode = “2” Full Outdoor reset with no heat demand
—
CH Mode = “3” Permanent set point demand
—
CH Mode = “4” Analog control (0-10Vdc) of set point
temperature
Parameter #72 Permit Emergency Mode – Set value to “YES”.
Parameter #73 Boiler Address - Set Value to “1” on Managing
boiler.
Parameter #74 Emergency Setpoint – Set desired emergency
supply temperature.
Parameter #75 Delay start Next Boiler – Recommend setting value
to 120 seconds (2 minutes) minimum.
Parameter #78 Differential UP Stop All Boilers – Set Value to 10
degrees.
6.
Turn Power “OFF” to the managing boiler and turn Power “ON” to the next
boiler in the Cascade.
7.
Repeat steps from Step #4 and enter into the parameter menu for the 2nd
boiler.
8.
Scroll to each of the following parameters and adjust the default values:
Parameter #72 Permit Emergency Mode – Set value to “YES”
Parameter #73 Boiler Address - Set Value to “2” on the 2nd boiler
Parameter #74 Emergency Setpoint – Set desired emergency
supply temperature
9.
Repeat Steps 7 and 8 for all other boilers in the cascade.
