Different start and stop procedures depending on boiler type configuration

On initial start-up or after power failure the boiler control will be enabled and started if heating demand is required.  Depending on the boiler type selection the sensors “SupplyTemp” and “RetTemp” are required or optional, also the start and stop procedures are different, as shown in the next table.


Table 4.   Boiler Start procedures large water volume SYS-03 = 1

SYS-02

1

2

3

SupplyTemp

option

option

option

RetTemp

required

required

option

Start procedure

A

B

B

Stop procedure

E

F

F


Table 5.   Boiler Start procedures small water volume SYS-03 = 2

SYS-02

1

2

3

SupplyTemp

option

option

option

RetTemp

required

required

option

Start procedure

C

D

D

Stop procedure

E

F

F


The start and stop procedures of the different configurations are as follows:

Start procedure A:

  1. the pump starts
  2. the burner starts when “PumpStatus” is true (if “PumpStatus” is not available: when “PumpCmd” is on)
  3. “RetTemp” controls the boiler valve


Start procedure B:

  1. the burner starts
  2. the valve opens: when “SupplyTemp” > BST-04 (if “SupplyTemp” is not available, it opens directly)
  3. the pump starts: when “ValveEndSwitch” is true (if “ValveEndSwitch” is not available: after 120 sec. fixed time)


Start procedure C:

  1. the pump starts
  2. the burner starts: when “PumpStatus” is true (if “PumpStatus” is not available: when “PumpCmd” is on)
  3. BRT controls the boiler valve


Start procedure D:

  1. the valve opens
  2. the pump starts: when “ValveEndSwitch” is true (if “ValveEndSwitch” is not available: after 120 sec. fixed time)
  3. the burner starts: when “PumpStatus” is true (if “PumpStatus” is not available: when “PumpCmd” is on)


Stop procedure E:

  1. the burner stops
  2. the valve closes: after delay BPU-01 and “SupplyTemp” – “RetTemp” < BPU-02 (if “SupplyTemp” and “RetTemp” are the available)
  3. pump stops: after delay BPU-01 and “SupplyTemp” – “RetTemp” < BPU-02 (if “SupplyTemp” and “RetTemp” are available)


Stop procedure F:

  1. the burner stops
  2. the valve closes: after delay BPU-01 and SupplyTemp - RetTemp < BPU-02 (if “SupplyTemp” and “RetTemp” are available)
  3. the pump stops: when “ValveEndSwitch” is false (if “ValveEndSwitch” is not available: when “ValveControl” is closed)

Table 6.   Parameter List

Description

Value Range

Default Value

Unit

SYS-02: configuration boiler type

1 = minimum return temperature control

2 = maximum return temperature control

3 = no return temperature control

1...3

3

-

SYS-03: heat generator water volume

1 = large

2 = small

1 / 2

1

-

BST-03: maximum boiler supply temp. modulating stage

50...500

85

°C

BPU-01: pump off delay

0...3600

300

sec

BPU-02: temperature difference pump stop

0...50

5

K