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Krom Schroder
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BCU 560
Technical Information
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Krom Schroder BCU 560, BCU 565 Technical Information

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Burner control units BCU 560, BCU 565

Technical Information · GB
6 Edition 02.16
• For monitoring and controlling modulating or staged burners for multiple burner applications with a central air supply
• For directly ignited burners of unlimited capacity in intermittent or continuous operation
• Optionally with valve proving system
thermal NO
• Flexible range of applications due to parameterization possibilities
• PROFINET fieldbus connection using optional bus module
• Assume safety functions pursuant to EN746-2
• EU certified
• Certified for systems up to SIL 3 and PL e
x
®
operating mode to reduce the formation of

Contents

Burner control units BCU 560, BCU 565 ............... 1
Contents........................................2
1 Application.....................................5
1.1 Examples of application..........................7
1.1.1 Single-stage-controlled burner........................7
1.1.2 Two-stage-controlled burner ........................ 8
1.1.3 Modulating-controlled burner ........................9
1.1.4 Flame control using the temperature .................10
1.1.5 menox
1.1.6 PROFINET connection using bus module BCM ..........12
1.1.7 ON/OFF rotary impulse control for burners up to 360kW . 13
1.1.8 Modulating burner control . . . . . . . . . . . . . . . . . . . . . . . . . .14
2 Certification ................................... 15
3 Function...................................... 16
3.1 Connection diagram ...........................16
3.1.1 BCU560..F3 with ionization control in double-electrode
operation ............................................16
3.1.2 BCU560..F1......................................17
3.1.3 BCU560..F2 .....................................18
3.1.4 BCU565..F3 with ionization control in double-electrode
operation ............................................19
3.1.5 BCU565..F1..................................... 20
3.1.6 BCU565..F2 .....................................21
3.1.7 Flame control ................................... 22
3.2 BCU 560 program sequence ....................23
3.3 BCU 565 program sequence ....................24
4 Air control ....................................25
4.1 Capacity control ...............................26
4.1.1 BCU..F1/F2 ...................................... 26
4.1.2 BCU..F3 .........................................27
5 menox® low NOx mode .........................28
5.1 System structure and function....................28
5.2 BCU..D2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30
6 Valve proving system ........................... 31
®
mode to reduce NOx formation ..............11
6.1 Tightness control ..............................31
6.1.1 Test instant...................................... 32
6.1.2 Program sequence............................... 33
6.1.3 Test period t
6.1.4 Opening time t
6.1.5 Measurement time t
................................... 35
P
................................. 35
L
............................ 35
M
6.2 Proof of closure function........................38
6.2.1 Program sequence............................... 38
7 BCSoft .......................................39
8 Profinet ......................................40
8.1 BCU and bus module BCM......................41
8.2 GSD file for PLC configuration....................42
8.2.1 Modules for cyclic data exchange .................. 43
8.2.2 Indexes for acyclic communication ................. 48
9 Program step/status............................49
10 Fault signalling................................50
11 Parameters...................................53
11.1 Scanning the parameters.......................58
11.2 Flame control ................................58
11.2.1 Burner 1 FS1 flame signal switch-off threshold......... 58
11.2.2 Flame control................................... 59
11.2.3 High temperature operation ...................... 60
11.3 Behaviour during start-up ......................62
11.3.1 Burner 1 start-up attempts......................... 62
11.3.2 Burner application............................... 63
11.3.3 Safety time 1 t
11.3.4 Flame proving period 1 t
SA1 ............................................71
........................71
FS1
11.4 Behaviour during operation.....................72
11.4.1 Restart..........................................72
11.4.2 Minimum operating time t
........................73
B
11.5 Safety limits ..................................74
11.5.1 Low air pressure protection ....................... 74
11.5.2 Air pressure cut-out delay ........................ 74
11.5.3 Safety time during operation .......................75
11.6 Air control ...................................76
BCU 560, BCU 565 · Edition 02.16 2
= To be continued
▼
Contents
11.6.1 Pre-purge time tPV ................................76
11.6.2 Air flow monitoring during pre-purge ................76
11.6.3 Pre-ventilation time t
11.6.4 Post-ventilation time t
11.6.5 Capacity control..................................78
11.6.6 Running time selection ........................... 85
11.6.7 Running time ................................... 85
11.6.8 Low fire over-run ................................ 86
11.6.9 Controller enable signal delay time t
11.6.10 Air actuator control ..............................87
11.6.11 Air actuator can be activated externally on start-up ... 89
11.6.12 Air actuator in the event of fault ................... 89
11.6.13 Capacity control (bus) ........................... 90
11.7 menox
11.7.1 menox pre-ventilation time t
11.7.2 Switchover to menox
® ................................................95
VL..................................... 77
NL ................................... 77
.............. 86
RF
.................... 95
VLM
®
operating mode ............. 95
11.8 Valve check..................................96
11.8.1 Valve proving system ............................ 96
11.8.2 Relief valve (VPS) ................................ 96
11.8.3 Measurement time V
11.8.4 Valve opening time t
...........................97
p1
............................97
L1
11.9 Behaviour during start-up ......................98
11.9.1 Minimum pause time tBP ......................... 98
11.10 Manual mode ...............................99
11.10.1 Operating time in Manual mode .................. 99
11.11 Functions of terminals 50, 51, 65, 66, 67 and 68 ..100
11.11.1 Function of terminal 50 ...........................100
11.11.2 Function of terminal 51 ...........................100
11.11.3 Function of terminal 65 ..........................100
11.11.4 Function of terminal 66 ..........................101
11.11.5 Function of terminal 67...........................102
11.11.6 Function of terminal 68 ..........................103
11.12 Password..................................104
11.13 Fieldbus communication .....................104
12 Selection.................................... 105
12.1 Type code ..................................105
13 Project planning information....................106
13.1 Installation..................................106
13.2 Commissioning .............................106
13.3 Electrical connection ......................... 107
13.3.1 OCU ..........................................107
13.3.2 Safety current inputs.............................108
13.3.3 UVD control....................................109
13.4 Actuators .................................. 110
13.4.1 IC20..........................................110
13.5 Parameter chip card ......................... 110
13.6 Overload protection.......................... 110
13.7 Calculating the safety time t
SA.........................111
13.8 Fourth or switchable gas valve on BCU..F3 ........112
14 Accessories ..................................113
14.1 BCSoft ..................................... 113
14.1.1 Opto-adapter PCO 200 ...........................113
14.1.2 Bluetooth adapter PCO 300 .......................113
14.2 OCU ...................................... 113
14.3 Connection plug set.......................... 113
14.4 Stickers for labelling.......................... 114
14.5 “Changed parameters” stickers ................ 114
15 OCU ........................................115
15.1 Application ................................. 115
15.2 Function ....................................116
15.2.1 Manual mode ..................................116
15.3 Electrical connection ..........................117
15.4 Installation ..................................117
15.5 Selection ....................................117
15.6 Technical data for OCU ....................... 118
16 BCM 500 ....................................119
16.1 Application ................................. 119
16.2 Function ................................... 119
16.3 Electrical connection ......................... 119
16.4 Installation ................................. 119
16.5 Selection ...................................120
16.6 Technical data ..............................120
BCU 560, BCU 565 · Edition 02.16 3
Contents
17 Technical data ................................121
17.1 Electrical data ............................... 121
17.2 Mechanical data ............................122
17.3 Environment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122
17.4 Dimensions.................................122
17.5 Safety-specific characteristic values .............123
17.6 Converting units .............................124
18 Maintenance ................................ 125
19 Legend ..................................... 126
20 Glossary ................................... 127
20.1 Safety time on start-up t
20.2 Ignition time t
............................. 127
Z
20.3 Safety time during operation t
20.4 Safety interlocks ............................ 127
20.5 Safety shut-down ........................... 127
20.6 Safety shut-down with subsequent fault lock-out
(fault lock-out) .................................. 127
20.7 Warning signal .............................128
20.8 Timeout ...................................128
20.9 Lifting .....................................128
20.10 Air valve . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128
20.11 Diagnostic coverage DC .....................128
20.12 Operating mode ...........................128
20.13 Safe failure fraction SFF ......................129
20.14 Probability of dangerous failure PFH
20.15 Mean time to dangerous failure MTTF
Feedback .....................................130
Contact.......................................130
.................... 127
SA1
SB ..................... 127
.........129
D
........129
d
BCU 560, BCU 565 · Edition 02.16 4

1 Application

▼
Burner control unit with plug-in spring force connection terminals
Burner control units BCU 560 or BCU 565 control, ignite and monitor gas burners in intermittent or continuous operation. They can be used for directly ignited industrial burners of unlimited capacity. The burners may be modulating-controlled or stage-controlled. Their fast reaction to various process requirements makes the BCUs suitable for frequent cycling operation.
On industrial furnaces, they reduce the load on the central furnace control by taking over tasks that relate to the burner, for example they ensure that the burner ignites in a safe condition when it is restarted.
The air control on the BCU..F1, F2 or F3 assists the furnace control for cooling, purging and capacity control tasks.
The burner control units have an interface via which an air valve or actuator (IC20, IC40 or RBW) can be controlled for staged or modulating burner capacity control.
The BCU 565..F3 is equipped with air flow monitoring and
pre- and post-ventilation for use on self recuperative burners.
The program status, the unit parameters and the level of the
flame signal can be read directly from the unit. The burner or a connected control element can be activated manually using the integrated Manual mode for setting and diagnostic purposes.
Thanks to the optionally integrated valve proving system, the
valves can be checked for leaks by querying an external gas pressure switch or it can be checked whether the gas valve on the inlet side is closed.
Using the BCSoft program, the parameters, analysis and diagnostic information can be read from a BCU via the optionally available opto-adapter. All valid parameters are saved on an integrated parameter chip card. The parameter chip card can be removed from the old unit and inserted into a new BCU to transfer the parameters, for example when replacing the unit.
BCU 560, BCU 565 · Edition 02.16 5
Application
The monitored outputs for the actuator and valves are ac- commodated in a plug-in power module. This can simply be replaced if necessary.
Once the plug-in power module has been removed, the parameter chip card and fuses are accessible.
The BCU can be installed on a DIN rail in the control cabinet. Plug-in connection terminal strips on the BCU make it easier to install and remove.
The external operator-control unitOCU is available as an option
for the burner control units. The OCU can be installed in the control cabinet door instead of standard control units. The program status or fault messages can be read on the OCU. For burner adjustment, the operating points can be approached conveniently in Manual mode using the operator-control unit.
The address for the fieldbus communication is set using
three code switches.
The optional bus module BCM500 makes it possible to con-
nect the BCU to a fieldbus interface in a PROFINET network. Networking via the fieldbus enables multiple BCUs to be con­trolled and monitored by an automation system (e.g.PLC). The bus module is prepared for DIN rail installation. It is pushed on to the BCU from the side.
Thanks to the operator-control unitOCU, display functions and operation of the BCU can be relocated to the control cabinet door.
BCU 560, BCU 565 · Edition 02.16 6
Application
FCU 500
HT
P
Process control (PCC)
ϑ
A
1 2 3
38371817
BCU 565..F3
46
µC
49
50
47
V1 V2
VG
VG..L
PLC
VMV
ECOMAX
41
42
13 14
9
10
VR..R
TZI/TGI
PDZ
DG

1.1 Examples of application

1.1.1 Single-stage-controlled burner

Control: ON/OFF. The gas/air mixture is adjusted to the requirements of the
applications using the parameters of pre-ventilation and post- ventilation. The pressure switch monitors the air flow in the air supply line or in the flue gas exhaust.
BCU 560, BCU 565 · Edition 02.16 7
Application > Examples of application
Process control (PCC)
FCU 500
HT
P
ϑ
38371817
BCU 560..C0F3
46
µC
49
50
10
1 2 3
PLC
A
41
42
13 14
9 7
V1 V2
VAS VAG
VR..L

1.1.2 Two-stage-controlled burner

Control: ON/OFF or High/Low
The BCU provides the cooling and purg-
ing processes. The burner starts at low­fire rate. When the operating state is reached, the BCU advises the control unit. Depending on the parameter set­ting, the air valve is actuated to open and close by the program or externally via the input at terminal 2.
TZI/TGI
UVS
BCU 560, BCU 565 · Edition 02.16 8
Application > Examples of application
Process control (PCC)
FCU 500
DI
P
ϑ
38371817
BCU 560..C0F1
46
µC
49
50
52 53 54 55 56
1 2 3
PLC
A
41
42
13 14 15
9 7
V1
VAS VAG
VAS 1

1.1.3 Modulating-controlled burner

Control: continuous
V3
The BCU provides the cooling and purg-
ing processes. The BCU moves the but­terfly valve for air to ignition position. The
V2
burner starts at low-fire rate, a three­point step controller controls the burner capacity via the butterfly valve for air after the operating state has been signalled.
TZI/TGI
UVS
M
BCU 560, BCU 565 · Edition 02.16 9
Application > Examples of application
FCU 500..H1
M
HT
18
HT
HT
BCU 56x..D
49
5
µC
BCU 56x..D
49
5
µC
5-8
STM

1.1.4 Flame control using the temperature

In high temperature systems (temperature >750°C), the flame may be controlled indirectly via the temperature. As long as the temperature in the furnace chamber is below 750°C, the flame must be controlled by conventional methods.
If the temperature in the furnace chamber rises above the spontaneous ignition temperature of the gas/air mixture (>750°C), the FCU signals to the burner control units via the fail-safe HT output that the furnace system is in High tempera- ture mode (HT). When the HT input is activated, the burner control units switch to High temperature mode. They operate without evaluating the flame signal and their internal flame control is non-functional.
If the furnace temperature falls below the spontaneous ignition temperature (<750°C), the FCU disconnects the HToutput from the electrical power supply. There is no longer an active signal at the HT inputs of the burner control units. The flame signals are monitored once again by the UV sensor or ioniza­tion electrode.
In the event of a fault in a temperature monitoring component (e.g. sensor discontinuity, sensor short-circuit) or in the event of a mains failure, the flame control task is transferred to the burner control units.
BCU 560, BCU 565 · Edition 02.16 10
Application > Examples of application

1.1.5 menox® mode to reduce NOx formation

Process Control (PCC)
STM
AKT
M
IC 40 + BVH
VAD
BCU 565..D2
PZL
VAS..L
DG
VMV
TZI/
TGI
BIC..M
The burner control unit BCU 565 switches the burner BIC..M ON/OFF in cycles. Burner BIC..M is controlled without pneu- matic air/gas ratio control system. The gas supply pressure is controlled by the gas pressure regulatorVAD; the required burner capacity is set using the fine-adjusting valveVMV. The capacity is controlled by actuator IC40 and butterfly valveBVH. An air pressure switch upstream of the burner monitors the functioning of the butterfly valve. In addition, air/gas ratio monitoring for the zone or the furnace is required.
As soon as the safety temperature monitor STM signals a furnace temperature of ≥850°C(1562°F), the burner can be switched to flameless combustion (menox® low NOx mode) to significantly reduce NOx emissions.
Switching to menox
®
low NOx mode eliminates the counter­pressure by the flame in the ceramic tubeTSC. At a constant gas supply pressure, the gas volume increases by approxi­mately15%. In menox® low NOx mode, the butterfly valve moves to a smaller open position which has been adapted to the pressure ratios.
BCU 560, BCU 565 · Edition 02.16 11
Application > Examples of application
1
2 3
BCU 56x
BCM
BCU 56x
BCM
BCU 56x
BCM
PROFINET
L1
BUS
FCU
P
HT
PLC

1.1.6 PROFINET connection using bus module BCM

The bus system transfers the control signals from the auto- mation system (PLC) to the BCU/BCM for starting, resetting, controlling the air valve, purging the furnace or for cooling and heating during operation. In the opposite direction, it sends operating status, the level of the flame signal and the current program status.
Control signals that are relevant for safety, such as the safety interlocks, purge and HT input, are transferred independently of the bus communication by separate cables.
BCU 560, BCU 565 · Edition 02.16 12
Application > Examples of application
PZL PZH PZ
45
P
>750°
47 4858
DL
minDLPurge
PZL PDZ
DG DG
VAS
VAS
pu/2
DG DG DG
DG
46
1
ϑ
2
3
min
49 15 131450
DG
max
µC
FCU 500..F0
STM
M
VAS
BCU 560..F3
BCU 560..F3
VCG
VR..L
VCG
VR..L
1.1.7 ON/OFF rotary impulse control for burners up to 360kW
For processes which require a turndown of more than 10:1 and/or those which require heavy circulation of the furnace atmosphere to ensure a uniform tem-
M
perature, e.g. heat treatment furnaces operating at low and medium tempera­tures in the metallurgical industry.
With ON/OFF cyclic control, the capacity supplied to the process is controlled by means of a variable ratio of the operat­ing time to the pause time. In this type of control, the burner output pulse frequen­cy always maintains full momentum and results in maximum convection in the furnace chamber, even with regulated heating.
The pneumatic ratio control system con-
trols the gas pressure on the burner pro­portionally to the air pressure and thus maintains a constant air/gas ratio. At the same time, it acts as a low air pressure protection device.
The ignition and monitoring of the in-
dividual burners is ensured by burner
TE
control unit BCU560.
The centrally checked safety functions
such as pre-purge, tightness test, flow detector and pressure switch check (gas
min.
, gas
max.
, air
) are provided
min.
by the FCU500.
BCU 560, BCU 565 · Edition 02.16 13
Application > Examples of application
PZL PZH PZ
DG DG DG
min
49 15 131450
DG
max
µC
DG
1
ϑ
2
3
FCU 500..F1
STM
DL
minDLPurge
M
PZL PDZ
VAS
pu/2
45
P
57
16
>750°
TC
0°➔90°
53
90°➔0°
54 55
47 4858
VAS
M
VAS
BCU 560..F0
66
BCU 560..F0
66
VCG
VCG

1.1.8 Modulating burner control

For processes that do not require heavy circulation in the furnace, e.g. aluminium smelting furnaces.
This system is suitable for processes in
which infiltrated air may flow into the
M
furnace through switched off burners.
The capacity can be adjusted continu-
ously by activating the control element (analogue or 3-point step signal). The pneumatic ratio control system controls the gas pressure proportionally to the air pressure and thus maintains a constant air/gas ratio. At the same time, it acts as a low air pressure protection device.
One burner control unit per burner is required for ignition and monitoring.
The centrally checked safety functions
such as pre-purge, setting the valve to ignition position via a butterfly valve control system, tightness test, flow detec­tor and pressure switch check (gas gas
max.
, air
) are provided by the
min.
min.
,
FCU500.
DGDG
TE
BCU 560, BCU 565 · Edition 02.16 14
2 Certification
Certified to SIL and PL
For systems up to SIL 3 pursuant to EN 61508 and PL e pursu- ant to ISO 13849
EU certified pursuant to
– Gas Appliances Directive (2009/142/EC)
Meets the requirements of the
– Low Voltage Directive (2006/95/EC), – EMC Directive (2004/108/EC).
FM approved
Factory Mutual Research Class: 7400 Process Control Valves. Designed for applications pursuant to NFPA 85 and NFPA 86. www.approvalguide.com
Eurasian Customs Union
The products BCU 560 and BCU 565 meet the technical speci- fications of the Eurasian Customs Union.
BCU 560, BCU 565 · Edition 02.16 15

3 Function

3.1 Connection diagram

3.1.1 BCU560..F3 with ionization control in double- electrode operation
Alternative flame control, see page22 (Flame control).
Electrical connection, see page106 (Project planning infor­mation)
Explanation of symbols, see page126 (Legend)
Z
I
HT
P
0,6 × I
ϑ
A
p
u
PZL
GZL
2
P69
P70
P70
P72P71
P72P72
P73
N
1 2 3 4645 65 66 67 6849 50 51
5 6 9 11
61
c
24V
DC
c
230V
2AT
1210762
3,15AT
41 42
17 18 37 38
max. 1 A; 24
V
DC,
250 V AC
V3
88
µC
13 14 15
53 54
V2
V1
BCU 560..F3
0 V+24 V
NL1
BCU 560, BCU 565 · Edition 02.16 16
Function > Connection diagram
3.1.2 BCU560..F1
Alternative flame control, see page22 (Flame control). Detailed connection diagrams for actuators and frequency
converters, see from page78 (Capacity control) Electrical connection, see page106 (Project planning infor-
mation) Explanation of symbols, see page126 (Legend)
Z
I
ϑ
A
p
u
PZL
GZL
2
HT
P
P69
P70
P70
P72P71
P72P72
P73
1 2 3 4645 65 66 67 6849 50 51
5 6 9 11
61
c
24V
DC
c
230V
1210762
3,15AT
41 42
17 18 37 38
max. 1 A; 24
V
DC,
250 V AC
V3
88
µC
13 14 15
53 54 55 56
V2
V1
mA
52
0,6 × I
N

BCU 560..F1

(P40 = 2/3) => 51
0 V+24 V
NL1
BCU 560, BCU 565 · Edition 02.16 17
Function > Connection diagram
3.1.3 BCU560..F2
Alternative flame control, see page22 (Flame control). Detailed connection diagrams for actuators and frequency
converters, see from page78 (Capacity control) Electrical connection, see page106 (Project planning infor-
mation) Explanation of symbols, see page126 (Legend)
Z
I
HT
P
0,6 × I
ϑ
A
p
u
PZL
GZL
2
(P69 = 13)
P70P70
P72P71
P72P72
P73
N
1 2 3 4645 65 66 67 6849 50 51
52
5 6 9 11
61
c
230V
24V
DC
88
µC

BCU 560..F2

1210762
3,15AT
41 42
17 18 37 38
max. 1 A; 24 V DC, 250 V AC
c
V3
V2
V1
mA
0 V+24 V
NL1
AUTO
LO
COM
13 14 15
HI
53 54 55 56
BCU 560, BCU 565 · Edition 02.16 18
Function > Connection diagram
3.1.4 BCU565..F3 with ionization control in double- electrode operation
Alternative flame control, see page22 (Flame control) Electrical connection, see page106 (Project planning infor-
mation) Explanation of symbols, see page126 (Legend)
Z
I
ϑ
A
p
u
PZL
GZL
2
PZL
PZL
Air
min
HT
P
P70P70
P72P71
PDZ
PDZ
Air
P69
P72P72
P73
1 2 3
44
4645 4847 65 66 67 6849 50 51
5 6 9 11
62 61
c
24V
DC
88
7
c
2AT
1210
3,15AT
41 42
17 18 37 38
max. 1 A; 24 V DC, 250 V AC
V3
13 14 15
µC
53 54
V2
V1
52
0.6 × I
N
L1
BCU 565..F3
0 V+24 V
N
BCU 560, BCU 565 · Edition 02.16 19
Function > Connection diagram
3.1.5 BCU565..F1
Alternative flame control, see page22 (Flame control). Detailed connection diagrams for actuators and frequency
converters, see from page78 (Capacity control) Electrical connection, see page106 (Project planning infor-
mation) Explanation of symbols, see page126 (Legend)
Z
I
ϑ
A
p
u
PZL
GZL
2
PZL
PZL
Air
min
HT
P
P70P70
P72P71
PDZ
PDZ
Air
P69
P72P72
P73
1 2 3 4645 4847 65 66 67 6849 50 51
44
5 6 9 11
62 61
c
24V
DC
88
7
c
1210
3,15AT
41 42
17 18 37 38
max. 1 A; 24 V DC, 250 V AC
V3
13 14 15
µC
53 54 55 56
V2
V1
mA
52
0.6 × I
N
L1

BCU 565..F1

(P40 = 2/3) => 51
0 V+24 V
N
BCU 560, BCU 565 · Edition 02.16 20
Function > Connection diagram
3.1.6 BCU565..F2
Alternative flame control, see page22 (Flame control). Detailed connection diagrams for actuators and frequency
converters, see from page78 (Capacity control) Electrical connection, see page106 (Project planning infor-
mation) Explanation of symbols, see page126 (Legend)
Z
I
ϑ
A
p
u
PZL
GZL
2
PZL
PZL
Air
HT
0.6 × I
min
P
P70P70
P72P71
N
PDZ
PDZ
Air
(P69 = 13)
P72P72
P73
L1
1 2 3 4645 4847 65 66 67 6849 50 51
52
5 6 9 11
62 61
7
c
24V
DC
c
88
µC

BCU 565..F2

1210
3,15AT
AUTO
COM
41 42
max. 1 A; 24 V DC, 250 V AC
17 18 37 38
V3
13 14 15
LO
HI
53 54 55 56
V2
V1
mA
0 V+24 V
N
BCU 560, BCU 565 · Edition 02.16 21
Function > Connection diagram
1 2 3 4645 65 66 67 6849 50 51
41 42
5 6 9 11
1210762
61
Z
NL1
1 2 3 4645 65 66 67 6849 50 51
41 42
5 6 9 11
1210762
61
UVS
1 2 3
Z
NL1
1 2 3 4645 65 66 67 6849 50 51
41 42
5 6 9 11
1210762
61
ϑ
0 V
24 V
+–
0–20 mA
UVD1
1
2
4
3
5 6
Z
NL1

3.1.7 Flame control Ionization control in single-electrode operation

UVS control
UVD control
A voltage supply of 24 VDC is required to operate the UV sensor for continuous operation UVD1.
The 0 – 20mA current output can be used to display the flame
signal. The cable to the control room must be screened. The 0 – 20mA current output is not required for normal operation.
BCU 560, BCU 565 · Edition 02.16 22
Function

3.2 BCU 560 program sequence

Parameters 48 and 49 = 0: High/Low control during operation, cooling in standby
Example of application, see page8 (Two-stage-controlled burner)
Switch on BCU 560
▼
In the event of fault signal: reset
▼
00
P0
A0
H1
02
External actuation of the air valve for purging
External actuation of the air valve for cooling
Wait until the running time has elapsed (P42)
Safety interlocks
Start-up position/standby
▼
Flame simulation check
▼
▼
▼
Start-up with ϑ signal
▼
▼
Safety time 1 t
(P94) running,
SA1
ignition in process,
valves for 1st gas stage open.
▼
If no flame detected:
max. 3 start-up attempts (P07)
or fault lock-out
▼
03
Flame proving period 1 t
FS1
▼
running (P95)
In the event of flame failure:
fault lock-out
▼
04
Operation signalling contact closes,
valve for 2nd gas stage opens and
min. operating time tB starts to elapse (P61)
▼
In the event of flame failure:
restart or fault lock-out
▼
A4
External actuation of the air valve for capacity control
04
00
Controlled shut-down via ϑ signal
▼
If min. operating time tB has elapsed:
operation signalling contact opens,
gas valves close and
running time (P42) starts to elapse
BCU 560, BCU 565 · Edition 02.16 23
Function

3.3 BCU 565 program sequence

Switch on BCU 565
▼
In the event of fault signal: reset
▼
00
A0
The air actuator can be opened for cooling
00
H1
Wait until the running time has elapsed (air actuator
verification of air “no flow” state check
P1
A1
Pre-purge after safety shut-down running (P34)
Pre-ventilation time tVL running (P36),
A2
Safety interlocks
Start-up position/standby
▼
▼
Flame simulation check
▼
Start-up with ϑ signal
▼
in ignition position) (P42)
If P15 and P35 = 1 or 2:
▼
If P15 and P35 = 1 or 2:
air flow monitoring
▼
air actuator opens
▼
Safety time 1 t
running (P94),
SA1
ignition in process,
valves for 1st gas stage open.
▼
A3
A4
A4
A0
00
If no flame detected:
max. 3 start-up attempts (P07)
or fault lock-out
▼
Flame proving period 1 t
FS1
▼
running (P95)
In the event of flame failure:
fault lock-out
▼
Operation signalling contact closes,
valve for 2nd gas stage opens and
min. operating time tB starts to elapse (P61)
▼
In the event of flame failure:
restart or fault lock-out
Controlled shut-down via ϑ signal
▼
If min. operating time tB has elapsed:
operation signalling contact opens,
gas valves close and
running time (P42) starts to elapse
▼
Post-ventilation time tNL running (P39)
Air actuator is closed,
running time starts to elapse (P42)
BCU 560, BCU 565 · Edition 02.16 24

4 Air control

M
PZL PZH PZ
PZL PDZ
TE
M
FCU 500..F0
µC
P
DG DG DG
VAS
VAS
VCG
VCG
VR..L
VR..L
DG DG
DG
minDGmax
49 15 131450
45
47 4858
>750°
pu/2
DL
minDLPurge
BCU 5xx..F3
BCU 5xx..F3
ϑ
1
46
2
3
A central protective system such as the FCU500 takes over air control. It monitors the static air pressure as well as the air volume required for pre-purge, start-up and after the furnace has been shut down. The air actuators (BCU..F1 = actuators IC 20/40, BCU..F2 = RBW actuators, BCU..F3 = valve) are actuated for this purpose by the capacity control system of the BCU.
After being enabled by the protective system, the BCU can start the burners. The capacity is controlled during operation by an external temperature control system.
VAS
BCU 5xx..F3
49 15 131450
46
1
2
3
FCU 500
M
µC
P
>750°
DL
minDLPurge
PZL PDZ
DG DG
45
BCU 5xx..F3
BCU 560, BCU 565 · Edition 02.16 25
Air control
BCU 560..C0F1
µC
VAS VAG
TZI/TGI
V1
V2
V3
14 15
13
9 7
UVS
38371817
1 2 3
46
49
50
41
42
M
52 53 54 55 56
VAS 1
Process control (PCC)
ϑ
A
P
DI
FCU 500
SPS

4.1 Capacity control

4.1.1 BCU..F1/F2

system (FCU 500) starts the pre-purge time if there is adequate air flow. After the elapse of the pre-purge time, the control element moves to the ignition position. Once the protective system (terminal 46, safety interlocks) has issued the enable signal, the burner can be started by the start-up signal at terminal 1. The control element can be activated to control the burner’s capacity dependent on parameters 48 and 49.
Modulating control
Parameter 48 = 3 After the operating signal has been received from the burner
and after expiry of the delay time for the controller enable signal (parameter 44), the BCU issues the controller enable signal via the output at terminal 56. Access to the control ele­ment is thus transferred to an external temperature controller (3-point step). The temperature controller controls the burner capacity (air volume) on the basis of the required temperature. Depending on the wiring of the temperature controller, the actuator may be adjusted between maximum capacity and ignition capacity or minimum capacity.
Depending on parameter40, an actuator IC20, IC40, IC50 or an actuator with an RBW interface can be actuated via the outputs for capacity control. Detailed information about parameter 40, see from page78 (Capacity control).
The BCU..F1/F2 activates a control element via the outputs for capacity control (terminals 53 to56) for purging, cooling or starting the burner. This control element moves to the required position for the relevant operating situation.
As soon as there is a purge signal at terminal 50 of BCU..F1/ F2, the control element is activated by the outputs for capacity
Staged control
P48 = 0, 1 or 2 Depending on parameters 48 and 49, the control element may
be activated either by the program or externally via the input at terminal 2, see also from page87 (Air actuator control).
control to approach the position for pre-purge. The protective
BCU 560, BCU 565 · Edition 02.16 26
Air control > Capacity control
BCU 560..C0F3
µC
VAS VA G
TZI/TGI
VR..L
V1 V2
14
13
9 7
10
UVS
38371817
1 2 3
FCU 500
Process control (PCC)
46
49
50
P
HT
ϑ
41
42
A
SPS

4.1.2 BCU..F3

The BCU..F3 activates an air valve for purging, cooling or start- ing the burner. The required air capacity is released by the air valve.
As soon as there is a purge signal at terminal 50 of BCU..F3, the air valve is activated by the output at terminal 10. The protective system (FCU 500) starts the pre-purge time if there is adequate air flow. After the elapse of the pre-purge time, the air valve closes for ignition. Once the protective system (terminal 46, safety interlocks) has issued the enable signal, the burner can be started by the start-up signal at terminal 1. The gas valves for the 1st stage are opened and the burner is ignited (on the BCU..C1 after a successful valve check). After the operating
signal has been received from the burner, the gas valve for the 2ndstage opens.
Staged control
P48 = 0, 1 or 2 Depending on parameters 48 and 49, the control element may
be activated either by the program or externally via the input at terminal 2, see also from page87 (Air actuator control).
BCU 560, BCU 565 · Edition 02.16 27

5 menox® low NOx mode

▼
menox® low NOx mode leads to a drastic reduction in thermal NOx formation in ON/OFF-controlled high-velocity burners.

5.1 System structure and function

The system consists of a burner BIC..M with system compo- nents tailored to the application. The system components make it possible to operate the burner in two operating modes: conventional flame mode in low furnace temperatures and menox® low NOx mode with flameless combustion at higher furnace temperatures.
Process Control (PCC)
STM
AKT
VAD
M
VAS..L
BCU 565..D2
PZL
VMV
TZI/
TGI
BIC..M
The gas and air for flame mode and low NO
mode are sup-
x
plied via the same connections. The gas pressure upstream
of the burner is adjusted using a pressure regulator (e.g. VAD). The gas volume is set using a fine-adjusting valve (e.g. VMV). The air volume for the operating modes is set by adjusting
the butterfly valve (e.g. BVH). The air pressure is monitored
on each burner by a pressure switch to check the functioning
of the butterfly valve. In addition, air/gas ratio monitoring
for the zone or the furnace is required since the air pres-
sure switch is not sufficient for use as a low air pressure
protection device.
The menox
®
burner BIC..M has a special mixing unit whose geometric design ensures reliable ignition and a stable flame while also making sure that the combustion process is trans­ferred to the furnace chamber for menox® mode.
In menox
®
mode, the inflammable gas/air mixture must be prevented from igniting prematurely in the ceramic combustion chamber each time the burner is switched on. The flow velocity at the burner nozzle must be adequately high to prevent the danger of flashback into the combustion chamber. Burners BIC..M are tailored to the appropriate capacity and combined with tapered ceramic tubes (TSC..B).
IC 40 + BVH
DG
A burner BIC..M in conjunction with a burner control unit BCU..D2 is required for safe burner operation in menox® low NOx mode.
BCU 560, BCU 565 · Edition 02.16 28
menox® low NOx mode > System structure and function
850 1050 1250120011501100900 1000950
0
100
200
300
400
Furnace temperature [°C]
NO
x
[mg/m
3
, ref. 5% O
2
]
Flame mode
Natural gas, air preheating to 450°C
Flame mode
In order to heat up the furnace, the burner operates in flame mode.
The ignitable gas/air mixture is ignited using an electrical ignition spark and combusts inside and outside of the ce- ramic burner tube. The presence of the flame is monitored in compliance with EN746-2.
®
menox
mode
As soon as the combustion chamber temperature is ≥ 850°C, the burner control unit BCU..D2 can switch to menox® mode.
considerably larger and the reaction density considerably lower. This prevents the occurrence of peak temperatures which are responsible for high NOx values. Emissions of NOx are drastically reduced.
In menox® mode, NOx values can be reduced to below
150mg/m³ (reference value of 5% O2) even at a furnace tem-
perature of 1200°C and hot air at 450°C– without expensive additional piping. The high output pulse frequency and rotary impulse control ensure temperature uniformity which is of great advantage.
For further information on burner BIC..M, see www.docuthek.com
Gas and air are supplied through the same connections as in flame mode. No ignition takes place in the burner tube. The combustion process is relocated to the combustion chamber. The oxidation reactions take place without a visible flame. Compared to traditional flame mode, the reaction zone is
BCU 560, BCU 565 · Edition 02.16 29
menox® low NOx mode
38371817
1 2 3
46
50
41
44
42
ϑ
A
P

5.2 BCU..D2

The BCU coordinates the signals for starting the burner and the fail-safe monitoring of the burner in flame mode. In menox® mode, the BCU switches off the ignition device and flame control. The furnace chamber temperature must be monitored by a safety temperature monitor (STM) for menox® mode. This function must satisfy the requirements of a protective system pursuant to EN746-2.
Parameter 06 must be set to 5 to switch to menox® low NOx mode. The BCU..D2 must signal via terminal 49 that the required temperature for high temperature operation has been reached. A higher switching point of 850°C is required for menox® mode. menox® mode is enabled via the input at terminal 44: depending on parameter 64, the system is either switched over immediately or the next time the burner starts with the parameters of menox® pre-ventilation time, burner application and settings for the control element coordinated for menox® mode.
Parameter settings for switching between flame mode and menox® mode, see pages 63 (Burner application), 95 (menox pre-ventilation time tVLM) and 95 (Switchover to menox® operating mode).
Process control (PCC)
FCU 500
HT
BCU 565..C0F1
µC
49
SPS
44
If there is no signal at terminal 44, the system switches from menox® mode to flame mode.
If the enable signal for High temperature mode (HT mode) drops out as the furnace temperature falls, the BCU automati­cally switches from menox® mode to flame mode. To avoid a pressure surge in the gas supply due to several burners being switched off at the same time, it is recommended that the furnace control unit switches the burners to flame mode again zone by zone, for example.
Hot air compensation and ratio control are not the respon­sibility of the BCU. These functions must satisfy the require-
ments of a protective system pursuant to EN 746-2 and be implemented externally.
BCU 560, BCU 565 · Edition 02.16 30

6 Valve proving system

V2
p
u
V
p1
V1
PZ
p
u
2
The BCU500..C1 is fitted with an integrated valve proving system. This allows either the tightness of the gas solenoid valves and the pipework between them to be checked (tight- ness test) or the closed position of a solenoid valve (proof of closure function) to be checked.
Once the test has been carried out successfully, the burner enable signal is issued.
For details, see pages31 (Tightness control) and38 (Proof of closure function)

6.1 Tightness control

The aim of the tightness control is to identify an inadmissible
leak on one of the gas solenoid valves and to prevent burner start. Gas solenoid valves V1 and V2 are tested as is the pipe­work between the valves.
European standards EN 746-2 and EN 676 stipulate tightness controls for capacities over 1200kW (NFPA 86: from 117kW or
400,000 Btu/h). The tightness control function satisfies the requirements of
EN1643 (Valve proving systems for automatic shut-off valves for gas burners and gas appliances).
BCU 560, BCU 565 · Edition 02.16 31
Valve proving system > Tightness control
PZH
VAS
VAS 1
VAG
TZI/TGI
V1
V2
V3
p
u
/2
14 151345
9
V
p1

6.1.1 Test instant

Depending on the parameter setting, the tightness control checks the tightness of the pipework and the gas solenoid valves before each start-up and/or after each shut-down of the burner, see page96 (Valve proving system).
The gas line is always safeguarded by a gas solenoid valve during this check.
Before burner start-up
The valve check is started when the start-up signalϑ is present at terminal1. The BCU checks the tightness of the gas solenoid valves and the pipework between the valves. The gas line is always safeguarded by a gas solenoid valve during this check. The burner is ignited when pre-purge is ended and the tightness has been checked successfully.
After burner shut-down
After the burner has been shut down, the BCU checks the tight­ness of the gas solenoid valves and the pipework between them. Once the test has been carried out successfully, the next burner start is enabled. The BCU immediately conducts a tightness test if mains voltage is available or if it is reset after a fault lock-out.
An additional bypass/relief valve must be installed in gas sections with an air/gas ratio control. This ensures that the test volume V
can be vented during the tightness test with
p1
the air/gas ratio control closed.
BCU 560, BCU 565 · Edition 02.16 32
Valve proving system > Tightness control
▼
START
V1
tL = P59
V1
tM = P56
p
u
pZ >
2
+
V2
OK
V2
tL = P59
V2
tM = P56
+
Programm A Programm B
pZ >
V1 V2
–
V2
PZ
pu/2
–
p
u
2
p
z
V1
+
V2
tL = P59
V2
tM = P56
p
u
pZ >
2
–
V1
OK
V1
tL = P59
V1
tM = P56

6.1.2 Program sequence

The tightness test starts by checking the external pressure
switch. If pressure pZ> pu/2, programA starts. If pressure pZ < pu/2, programB starts, see page34 (Pro-
gram B).
Program A
Valve V1 opens for the opening timet
set in parameter59. V1
L
closes again. During the measurement time tM, the tightness control checks the pressurepZ between the valves.
If pressurepZ is less than half the inlet pressurepu/2, valveV2 is leaking.
If pressure pZ is greater than half the inlet pressurepu/2, valveV2 is tight. ValveV2 is opened for the set opening timetL. V2 closes again.
During the measurement time tM, the tightness control checks the pressurepZ between the valves.
If pressurepZ is greater than half the inlet pressurepu/2, valveV1 is leaking.
If pressurepZ is less than half the inlet pressurepu/2, valveV1 is tight.
The tightness test can only be performed if pressurepd down-
stream of V2 is around atmospheric pressure and the volume downstream of V2 is at least 5 × higher than the volume between the valves.
+
p
u
pZ >
2
–
V1
OK
BCU 560, BCU 565 · Edition 02.16 33
V1
V2
–
p
u
pZ >
2
+
V2
OK
Valve proving system > Tightness control > Program sequence
Program B
Valve V2 opens for the set opening timetL. V2 closes again. During the measurement time tM, the tightness control checks the pressurepZ between the valves.
If pressurep If pressure p
the set opening timetL. V1 closes again. During the measurement time tM, the tightness control checks
the pressurepZ between the valves. If pressurep If pressurep
The tightness test can only be performed if pressurepd down-
stream of V2 is around atmospheric pressure and the volume downstream of V2 is at least 5 × higher than the volume between the valves.
V1
tL = P59
V1
tM = P56
p
u
pZ >
2
+
V2
OK
START
+
Programm A Programm B
pZ >
V1 V2
PZ
pu/2
–
p
u
2
p
z
–
V2
V1
+
V2
tL = P59
V2
tM = P56
p
u
pZ >
2
–
V1
OK
>pu/2, valveV1 is leaking.
Z
< pu/2, valve V1 is tight. ValveV1 is opened for
Z
<pu/2, valveV2 is leaking.
Z
>pu/2, valveV2 is tight.
Z
V2
tL = P59
V2
tM = P56
+
p
u
pZ >
2
–
V1
OK
BCU 560, BCU 565 · Edition 02.16 34
V1
V2
tL = P59
tM = P56
–
pZ >
V1
V1
p
u
2
+
V2
OK
Valve proving system > Tightness control
P
13
1
4
4
5
p
u
/2
PZ
ϑ
1
pu/2
PZ
V
p1
V1 V2
p
u
p
z
p
d
▼

6.1.3 Test period tP

Depending on the burner capacity, the tightness of the gas so- lenoid valves must be checked in accordance with the relevant application standard, e.g. EN676, EN746, NFPA85 and NFPA86.
The test period tP is calculated from:
– Opening times t – Measurement times t
for V1 and V2,
L
for V1 and V2.
M
tP [s] = 2 x tL + 2 x t
M

6.1.4 Opening time tL

Standard EN1643:2000 allows a maximum opening time of 3s for the tightness test if the main gas valves are actuated directly. If gas can flow into the combustion chamber when a valve is opened, the gas volume must not exceed 0.083% of the maximum flow rate.
6.1.5 Measurement time t
M
The sensitivity of the tightness control in the BCU can be ad- justed for each individual system by adapting the measure- ment timetM. The longer the measurement timetM, the greater the sensitivity of the tightness control. The measurement time is set using parameter 56 to a value between 3 and 3600s, see page97 (Measurement time Vp1).
The required measurement time tM is calculated from:
Inlet pressure pu [mbar]
Leakage rate QL [l/h] Test volume Vp1 [l] Calculation of the test volume, see page36 (Test vol-
ume Vp1)
For one test volume V
between 2gas solenoid valves
p1
Adjustable using parameter56
t
M
[s] =
(
2 x pu x V
Q
p1
L
)
For a large test volume Vp1 with reduced testing time
Adjustable using parameter56
t
M
[s] =
0.9 x pu x V
(
Q
p1
L
)
Conversion into US units, see page124 (Converting units)
Leakage rate
The BCU tightness control makes it possible to check a specific
leakage rate QL. Within the scope of the European Union, the maximum leakage rate QL is 0.1% of the maximum flow rate Q
[m3/h].
(N)max.
Leakage rate QL [l/h] =
Q
(N)max.
[m3/h] x 1000 [l/h]
3
1000 x 1 [m
/h]
BCU 560, BCU 565 · Edition 02.16 35
Valve proving system > Tightness control > Measurement time tM
▼
Test volume Vp1
Test volume Vp1 is calculated from the valve volume VV, add- ed to the volume of the pipe VR for each additional metre in lengthL.
V
L
= VV + L x V
p1
R
Valves Pipework
Type Volume VV [l] DN
VAS 1 0.25 10 0.1 VAS 2 0.82 15 0.2 VAS 3 1.8 20 0.3 VAS 6 1.1 25 0.5 VAS 7 1.4 40 1.3 VAS 8 2.3 50 2 VAS 9 4.3 65 3.3 VG 10 0.01 80 5 VG 15 0.07 100 7.9 VG 20 0.12 125 12.3 VG 25 0.2 150 17.7 VG 40/VK 40 0.7 200 31.4 VG 50/VK 50 1.2 250 49 VG 65/VK 65 2 VG 80/VK 80 4 VK 100 8.3 VK 125 13.6 VK 150 20 VK 200 42 VK 250 66
Volume per metre
V
[l/m]
R
The measurement time required for the test volumeVp1 must
be set on the basis of the calculation using parameter56. For the calculation, see page37 (Calculation examples).
BCU 560, BCU 565 · Edition 02.16 36
Valve proving system > Tightness control > Measurement time tM
µC
131415
V
p1
VAS 665 VAS 665
p
u
= 50 mbar
Q
(N) max.
=
200 m
3
/h
DN65
9,5 m
Calculation examples
2 valves VAS 665, distance L = 9.5 m, inlet pressure pu = 50 mbar, max. flow rate Q
Leakage rate Q
=
L
Test volume V
= 200 m3/h.
(N)max.
3
200 m
/h x 1000 l/h
1000 x 1 m
= 1.1 l + 9.5 m x 3.3 l/m = 32.45 l
p1
see page36 (Test volume Vp1)
Measurement time for one test volume V
tM [s] =
2 x 50 mbar x 32.45 l
200 l/h
p1
= 16.23 s
Set the next highest value (20s) using parameter56, see page97 (Measurement time Vp1).
/h
= 200 l/h
3
BCU 560, BCU 565 · Edition 02.16 37
Valve proving system
13
14
ϑ
1
V1 V2
45
GZL

6.2 Proof of closure function

The proof of closure function monitors the function of the gas solenoid valveV1. The proof of closure function can be activated using parameter51=4, see page96 (Valve proving system).
A limit switch on gas solenoid valveV1 signals the closed position of the valve to the BCU (terminal 45) for this purpose.
By checking the closed position using the proof of closure function, the BCU complies with the requirements of NFPA85 (Boiler and Combustion Systems Hazards Code) and NFPA86 (Standard for Ovens and Furnaces).

6.2.1 Program sequence

When the start-up signalϑ is received at terminal1, the BCU checks that valve V1 is in its closed position using the POC switch. If a signal is not received at terminal45 from the POC switch after a timeout time of 10s (valve V1 is closed), the BCU performs a fault lock-out with fault messagec1.
As soon as the BCU has opened valve V1, it queries the open position of the valve via the POC switch. If a signal is still re- ceived at terminal45 from the POC switch after a timeout time of 10s, the BCU performs a fault lock-out with fault messagec8.
BCU 560, BCU 565 · Edition 02.16 38

7 BCSoft

The BCSoft engineering tool provides extended access to the BCU via the optical interface. BCSoft makes it possible to set device parameters on Windows-based PCs in order to adjust the BCU to the specific application. In addition, BCSoft provides extended access to the individual statistics and protocol func- tions.
In addition to the engineering tool BCSoft, an opto-adapter or Bluetooth adapter is required to read the device parameters in and out, see also page113 (BCSoft).
BCU 560, BCU 565 · Edition 02.16 39
8 Profinet
1
2 3
BCU 56x
BCM
BCU 56x
BCM
BCU 56x
BCM

PROFINET

L1
BUS
FCU
P
HT
PLC
Profinet is a manufacturer-independent, open standard for industrial Ethernet. It covers the requirements for automation technology (manufacturing automation, process automation, drive applications with or without functional safety).
Profinet is a bus variant for fieldbus communication, optimized for speed and low connection costs.
The basic function of Profinet is the exchange of process and required data between an IO controller (e.g. PLC) and several distributed IO devices (e.g. BCU/FCU).
The signals from the IO devices are read into the IO controller cyclically. There, they are processed and are then output to the IO devices again.
In addition to cyclic data exchange, Profinet also provides acyclic data exchange for events which are not constantly repeated such as sending parameter settings and configu- ration data when the IO devices start up or sending a diag- nostic message from the IO device to the IO controller during operation. The data read or written acyclically by read/write
services are specified by an index, see page48 (Indexes for acyclic communication).
The technical properties of an IO device are described by the
manufacturer in a device master data file (GSD file). The GSD file contains the device image, the communications properties and all fault messages from the IO device in text form which are important for the configuration of the Profinet network and the data exchange. The configuration is completed using an engineering tool which is supplied by the manufacturer of the IO controller. Modules defined in the GSD file may be selected for configuration to include them in the system, see also page42 (GSD file for PLC configuration).
BCU 560, BCU 565 · Edition 02.16 40
Profinet
BUS
FCU
P
HT
56
BCUBCM
L1,
M
ϑ
PROFINET
53 55 5254
90° ➔ 0
0 ➔ 90°
3PS
Temperature controller
PLC

8.1 BCU and bus module BCM

The optional bus module BCM 500 is required to integrate the BCU in the Profinet system.
Control signals (for start, reset and air actuator control), signal states from the device inputs and outputs and information about the device status (operating states, flame signal and current program step), warnings and faults can be transferred via the bus module between the BCU (IO device) and PLC (IOcontroller).
Bus module BCM 500 has two RJ45 connection sockets for connection to the fieldbus on its front. The connection sockets are combined with an internal 2-port switch. This allows the BCM500 together with the BCU to be integrated in various network topologies (star, tree or line topology). Requirements such as Auto Negotiation and Auto Crossover are satisfied.
Safety-related signals and interlocks (e.g. safety interlock) must be wired independently of the fieldbus communication direct to the BCU and the protective system (e.g. FCU).
All network components which connect the automation system and the field devices must be certified for Profinet use.
For information on planning and the structure of a Profibus network and the components to be used (e.g. cables, lines and switches), see Profinet Installation Guide at www.profibus.com.
BCU 560, BCU 565 · Edition 02.16 41
Profinet
8.2 GSD file for PLC configuration
Before commissioning, the Profinet system must be configured for data exchange using an engineering tool.
The device master data file (GSD) is required for the integra- tion of the BCU in the configuration of the PLC. The GSD file contains the device image and communications properties of the BCU. Modules defined in the GSD file may be selected for configuration to integrate the BCU, see page43 (Modules for cyclic data exchange).
The GSD file for the bus module can be ordered at www.docuthek.com. The steps required to integrate the file are described in the instructions for the engineering tool for your automation system.
For parameter settings on the BCU and code switch settings on the BCM, see page104 (Fieldbus communication).
BCU 560, BCU 565 · Edition 02.16 42
Profinet > GSD file for PLC configuration
▼

8.2.1 Modules for cyclic data exchange

The modules for cyclic data exchange are defined in the GSD file for the bus module BCM 500. All modules required for cyclic data exchange between the controller and the burner control units BCU 560 and BCU 565 are shown in the following table. The modules are assigned to the slots.
Module Slot
Input ad-
dress
Output ad-
dress
Inputs/outputs 1 n…n+2 n Burner 1 flame signal 2 n Free 3 n Status signal 4 n Fault and warning signals 5 n…n+1 Remaining times 6 n…n+1
TC remaining times
1)
7 n…n+1 PLC output information 8 n BCU input terminal informa- tion BCU output terminal informa- tion
1) Only for BCU..C1. Slot 7 is not transferred with other device ver-
sions.
9 n…n+2
10 n…n+1
BCU 560, BCU 565 · Edition 02.16 43
Profinet > GSD file for PLC configuration > Modules for cyclic data exchange
▼
“Inputs/outputs” module – slot 1
The digital input and output signals from the burner control units BCU 560, BCU 565 and BCU 580 are included in this module.
Input bytes (device ➔ controller)
The input bytes describe the digital signals which are trans- ferred from the BCU(IO device) to the digital inputs of the PLC (IO controller). The digital signals take up 2bytes (16bits).
Bit Byte n Byte n+1 Byte n+2 Format
Burner 1 operat-
0
ing signal
Free
1
BCU system
2
fault
3 Fault lock-out
Safety shut-
4
down
5 Warning
6 ON
Manual
7
mode
1)
Only with three-point step control via bus.
Max. capacity
reached
1)
Min. capacity
reached
1)
menox ON BOOL
Free BOOL
Air ON Free
Pre-purge ON Free
DI ON Free
Ready for op-
eration
Free Burner 1 flame
signal
Free
Free
Free
BOOL
BOOL
BOOL
BOOL
BOOL
BOOL
Output byte (controller ➔ device)
The output byte describes the digital signals which are output
by the PLC (IO controller) to the BCU (IO device). The digital sig­nals to control the burner control unit BCUoccupy 1byte (8bits).
Parallel to the bus communication, terminals 1 to3, 44 and 50 of the BCU can be wired. This allows the BCU to be con­trolled using the digital signals of the bus communication or the inputs at the terminals.
In the event that the bus communication is faulty or interrupted and during the initialization of the bus communication after switching on, the digital signals are interpreted as“0”. If the BCU is controlled using the inputs at the terminals during this time, the normal program runs even if the bus communication is faulty or interrupted.
Bit Byte n
0 Reset
1)
1 Burner 1 star 2 External air ON
1)
1)
Format
BOOL BOOL BOOL
3 Pre-purge ON BOOL
4 Free BOOL
5 menox ON BOOL
2)
2)
BOOL BOOL
6 Open control element, three-point step Open 7 Close control element, three-point step Close
1)
Parallel to the bus communication, terminals 1 to 3 can be
wired.
2)
Only with three-point step control via bus.
BCU 560, BCU 565 · Edition 02.16 44
Profinet > GSD file for PLC configuration > Modules for cyclic data exchange
▼
“Burner 1 flame signal” module (device ➔ controller) – slot 2
The flame signal is transferred from the BCU to the PLC as an analogue value using this module. The flame signal occupies one byte with values from 0 to255 (=flame signal from 0 to
25.5µA).
Bit Byte n Data type Format Value
0
1 2 3
Burner 1 flame signal
4
Byte DEC
0 – 255
(0 – 25.5 μA) 5 6 7
“Status signal” module (device ➔ controller) – slot 4
This module transfers the status signals from the BCU to thePLC. The status signals occupy one byte (0to255). Every status signal is allocated a code. The allocation is described in the code table “BCU56x_GSD_Codetabelle.xlsx”.
Bit Byte n Data type Format Value
0
1 2 3
Status signals Byte DEC
4
5
0 – 255
(see
code table “BCU56x_
GSD_Codetabelle.
xlsx” at
www.docuthek.com)
6 7
“Fault and warning signals” module (device ➔
controller) – slot5
The fault and warning signals are transferred from the BCUto
the PLC using this module. The fault and warning signals oc­cupy one byte each (0to255).
The allocation of the output codes to the fault and warning sig-
nals is described in the code table “BCU56x_GSD_Codetabelle. xlsx”. The same allocation table applies to the fault signals and the warning signals.
Bit Byte n Data type Format Value
0 1 2 3
Fault signals Byte DEC
4
5
0 – 255
(see
code table “BCU56x_
GSD_Codetabelle.
xlsx” at
www.docuthek.com)
6 7
Bit Byte n+1 Data type Format Value
0 1 2 3
Warning signals Byte DEC
4
5
0 – 255
(see
code table “BCU56x_
GSD_Codetabelle.
xlsx” at
www.docuthek.com)
6 7
BCU 560, BCU 565 · Edition 02.16 45
Profinet > GSD file for PLC configuration > Modules for cyclic data exchange
▼
“Remaining times ” module (device ➔ controller) – slot 6
This module transfers the remaining times of various processes from the BCU to thePLC. The remaining time occupies 2bytes.
Bit Byte n Byte n+1 Data type Format Value
0
1 2 3
Remaining times Word DEC
4
0 – 6554
(0 – 6554 s) 5 6 7
“Remaining times of the valve proving system” module
(device ➔ controller) – slot 7
Only for BCU..C1. The module in BCU..C0 contains no information. This module transfers the remaining time of the valve prov-
ing system from the BCU..C1 to thePLC. The remaining time
occupies 2bytes. The valve check runs parallel to other time-related processes,
e.g. pre-purge. To display the remaining time of the valve
proving system separately, it is transferred separately.
Bit Byte n Byte n+1 Data type Format Value
0 1 2
Remaining times
3
of the valve prov-
4
ing system
5
Word DEC
0 – 6554
(0 – 6554 s)
6 7
BCU 560, BCU 565 · Edition 02.16 46
Profinet > GSD file for PLC configuration > Modules for cyclic data exchange
“PLC output information” module (device ➔ controller) –
slot8
This module transfers information on signals which the PLC uses to control the BCU back to the PLC. This allows the signal transfer from the PLC to the BCUto be checked.
Bit Byte n
Format
0 Reset BOOL
1 Burner 1 start BOOL 2 External air ON BOOL 3 Pre-purge ON BOOL
4 Free BOOL
5 menox ON BOOL
1)
1)
BOOL BOOL
6 Open control element, three-point step Open 7 Close control element, three-point step Close
1)
Only with three-point step control via bus.
“BCU input terminal information” module (device ➔
controller) – slot 9
This module transfers the signal states of the digital inputs on the BCU(input terminals) to thePLC.
Bit Byte n Byte n+1 Byte n+2 Format
0 Terminal 1 Terminal 48
1 Terminal 2 Terminal 49 2 Terminal 3 3 Free
4 Terminal 44
5 Terminal 45 6 Terminal 46 7 Terminal 47
Terminal 50 Free Terminal 51 Free Terminal 52 Free Terminal 65 Free Terminal 66 Free Terminal 67 Free
Terminal 68
Free
BOOL BOOL BOOL BOOL BOOL BOOL BOOL BOOL
“BCU output terminal information” module (device ➔
controller) – slot 10
This module transfers the signal states of the digital outputs
on the BCU(output terminals) to thePLC.
Bit Byte n Byte n+1 Format
0 Terminal 9 1 Terminal 10 2 Terminal 13 Terminal 53
Terminal 42 Terminal 43
BOOL BOOL
1)
BOOL
3 Terminal 14 Terminal 54 BOOL
4 Terminal 15
5 Terminal 17/18 6 Terminal 37/38 7 Terminal 41
1)
Only for BCU..F2: terminal53 is used as an input. Bit 6 has no
function.
Terminal 55 Terminal 56 Terminal 57
Free
BOOL BOOL BOOL BOOL
BCU 560, BCU 565 · Edition 02.16 47
Profinet > GSD file for PLC configuration

8.2.2 Indexes for acyclic communication

With the help of acyclic communication between the PLC (IO controller) and BCU/FCU (IO devices), it is possible to read infor- mation on parameters, statistics and fault history on an event basis (e.g. using system function block Siemens FSB52RDREC).
The available data records differ in terms of their indexes.
Index Description 1001 Parameters 1002 Device statistics, counter 1003 Device statistics, faults/warnings 1004 Operator statistics, counter 1005 Operator statistics, faults/warnings 1006 Fault history 1007 Power module statistics
The contents and description of the indexes are described in the code table “GSD Codes BCU56x” (download from www.docuthek.com).
BCU 560, BCU 565 · Edition 02.16 48

9 Program step/status

1)
DISPLAY
00
A0
P0
H0
01
A1
0
A
A
P0
P1
A
H2
02
03
04
09
P9
U I
– –
1)
In Manual mode, two dots blink on the display.
2)
Air actuator (control element/valve) is open.
Program step/status Start-up position/standby
Cooling
2)
Pre-purge Delay Burner pause time t Pre-ventilation
BP
2)
Fan OFF check Low air pressure protection check
1
Approaching minimum capacity Approaching maximum capacity Pre-purge Pre-purge Approaching ignition capacity Delay Valve check Safety time 1 Flame proving period 1 t Burner 1 operation/controller enable Over-run up to minimum capacity Post-purge Remote control with OCU Data transfer (programming mode) Device Off
2)
FS1
2)
2)
BCU 560, BCU 565 · Edition 02.16 49

10 Fault signalling

▼
Fault message (blinking)
Burner 1 flame simulation
No flame after safety time 1
Flame failure during flame proving period1 t
Flame failure during burner 1 operation
Too many remote resets
Too many restarts
Controller enable output (terminal 56)
Simultaneous activation (terminals 51 and 52)
Actuator wiring (terminals 52 – 55)
Actuator feedback (terminal 52)
Simultaneous Min./Max. bus command
Non-fail-safe parameters (NFS) inconsistent
Fail-safe parameters (FS) inconsistent
Mains voltage
Faulty parameterization
Air valve control defective
Incompatible bus module
Power module defective
Fuse defective
Inlet valve(s) leaking
FS1
DISPLAY
01
02
03
04
10
11
20
21
22
23
24
30
31
32
33
34
35
36
39
40
Description
Flame simulation/flame signal before ignition No flame formation to end of 1st safety time
Flame failure during operation Remote reset activated >5× in 15min.
> 5 restarts in 15 minutes Controller enable output incorrectly connected/
supplied with power from an external source
“Maximum capacity” and “Ignition capacity” posi-
tion feedback from butterfly valve set simultane­ously
Faulty wiring of terminals 52 – 55 Maximum or ignition capacity is not constantly
signalled back to terminal52
“Open actuator” and “Close actuator” bus signals
set simultaneously NFS parameter range is inconsistent
FS parameter range is inconsistent
Operating voltage too high/low
Parameter set contains illegal settings
Relay contact error Device fuse F1 is defective Leak found on inlet valve
BCU 560, BCU 565 · Edition 02.16 50
Fault signalling
▼
Fault message (blinking)
Outlet valve(s) leaking
Pressure switch/gas valve wiring
Gas valve wiring
Safety interlock failure
Permanent remote reset
Timing cycle too short
Waiting for ignition position (LDS)
Wiring for multi-flame control
Incorrect voltage supply to terminal44
Internal error Internal error Internal error Internal error Internal error Internal error Internal error
emBoss
Minimum capacity not reached
Maximum capacity not reached
Ignition capacity not reached
Communication with bus module
Parameter chip card (PCC)
DISPLAY
41
44
45
51
52
53
54
56
57
80
89
94
95
96
97
98
99
A
A
A
E
Description
Leak found on outlet valve
Reversed valve connection
Remote reset input activated >25s Minimum timing cycle not observed
Faulty feedback signal of the control element po­sition for ignition capacity
Faulty wiring for multi-flame control menox® mode without HT signal Flame amplifier error/device error Error in processing internal data Error at digital inputs Error at digital outputs Error when checking the SFR Error when reading the EEProm Error when writing to the EEProm Shut-down without application error
Position for minimum capacity has not been reached after 255s Position for maximum capacity has not been reached after 255s Position for ignition capacity has not been reached after 255s
Bus module fault Incorrect or defective PCC
BCU 560, BCU 565 · Edition 02.16 51
Fault signalling
Fault message (blinking)
POC valve open
POC valve closed
Air monitor “no flow” state
Low air pressure
Low air pressure
Air flow during pre-purge
Waiting for connection
Invalid address
Invalid configuration
Invalid network name
Controller in STOP position
Burner 1 flame simulation
No flame after safety time 1
Flame failure during flame proving period 1
Flame failure during burner 1 operation
DISPLAY
1
8
0
1
2
,
4
,
6
,
8
P
0
1
2
3
4
F 1
F 2
F 3
F 4
Description
Valve not closed Valve not open
Fault Air monitor “no flow” state check Fault Air monitor operating check
3
,
Low air pressure during program step 2, 3, 4, 5,
5
,
6, 7 or8
7
,
Air flow failure during pre-purge
BCU waiting for connection to controller Invalid or incorrect address set on bus module
The bus module has received an incorrect con­figuration from the controller
Invalid network name or no address allocated in the network name
Controller in STOP position
Burner 1 flame simulation during multi-flame control No flame during safety time 1 during multi-flame
control Flame failure during flame proving period 1 dur­ing multi-flame control Flame failure during burner 1 operation during multi-flame control
BCU 560, BCU 565 · Edition 02.16 52

11 Parameters

▼
Any changes to parameters will be saved to the parameter chip card.
Name Parameter Value range Description
Burner 1 FS1 flame signal switch-off
threshold
Flame control 04
High temperature operation 06
Burner 1 start-up attempts 07
Restart 09
Low air pressure protection 15
Air pressure cut-out delay 16
Safety time during operation 19 0; 1; 2 Time in seconds 1 menox pre-ventilation time tVLM 28 0 – 250 Time in seconds 0 Pre-purge time tPV 34 0 – 6000 Time in seconds 6000
Air flow monitoring during pre-
purge
Pre-ventilation time tVL 36 0 – 250 Time in seconds 0
01 0 – 20
0
1 2 0 2 3 5
1 2 3 0
1 4 0
1 2 0
1
0
35
1 2
Burner 1 FS1 flame signal switch-off thresh­old in µA Ionization electrode UVS sensor UVD sensor
Off
Intermittent operation with UVS
Continuous operation with ionization/UVD
menox intermittent
1 start-up attempt 2 start-up attempts 3 start-up attempts Off
Burner 1 Max. 5× for burner 1 in 15min.
Off With safety shut-down With fault lock-out Off On
Off With safety shut-down With fault lock-out
Factory default
settings
2
(5 when P04 = 1)
0
0
1
0
2
2
BCU 560, BCU 565 · Edition 02.16 53
Parameters
▼
Name Parameter Value range Description
Post-ventilation time tNL 39 0; 1; 2; 3 Time in seconds 0
0
1
Capacity control 40
Running time selection 41
Running time 42 0 – 250
Low fire over-run 43
Controller enable signal delay time tRF
44 0 – 250 Time in seconds 0
2 3 5 0
1
2
3
0
1 2 3 4 5 6 7 8 9
10
Off With IC 20 With IC 40 With RBW With air valve Off; checking the positions for minimum/
maximum capacity
On; for approaching the positions for mini-
mum/maximum capacity
On; for approaching the position for maxi-
mum capacity
On; for approaching the position for mini-
mum capacity Running time in seconds if parameter 41 = 1, 2 or 3
Off
Up to minimum capacity 1 s 2 s 3 s 4 s 5 s 10 s 20 s 30 s 40 s
Factory default
settings
BCU..F0 = 0
BCU..F1 = 1 BCU..F2 = 3 BCU..F3 = 5
30
0
1
BCU 560, BCU 565 · Edition 02.16 54
Parameters
▼
Name Parameter Value range Description
Air actuator control 48
0
1 2 3
Opens on external activation Opens with valve V1 (1 Opens with valve V2 (2nd stage) Controller enable following operating sig-
st
stage)
Factory default
settings
nal or in standby
Air actuator can be activated exter-
nally on start-up
49
Air actuator in the event of fault 50
Valve proving system 51
Relief valve (VPS) 52
Measurement time Vp1 56
0
1 0
1 0
1 2 3
4 2 3 3
5 – 25
30 – 3600
Cannot be activated Can be activated externally Cannot be activated Can be activated externally Off Tightness test before start-up Tightness test after shut-down Tightness test before start-up and after
shut-down
Proof of closure function V2 V3 Time in seconds
in 5 s steps
in 10 s steps
Valve opening time tL1 59 2 – 25 Time in seconds 2
Minimum operating time tB 61 0 – 250 Time in seconds 0 Minimum pause time tBP 62 0 – 3600 Time in seconds 0
®
Switchover to menox mode
operating
64
Operating time in Manual mode 67
Function of terminal 50 68
0
0
23
24
On next burner start
1
Immediately
Unlimited
1
5 minutes
Purge with Low signal
Purge with High signal
0
0
1
0
2
10
1
1
24
BCU 560, BCU 565 · Edition 02.16 55
Parameters
▼
Name Parameter Value range Description
Function of terminal 51 69
0 8
9 10 13
Off AND with emergency stop (trm.46) AND with air AND with air flow monitoring (trm.48) Max. capacity position feedback (IC40/
RBW)
Function of terminal 65 70
Function of terminal 66 71
Function of terminal 67 72
0
8
9 10
0
8
9 10
20
0
8
9 10 21
Off AND with emergency stop (trm.46) AND with air AND with air flow monitoring (trm.48) Off AND with emergency stop (trm.46) AND with air AND with air flow monitoring (trm.48)
LDS ignition position check Off AND with emergency stop (trm.46) AND with air AND with air flow monitoring (trm.48) Multi-flame control (MFC) start-up condi-
tions
Function of terminal 68 73
0 8
9 10 22
Off AND with emergency stop (trm.46) AND with air AND with air flow monitoring (trm.48) Multi-flame control (MFC) operating condi-
tions
(trm.47)
min.
(trm.47)
min.
(trm.47)
min.
(trm.47)
min.
(trm.47)
min.
Factory default
settings
0
0
0
0
0
BCU 560, BCU 565 · Edition 02.16 56
Parameters
Name Parameter Value range Description
Capacity control (bus) 75
0
1
2
3
4
5
Off MIN. to MAX. capacity; standby in position
for MIN. capacity
MIN. to MAX. capacity; standby in CLOSED
position
IGNITION to MAX. capacity; standby in CLOSED position MIN. to MAX. capacity; standby in position
for MIN. capacity; burner quick start
IGNITION to MAX. capacity; standby in
Factory default
settings
0
CLOSED position; burner quick start
Password 77 0000 – 9999 Four-digit number code 1234
Burner application 78
Fieldbus communication 80
0
1
4
11 12 13
0
1
2
Burner 1
Burner 1 with pilot gas Two-stage burner 1 1/0 in menox and 1/0 in flame mode 1/0 in menox and L/H/O in flame mode 1/0 in menox mode with 2 gas paths Off With address check
No address check
1
1
Safety time 1 tSA1 94 2, 3, 5, 10 Time in seconds 5 Flame proving period 1 tFS1 95 0 – 20 Time in seconds 2
BCU 560, BCU 565 · Edition 02.16 57
Parameters

11.1 Scanning the parameters

During operation, the 7-segment display shows the program step/status.
All the parameters of the BCU can be scanned in numerical order by repeatedly pressing the Reset/Information button (for 1s).
The parameter display is ended 60seconds after the last time the button is pressed or by switching off theBCU.
The BCU indicates when the mains switch has been switched off. The parameters cannot be scanned when the BCU is switched off or when a fault message is displayed.

11.2 Flame control

The BCU is fitted with a flame amplifier which evaluates whether an adequate flame signal is supplied by the burner using an ionization electrode or UV sensor.
11.2.1 Burner 1 FS1 flame signal switch-off threshold
Parameter 01 The sensitivity at which the burner control unit detects a flame
can be set using parameter01. In the case of UV control, this value can be increased, should
the burner to be monitored be influenced by other burners for example.
During operation
If the measured flame signal falls below the set value (2 to 20µA) during operation after elapse of the safety time during operation (parameter 19), the BCU performs a safety shut-down with subsequent fault lock-out or a restart. The restart function can be defined using parameter09, see page72 (Restart).
During start-up
If the measured flame signal falls below the set value (2 to 20µA) during the start-up after elapse of the safety time, the BCU performs a safety shut-down with subsequent fault lock- out or up to two further start-up attempts. The number of start-up attempts can be defined using parameter07, see page62 (Burner 1 start-up attempts).
BCU 560, BCU 565 · Edition 02.16 58
Parameters > Flame control

11.2.2 Flame control

Parameter 04 Parameter 04 = 0: flame control is performed with an ioniza-
tion electrode. Parameter 04 = 1: flame control is performed with a UV sen-
sor for intermittent operation (UVS). For intermittent operation, the operating state of the complete system is limited to 24 h pursuant to EN298. To meet the requirement for intermittent operation, the burner is shut down and restarted automati- cally after a continuous operating time of 24hours if it is not operated in compliance with the standard. The restart does not meet the requirements of EN298 for UV sensor continu- ous operation because the required self-test (at least once per hour) is not performed while the burner is operating. This shut-down and subsequent restart are performed in the same way as a normal controlled shut-down. Depending on the parameterization, the burner is started with or without pre- purge. This process is controlled independently by the BCU and therefore it must be checked whether the industrial process permits the pause in heat supply it creates.
Parameter 04 = 2: flame control is performed with a UV sensor for continuous operation (UVD).
The reaction times of the BCU and UV sensor for continuous operation are coordinated so that the set safety time during operation (parameter 19) is not extended.
BCU 560, BCU 565 · Edition 02.16 59
Parameters > Flame control
FCU 500..H1
M
HT
18
HT
HT
BCU 56x..D
49
5
µC
BCU 56x..D
49
5
µC
5-8
STW
t
SA1
t
Z
88 04 02 03 00
ϑ
t
t
FS1
1
46
11
9 5 13
V1
14 V2
49
HT
11 L1
42
41
▼

11.2.3 High temperature operation

Parameter 06 Operation of firing systems above 750°C. The BCU..D1 and
BCU..D2 have a fail-safe input with the function “High tempera- ture operation”. If firing systems are operated above 750°C, the system is considered to be an item of high temperature equipment (see EN746-2). Here, flame control must be in op- eration until the furnace wall temperature has exceeded 750°C.
Below 750°C, the flame is monitored by conventional means (UV sensor or ionization electrode). In High temperature mode (>750°C), the flame may be controlled via the temperature using a safety temperature monitor (STM) in order to increase the system’s availability. This means that no incorrect flame signals, e.g. signals from a UV sensor which interprets reflected UV radiation as extraneous signals, may lead to faults.
without evaluation of the flame signal. The safety function of the device-internal flame control system is deactivated.
In High temperature mode, the gas valves are opened and the burners are started as usual without monitoring the pres­ence of a flame.
The precondition for this operating mode is that an external
flame supervision device ensures the presence of the flame in a fail-safe manner indirectly via the temperature. For this purpose, we recommend a safety temperature monitor with double thermocouple (DIN 3440). The flame must be moni­tored again by conventional means (UV sensor or ionization electrode) in the event of sensor discontinuity or short-circuit, failure of the safety temperature monitor or power failure.
Only if the temperature at the furnace wall has exceeded
750°C may voltage be applied to the HT input (terminal 49)
so as to activate High temperature mode.
When the HT input is activated (terminal 49), the burner control unit reverts to High temperature mode, i.e.: the BCU operates
BCU 560, BCU 565 · Edition 02.16 60
If the temperature in the furnace chamber drops below 750°C, the HTinput must be disconnected from the electrical power supply and the furnace must then be operated with flame control.
Parameters > Flame control > High temperature operation
t
SA1
t
Z
88 04 04 02 03 01
ϑ
t
t
FS1
1
46
11
9 5 13
V1
14 V2
t
W
49
HT
11 L1
42
41
88 04 04
ϑ
t
1
46
11 L1
9 5 13
V1
14 V2
49
HT
42
41
t
SA1
t
Z
88 02 0304
ϑ
t
t
VLM
1
46
11
L1
9 5 13
V1
14
V2
01
49 44
04
t
FS1
HT
42
41
04
t
04 88
ϑ
1
46
11
L1
9 5 13
V1
14 V2
49
HT
42
41
The BCU then responds, depending on setting: Parameter 06 = 0
The High temperature mode function is switched off. Flame control takes place dependent on the setting in parameter 04 (by ionization electrode, UVS sensor or UVD sensor).
Parameter 06 = 2 (BCU..D1)
The BCU switches off the burner and restarts with flame simula- tion check (recommended in the case of UV control with UVS).
Parameter 06 = 3 (BCU..D1)
The burner remains in operation and the BCU performs flame
control again (recommended in the case of ionization control or UV control with UVD).
Parameter 06 = 5 (BCU..D2)
The BCU switches off the burner and restarts with the menox
pre-ventilation time t
set in parameter 28.
VLM
If no flame signal is present when High temperature mode is deactivated, the burner control unit performs a fault lock-out, regardless of parameter 06.
BCU 560, BCU 565 · Edition 02.16 61
Parameters
t
SA1
t
Z
02 00
t
04
88
ϑ
1
46
11
L1
9 5
42
13
V1
14 V2 41
t
SA1
t
Z
02 00
t
t
SA1
t
Z
88
ϑ
1
46
11
L1
9 5
42
13
V1
14 V2 41

11.3 Behaviour during start-up

11.3.1 Burner 1 start-up attempts

Parameter 07 This parameter defines the maximum number of possible
start-up attempts of the burner.
Up to three start-up attempts are possible in certain condi- tions. In accordance with EN746-2, a restart may be con- ducted only if the safety of the installation is not impaired. Note the requirements of the Standards!
If no flame is detected during start-up, an immediate fault lock-out (P07=1) or up to two additional start-up attempts (P07=2,3) are performed depending on parameter07.
Parameter 07 = 1: 1 start-up attempt.
Parameter 07 = 2, 3: 2 or 3 start-up attempts.
If no flame is formed during the start-up so that at the end of the safety timet
no flame signal is detected, the BCU closes
SA1
the gas valves and repeats the start-up. Each start-up attempt begins with the parameterized start-up behaviour.
If the safety timet
elapses without a flame signal having
SA1
been detected, even after the last parameterized start-up attempt, this will result in a BCU safety shut-down with sub­sequent fault lock-out. The fault message 04 will flash in the BCU display depending on the burner operating mode.
If no flame is formed during the start-up so that at the end of the safety time t
no flame signal is detected, this will result
SA1
in a BCU safety shut-down with subsequent fault lock-out. The fault message 04 will flash in the BCU display depending on the burner operating mode.
BCU 560, BCU 565 · Edition 02.16 62
Parameters > Behaviour during start-up
V1
V2
14 1513
V1
V2
V3
14 1513
▼

11.3.2 Burner application

Parameter 78 This parameter enables the BCU to be adjusted to various
burner applications. In addition, an optional pilot gas valve (V3) can be parameterized via which the burner is started with a defined ignition capacity.
Parameter 78 = 0: Burner 1. Two valves (V1,V2) are included for the burner. These are connected to the valve outputs (terminals
13 and14). Valves V1 and V2 are opened in parallel to start
the burner in order to release the gas supply to the burner.
030201 04
9 13
1
14
2
15
3
5 17-18
t
BP
SA1
FS1
t
t
t
Parameter 78 = 1: Burner 1 with pilot gas. Three valves (V1, V2 andV3) are included for a burner with a pilot gas valve. These are connected to the valve outputs (terminals 13, 14 and15). Valves V1 and V3 open to start the burner. The burner is started with a limited ignition capacity using gas valveV3. After the elapse of the safety time t
(program step02), valve V2 opens.
SA1
Valve V3 limits the ignition capacity. After the elapse of the flame proving period t
(program step04), it is closed again.
FS1
For this application, it must be ensured that the flame proving period (P95) is set to a value ≥2s.
030201 04
9 13
1
14
2
15
3
5 17-18
t
BCU 560, BCU 565 · Edition 02.16 63
BP
SA1
FS1
t
t
t
Parameters > Behaviour during start-up > Burner application
V1
V2
V3
14 1513
▼
Parameter 78 = 4: two-stage burner 1. Three valves (V1, V2 andV3) are included for a two-stage burner. These are con- nected to the valve outputs (terminals 13, 14 and15).
030201 04
9 13
1
14
2
15
3
5 17-18
t
BP
SA1
FS1
t
t
t
Valves V1 and V3 open to start the burner. The burner is started with a limited ignition capacity using gas valveV3. After the flame proving period t
has elapsed, valve V2 opens to en-
FS1
able the 2nd gas stage.
BCU 560, BCU 565 · Edition 02.16 64
Parameters > Behaviour during start-up > Burner application
▼
Parameter 78 = 11: 1/0 in menox and 1/0 in flame mode. Burner is operated On/Off in flame mode and in menox®.
Process Control (PCC)
PLC
HT
BCU 565..F1
µC
FCU
V1 V2
14134944
STM
47
51 52 53 55
M
IC 40 + BVH
PZL
DG
In flame mode (< 850°C), the burner is started conventionally (as when P78 = 0) with the pre-ventilation time defined in parameter 36. The air control valve is in the ”high” position for flame mode.
0302 04
49
HT
44
ϑ
1 9
1
13 14
2
55
M
53 52 51
PZL
47
t
t
FS1
SA1
t
BCU 560, BCU 565 · Edition 02.16 65
Parameters > Behaviour during start-up > Burner application
▼
The switchover from flame to menox® mode is performed either immediately or the next time the burner is started de- pending on the setting made in parameter 64. To switch to menox® mode, the HT signal from the STM (terminal 49) and the menox® signal from a separate control unit (terminal 44) must be applied to the BCU.
In menox® mode, the burner is started with the pre-ventilation time defined in parameter 28. The air control valve is in the
“middle” position for menox® mode. No ignition using the
transformer takes place during safety time tSA. The gas valves V1 and V2 are opened at the start of the safety time tSA.
0302 04
49
HT
44
ϑ
1 9
1
13 14
2
55
M
53 52 51
PZL
47
t
SA1
t
FS1
t
t
high
middle
low
closed
DI 1 DI 2
t
1
2
t
3
t
4
t
t
5
6
t [s]
t [s]
BCU IC40 (operating mode 6)
Signal from
terminal
Position Butterfly valve position
55 53
OFF OFF closed Closed ON OFF low
Closed OFF ON middle menox ON ON high Flame
Wiring of BCU/IC 40, see page81 (Parameter 40 = 2: with IC40.)
An IC 40 with operating mode 06 is used as the actuator. The relevant position is approached via terminals 53 and55 of the BCU. The air pressure switch and the position of the IC are checked by terminals 48, 51 and52 of the BCU. The BCU signals a fault if the desired state is not reached within the time set in parameter42.
BCU 560, BCU 565 · Edition 02.16 66
Parameters > Behaviour during start-up > Burner application
▼
Parameter 78 = 12: 1/0 in menox and L/H/O in flame mode. Low/High/Off burner operation in flame mode and On/Off control in menox® mode.
Process Control (PCC)
47
51 52 53 55
STM
V1
M
IC 40 + BVHS
V3
V2
PZL
PLC
HT
BCU 565..F1
µC
FCU
14 15134944
In flame mode (< 850°C), the burner is started conventionally (as when P78 = 4) with the pre-ventilation time defined in parameter 36. The air control valve is set to the ”low” position. Valves V1 and V3 then open. The burner is started with a limited ignition capacity using gas valveV3. After the flame proving period t
has elapsed, valve V2 opens to enable the 2nd gas
FS1
stage and the air control valve is moved to the ”high” position.
0302 04
49
HT
44
ϑ
1 9 13
1
14
2
15
3
55
M
53 52 51
PZL
47
t
t
FS1
SA1
t
BCU 560, BCU 565 · Edition 02.16 67
Parameters > Behaviour during start-up > Burner application
FS1
SA1
▼
The switchover from flame to menox® mode is performed either immediately or the next time the burner is started de- pending on the setting made in parameter 64. To switch to menox® mode, the HT signal from the STM (terminal 49) and the menox® signal from a separate control unit (terminal 44) must be applied to the BCU.
In menox® mode (> 850°C), the burner is started with the pre- ventilation time defined in parameter 28. The air control valve is set to the ”middle” position. No ignition using the ignition transformer takes place during safety time t V1, V2 and V3 are opened at the start of the safety time t
. Gas valves
SA1
SA1
.
0302 04
49
HT
44
ϑ
1 9 13
1
14
2
15
3
55
M
53 52 51
PZL
47
t
t
t
t
high
middle
low
closed
DI 1 DI 2
t
1
2
t
3
t
4
t
t
5
6
t [s]
t [s]
BCU IC40 (operating mode 6)
Signal from
terminal
Position Butterfly valve position
55 53
OFF OFF closed Closed ON OFF low
Closed OFF ON middle menox ON ON high Flame
Wiring of BCU/IC 40, see page81 (Parameter 40 = 2: with IC40.)
An IC 40 with operating mode 6 is used as the actuator. The relevant position is approached via terminals 53 and55 of the BCU. The positions are checked by terminals 51 and52 of the BCU. The BCU signals a fault if the relevant position is not reached within the time set in parameter42.
BCU 560, BCU 565 · Edition 02.16 68
Parameters > Behaviour during start-up > Burner application
▼
Parameter 78 = 13: 1/0 in menox mode with 2 gas paths. On/Off burner operation with different gas paths in flame and in menox® mode.
Process Control (PCC)
PLC
BCU 565..F1
FCU
V1
HT
µC
STM
V3
V4
1557134944
V3
47
51 52 53 55
M
IC 40 + BVH
PZL
In flame mode (< 850°C), the burner is started conventionally with the pre-ventilation time defined in parameter 36. The air control valve is set to the "high" position for this purpose.
0302 04
49
HT
44
ϑ
1 9 13
1
15
3
57
4
55
M
53 52 51
PZL
47
t
t
FS1
SA1
t
BCU 560, BCU 565 · Edition 02.16 69
Parameters > Behaviour during start-up > Burner application
The switchover from flame to menox® mode is performed either immediately or the next time the burner is started de- pending on the setting made in parameter 64. To switch to menox® mode, the HT signal from the STM (terminal 49) and the menox® signal from a separate control unit (terminal 44) must be applied to the BCU.
In menox® mode (> 850°C), the burner is started with the pre- ventilation time defined in parameter 28. The air control valve is set to the "middle" position. No ignition using the transformer takes place during safety time t are opened at the start of the safety time t
. The gas valves V1 and V4
SA1
SA1
.
0302 04
49
HT
44
ϑ
1 9 13
1
15
3
57
4
55
M
53 52 51
PZL
47
t
SA1
t
FS1
t
t
high
middle
low
closed
DI 1 DI 2
t
1
2
t
3
t
4
t
t
5
6
t [s]
t [s]
BCU IC40 (operating mode 6)
Signal from
terminal
Position Butterfly valve position
55 53
OFF OFF closed Closed ON OFF low
Closed OFF ON middle menox ON ON high Flame
Wiring of BCU/IC 40, see page81 (Parameter 40 = 2: with IC40.)
An IC 40 with operating mode 6 is used as the actuator. The relevant position is approached via terminals 53 and55 of the BCU. The air pressure switch and the position of the IC are checked by terminals 48, 51 and52 of the BCU. The BCU signals a fault if the desired state is not reached within the time set in parameter42.
BCU 560, BCU 565 · Edition 02.16 70
Parameters > Behaviour during start-up
11.3.3 Safety time 1 t
SA1
Parameter 94 During the safety time 1 t
, the flame (pilot flame) is ignited.
SA1
It can be set to 2, 3, 5 or 10s.
04
00
t
Z
t
SA1
t
FS1
88 02 03
L1
11 46
ϑ
1 9 5 13
V1
14 V2 41 42
t
Safety time 1 starts with the application of the ϑ signal (terminal
1). The valves open at the start of safety time1. The fuel supply to burner1 is released so that a flame can form. If no flame is detected at the end of safety time1, the valves are closed again. Depending on parameter07 (Burner 1 start-up attempts), the BCU reacts either with an immediate safety shut-down with fault lock-out (P07=1) or with one or two additional start-up attempts (P07= 2 or3). The BCU will complete a maximum of three start-up attempts.
Safety time 1 must be determined on the basis of current na- tional standards and regulations. The burner application and the burner capacity are the main criteria for this.
If the ϑ signal (terminal 1) drops out during safety time 1, the valves will not be switched off until the end of safety time1.
11.3.4 Flame proving period 1 t
FS1
Parameter 95 Flame proving period 1 (t
) can be parameterized to enable
FS1
the flame on burner1 to stabilize after the elapse of safety time1. Only when the flame proving period has elapsed will the next program steps be initiated by the BCU. The flame proving period can be set between 0 and 20s.
04
00
t
Z
t
SA1
t
FS1
88 02 03
L1
11 46
ϑ
1 9 5 13
V1
14 V2 41 42
t
BCU 560, BCU 565 · Edition 02.16 71
Parameters
04
t
t
SB
04
88
ϑ
1
46
11
9 5 13
V1
14 V2
L1
42
41
t
SA
t
Z
04 04 02 03 01
t
t
FS
t
W
t
SB
1x
>2 s
88
ϑ
1
46
9 5 13
V1
14 V2
11
L1
42
41

11.4 Behaviour during operation

Parameter 09 = 1: burner 1. The restart function is active.

11.4.1 Restart

Parameter 09 This parameter determines whether the BCU initiates an im-
mediate safety shut-down with fault lock-out or an automatic restart after a flame failure during operation. Excessive restarts (max.5) can also be detected.
In accordance with EN746-2, a restart may be conducted only if the safety of the installation is not impaired. A restart is recommended for burners which occasionally display unstable behaviour during operation.
The precondition for an automatic restart is that the burner can restart (as intended in all operating phases). In this case, it must be ensured that the program sequence started by the BCU matches the application.
Parameter 09 = 0: Off.
If a flame failure occurs during operation (minimum operating time of 2s), the valves are closed and the operation signalling contact is opened within the safety time during operationtSB.
The burner control unit then attempts to restart the burner
once. If the burner does not function, a safety shut-down with fault lock-out occurs. The display blinks and shows the fault message.
Parameter 09 = 4: max. 5× for burner 1 in 15min. The restart function is active and is also monitored. In certain conditions, it is possible that the restart function is repeated continu­ously without a safety shut-down with subsequent fault lock­out being performed. The BCU has a safety shut-down with subsequent fault lock-out option if more than 5restarts are
A safety shut-down with subsequent fault lock-out takes place in the event of flame failure during operation.
BCU 560, BCU 565 · Edition 02.16 72
performed within a period of 15minutes.
Taking into account national standards and requirements, it must be clarified whether the option may be used.
Parameters > Behaviour during operation

11.4.2 Minimum operating time tB

Parameter 61 A minimum operating time (0 to 250s) may be defined to
ensure that the heating equipment operates stably. If the minimum operating time is active, burner operation
will be maintained until the set time has elapsed even if the start-up signal fails.
The minimum operating time starts as soon as the program step for operation/controller enable (display04) has been reached.
If the start-up signal drops out before the start of operation/ controller enable, e.g. during pre-purge, the burner control unit reverts directly to the start-up position (standby) and the burner is not ignited.
The minimum operating time can be cancelled by switching off the BCU or if a safety shut-down occurs.
BCU 560, BCU 565 · Edition 02.16 73
Parameters
BCU 565
µC
P
4915131450
45pe
/
2
TC
PZL
PZH
PZ
ϑ
123
47
PDZ

11.5 Safety limits

Parameters 15, 16 and19 can be used to adjust the safety limits (low air pressure protection and safety time during operation) to the system requirements.

11.5.1 Low air pressure protection

Parameter 15 The minimum air pressure is ensured using the air
pressure switch connected to terminal47 while the fan for the combustion air is switched on. Activation of the low air pressure protection device and the shut-down properties can be set using parameter15. If the air pressure falls below the value set on the air
air pressure switch, the signal to
min.
terminal47 is interrupted and the BCU initiates a reaction depending on parameter15.
When the fan is switched off, the “no flow” state (default posi- tion) of the air pressure switch (PDZ) is checked. To bypass switching off the fan, the air supply to the pressure switch can be interrupted by a 2/3-way valve. The 2/3-way valve is actuated by terminal58.
Parameter 15 = 0: Off; the low air pressure protection function is deactivated.
Parameter 15 = 1: with safety shut-down. A safety shut-down will be performed if there is no signal at the air
min.
minal47). Parameter 15 = 2: with fault lock-out. A safety shut-down with
fault lock-out will be performed if there is no signal at the air
input (terminal47).
min.
air
min.
input (ter-
If air flow monitoring during pre-purge is active (P35= 1 or2), the “no flow” state of the air flow monitoring pressure switch(PDZ) is also checked.
For further information on the low air pressure protection func­tion (air
, terminal47, and air flow, terminal48) during pre-
min.
purge, see page76 (Air flow monitoring during pre-purge).

11.5.2 Air pressure cut-out delay

Parameter 16
This parameter defines whether the gas enable is sent to
terminal 47 with or without an air pressure switch signal. The parameter can be adjusted if the low air pressure protection is active (parameter 15 = 1 or 2).
Parameter 16 = 0: Off. Air pressure monitoring takes place immediately. The gas is only released when the signal is re­ceived from the air pressure switch. Parameter 48 (Air actuator control) must be set to 1 for this function (air with 1st gas stage).
Parameter 16 = 1: On. The air pressure is monitored after a delay of up to the maximum running time set in parameter
42 or until the position for maximum capacity is confirmed
by the actuator.
BCU 560, BCU 565 · Edition 02.16 74
Parameters > Safety limits

11.5.3 Safety time during operation

Parameter 19 Parameter 19 = 1; 2: time in seconds The safety time during operation is the time that the BCU needs
to stop the fuel supply after a flame failure during operation or an interruption at the safety current inputs (terminals 45 to51 and 65 to68). The safety time can be set to 1 or 2s. Prolong- ing the safety time during operation increases the installation availability in the case of brief-duration signal fades (e.g. fades of the flame signal).
In accordance with EN298, the maximum reaction time to a flame failure must not exceed 1s. In accordance with EN746-2, the safety time of the installation during operation (total closing time) may not exceed 3s.
The requirements of national standards and regulations must be satisfied.
BCU 560, BCU 565 · Edition 02.16 75
Parameters
BCU 565
µC
P
491513
1
450
45
48
p
e
/
2
T
C
PZL
PZH
PZ
PD
Z
ϑ
123
48
PDZ

11.6 Air control

11.6.1 Pre-purge time tPV

Parameter 34 A burner start may only occur if it has been ensured that the
concentration of inflammable components in all sections of the combustion chamber and the connected areas and the flue gas ducts is less than 25% of the lower flammability limit of the fuel gas. In general, a pre-purge is performed by the protective system (FCU) to ensure compliance with these requirements.
Parameter 34 determines the time for which pre-purge is to occur after a safety shut-down (0 to 6000 s).
With this function, the combustion chamber of the burner can be purged after a safety shut-down in compliance with stand- ards (on the basis of EN676, EN746-2, NFPA85 or NFPA86, for example), especially on radiant tube burners. This task is not implemented by the central protective system but by the BCU565.
If air monitoring has been activated in parameter 15 or35, the pre-purge timetPV starts as soon as the air monitor detects an adequate flow for purging, see page74 (Low air pres- sure protection).
11.6.2 Air flow monitoring during pre-purge
Parameter 35 Function of the air flow input (terminal 48)
The air flow is monitored during pre-purge by the differential
pressure switch connected to terminal48. If the air volume and therefore the differential pressure on the air pressure switch falls below the set value, the BCU will perform a safety shut-down or fault lock-out.
When the air actuator is switched off, the “no flow” state (default position) of the differential pressure switch is also checked if air flow monitoring has been activated. Activation of air flow monitoring and the shut-down properties can be set using parameter35.
Parameter 35 = 0: Off; the air flow monitoring function is de­activated.
Parameter 35 = 1: with safety shut-down. If there is no signal at the input (terminal48), a safety shut-down will be performed.
Parameter 35 = 2: with fault lock-out. If there is no signal at the input (terminal48), a safety shut-down with subsequent fault lock-out will be performed.
Air flow monitoring is to be set on the basis of the relevant ap-
plication standard (e.g. EN676, EN746-2, NFPA85 or NFPA86).
BCU 560, BCU 565 · Edition 02.16 76
Parameters > Air control
11.6.3 Pre-ventilation time t
VL
Parameter 36 This parameter is used to define the length of time during
which the air valve is open before the normal start-up. This time may be used for pre-purge. Suitable for burners starting with full air capacity.
The possible settings are from 0 to 10 s in 0.1 s steps, from 10 to 250 s in 1 s steps.
A2 A4 00
A1
t
t
Z
VL
t
SA1
88
11 46
ϑ
1 9 5 13 14 V2 2 10
PZL
47 17-18 37-38
V1
A
t
After the start-up signal (ϑ) has been applied and after the flame simulation check and “no flow” state check have been conducted successfully, the air valve is opened. Start-up of the burner commences with no interruption of the air supply after expiry of the programmable pre-ventilation time tVL.
Parameter setting for this example sequence: P23 = 0; P48 = 1; P36 > 0, see also page74 (Air pressure
cut-out delay). The gas valve does not open until the pressure switch has switched.
11.6.4 Post-ventilation time t
NL
Parameter 39
00 A0 A4
88
11 46
ϑ
1 9 5
V1
13 14 V2
A
2 10
PZL
47 17-18 37-38
t
NL
t
The air valve remains open for the programmed time (0 to 3s)
after the start-up signal (ϑ) has been deactivated following a controlled shut-down. The burner control unit closes the air actuator (valve, actuator) after expiry of the post-ventilation time tNL.
BCU 560, BCU 565 · Edition 02.16 77
Parameters > Air control
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
PE
L1 N
3PS
3 2 116 67 4812 1115 13
S3 S4
S11
S10
0°
90°
M
IC 20
PE
S1S2
90°➔0°
0°➔90°
S1
Min Max
▼

11.6.5 Capacity control

Parameter 40 The BCU is fitted with an interface for connecting air actuators. The BCU..F1/F2 activates a control element via the outputs for
capacity control (terminals 53 to56) for purging, cooling or starting the burner. This control element moves to the required position for the relevant operating situation.
The BCU..F3 activates an air valve for purging, cooling or start- ing the burner via the output at terminal 10. The required air capacity is released by the air valve.
Using parameter 40, you can set which actuator is used for capacity control (actuators IC20, IC40, RBW or air valve).
Parameter 40 = 0: Off; no capacity control (no air actuator). Parameter 40 = 1: with IC20. The interface is configured to the requirements of actuators
IC20, IC20..E, IC50 or IC50..E. Alternatively, comparable three-point step actuators may be
used.
IC20
The positions for maximum capacity, ignition capacity
and minimum capacity can be set using the actuator. It is checked whether the relevant position has been reached using terminal52. If the position is not reached within the timeout time of 255s, the BCU will display fault message A , A or A (maximum, ignition or minimum capacity not reached), see page50 (Fault signalling).
BCU 560, BCU 565 · Edition 02.16 78
Parameters > Air control > Capacity control
0° 90°
S4
S1 S3
Burner control range
Butterfly valve setting range
Control range
Move to ignition position
Ignition pos.
Min.
pos.
Closed
pos.
Max. pos.
MIN
MIN
MIN
MAX
MAX
MAX
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
3PS
0° 90°
S4
S2
S1 S3
Burner control range
CLOSED
Butterfly valve setting range
Control range
Move to ignition position
Ignition pos.
Max. pos.
OPEN
S4
S2
Min.
pos.
Closed
pos.
MIN
MIN
MAX
MAX
▼
In the event of a fault, the actuator is moved to the position set via camS4 for minimum capacity via the output at terminal54.
The control system is enabled for operation via the control- ler enable output (terminal56). During the controller enable procedure, the actuator can be adjusted infinitely between the positions for maximum and minimum capacity by an external three-point step controller or using bus signals. There is no timeout active in this case.
If bus control is active (parameter75), the controller enable out- put (terminal56) has a different function. The wiring between the BCU and the 3-point step controller can be adjusted so that the control range of the actuator is between the positions for maximum and ignition capacity.
The minimum position which can be reached is the closed
position.
Manual mode
In Manual mode, the actuator can be moved between the positions for maximum and minimum capacity in 3-point step operation. No timeout is active when approaching these posi­tions. The controller enable output (terminal56) is not active and not checked.
BCU 560, BCU 565 · Edition 02.16 79
Parameters > Air control > Capacity control
20 19 18 3 2 167 4812 11
S3
S4
S1 0
OUT
0°
➔
90°
0°
90°
90°
➔
0°
IC 20..E
S1
S2
517
+ +
IN
OK
R
R
PE
A
D
A
D
R
1 2 3 4 5 6
ON
µC
131516
M
PE
L1 N
S1
Min Max
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
▼
IC20..E
The positions for minimum capacity, maximum capacity and ignition capacity can be set using the actuator. When the appropriate position has been reached, this information is signalled back via terminal52. If no signal is received that the position has been reached within the timeout time of 255s, a safety shut-down of the BCU will be performed and a fault message (A , A or A ) will be displayed, see page50 (Fault signalling). In addition, the actuator will be moved to the set position for minimum capacity using the output at terminal54.
The control system is enabled during operation via the control-
ler enable output (terminal56). During the controller enable procedure, the actuator can be adjusted infinitely between the positions for maximum and minimum capacity by a controller (0(4)–20mA, 0–10 V) using the setpoint device on terminals 17 and18 or the bus signal. There is no timeout active in this case.
If bus control is active (parameter75), the controller enable output (terminal56) has a different function.
Manual mode
In Manual mode, the actuator can be moved between the positions for maximum and minimum capacity in 3-point step operation. No timeout is active when approaching these posi­tions. The controller enable output (terminal56) is not active and not checked.
BCU 560, BCU 565 · Edition 02.16 80
Parameters > Air control > Capacity control
N
IC 40
PE
19 18 16 15 14 12 11 10 8 7 5 4 2 1
A
AC
D
DC
M
mA
L N
22 21 20
R..
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
t [s]
t [s]
t
1
t
2
t
3
t
4
t
5
t
6
DI 1
DI 2
Purge
Closed
Ignition
High
fire
▼
IC 40
Parameter 40 = 2: with IC40. To ensure that the actuator IC40 can be operated on the
BCU..F1, P40=2 (capacity control) must be set. The operating mode of actuator IC40 may be parameterized to11 or 27.
of the BCU will be performed. A fault message (A
, A or A )
will be displayed, see page50 (Fault signalling). If a controller enable is active, the control system is enabled
for operation via the outputs at terminals 53 and55.
Operating mode 11
Operating mode 11 allows cyclic operation (ON/OFF and OFF/ Low/High/OFF).
The actuator IC moves to the ”High fire” position during the
controller enable procedure. There is no timeout active in this case.
BCU IC40 (operating mode 11)
Signal at
The positions for maximum capacity and ignition capacity can be set using the actuator. Terminal51 checks whether the position for maximum capacity has been reached. Terminal52 checks the position for ignition capacity. If the position is not reached within the timeout time of 255s, a safety shut-down
BCU 560, BCU 565 · Edition 02.16 81
terminal
55 53
OFF OFF Closed Closed ON OFF Ignition
ON ON
OFF ON Purge Maximum capacity
Position Butterfly valve position
Minimum/Ignition capacity
High fire
rate
High fire rate
Parameters > Air control > Capacity control
t [s]
t [s]
t
1
t
2
t
3
t
4
t
5
t
6
0–20
mA
DI 1
DI 2
Spül
Zünd
Zu
▼
Operating mode 27
During the controller enable procedure, the actuator IC40 can be adjusted infinitely between the positions for maximum and minimum capacity using its analogue input (terminals18 and19). There is no timeout active in this case.
BCU IC40 (operating mode 27)
Signal at
terminal
Position Butterfly valve position
55 53
OFF OFF Closed Closed
ON OFF Ignition
ON ON 0 – 20 mA
Minimum/Ignition capacity
Any position between mini-
mum and maximum capacity
OFF ON Purge Maximum capacity
Fault
In the event of a fault, there will be no signal at terminals 53 and55 so that the actuator moves to the closed position. When approaching the closed position, no timeout of 255s is active since no feedback input is checked. This may result in a situation where the program is continued in the case of a request for the closed position, without the butterfly valve being closed. The outputs at terminals56 (controller enable) and54 (closed position) on the BCU are non-functional and are not activated.
Manual mode
In Manual mode, no external controller is enabled. The actua­tor can be moved to the positions for maximum capacity or ignition capacity by the user. 3-point step operation is not pos­sible. No timeout is active when approaching these positions.
BCU 560, BCU 565 · Edition 02.16 82
Parameters > Air control > Capacity control
N
M
R B W
90°➔0°
0°➔90°
L1
RBW
COM
HI
LO
AUTO
53 54 55 56
52
1 2 3 4645
65
66
67
68
17 18 37 38
13 14 15
BCU 560..F2
3,15AT
µC
49 50 51
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
N
M
+ F -
0°➔90°
L1
mA
A
D
OUT
+
-
RBW
COM
HI
LO
AUTO
53 54 55 56
52
1 2 3 4645
17 18 37 38
13 14 15
BCU 560..F2
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
65
66
67
68
49 50 51
PLC
▼
RBW
Parameter 40 = 3: with RBW. The actuator can be moved to the positions for maximum ca-
pacity (contact COM to HI) and minimum capacity (contact COM to LO) using the interface and by closing the various contacts.
The RBW actuator reports that it has reached the position for
maximum capacity via a signal to terminal51. The actuator reports that it has reached the position for minimum capac­ity via a signal to terminal52. The simultaneous activation of terminals 51 and52 results in a fault lock-out of theBCU.
If parameter 41 = 0, the system monitors the movement to the positions for maximum and minimum capacity with a timeout time of 255s. Reaching the relevant position imme­diately triggers the program continue switch conditions. If reaching the position is not signalled within the timeout time of 255s, a safety shut-down of the BCU will be performed. A fault message (A or A ) will be displayed, see page50 (Fault signalling).
If parameter 41 = 1, the system does not monitor whether the positions for minimum and maximum capacity are reached. In this case, a running time of up to 250s must be defined using parameter42, see page85 (Running time). The program continue switch conditions are then controlled dependent on this time.
If a fault occurs, the actuator is moved to the position for mini­mum capacity.
Manual mode
In Manual mode, no external controller is enabled during the controller enable procedure. The actuator can be moved to the positions for maximum capacity or ignition capacity by the user. 3-point step operation is not possible. No timeout is active when approaching these positions.
BCU 560, BCU 565 · Edition 02.16 83
Parameters > Air control > Capacity control
BCU 560..F3
µC
VAS VAG
TZI/TGI
VR..L
V1
V2
14
13
9 7
10
UVS
Parameter 40 = 5: with air valve. The positions for maximum capacity and ignition capacity can
be set using the air valve. If the air valve is closed, the igni- tion capacity is reached, if it is open, the maximum capacity is reached.
Parameter 42 (Running time) can be used to adjust the behav- iour of slow opening and closing air valves so that the system can be set to ignition position before a start-up is initiated, see page85 (Running time). Parameter 41 (Running time selection) must be set to 1 to adjust this behaviour.
BCU 560, BCU 565 · Edition 02.16 84
Parameters > Air control

11.6.6 Running time selection

Parameter 41 Parameter 41 = 0: Off; checking the positions for minimum/
maximum capacity. A signal that the positions for minimum and maximum capacity have been reached is returned and monitored with a timeout time of max. 255s. When the position has been reached, the BCU will initiate the next program step.
Parameter 41 = 1: On; for approaching the positions for mini- mum/maximum capacity. The running time set using pa- rameter42 is activated for approaching these positions, see page85 (Running time). After this time has elapsed, the BCU will initiate the next program step.
Parameter 41 = 2: On; for approaching the position for maxi- mum capacity. The running time set using parameter42 is activated for approaching the position for maximum capacity, see page85 (Running time). After this time has elapsed, the BCU will initiate the next program step. Approaching the position for minimum capacity is signalled and monitored.
Parameter 41 = 3: On; for approaching the position for mini- mum capacity. No signal is returned that the position for mini- mum capacity has been reached. The running time set using parameter42 is activated for approaching the position for minimum capacity, see page85 (Running time). After this time has elapsed, the BCU will initiate the next program step. Approaching the position for maximum capacity is signalled and monitored.

11.6.7 Running time

Parameter 42
This parameter can be used to adjust the behaviour of slow
opening and closing air valves. The running time starts when the air actuator is switched off. A restart of the burner after a controlled shut-down, a start-up attempt, restart, cooling or purging is delayed until the end of the running time. After the running time has elapsed, the burner is started if the start-up signal (ϑ) is applied.
The time should be adjusted such that the system can be set
to ignition position, i.e. that the air actuator is closed before a start-up is initiated.
BCU 560, BCU 565 · Edition 02.16 85
Parameters > Air control
11.6.8 Low fire over-run
Parameter 43 The low fire over-run (tKN) is applicable to systems with a pneu-
matic air/gas ratio control system and On/Off control. Using the low fire over-run function reduces the O2 content in the furnace atmosphere.
00 A4
t
KN
88
L1
11 46
ϑ
1 9 5 13 14 V2 2 10
41 42
V1
A
t
Parameter 43 = 0: Off. No low fire over-run is performed. The gas circuit is closed immediately owing to a quick closing gas valve in the case of On/Off control. The air circuit is closed more slowly. The air flowing in during this time increases the O2 content in the combustion chamber.
Parameter 43 = 1 (only for BCU..F1/F2): up to minimum capacity. The burner is not immediately switched off after the start-up signal ϑ (terminal1) has been removed. During low fire over- run, the control element is moved to the position for minimum capacity and the gas valves remain open until the flame fails or the position for minimum capacity is reached. If the flame is extinguished, this does not result in a fault.
Parameter 43 = 2, 3, 4, 5, 10, 20, 30 or 40 (only for FCU..F3): time in seconds. During this time, the gas valve remains open. The air valve is closed with deactivated start-up signal (ϑ).
V1 V2
BCU 560..F3
µC
10
13 14
9 7
VAS VAG
VR..L
TZI/TGI
UVS
This means that the burner is initially adjusted down to low
fire and then switched off completely. Flame control is still operational. It must be ensured that no excess gas occurs.
11.6.9 Controller enable signal delay time t
RF
Parameter 44 (only on BCU..F1/F2)
The controller enable signal is delayed by 0, 10, 20 or 30 up
to 250s using parameter44. If the BCU has successfully started the burner, after the elapse
of the safety time and the flame proving period, if parameter­ized, the controller enable signal to the external temperature controller is delayed. The BCU shows program statusH4. After the elapse of the delay timetRF, the burner operation signalling contact (terminals 17,18) is closed and the controller enable output (terminal56) activated. The display changes to04.
BCU 560, BCU 565 · Edition 02.16 86
Parameters > Air control
t
SA
t
Z
A402 0300 A0
t
t
FS
2 10
∨
53
A
88
ϑ
46 1
11
9 5
37-38
13
V1
14 V2
17-18
M
t
SA
t
Z
A4 A2 A3 00 A0 00
t
t
FS
A0
2 10
∨
53
A
88
ϑ
46 1
11
9 5
37-38
13
V1
14 V2
17-18
M
t
SA
t
Z
A4 02 03 00
t
t
FS
00 A0
2 10
∨
53
A
88
ϑ
46 1
11
9 5
37-38
13
V1
14 V2
17-18
M
▼

11.6.10 Air actuator control

Parameter 48 = 1: opens with valve V1 1
st
stage
Parameter 48 In cyclic operation, parameters 48 and 49 on BCU..F1, F2 and F3
determine the behaviour of the air actuator during burner start. Parameter 48 = 0: opens on external activation.
Parameter 48 = 2: opens with valve V2 2nd stage
This setting together with parameter 49 = 0, see page89 (Air actuator can be activated externally on start-up), is re- quired for burners on which the air/gas ratio is controlled by a pneumatic air/gas ratio control system and which need to be started at low-fire rate, e.g. on two-stage-controlled burn- ers, see page8 (Two-stage-controlled burner). In this case, activation of the air actuator during burner start via the input at terminal 2 must be prevented.
External control allows switchover between low fire and high fire during operation.
BCU 560, BCU 565 · Edition 02.16 87
The air actuator can be activated externally via the input at ter-
minal 2 for cooling the burner in the start-up position (standby).
This function is not available during burner start-up and during
operation.
Parameters > Air control > Air actuator control
Parameter 48 = 3: Controller enable following operating signal or in standby. This parameter is used to activate modulating capacity control on BCU..F1 and F2. The controller enable signal is issued via the output at terminal 56 in the start-up position (standby) and during operation.
Cooling is then only possible in the start-up position/standby. The air actuator can be opened via the input at terminal 2 for this purpose.
BCU 560, BCU 565 · Edition 02.16 88
Parameters > Air control
t
SA
t
Z
A4 A2 A3 00 A0 00
t
t
FS
A0
2 10
∨
53
A
88
ϑ
46 1
11
9 5
37-38
13
V1
14 V2
17-18
M

11.6.11 Air actuator can be activated externally on start-up

Parameter 49 Parameter 49 = 0: cannot be activated. During start-up, the
air actuator remains closed. The air actuator cannot be acti- vated externally.
Parameter 49 = 1: can be activated externally.
The air actuator can be activated externally via the input at terminal 2 during start-up. Parameter48 must be set to0 for this purpose, see also page87 (Air actuator control).

11.6.12 Air actuator in the event of fault

Parameter 50
This parameter decides whether the air actuator can be ac-
tivated externally via the input at terminal 2 in the event of a fault lock-out.
Parameter 50 = 0: cannot be activated. The air actuator re­mains closed in the event of a fault lock-out. It cannot be activated externally via terminal 2.
Parameter 50 = 1: can be activated externally. The air actuator can be activated externally via the input at terminal 2 during a fault, e.g. for cooling.
BCU 560, BCU 565 · Edition 02.16 89
Parameters > Air control
0° 90°
S4
S1 S3
Burner control range
Butterfly valve setting range
Control range
Move to ignition position
Ignition pos.
Min.
pos.
Closed
pos.
Max. pos.
MIN
MIN
MIN
MAX
MAX
MAX
PE
L1 N
3 2 116 67 4812 1115 13
S3 S4
S11
S10
0°
90°
M
IC 20
PE
S1S2
90°➔0°
0°➔90°
S1
Min Max
Y­Y+
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
▼

11.6.13 Capacity control (bus)

Parameter 75 Controlling the burner capacity using the fieldbus is only pos-
sible with bus module BCM500 connected and enabled (P80=
1 or2).
The output at terminal 56 has a different function. Parameter 75 = 0: Off. No capacity control possible using
the fieldbus. Parameter 75 = 1: MIN. to MAX. capacity; standby in position
for MIN. capacity. The control range while the burner is oper- ating is between the positions for minimum capacity(S4) and maximum capacity(S3). The burner is ignited in the position for ignition capacity(S1). When the burner is switched off, the actuator is moved to the position for minimum capacity(S4).
This operating mode can be achieved with an actuator IC20, RBW or alternatively with a comparable three-point step ac- tuator.
If the air supply is stopped on a heated furnace with the burner switched off, the controls may be damaged by the hot furnace atmosphere as a result of the lowest possible position of the butterfly valve, limited byS4.
IC 20
Switching cam setting for ignition capacity, minimum and maximum capacity as well as pre-purge and standby:
S1: for ignition capacity of the burner. S3: for maximum capacity of the burner and pre-purge. S4: for minimum capacity of the burner and standby.
BCU 560, BCU 565 · Edition 02.16 90
Parameters > Air control > Capacity control (bus)
0° 90°
S4
S2
S1 S3
Burner control range
CLOSED
Butterfly valve setting range
Control range
Move to ignition position
Ignition pos.
Max. pos.
OPEN
S4
S2
Min.
pos.
Closed
pos.
MIN
MIN
MAX
MAX
PE
L1 N
3 2 116 67 4812 1115 13
S3 S4
S11
S10
0°
90°
M
IC 20
PE
S1S2
90°➔0°
0°➔90°
S1
Min Max
Y-
Y+
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
▼
Parameter 75 = 2: MIN. to MAX. capacity; standby in CLOSED position. The control range while the burner is operating is be- tween the positions for minimum capacity(S2) and maximum capacity(S3). The burner is ignited in the position for ignition capacity(S1). When the burner is switched off, the actuator is moved to the closed position(S4).
This operating mode can be achieved with an actuator IC20 or alternatively with a comparable three-point step actuator.
If the air supply is stopped on a heated furnace with the burner switched off, the controls are protected from the hot furnace atmosphere as a result of the butterfly valve being in the closed position (limited byS4). Check whether the burner can cope without cooling in this situation.
IC 20
Switching cam setting for ignition capacity, minimum and maximum capacity as well as pre-purge and standby:
S1: for ignition capacity of the burner. S2: for minimum capacity of the burner. S3: for maximum capacity of the burner and pre-purge. S4: for the closed position of the butterfly valve and standby.
BCU 560, BCU 565 · Edition 02.16 91
Parameters > Air control > Capacity control (bus)
0° 90°
S4
S1 S3
Move to ignition position
Burner control range
CLOSED
IGNITION
Butterfly valve setting range
Control range
Ignition pos. Max. pos.
OPEN
Min.
pos.
Closed
pos.
MIN MAX
MAX
PE
L1 N
3 2 116 67 4812 1115 13
S3 S4
S11
S10
0°
90°
M
IC 20
PE
S1S2
90°➔0°
0°➔90°
S1
Min Max
Y­Y+
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
▼
Parameter 75 = 3: IGNITION to MAX. capacity; standby in CLOSED position.
The control range while the burner is operating is between the positions for minimum capacity(S1) and maximum capacity(S3). The burner is ignited in the position for minimum capacity(S1). When the burner is switched off, the actuator is moved to the closed position(S4).
This operating mode can be achieved with an actuator IC20, RBW or alternatively with a comparable three-point step ac- tuator.
If the air supply is stopped on a heated furnace with the burner switched off, the controls are protected from the hot furnace atmosphere as a result of the butterfly valve being in the closed position (limited byS4). Check whether the burner can cope without cooling in this situation.
IC 20
Switching cam setting for ignition capacity, minimum and maximum capacity as well as pre-purge and standby:
S1: for minimum capacity and ignition capacity of the burner. S3: for maximum capacity of the burner and pre-purge. S4: for the closed position of the butterfly valve and standby.
BCU 560, BCU 565 · Edition 02.16 92
Parameters > Air control > Capacity control (bus)
S4
S2
S3
S1
0° 90°
Move to ignition position
Burner control range
Butterfly valve setting range
Control range
Max. pos.
OPEN
Ignition
pos.
Reversing direction of rotation for quick start
Min.
pos.
Closed
pos.
MIN
MIN
MIN
MAX
MAX
PE
L1 N
3 2 116 67 4812 1115 13
S3 S4
S11
S10
0°
90°
M
IC 20
PE
S1S2
90°➔0°
0°➔90°
S1
Min Max
S2
Y-
Y+
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
▼
Parameter 75 = 4: MIN. to MAX. capacity; standby in position for MIN. capacity; burner quick start.
The control range while the burner is operating is between the positions for minimum capacity(S4) and maximum capac- ity(S3). The burner is ignited in the position for ignition capac- ity(S1). Switching cam S2 (reverse direction of rotation) ensures that the position for ignition capacity is approached without pre-purging first (quick start). When the burner is switched off, the actuator is moved to the position for minimum capacity(S4).
This operating mode can be achieved with an actuator IC20 or alternatively with a comparable three-point step actuator.
If the air supply is stopped on a heated furnace with the burner switched off, the controls may be damaged by the hot furnace atmosphere as a result of the lowest possible position of the butterfly valve, limited byS4. If pre-purge is active, considerably lower air capacity than the maximum air capacity will be used for purging.
IC 20
Switching cam setting for ignition capacity, minimum and maximum capacity and reverse direction of rotation to ap- proach the position for ignition capacity:
S1: for ignition capacity of the burner. S2: for reversing the direction of rotation to approach the posi-
tion for ignition capacity. S3: for maximum capacity of the burner and pre-purge. S4: for the closed position of the butterfly valve and standby.
BCU 560, BCU 565 · Edition 02.16 93
Parameters > Air control > Capacity control (bus)
S2
S3
S1
S4
0° 90°
Move to ignition position
Burner control range
CLOSED
IGNITION
Butterfly valve setting range
Control range
OPEN
Max. pos.Ignition
pos.
Reversing direction of rotation for quick start
Min.
pos.
Closed
pos.
MIN MAX
MAX
PE
L1 N
3 2 116 67 4812 1115 13
S3 S4
S11
S10
0°
90°
M
IC 20
PE
S1S2
90°➔0°
0°➔90°
S1
Min Max
S2
Y-
Y+
53 54 55 56
52
1 2 3 4645 65 66 67 6849 50 51
17 18 37 38
13 14 15
BCU 560..F1
3,15AT
µC
88
c
c
41 42
24V
DC
5 6 9 11
1210762
61
Parameter 75 = 5: IGNITION to MAX. capacity; standby in CLOSED position; burner quick start.
The control range while the burner is operating is between the positions for ignition capacity(S1) and maximum capacity(S3). The burner is ignited in the position for ignition capacity(S1). Switching cam S2 (reverse direction of rotation) ensures that the position for ignition capacity is approached without pre- purging first (quick start). When the burner is switched off, the actuator is moved to the closed position(S4).
This operating mode can be achieved with an actuator IC20 or alternatively with a comparable three-point step actuator.
If the air supply is stopped on a heated furnace with the burner switched off, the controls are protected from the hot furnace atmosphere as a result of the butterfly valve being in the closed position (limited byS4). Check whether the burner can cope without cooling. If pre-purge is active, considerably lower air capacity than the maximum air capacity will be used for purging.
IC 20
The position for maximum capacity is achieved by the controller enable output (terminal56).
Switching cam settings S1, S2, S3 and S4: S1: for minimum capacity and ignition capacity of the burn-
er.
S2: for reversing the direction of rotation to approach the
position for ignition capacity. The actuator will move to the position for ignition capacity without reaching the
position for maximum burner capacity. S3: for maximum capacity of the burner and pre-purge. S4: for the closed position of the butterfly valve and standby.
BCU 560, BCU 565 · Edition 02.16 94
Parameters
11.7 menox
11.7.1 menox pre-ventilation time t
®
VLM
Parameter 28 This parameter is used to define the time during which the air
valve is open in menox® mode before the normal start-up. Suitable for burners starting with full air capacity.
The possible settings are from 0 to 10 s in 0.1 s steps, from 10 to 250 s in 1 s steps.
A2 A400
A1
t
t
Z
VLM
t
SA1
88
11 46
ϑ
1 9 5 13 14 V2 2 10
PZL
47 17-18 37-38
V1
A
t
After the start-up signal (ϑ) has been applied and the “no flow” state check has been conducted successfully, the air valve is opened. Start-up of the burner commences with no interruption of the air supply after expiry of the programmable pre-ventilation time t
VLM
.
Parameter setting for this example sequence: P06 = 5; P16 = 0, see also page74 (Air pressure cut-out delay). The gas valve does not open until the pressure switch has switched.
If the menox® pre-ventilation time t
(P28) > the running
VLM
time (P42) and there is no signal from the pressure switch at terminal 47 after expiry of the running time (P42), the BCU
performs a shut-down depending on parameter 15 (Low air pressure protection).
®
11.7.2 Switchover to menox
operating mode
Parameter 64 As soon as there is a signal at the menox® input (terminal 44),
the BCU can switch to flame or menox® mode immediately or upon the next burner start.
®
Switchover from flame mode to menox
mode
Parameter 64 = 0: on next burner start. As long as the start-up signal is present, the burner control unit will remain in flame mode. The switchover to menox® mode does not take place until the next burner start.
Parameter 64 = 1: immediately. The switchover to menox® mode takes place immediately. The start-up signal must be applied to terminal1. The burner in flame mode is switched off and restarted in menox® mode.
®
Switchover from menox
mode to flame mode
Parameter 64 = 0: on next burner start. As long as the start­up signal is present, the burner control unit will remain in menox® mode. The switchover to flame mode does not take place until the next burner start.
Parameter 64 = 1: immediately. The switchover to flame mode takes place immediately. The start-up signal must be applied to terminal1. The burner in menox® mode is switched off and restarted in flame mode.
BCU 560, BCU 565 · Edition 02.16 95
Parameters
PZL
PZH
4913
1
450
ϑ
1
V1 V2
45
GZL
PZH
VAS
TZI/TGI
V
1
V2
V3
p
u
/2
14151345
9
V
p
1
V3
V
2
14 15
V3
V2

11.8 Valve check

11.8.1 Valve proving system

Parameter 51 Parameter 51 is used to define whether and at what time in
the BCU program sequence the valve check is activated. This allows either the tightness of the gas solenoid valves and the pipework between them to be checked (tightness test) or the closed position of a solenoid valve (proof of closure function) to be checked. If the proof of closure function is activated, the closed position of the gas solenoid valve at the inlet side is checked using a POC switch.
Parameter 51 = 0: Off. No valve check is activated. Parameter 51 = 1: tightness test before start-up. Parameter 51 = 2: tightness test after shut-down. With this
setting, a tightness test is also performed after a fault is reset and after mains on.
Parameter 51 = 3: tightness test before start-up and after shut-down.
An additional bypass valve must be installed in gas sections with an air/gas ratio control. This valve allows the closed air/gas ratio control to be bypassed during the tightness test.
Parameter 51 = 4: proof of closure function (POC).
A signal is sent to the BCU via the POC switch on the gas solenoid valve on the inlet side before burner start-up stating that the valve is closed. After burner start-up, the signal must drop out to indicate to the BCU that the valve is open.

11.8.2 Relief valve (VPS)

Parameter 52 A valve connected to terminal 14 or15 can be selected to act
as a relief valve during a tightness test.
Parameter 52 = 2: V2. The valve on terminal14 acts as the relief valve.
Parameter 52 = 3: V3. The valve on terminal15 acts as the relief valve.
BCU 560, BCU 565 · Edition 02.16 96
Parameters > Valve check
P
13
1
4
4
5
p
u
/2
PZ
ϑ
1
pu/2
PZ
V
p1
V1 V2

11.8.3 Measurement time Vp1

Parameter 56 The required measurement time must be determined ac-
cording to the requirements of the appropriate application standards, e.g. EN1643.
The required measurement time for the tightness test of Vp1 can be set using parameter56. The possible settings are 3s, 5 to 25s (in 5s steps) or 30 to 3600s (in 10s steps).
See also page35 (Measurement time t
).
M
11.8.4 Valve opening time t
L1
Parameter 59
This parameter is used to define the opening time for the
valves (2 to 25s) which are opened to fill or discharge the test volume between the gas valves. If the preset opening timetL
= 2s is inadequate (e.g. if slow opening valves are used) to
fill the test volume or reduce the pressure between the valves, bypass valves can be used instead of the main valves.
On condition that the gas volume which flows into the combus­tion chamber is no larger than 0.083% of the maximum flow rate, the opening time of the bypass valves may be longer than the 3s permitted by the standard (EN1643:2000).
BCU 560, BCU 565 · Edition 02.16 97
Parameters

11.9 Behaviour during start-up

11.9.1 Minimum pause time tBP

Parameter 62 A minimum pause time tBP (0 to 3600 s) can be defined to
achieve stable operation of the burners. If the post-ventilation time set using parameter39 has elapsed and no signal (ϑ) is received at terminal1 (burner shut down), a restart and cooling are prevented for the duration of the minimum pause time tBP.
If a signal is applied to terminal 1 (burner start-up) or terminal 2 (cooling) during the minimum pause time, status displayDelay
H0
will appear.
BCU 560, BCU 565 · Edition 02.16 98
Parameters

11.10 Manual mode

If the Reset/Information button is pressed for 2s during switch- on, the BCU reverts to Manual mode. Two dots blink on the display. The BCU is now operating in Manual mode inde- pendently of the status of the inputs of the start-up signal (terminal1), controlled air flow (terminal2) and remote reset (terminal3). The functions of the safety-relevant inputs such as controller enable/emergency stop (terminal46) are retained. The manual start-up of the BCU can be started in Manual mode by pressing the Reset/Information button. Each time the button is pressed again, the BCU moves to the next step of the program sequence and stops there, for example for adjusting an actuator or the gas/air mixture.
Actuator IC20, IC 40 and RBW
04
Following controller enable (status display actuator can be opened and closed as required. By holding the button, the actuator is first opened further. The BCU indicates
A
with blinking dots. Once the button has been released, the actuator stops in the relevant position. Pressing it again will result in closing the actuator to the position for minimum capacity. The BCU indicates A with blinking dots. A change of direction takes place each time the button is released and pressed again. When the actuator has reached its final posi- tion, the dots disappear.
), a connected

11.10.1 Operating time in Manual mode

Parameter 67 Parameter 67 determines when Manual mode is terminated. Parameter 67 = 0: Manual mode is not limited in time. If this function has been selected, operation of the burner may
be continued manually in the event of failure of the control system or the bus activation.
Parameter 67 = 1: the BCU will terminate Manual mode 5min­utes after the last time the button is pressed. It then moves abruptly back to the start-up position (standby).
If the unit is switched off or a power failure occurs, Manual mode on the BCU will be terminated regardless of param­eter67.
BCU 560, BCU 565 · Edition 02.16 99
Parameters

11.11 Functions of terminals 50, 51, 65, 66, 67 and 68

The BCU is informed via terminal 50 by a separate automation system that purging is currently being performed.
Terminals 51, 65, 66, 67 and 68 can each be assigned a logi- cal AND gating with one of the inputs for the safety functions (terminals 46–50) using an appropriate parameter. If AND gating is required, the input concerned can be enabled.
Terminal51 can also be used as a feedback input for the maximum capacity position when operated with IC40/RBW.

11.11.1 Function of terminal 50

Parameter 68 The BCU..F1, F2 or F3 supports centrally-controlled pre-purge
or post-purge. In the case of multiple burner applications, burners with mechanical combustion air supply are used. The air for combustion and pre-ventilation is supplied by a central fan controlled by a separate automation system. The automation system sends a signal to terminal 50 during purg- ing. At this point, the BCU opens the air actuator (actuator, air valve) regardless of the status of the other inputs. The display
P
shows Parameter 68 = 23: purge with Low signal Parameter 68 = 24: purge with High signal
0
.

11.11.2 Function of terminal 51

Parameter 69 Parameter 69 = 0: Off Parameter 69 = 8: AND with input at terminal46 (emergency
stop) Parameter 69 = 9: AND with input at terminal47 (air
min.
pres-
sure switch) Parameter 69 = 10: AND with input at terminal48 (air flow
pressure switch) Parameter 69 = 13: IC40/RBW feedback of position for maxi-
mum capacity, see page83 (Parameter 40 = 3: with RBW.).

11.11.3 Function of terminal 65

Parameter 70 Parameter 70 = 0: Off Parameter 70 = 8: AND with input at terminal46 (emergency
stop) Parameter 70 = 9: AND with input at terminal47 (air
min.
pres-
sure switch) Parameter 70 = 10: AND with input at terminal48 (air flow
pressure switch)
BCU 560, BCU 565 · Edition 02.16 100
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