bosch buderus ssb255399512 controls operations guide · 2018-06-28 · there are 6 onboard ch mode...

Bosch Buderus SSB Boiler Control OperationsSSB255 | SSB399 | SSB512

Control Operations Guide

WARNING:

the heating system can cause personal injury and property damage.Follow these instructions precisely.If you require assistance or further information, contact a licensed

2 | Bosch Buderus SSB255 | SSB399 | SSB512 Boilers Control Operations Guide

03.2018 | Bosch Thermotechnology Corp.Data subject to change

Control Operations Guide Bosch Buderus SSB255 | SSB399 | SSB512 Boilers | 3

Bosch Thermotechnology Corp. | 03.2018 Data subject to change

Table of Contents

1 Key to Symbols and Safety Instructions 4

1.1 Key to symbols 4

1.2 Safety 4

2 Boiler Settings Menu 5

3 Heating Modes 6

3.1 Central heating (CH) mode 6

4 General Operation Settings 12

5 Outdoor Reset Curve Settings 14

6 Domestic Hot Water 16

6.1 Domestic hot water settings 16

6.2 Domestic hot water operation 17

7 Cascade Operation 18

7.1 Cascade operation settings 18

7.2 Cascade operation - set-up of boilers 20

7.3 Cascade - start sequence 22

7.4 Cascade - stop sequence 22

8 Start-up & Commissioning Settings 23

9 Cascade Quick Set-Up 24



1 Key to Symbols and Safety Instructions

1.1 Key to symbols

Warnings

Warnings in this document are identifi ed by a warning triangle printed against a grey background.Keywords at the start of a warning indicate the type and seriousness of the ensuing risk if measures to prevent the risk are not taken.

The following keywords are defi ned and can be used in this document:

DANGER indicates a hazardous situation which, if not avoided, will result in death or serious injury.

WARNING indicates a hazardous situation which, if not avoided, could result in death or serious injury.

CAUTION indicates a hazardous situation which, if not avoided, could result in minor to moderate injury.

NOTICE is used to address practices not related to personal injury.

Important information

This symbol indicates important information wherethere is no risk to people or property.

1.2 Safety

Please read safety precautions before installation

WARNING:

Improper installation, set-up, modification, operation or maintenance of the heating system can cause personal injury and property damage.

Follow these instructions precisely.

If you require assistance or further information, contact a licensed contractor / gas fitter.



2 Boiler Settings Menu

Function Parameter Description

General Operation

1 Central Heating (CH) Mode2 Pump Mode3 CH Setpoint4 System Pump Overrun5 Boiler Pump Overrun7 Central Heating Hysteresis (Diff erential)9 Anti Cycle Period

10 Anti Cycle Temperature Diff erential11 Ramp Delay Step Modulation14 Maximum Power Central Heating15 Minimum Power Central Heating / DHW

Outdoor Reset Curve

19 Design Supply Temperature20 Design Outdoor Temperature21 Baseline Supply Temperature22 Baseline Outdoor Temperature23 Design Supply Minimum Limit24 Design Supply Maximum Limit25 Warm Weather Shutdown26 Boost Temperature Increment27 Boost Time Delay28 Night Setback Temperature29 Weather Setpoint

Domestic Hot Water

35 Domestic Hot Water Mode36 Domestic Hot Water Tank Diff erential DOWN37 Domestic Hot Water Tank Diff erential UP38 Domestic Hot Water Tank Supply Extra42 Domestic Hot Water Priority43 Domestic Hot Water Priority Time44 Domestic Hot Water Pump Overrun48 Domestic Hot Water Tank Setpoint

Cascade Operation

72 Permit Emergency Mode73 Boiler Address74 Emergency Setpoint75 Delay Period Start Next Boiler76 Delay Period Stop Next Boiler77 Diff erential DOWN Start Boiler78 Diff erential UP Stop Boiler79 Maximum Setpoint Off set DOWN80 Maximum Setpoint Off set UP81 Start Modulation Delay Factor82 Next Boiler START Rate83 Next Boiler STOP Rate84 Boiler Rotation Intervale85 Domestic Hot Water Boiler Assign

Start-up & Commisioning

89 Frost Protection90 Frost Protection Setpoint91 Domestic Hot Water Maximum Limit92 Fan Speed Maximum93 Fan Speed Minimum94 Fan Speed Ignition97 Appliance Model98 Gas Type99 Flue Length Range

Table 1



3 Heating Modes

3.1 Central heating (CH) mode

There are 6 onboard CH Mode settings which may be selected with the SSB Boiler.

1. CH Mode = “0” [default mode] Setpoint control of the boiler using dry contacts (TT)

2. CH Mode = “1” Outdoor Reset using ON/OFF control of the boiler using dry contacts (TT)

3. CH Mode = “2” Full Outdoor reset with no heat demand

4. CH Mode = “3” Permanent Setpoint Demand

5. CH Mode = “4” Analog control (0-10Vdc) of set point temperature

6. CH Mode = “5” Analog control (0-10Vdc) of Boiler Power (%)

Central Heating Mode 0 [default mode](Setpoint control of the boiler using dry contacts #11 and #12)

CH Mode “0” - Boiler demand is generated thru a call for heat on low voltage contacts #11 and #12 (dry contacts only). The Boiler will then target a temperature equal to “CH Setpoint” (par.#3) at the Supply Temperature Sensor. If Temperature exceeds the target Setpoint temperature by “CH Hysteresis” (par.#7) the burner will shut off until the Supply Temperature Sensor drops the value of “CH Hysteresis” below the target Setpoint Temperature.

Example: If “CH Setpoint” is set for 140°F and CH Hysteresis is set for 10°F and there is a call for heat on #11 and #12 the burner will start when the Boiler Supply Temperature (System Supply Temperature sensor for cascade) reads a temperture of 130°F or less and will remain operating until the call for heat is satisifi ed or until the sensor reads a temperature of 150°F or greater. As long as the call for heat remains the Boiler and CH Pump contacts will remain energized. The Burner will remain off until temperature falls to 130°F.

Central Heating (CH) Mode

DescriptionSet these Parameters

Parameter # Description Default Range

CH Mode = “0”Setpoint control using dry

contacts (TT)

3 CH Setpoint 176°F 68 - 194°F

4 System pump overrun 300 sec. 0 – 900 sec.

5 Boiler pump overrun 300 sec. 0 – 900 sec.

7 CH Hysteresis 5.4°F 0 - 36°F

9 Anti-cycle period 180 sec. 10 – 900 sec.

10 Anti-cycle Temp Diff 12.6°F 0 - 36°F

23 Design Supply Min 68°F 39.2 – 179.6°F

24 Design Supply Max. 194°F 80.6 - 194°F

Table 2



Central Heating Mode 1 (On/Off with Outdoor Reset using dry contacts #11 and #12)

CH Mode “1” - Boiler demand is generated thru a call for heat on low voltage contacts #11 and #12 (dry contacts only). Boiler will target a system supply water temperature equal to the corresponding point on the installer programmed heating curve. (See page 7 for details on how-to program the heating curve). If the System Temperature sensor exceeds the calculated heating curve temperature by “CH Hysteresis” (par.#7) the burner will shut off until the System Temperature sensor reads “CH Hysteresis” below the target Setpoint Temperature.

Example: Based on the heating curve programmed by the installer, the calculated supply water temperature on a 32°F degree day outside corresponds with a target boiler water temperature of 140°F. If CH Hysteresis is set for 10°F, and there is a call for heat on #11 and #12, then the burner will turn on when the Boiler Supply Temperature sensor (System Supply Temperature sensor for cascade) reads a temperture of 130°F or less and will remain operating until the call for heat is satisifi ed or until the sensor reads a temperature of 150°F or greater. As long as the call for heat remains the Boiler and CH Pump contacts will remain energized. The Burner will remain off until temperature measured at the system supply sensor falls to 130°F




CH Mode = “1”On/Off with reset water

temperature

19 Design Supply °F 176°F 68 - 194°F

20 Design Outdoor °F 24.8°F -13 - 77°F

21 Baseline Supply °F 104°F 68 - 194°F

22 Baseline Outdoor °F 69.8°F 35.6 - 86°F

23 Design Supply min 68°F 39.2 – 179.6°F

24 Design Supply max 194°F 80.6 - 194°F

25 WWSD 69.8°F 35.6 - 95°F

26 Boost Temp Incr. 0°F 0 - 54°F

27 Boost Temp Delay 20 min. 1 – 120 min.

Table 3



Central Heating Mode 2 (Full Outdoor reset with no heat demand)

CH Mode“2” - Boiler demand is generated when the outdoor temperature falls below the value of “Weather Setpoint” (par.#29). When this occurs the Boiler and CH pump contacts are energized and the Boiler will target a system supply water temperature corresponding to a point on the installer programmed heating curve. (See “How to Program the Heating Curve” for details). If the System Temperature sensor exceeds the calculated heating curve temperature by “CH Hysteresis” (par.#7) the burner will shut off until the System Temperature sensor reads “CH Hysteresis” below the target Setpoint Temperature. This CH Mode is for constant circulation applications. The Boiler and CH pump contacts will remain energized as long as the outdoor temperature is less than the value of “Weather Setpoint” (par.#29). Using the low voltage contacts #11 and #12 it is possible to apply a set-back to the heating curve. “Night Setback Dif” (par.# 28) controls the parallel temperature shift that is applied to the curve when #11 and #12 contacts are “closed” using a clock or switch.

Example: “Weather Setpoint” is programmed for 60°F. The outdoor temperature falls below this value. The boiler energizes Boiler and CH pump contacts. Based on the heating curve programmed by the installer in this application, the calculated supply water temperature on this particular temperature day corresponds to a target boiler water temperature of 140°F. If CH Hysteresis is set for 10°F, and and the outdoor temperature remains below the value of “Weather Setpoint”, then the burner will turn on when the Boiler Supply Temperature sensor (System Supply Temperature sensor for cascade) reads a temperature of 130°F or less and will remain operating until the outdoor temperature exceeds the value of “Weather Setpoint” or if the sensor reads a temperature of 150°F or greater. As long as the outdoor temperature remains below the value of “Weather Setpoint” the Boiler and CH Pump contacts will remain energized. The burner will remain off until the system supply temperature falls to 130°F.




CH Mode = “2”Full Outdoor reset

with no heat demand

19 Design Supply °F 176°F 68 - 194°F

20 Design Outdoor °F 24.8°F -13 - 77°F

21 Baseline Supply °F 104°F 68 - 194°F

22 Baseline Outdoor °F 69.8°F 35.6 - 86°F

23 Design Supply min 68°F 39.2 – 179.6°F

24 Design Supply max 194°F 80.6 - 194°F

25 WWSD 69.8°F 35.6 - 95°F

26 Boost Temp Incr. 0°F 0 - 54°F

27 Boost Temp Delay 20 min. 1 – 120 min.

28 Night Setback 18°F 0 - 90°F

29 Weather Setpoint 68°F 32 - 122°F

Table 4



Central Heating Mode 3 (Permanent set point demand)

CH Mode“3” - Boiler demand is always “ON” in CH Mode 3 – “Permanent Demand Mode”. In this mode the Boiler and CH Pump contacts will always be energized. When the Supply Temperature Sensor falls below the value of “CH Setpoint” (par.#3) minus the value of “CH Hysteresis” (par.#7), the burner will turn on. The burner will remain on as long as the supply temperature remains below the value of “CH Setpoint” plus “CH Hysteresis”. Using the low voltage contacts #11 and #12 it is possible to apply a set-back to the “CH Setpoint” target temperature. “Night Setback Dif” (par.# 28) controls the temperature shift that is applied to the “CH Setpoint” when #11 and #12 contacts are “closed” using a clock or switch.

Example: With both Boiler and CH Pump contacts energized, the boiler will monitor the Supply Temperature Sensor. The application calls for a setpoint of 140°F with and Hysteresis setting of 10°F. When the temperature of the Boiler Supply Temperature sensor (System Supply Temperature sensor for cascade) falls below 130°F ( the value of “CH Setpoint” minus “CH Hysteresis”) the burners will turn on. Burners will remain on as long as the sensor does not exceed 150°F ( the value of “CH Setpoint” plus “CH Hysteresis”). In the evening the application calls for a reduced supply water temperature of 120°F. A timer/clock is installed and wired to contacts #11 and #12 of the boiler and these contacts are “closed” between the hours of 10 pm and 5 am. During that time period the “CH Setpoint” is reduced by the value programmed into “Night Setback Dif”. In this example the value is set for 20°F.




CH Mode = “3”Permanent

Setpoint Demand

3 CH Setpoint 176°F 68 - 194°F



7 CH Hysteresis 5.4°F



24 Setpoint Max. 194°F 80.6 - 194°F

28 Night Setback 18°F 0 - 90°F

Table 5

1 0 | Bosch Buderus SSB255 | SSB399 | SSB512 Boilers Control Operations Guide


Central Heating Mode 4 (Analog 0-10 Vdc Setpoint Control)

CH Mode“4” - Boiler demand is generated by a 0-10 Vdc analog signal from a Building Management System (BMS). An initial heat request is generated via a signal of 1.5 VDC or greater. Boiler modulation between “Design Supply Min” (par.#23) and “Design Supply Max” (par.#24) will occur between 2 and 10 Vdc. When a demand voltage of 1.5 VDC or greater is applied the Boiler and CH pump contacts are energized and the Boiler will target a system supply water temperature corresponding to the appropriate setpoint temperature based upon the voltage signal and the minimum and maximum setpoint settings. If the Boiler Supply Temperature sensor (System Supply Temperature sensor for cascade) exceeds the targeted setpoint plus “CH Hysteresis” (par.#7) the burner will shut off until the sensor reads “CH Hysteresis” below the targeted Setpoint Temperature. Once the initial demand has occurred The Boiler and CH pump contacts will remain energized as long as the voltage from the BMS remains greater than 1 VDC.

Figure 1

OFF1.0 1.5 2.0

ON9

Modulation

CH Setpoint Max

CH Setpoint Min

Voltage (Vdc)

Set P

oint

F°




CH Mode = “4”Analog 0-10 VDCSetpoint Control






23 Design Supply Min 68°F 39.2 – 179.6°F


Table 6



Central Heating Mode 5 (Analog 0-10 Vdc Power % Modulation)

CH Mode“5” - Boiler demand is generated by a 0-10 VDC analog signal from a Building Management System (BMS). An initial heat request is generated via a signal of 1.5 VDC or greater. Boiler modulation between “Minimum Power” (par.#15) and “Maximum Power” (par.#14) will occur between 2 and 10 VDC. When a demand voltage of 1.5 VDC or greater is applied the Boiler and CH pump contacts are energized and the Boiler will operate at the corresponding Power %. The Power % will be based upon the voltage signal and scaled between the Minimum and Maximum power settings. Once the initial demand has occurred The Boiler and CH pump contacts will remain energized as long as the voltage from the BMS remains greater than 1 VDC.

Figure 2

OFF1.0 1.5 2.0

ON9

Voltage (VDC)

Max Power

Min Power

Modulation

Pow

er (%

)




CH Mode = “5”Analog 0-10 VDCPower Modulation






14 Max Power CH 100 % 50 – 100 %

15 Min Power CH/DHW 1% 1 – 30%


Table 7



4 General Operation Settings

Parameter Description

CH Mode(parameter #1)

Set Central Heating (CH) Mode based upon the desired control strategy for the boiler. See pages 2 thru 7 of this manual for a detailed explanation of each CH Mode.

Pump Mode(parameter #2)

Three diff erent pump modes may be selected for the boiler depending upon how the boiler is piped and how many pumps are controlled by the boiler. Diagrams (Fig. 3,4,5) for the three diff erent pump modes are shown on the following page.

CH Setpoint(parameter #3)

Central Heating Setpoint only applies to CH Mode #0 ( On/Off using dry contacts) and CH Mode #3 (Permanent set point demand). The value set for CH Setpoint will be the boiler supply water temperature (system supply for cascade).

System Pump Overrun(parameter #4)

The amount of time in seconds the CH Pump contacts (#104 thru #106) will be energized after the demand for heat has ended. Default is 300 seconds (5 minutes). The parameter is adjustable from 0 seconds to 900 seconds in 10 second increments.

Boiler Pump Overrun(parameter #5)

The amount of time in seconds the Boiler Pump contacts (#101 thru #103) will be energized after the demand for heat has ended. Default is 300 seconds (5 minutes). The parameter is adjustable from 0 seconds to 900 seconds in 10 second increments.

CH Hysteresis(parameter #7)

The temperature diff erential used by the boiler to control the on/off function of the burner. The Central Heating Diff erential applies to all CH Modes. If the target boiler supply sensor (system supply for cascade) registers a temperature above the target by more than the value of the diff erential, the burner will turn off . The burner will not turn on until the boiler supply (system supply for cascade) sensor value has fallen the same amount equal to the diff erential below the target setpoint temperature.

Anti Cycle Period(parameter #9)

The amount of time in seconds the boiler will wait before restarting. The parameter is adjustable from 10 seconds to 900 seconds in 10 second increments

Anti Cycle Temp. Diff erence(parameter #10)

In addition to the Anti Cycle Period (see above) the boiler will monitor the System Supply Temperature Sensor. If the Anti Cycle Period is active and there is a pending call for heat, the Anti Cycle Period will be overriden, and the burner will fi re, if the temperature at the Supply sensor drops a certain number of degrees prior to completing the Anti Cycle Period. Default value for this parameter is 12.6°F. The parameter is adjustable from 0°F to 36°F.

Ramp Delay Step Mod.(parameter #11)

Default setting for this parameter is “Disabled” but can be set to “Enabled”. By enabling this parameter the boiler follows a pre-defi ned set of modulation “steps”. The boiler will begin operating at a 10% power level after ignition for 60 seconds. Once this time period has passed, should there still be a call for heat from the system, the boiler power level will be increased +20%. Every 30 seconds thereafter the boiler power will be increased by an additional +20% until the call for heat is either satisfi ed, or the boiler reaches the CH Setpoint (par.#3) + Hysteresis (par.#7), or the boiler reaches 100% of it’s maximum power level.

Max. Power Central Heating(parameter #14)

The Maximum burner power for Central Heating can be limited during operation. Default value is 100% and may be adjusted down in 1% increments to 50%.

Min. Power Central Heating/DHW(parameter #15)

The Minimum burner power for Central Heating and DHW operation can be limited during operation. Default value is 1% power and may be adjusted up in 1% increments to 30%.

Table 8



Figure 3

Pump mode = 2 (default) Boiler with a manifold and two pump circuits CH/DHW

DHW_mode=1DHW_mode=0 (Ch only)

CH return CH supply

PrimaryHeat Exchanger

T_flue

CH PUMP

Manifold

T_supplySafety Limit

GENERALPUMP

N

LJ6-1

J6-3

J7-5

J6-2

DHW PUMP

CH /SYSTEMPUMP

L

N

L

J7-2

GENERALPUMP

J7-1 PE

CH return CH supply

GENERALPUMP

Manifold

inDHW

CHPUMP

T_store

DHW PUMP

out


Figure 4

Pump mode = 0 Boiler with two pump circuits Ch/DHW (move the internal pump wiring to the CH terminal)

DHWPUMP

T_store

CH supply

out inDHW

CH return

CHPUMP


DHW_mode=1

DHWPUMP

DHW_stat

CH supply

out inDHW

CH return

CHPUMP


DHW_mode=2

CH supply CH return

CHPUMP

T_return

T_flueT_supplySafety Limit


DHW_mode=0 (Ch only)

CHWPUMP

LJ6-1

J6-3

J6-2

J7-1

N

LPE

Figure 5

Pump mode = 1 Boiler with one primary pump and 3-way valve for DHW (move the internal pump wiring to the CH terminal)

3-WAYVALVE

T_store

CH supply

out inDHW

CH return

GENERALPUMP


DHW_mode=1

3-WAYVALVE

DHW_stat

CH supply

out inDHW

CH return

BOILERPUMP


DHW_mode=2

CH supply CH return

GENERALPUMP

T_return

T_flueT_supplySafety Limit


DHW_mode=0 (Ch only)



5 Outdoor Reset Curve Settings


Design Supply Temperature(parameter #19)

The water temperature the boiler will supply at Design Outdoor temperature

Design Outdoor Temperature (parameter#20)

The outdoor air temperature at which the boiler will supply the Design supply water temperature

Baseline Supply Temperature (parameter#21)

The water temperature the boiler will supply at the Baseline Outdoor temperature.

Baseline Outdoor Temperature (parameter#22)

The outdoor air temperature at which the boiler will target the Baseline Supply Temperature.

Design Supply Minimum Limit(parameter#23)

The minimum supply water temperature the heating system will provide to the system. May be the same value as Parameter #21

Design Supply Maximum Limit (parameter#24)

The maximum supply water temperature the heating system will provide to the system. May be the same value as Parameter #19

"Warm Weather Shutdown(parameter #25)

The temperature above which heating is no longer necessary. All calls for heat will be ignored as long as the outdoor temperature remains above the Warm Weather Shutdown value.

Table 9

Figure 6

Design Supply Temp (par. #19)

Design Supply Min Limit (par. #25)

Boi

ler S

uppl

y Te

mpe

ratu

re ºF

Outdoor Air Temperature

Baseline Supply Temp (par. #21)

Design Supply Max Limit (par. #24)

Design Outdoor Temp (par. #20)

Baseline Outdoor Temp (par. #22)

(par. #23)




Boost Temp Increment(parameter #26)

Boost Temp Increment is active for CH Modes 1. If a call for heat has not been satisfi ed within the period of time defi ned within Boost Time Delay (see below) the targeted supply temperature will be increased by the value of Boost Temp increment. This process of Boosting supply water will continue until the call for heat is satisifi ed. The default value for this parameter is 0°F. The parameter is adjustable from 0°F to 54°F.

Boost Time Delay(parameter #27)

Boost Time Delay is active only for CH Modes 1. If a call for heat has not been satisfi ed within the time limit (in minutes) defi ned within Boost Time Delay, the boiler supply water temperature will be increased by Boost Temp Increment (see above). The default value for this parameter is 20 minutes. The parameter is adjustable from 1 to 120 minutes.

Night Setback Temp.(parameter #28)

Only available for CH Modes #2 and #3. The value the heating curve will be reset as long as contacts #11 & #12 are “closed” (i.e. via an external clock timer or switch). Default value is 18°F. The parameter is adjustable from 0 to 90°F.

Weather Setpoint(parameter #29)

Weather Setpoint is only active for CH Modes #2 (full outdoor reset with no heat demand). When the outside temperature falls below the value set for Weather Setpoint, a heating demand is generated and the boiler will begin to operate. Boiler operation will continue until the outdoor temperature rises above the value set for warm weather shutdown

Table 10



6 Domestic Hot Water

6.1 Domestic hot water settings


DHW Mode(parameter #35)

When an Indirect tank is present in the system set DHW Mode to “1” when using the factory supplied 10K ohm sensor or set to “2” if using a third-party aquastat. Default value is “0” (Off ).

DHW Tank Hyst. Down(parameter #36)

The necessary temperature drop of the indirect tank temperature needed before the boiler will begin to recover the tank. Only active when DHW Mode (par. #35) is set to “1” and a 10k ohm sensor is used. Default value is 7.2°F. Adjustable between 36°F. Only applies to systems using a 10k ohm thermistor (Parameter #35 DHW Mode = “1”)

DHW Tank Hyst. Up(parameter #37)

The necessary temperature overshoot of the indirect tank temperature needed before the boiler will stop heating the indirect tank. Default value is 0°F. Adjustable between 0°F and 36°F. Only applies to systems using a 10k ohm thermistor (Parameter #35 DHW Mode = “1”)

DHW Tank Supply Extra (parameter #38)

The Target Supply Water temperature to the indirect coil is equal to DHW Tank Setpoint (par. #48) + DHW Tank Supply Extra.

DHW Priority(parameter #42)

Default setting is “0” - Timed DHW Priority. Timer starts when there is both a DHW and a call for heat. See DHW Priority Time (par. #43) for adjusting the length of time priority is given over a call for heat. Setting a value of “1” gives DHW unlimited priority over a call for heat. Setting the value to “2” gives a call for heat unlimited priority over a call for domestic hot water

DHW Max Priority Time(parameter #43)

Default DHW priority [see DHW Priority (par.#42)] time is 30 minutes Adjustable from 1 to 255 minutes.

DHW Pump Overrun(parameter #44)

Length of time the DHW pump contacts remain energized after a call for DHW has ended. Default setting is 15 seconds. Adjustable between 0 and 255 seconds.

DHW Tank Setpoint(parameter #48)

Target temperature of the indirect tank. Default value is 120°F. Adjustable between 104°F and 140°F.

Table 11



6.2 Domestic hot water operation

The SSB Boiler onboard control can support domestic hot water production using an indirect tank. The boiler can use either the supplied 10K ohm domestic sensor or a aquastat (dry contact only, aquastat supplied by installer) to control the heating of an indirect tank. The 10k ohm sensor or aquastat are wired to the #9 and #10 low voltage terminal block of the SSB boiler. Parameter #35 (Domestic Hot Water Mode) must be set to the appropriate value depending upon which type of sensor is used. Follow the instructions below for the sensor type you have chosen to use with the SSB Boiler.

Using the supplied 10k ohm Sensor:

1. Wire 10k ohm sensor to low voltage terminals #9 and #10 on the boilers main control panel.

2. Within the “Boiler Settings” menu set Parameter #35 to “1”.

3. Set desired domestic hot water temperature using Parameter # 48.

4. When the domestic hot water temperature falls 7.2 degrees below the desired set temperature for hot water the boiler will begin to heat the indirect tank. To change this switch-on diff erential adjust Parameter #36 to the desired value. The switch-off diff erential can be set separately using Parameter #37. The default value for this parameter is zero.

Using a fi eld-supplied aquastat:

1. Wire your fi eld-supplied aquastat to the low voltage terminals #9 and #10 on the boiler main control panel.

2. Within the “Boiler Settings” menu set Parameter #35 to “2”.

3. Adjust the fi eld-supplied aquastat to the desired tank temperature according to the manufacturers instructions .

4. Upon a call for heat from the aquastat the boiler will target a supply temperature of DHW Set point + DHW Extra. The burner will cycle on/off based upon a +/- 3.6 degree diff erential of the target supply temperature of 176 °F.

Depending upon which DHW Mode is selected (Mode 1 = 10 K ohm sensor or Mode 2 = Aquastat) will then determine which of the following parameters can be used to adjust the hot water operation.

DHW Parameter DHW Mode Description Default Value Range

35 - DHW Mode 0 0 - 2

36 1 DHW Tank Hyst. Down 7.2 0 – 36 °F

37 1 DHW Tank Hyst. Up 0 0 – 36 °F

38 1 DHW Supply Extra 54 0 – 54 °F

42 1 & 2 DHW Priority 0 0 - 2

43 1 & 2 DHW Max Priority Time 30 1 – 255 min.

44 1 & 2 DHW Pump Overrun 15 0 – 255 sec.

48 1 DHW/Tank Setpoint 120 104 – 140 °F

Table 12



7 Cascade Operation

7.1 Cascade operation settings


Permit Emergency Mode(parameter #72)

Enable Emergency Mode in a multiple boiler cascade installation to ensure that any dependent boiler can operate independently should communication with the lead boiler be interrupted or the lead boiler loses communication with the supply sensor. The dependent boiler will operate at a predetermined “emergency” set point which is set using Parameter #74. Default setting for this parameter is “Disabled”.

Boiler Address(parameter #73)

Boiler Address must be changed when setting up a multiple boiler cascade installation. The default address of every boiler is set to “0”. In a cascade application, the Managing or lead boiler must be set to Address = 1. All other boilers within the cascade must be set to the next address value. Default setting for Boiler Address is “0”. Adjustable from 0 to 16.

Emergency Setpoint(parameter #74)

"Emergency Setpoint is the fi xed set point which a boiler will operate at within a cascade installation if that boiler has lost communication with the Managing or lead boiler or the lead boiler loses communication with the supply sensor.Parameter #72 must be “Enabled” on each dependent boiler and Emergency Set point set for the desired Emergency temperature at which the boiler is to operate at should the boiler lose communication with the Managing boiler or the lead boiler loses communication with the supply sensor. Default setting is 113° F. Adjustable from 68 °F to 149 °F.

Delay Period Start Next Boiler (parameter #75)

The amount of time in seconds which must pass once the previous boiler in the cascade rotation is above the power percentage defi ned in parameter #82 (next boiler start rate) and the system supply sensor is below the target temperature by the value defi ned in parameter #77 – Diff erential Down Start Boiler. Default value is 15 seconds. Adjustable from 5 to 300 seconds.

Delay Period Stop Next Boiler (parameter #76)

The Amount of time in seconds which must pass once the last boiler turned on in the rotation has dropped below the power percentage defi ned in parameter #83 (next boiler stop rate). Default value is 15 seconds. Adjustable from 5 to 300 seconds.

Diff erential Down Start Boiler(parameter #77)

In a cascade installation the fi rst or next boiler will be enabled when the system supply sensor is less than the target system set point minus the value of “Diff erential Down Start Boiler” for a period of time equal to parameter #75 (delay period start next boiler).

Diff erential Up Stop Boiler (parameter #78)

If the temperature of the system supply sensor exceeds a temperature greater than System Target Temperature + Diff erential UP all boilers in the cascade will be stopped.

"Max. Setpoint Off set Down(parameter #79)"

In order to achieve the desired Target System Supply Temperature during a call for heat the boilers may need to operate at temperatures greater than or less than the desired Target System Supply Temperature. The operating range in which the boilers are allowed to adjust the individual boiler supply temperatures is defi ned by the Off set Down and Off set Up (parameter #80) values. Each dependent boiler will display a “Calculated Setpoint” temperature on the display which will be within this Off set Range either above or below the overall Target System Supply Temperature. Default value of Off set UP is 18 F. Adjustable from 0 F to 36 F.

Table 13




Max. Setpoint Off set UP.(parameter #80)

See Parameter #79 for explanation of Off set UP and Off set Down. Default value of Off set UP is 18 °F. Adjustable from 0 °F to 36 °F.

Start Modulation Delay Factor (parameter #81)

The Managing boiler will calculate the diff erence between the System Target Setpoint and the measured System Supply Temperature once a period of time equal to Delay Period Start Next Boiler x Start Modulation Delay Factor has passed. Default value for Modulation delay is 5. Adjustable from 0 to 60.

Next Boiler Start Rate(parameter #82)

"The percentage of burner power a boiler must reach before the Managing boiler will begin the process of bringing on the next boiler within the cascade. See Parameter#75 for further information on the amount of time which must pass at this power percentage before the next boiler in the cascade rotation is enabled. Default value is 80%. Adjustable from 10% to 100%."

Next Boiler Start Rate(parameter #83)

The percentage of burner power a boiler must reach before the Managing boiler will begin the process of turning off the last boiler enabled within the cascade rotation sequence. See Parameter #76 for further information on the amount of time which must pass at this power percentage before a boiler is turned off . Default value is 30%. Adjustable from 10% to 100%.

Boiler Rotation Interval(parameter #84)

The amount of time (in Days) which will defi ne the boiler rotation interval. Default value is 1 day. Adjustable from 0 (disable rotation) to 30 days.

Domestic Hot Water Boiler Assign (parameter #85)

Not available

Table 14



7.2 Cascade operation - set-up of boilers

1. Connect up to 16 boilers together using standard 18/2 thermostat cable. The Cascade connections can be found on the low voltage terminal block at contacts #1 and #2.

These connections are polarity sensitive.

Figure 7

1 2 3

CASCADELINK

1 2 3

CASCADELINK

Boiler 1

Boiler 2 Boiler 16...

1 2 3 4 5 6 7 8 9 10 11 12 13 14

CASCADELINK

MODBUS

GasSwitch

OutDoor

DHW TankSensor

RoomThermostat

SupplySensor

2. Determine which boiler in the cascade will be the “Managing” boiler. All system sensors (i.e. Outdoor air sensor, System Supply Temperature sensor, DHW Sensor) should be wired to the “Managing boiler”

3. The “S4” switch on the control board of the managing boiler must be in the “ON” position which means the switch should be in the “Up” position – default position from the factory is “ON”. The “S4” switch is located on a small cut-out on the front of the main control board of the boiler. All other boilers in the cascade should have the S4 switch in the “Off ” or “Down” position.

WARNING:

Never adjust the S4 switch with the power on – always turn power off fi rst before changing the S4 switch position.

Figure 8

ON

OFF

S4

4. Set the address of each boiler in the Cascade. The Managing boiler should be set for Address #1. All other boilers in the cascade should be set for an address of 2 thru 16. To Access the address setting of each boiler:

Press “Menu”

Use down Arrow on the keypad and highlight “Settings” then push the “OK” button

Highlight “Boiler Settings” then push the “OK” button

If requested, enter the installer setting password of “0300” using the keypad then press “OK”

Scroll to Parameter # 73 “Boiler Address”. Once highlighted, use the Right Arrow button to highlight the default value of “0” and use the “Up” or “Down” Arrow to set the correct address of the boiler.

Press “OK” button to confirm and set the new address value.

Repeat the steps above for each boiler in the cascade being sure not to set the same address for any two boilers in the cascade.



5. Set System settings on Managing Boiler: There are a number of parameter settings which only need to be set on the Managing boiler. Follow the steps outlined in step 4 to access and adjust the following parameters within the Managing boiler only:

Parameter #1 (CH Mode) – based upon the selected CH Mode, set those parameters which apply to that CH Mode. See detailed explanation of CH Modes and the list of those parameters which specifically impact the operation for that specific CH Mode. You will only set CH Mode and any parameter related to that CH Mode of operation on the “Managing” boiler’s control.

— CH Mode = “0” Setpoint control of the boiler using dry contacts #11 & #12

— CH Mode = “1” Outdoor Reset using ON/OFF control of the boiler using dry contacts (enable/disable on contacts 11 & 12 cascade will operate based upon reset curve set on Managing Boiler)

— CH Mode = “2” Full outdoor reset with no heat demand (Based on Weather Setpoint and WWSD)

— CH Mode = “3” Permanent set point demand

— CH Mode = “4” Analog control (0-10Vdc) of set point temperature

Parameter #35 (DHW Mode) only if there is an indirect tank connected to the system.

Cascade Parameters – See section Cascade Start and Stop Sequence for a detailed explanation of the Cascade operation. It is recommended to set the following Cascade Parameters for your specifi c system requirements.

— Parameter #72 Permit Emergency Mode – Set value to “YES” to allow Emergency operation

— 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 – Recommended to increase value to 120 seconds+

— Parameter #78 Differential UP Stop All Boilers – Set Value to 10 degrees

6. Parameters which should be set on all other boilers within the cascade:

Parameter #24 - Design Supply Maximum Limit - Maximum temperature for individual boilers

Parameter #72 – Permit Emergency Mode – must be turned “ON” on each invdividual boiler

Parameter #73 – boiler Address – Boiler address set to values 2 thru 16 – do not duplicate address on any two boilers

Parameter #74 – Emergency Setpoint – desired supply temp when in Emergency Mode (if enabled)



7.3 Cascade - start sequence

1. When the system temperature is less than Target Setpoint minus the value of CH Hysteresis (par. #7) the lead boiler in the cascade will start.

Cascade Parameter

DescriptionDefault Value

Range

7 CH Hysteresis 5.4°F 0-36°F

Table 15

The control will establish an initial Calculated Setpoint based upon the diff erence between the Target Setpoint and the measured system temperature. The larger the deviation between these two values will result in a larger response. This response will be linearly scaled between the values of Max Setpoint Offset Down (par.# 79) and Max Setpoint Offset Up (par.#80). The boiler will remeasure the diff erence between the Target Setpoint and the measured system temperature once a period of time equal to [Delay Period Start Next Boiler (par.#75) x Start Modulation Delay Factor (par.#81)] has passed. After this period of time has passed a new calculated setpoint will be targeted based upon the current conditions.

Cascade Parameter


Range

75 Delay Period Start Next Boiler 15 sec. 5 – 300 sec.

77 Diff erential Down Start Boiler 9°F 0 - 36°F

79 Max Setpoint Off set Down 7.2 0 - 36°F

80 Max Setpoint Off set Up 18°F 0 - 36°F

81 Start Mod Delay Factor 5 0 - 60

Table 16

2. The Managing boiler must wait to bring on the next boiler until a period of time equal to Delay Period Start Next Boiler (par.#75) has past. After this period of time has past the Managing boiler checks the power % of all boilers which are burning and if the system temperature is below the desired setpoint and the % power of the operating boilers is greater than the value of Next Boiler Start Rate (par.#82) then the next boiler in the cascade sequence is started. If system temperature is below Hyst Down Start Boiler (par.#77) then Delay Period Start Next Boiler (par.#75) will be ignored.

Cascade Parameter


Range

75 Delay Period Start Next Boiler 15 sec. 5 – 300 sec.

82 Next Boiler Start Rate 80% 10 – 100%

Table 17

This sequence of bringing on additional boilers within the cascade will be repeated.

7.4 Cascade - stop sequence

1. When the power (%) level of one boiler falls below the value of Next Boiler Stop Rate (par.#83) the last boiler brought on will be stopped. A delay period follows before any other boilers are stopped. This delay is equal to Delay Period Stop Next Dependent (par.#76)

Cascade Parameter


Range

76 Delay Period Stop Next Boiler 15 sec. 5 – 300 sec.

78 Hyst Up Stop Boiler 3.6°F 0 - 36°F

83 Next Boiler Stop Rate 30% 10 – 100%

Table 18

After the Delay Period, if the power (%) level of one boiler falls below the value of Next Boiler Stop Rate then another boiler is stopped and the Delay Period begins again. If system temperature is above Hyst Up Stop Boiler (par.#78) then Delay Period Stop Next Boiler (par.#76) will be ignored.



8 Start-up & Commissioning Settings


Frost Protection(parameter #89)

Default setting for Frost Protection is “Disabled”. When “Enabled” Frost Protection Setpoint will be actived when the temperature of the supply or return water sensor reaches Frost Protection Setpoint (see parameter#90 below).

Frost Protection Setpoint (parameter #90)

When the Supply or Return water temperature of the boiler reads temperatures below the value of Frost Protection Setpoint, both the Boiler and CH pump contacts will be energized. Should the temperature continue to fall an additional 9 degrees below the value of Frost Protection Setpoint the burner will start and operate at minimum power until both Supply and Return temperature sensors measure 9 degrees above the original Setpoint value of Frost Protection. Default value is 50°F and the parameter is adjustable from 34°F to 68°F.

DHW Max. Limit(parameter #37)

The maximum temperature limit for the domestic hot water. Default value is 140 °F. Adjustable range from 104 °F to 158 F. Note: Use parameter #48 to set the actual desired DHW temperature. This parameter is used to limit the user from being able to increase the domestic hot water temperature.

Fan Speed Maximum(parameter #92)

Maximum fan speed RPM – based upon Parameter #97 Appliance Model and Parameter #98 Gas Type (see below). This parameter is factory set and should not be adjusted.

Fan Speed Minimum(parameter #93)

Minimum fan speed RPM – based upon Parameter #97 Appliance Model and Parameter #98 Gas Type (see below). This parameter is factory set and should not be adjusted

Fan Speed Ignition(parameter #94)

Ignition Fan Speed is set based upon shorter exhaust/air-intake lengths. As your combined equivalent lengths increase the total straight length of pipe, number of fi ttings and pipe diameter may require higher ignition fan speeds. Altitude will also impact necessary fan speed at ignition. See Venting section of the installation manual for details. Initial fan speed is set by selecting the appropriate value for parameter #99 (Flue Length Range) once selected based upon installation specifi cs parameter #94 may be used to make smaller adjustments to the fan RPM. This parameter is factory set and should not be adjusted

Appliance Model(parameter #97)

The value for this parameter is based upon the Model SSB Boiler. SSB512 = 1SSB399 = 2SSB255 = 3SSB160 = 4SSB120 = 5SSB85 = 6Ensure the value for this parameter is set correctly for your model

Gas Type(parameter #98)

Set gas type to the appropriate value. NG = Natural GasLP = Liquid Propane Gas

Flue Length Range(parameter #99)

During commissioning, the value for Flue Length range must be set based upon the equivalent length of exhaust/air-intake pipe installed. See the Venting section of the installation manual for calculating the appropriate Flue Length Range based upon Model boiler installed, the straight length of pipe, number and type of fi ttings, the pipe diameter and the altitude of the installation. Refer to the installation manual, section 4.7.4 for fl ue length parameter ranges.

Table 19



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.

United States and Canada

Bosch Thermotechnology Corp.65 Grove StreetWatertown, MA 02472

Tel: 866-642-3198Fax: 954-776-5529www.boschheatingandcooling.com

BTC 438002101 B / 03.2018

bosch buderus ssb255399512 controls operations guide · 2018-06-28 · there are 6 onboard ch mode...

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