Page 1
AGA
Industrial & Commercial Thermal
Burner control units BCU 480
Technical Information · GB
6 Edition 03.16l
• For pilot and main burners in intermittent or continuous operation
• Replace the local control cabinet
• Flame control by UV, ionization or a further option of using the
furnace chamber temperature
• Display of the program status, unit parameters and flame signal;
Manual mode for burner adjustment and for diagnostic purposes
Page 2
Contents
Burner control units BCU 480 .......................1
Contents ............................................2
1 Application ........................................5
1.1 Examples of application ........................... 7
1.1.1 Stage-controlled main burner with alternating
pilot burner ..................................................7
1.1.2 Stage-controlled main burner with permanent
pilot burner ..................................................8
1.1.3 Two-stage-controlled main burner with
permanent pilot burner......................................9
1.1.4 Modulating-controlled burner ......................10
1.1.5 BCU 480..B1 for PROFIBUS DP ......................11
1.1.6 BCU 480..D:
High temperature equipment ..............................11
2 Certification ......................................12
3 Function ..........................................13
3.1 Connection diagrams .............................13
3.1.1 BCU 480..E1.........................................13
3.1.2 BCU 480 ............................................. 14
3.1.3 BCU 480..B1..E1 ....................................15
3.1.4 BCU 480..B1......................................... 16
3.1.5 BCU 460..P..E1 with industrial plug connector ......17
3.1.6 BCU 460..P with industrial plug connector . . . . . . . . . 18
3.2 BCU..P with 16-pin industrial plug connector ....19
3.3 PROFIBUS DP ................................... 20
3.3.1 Safet y-related control signals.......................20
3.3.2 BCSoft................................................21
3.3.3 Configuration, MasterSlave procedure .............21
3.3.4 Addressing............................................21
3.3.5 Network technology.................................22
3.3.6 Configuration........................................ 22
3.3.7 Bus communication .................................22
3.4 BCU 480 program sequence .....................24
3.5 Program status and fault messages..............27
4 Parameters ...................................... 29
4.1 Scanning the parameters ........................30
4.2 Flame control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.2.1 Flame signal, pilot burner ............................31
4.2.2 Flame signal, main burner............................31
4.2.3 Program status when the most recent fault
occurred . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31
4.2.4 Switch-of f threshold of the flame amplifier..........31
4.2.5 High temperature operation in the case of BCU..
D2 or BCU..D3 ............................................. 32
4.2.6 UVS check ...........................................35
4.3 Pilot and main burner monitoring ................36
4.3.1 Permanent pilot burner...............................37
4.3.2 Interrupted pilot burner ..............................37
4.4 Behaviour in start-up position/standby ..........38
4.4.1 Flame simulation check in start-up position/
standby ....................................................38
4.4.2 Minimum burner pause time t
....................39
BP
4.5 Behaviour during start-up ....................... 40
4.5.1 Safety time on start-up tSA .........................40
4.5.2 Flame proving period t
4.5.3 Minimum burner on time t
4.5.4 Burner start-up attempts ........................... 42
............................41
FS
..........................41
B
4.6 Behaviour during operation...................... 44
4.6.1 Safety time during operation tSB for pilot and main
burners ....................................................44
4.6.2 Fault lock-out or restart, pilot burner ...............44
4.6.3 Fault lock-out or restart, main burner...............46
4.6.4 Program status on last fault .........................47
4.7 Air valve control on BCU..L ....................... 48
4.7.1 Purge.................................................48
4.7.2 Cooling in start-up position/standby ...............48
4.7.3 Burner start ..........................................48
4.7.4 Air valve opens in the case of external activation
(not during start-up).......................................49
4.7.5 Air valve opens in the case of external activation
(even during start-up) .....................................50
4.7.6 Air valve opens with valve V2 .........................51
BCU 480 · Edition 03.16l 2
= To be continued
▼
Page 3
4.7.7 Air valve opens with operating signal ................52
4.7.8 Low fire over-run time t
down .......................................................53
4.7.9 Behaviour of the air valve in the event of a fault
lock-out....................................................54
after a controlled shut-
KN
4.8 Manual mode .....................................55
4.8.1 Manual mode limited to 5 minutes..................55
5 Selection ........................................ 56
5.1 Type code .........................................56
6 Project planning information .....................57
6.1 Cable selection ...................................57
6.1.1 Ionization cable.......................................57
6.1.2 Ignition cable .........................................57
6.1.3 UV cable ..............................................57
6.2 Ignition electrode .................................57
6.2.1 Electrode gap ........................................57
6.2.2 Star electrodes .......................................57
6.3 Calculating the safety time tSA ...................58
6.4 Minimum burner on time .........................59
6.5 Safety interlocks (Limits) .........................59
6.6 Protection of safety-relevant outputs ............59
6.7 Emergency off ................................... 60
6.7.1 In the event of fire or electric shock .................60
6.7.2 Via the safety interlocks (limits) .....................60
6.8 Reset ............................................. 60
6.8.1 Parallel reset.........................................60
6.8.2 Permanent remote reset ............................60
6.8.3 Automatic remote reset (PLC) ......................60
6.9 Burner start ...................................... 60
6.10 Restart and start-up attempts ................. 60
6.11 Fault signalling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
6.12 Protecting the pilot burner from overload.......61
6.13 Installation ......................................61
6.14 Wiring............................................62
6.15 BCU and BCU..E1 (with and without adapted
power management)..................................62
6.16 Signal distributor board .........................62
6.17 PROFIBUS DP ...................................63
6.17.1 Safety-related control signals .....................63
6.17.2 Wiring the PROFIBUS plug connector .............63
6 . 17. 3 E MC ................................................63
6.17.4 Unit replacement...................................63
6.17.5 Status and fault messages for PROFIBUS DP .....64
6.18 Third gas valve (can be shut down) on BCU..L . 66
6.19 BCU switched off................................67
6.20 Furnace control .................................67
6.21 Mains switch ....................................67
6.22 Note on EC type-examination ..................67
6.23 SIL/PL level for thermoprocessing equipment 67
6.24 Changing parameters .......................... 68
7 Flame control .................................... 69
7.1 With ionization sensor .............................69
7.2 With UV sensor ....................................69
7.3 Via the temperature in high temperature
equipment ............................................70
8 Accessories.......................................71
8.1 High-voltage cable ...............................71
8.2 Industrial plug connector, 16-pin.................71
8.3 PROFIBUS plug connector .......................71
8.4 BCSoft ............................................72
8.4.1 Opto-adapter PCO 200 ............................. 72
8.4.2 Bluetooth adapter PCO 300 ........................ 72
8.5 “Changed parameters” stickers ..................72
8.6 External securing bar .............................73
8.7 Fastening set .....................................73
8.8 Radio interference suppressed electrode plugs..73
9 Technical data ....................................74
9.1 BCU..B1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .75
9.2 PROFIBUS DP ....................................75
9.3 Safety-specific characteristic values .............76
BCU 480 · Edition 03.16l 3
= To be continued
▼
Page 4
9.4 Housing dimensions ..............................77
9.5 Operating controls................................77
9.6 Installation ........................................77
10 Legend ..........................................78
11 Glossary ........................................ 79
11.1 Waiting time t
11.2 Safety time on start-up t
11.3 Ignition time t
11.4 Flame simulation/Flame simulation delay time
.....................................................79
t
LV
11.5 Safety time during operation t
11.6 Flame signal .................................... 80
11.7 Fault lock-out ................................... 80
11.8 Safety interlocks (Limits) ....................... 80
11.9 Pilot gas valve V1 ............................... 80
11.10 Main gas valve V2 ..............................81
11.11 Continuous operation ..........................81
11.12 Air valve.........................................81
11.13 Diagnostic coverage DC........................81
11.14 Mode of operation..............................81
11.15 Safe failure fraction SFF .......................81
11.16 Probability of dangerous failure PFH
11.17 Mean time to dangerous failure MTTF
Feedback .......................................... 83
Contact............................................ 83
..................................79
W
......................79
SA
..................................79
Z
............... 80
SB
........82
D
.......82
d
BCU 480 · Edition 03.16l 4
= To be continued
▼
Page 5
Application
▼
The BCU unites
the functionally interrelated
components of
automatic burner
control unit, ignition transformer,
Manual/Automatic
mode and display
of operating and
fault statuses in
a compact metal
housing.
1 Application
The burner control units BCU 480 control, ignite and
monitor gas burners for intermittent or continuous operation. As a result of their fully electronic design, they
react quickly to various process requirements and are
therefore suitable for frequent cycling operation.
They can be used for industrial burners of unlimited
capacity which are ignited by pilot burners. Pilot and
main burners may be modulating or stage-controlled.
The BCU 480 monitors pilot and main burners inde-
pendently. The pilot burner can burn permanently or be
switched off. The BCU is installed near the burner to be
monitored.
only relate to the burner, for example it ensures that
the burner always ignites in a safe condition when it is
restarted.
The air valve control assists the furnace control for cool-
ing, purging and capacity control tasks.
The program status, the unit parameters and the level
of the flame signal can be read directly from the unit.
The burner can be controlled manually for commission-
ing and diagnostic purposes.
If the local requirements on the burner control unit
change, the PC software “BCSoft” can be adjusted to
the unit parameters of the application by using the optical interface.
On industrial furnaces, the BCU reduces the load on
the central furnace control by taking over tasks that
BCU 480 · Edition 03.16l 5
Page 6
Application
Bogie hearth forg-
ing furnace in
the metallurgical
industry
Intermittent shut-
tle kiln in the ce-
ramics industry
The service personnel is supported by a convenient vis-
ualization system of the input and output signals and
the error history.
The new power management scheme reduces installa-
tion and wiring costs. The power for the valves and ignition transformer is supplied via the power supply of the
BCU, protected by a replaceable fine-wire fuse.
The conventional wide-spread systems used in indus-
trial furnace and kiln construction require bridging of
large distances for signal processing. The optionally
available BCU..B1 for connection to the PROFIBUS DP
fieldbus is equipped for this purpose.
As a standardized fieldbus system, the PROFIBUS DP
considerably reduces development, installation and
commissioning costs compared to conventional wiring.
The use of a standard bus system offers massive ben-
efits compared to manufacturer-specific bespoke solutions. Time-tested hardware components, standardized
connection methods and a series of tools of bus diagnostics and optimization are available on the market
from a whole range of manufacturers. The widespread
use of the system ensures that the planning and service personnel are very familiar with how the system operates and how to handle it and can therefore operate
the system efficiently.
Walking beam
furnace with over-
head firing
BCU 480 · Edition 03.16l 6
Page 7
Application
BCU 480
26
14
1.1 Examples of application
1.1.1
Stage-controlled main burner
with alternating pilot burner
L1, N, PE
DI
P
SPS
PLC
API
DI
5
6
3
12
VAG
VR..L
A
ϑ
1
ϑ
P
23
22 4
VBY
1
2
21
µC
24
UV
2
18
19
16
1
17
28
2
29
02–04 02–04 06–08 06–08
ϑ
1
1
ϑ
2
2
Control:
Main burner ON/OFF.
The main burner can be started with
reduced capacity after the operating signal from the pilot burner has
been detected. The pilot burner is
switched off automatically after the
main burner has started up. When
the main burner is switched off, the
pilot burner automatically switches
on again. This reduces the main
burner start-up time.
A UV sensor monitors the flame signal from pilot and main burners. UV
sensor UVD 1 is used for continuous operation, UV sensor UVS for
intermittent operation.
The BCU provides the cooling and
purging processes.
t
BCU 480 · Edition 03.16l 7
Page 8
Application
BCU 480
26
14
1.1.2
Stage-controlled main burner
with permanent pilot burner
Control:
Main burner ON/OFF.
L1, N, PE
DI
SPS
PLC
API
P
The main burner can be started with
reduced capacity after the operating signal from the pilot burner has
been detected. Pilot and main burn-
DI
5
6
3
12
VAG
P
23
VBY
A
22 4
1
ϑ1 ϑ
µC
24
2
2
21
18
19
16
17
28
29
1
2
ers can be operated simultaneously.
This reduces the time required by
the main burner for starting up.
The BCU provides the cooling and
purging processes.
04 02–04 06–08 06–08
VR..R
04
ϑ
1
1
ϑ
2
2
t
BCU 480 · Edition 03.16l 8
Page 9
Application
BCU 480
26
50 51
1.1.3 Two-stage-controlled main burner with permanent pilot burner
L1, N, PE
DI
SPS
PLC
API
P
Control:
Main burner ON/OFF with ignition
via bypass.
The main burner can be started at
DI
5
6
3
A
ϑ1 ϑ
P
22 4
23
2
21
18
19
low-fire rate after the operating signal from the pilot burner has been
detected. When the operating state
µC
14
12
24
16
17
28
29
1
2
is reached, the BCU issues the Enable signal for the maximum burner
capacity. Pilot and main burners
can be operated simultaneously.
VBY
VAS
This reduces the time required by
the main burner for starting up.
The BCU provides the cooling and
1
2
VAG
purging processes.
4
M
7
IC 40
04 02–04 06–08 06–08
04
ϑ
1
1
ϑ
2
2
t
BV
BCU 480 · Edition 03.16l 9
Page 10
Application
BCU 480
14
1.1.4 Modulating-controlled burner
Control:
Main burner continuous.
L1, N, PE
DI
mA
SPS
PLC
API
P
The butterfly valve for air is moved
to ignition position in order to start
the main burner. The main burner
can be started at low-fire rate after
DI
5
6
3
12
ϑ
µC
24
ϑ
2
1
4
21
18
19
16
17
28
29
1
2
the operating signal from the pilot
burner has been detected. The control system controls the burner capacity via the butterfly valve for air
after the operating state has been
signalled. Pilot and main burners
can be operated simultaneously.
This reduces the time required by
VBY
1
2
VAG
the main burner for starting up.
M
BV+IC
BCU 480 · Edition 03.16l 10
Page 11
Application
L1, N, PE
SPS
PLC
API
BCU 480..D
6
DI
DI
µC
BCU 480..B
1–6
9
P
BUS
24
BUS
PROFIBUS-DP
BCU 480..B
1–61–6
BUS
STM > 750°C
BCU 480..B
1.1.5 BCU 480..B1 for PROFIBUS DP
The bus system transfers the control
signals for starting, resetting and
for controlling the air valve from the
control system to the BCU 480..B1.
In the opposite direction, it sends operating status, the level of the flame
signals and the current program
status.
BUS
Control signals that are relevant for
safety, such as the safety interlocks,
purge (optional) and digital input, are
transferred independently of the bus
communication by separate cables.
1.1.6 BCU 480..D: High temperature equipment
Indirect flame control using the
BCU 480..D
L1
µC
temperature. During the start-up
process, as long as the wall temperature is below auto ignition temper-
6
DI
24
9
ature, the flame must be controlled
by conventional methods. When the
working temperature has exceeded
750°C, the safety temperature
monitor (STM) takes over the indirect flame control.
BCU 480 · Edition 03.16l 11
Page 12
Certification
2 Certification
Certificates – see Docuthek.
Certified to SIL and PL
For systems up to SIL 3 pursuant to EN 61508 and PL
e pursuant to ISO 13849
EU certified pursuant to
– Gas Appliances Directive (2009/142/EC) in conjunc-
tion with
EN 298:2012
Meets the requirements of the
– Low Voltage Directive (2006/95/EC),
– EMC Directive (2004/108/EC).
ANSI/CSA approved
FM approved
Factory Mutual Research Class: 7610 “Combustion
Safeguards and Flame Sensing Systems”.
Suitable for applications pursuant to NFPA 86.
www.approvalguide.com
AGA approved
AGA
Australian Gas Association, Approval No.: 6478
http://ww w.aga.asn.au/product _directory
Eurasian Customs Union
The product BCU 480 meets the technical specifica-
tions of the Eurasian Customs Union.
American National Standards Institute/Canadian
Standards Association – ANSI Z21.20/CSA C22.2,
No. 199/UL 372
ww w.csagroup.org – Class numbers: 333501 and
333581.
BCU 480 · Edition 03.16l 12
Page 13
Function
F1
V1 V2 C N S M L
N1
O
I
4
1 2 PE
5 6 7 8 119 10 12 13 14 15 25 26 2718 19 20
3
ϑ
1
I
Z
µC
s1
Test
88
1
N1 N1
c1
c2
230V~
N1
N1
v1
v2
V1
V2
PE 7 8 9 10 24 25PE 7 8 9 24
s
16 17 28 2921
max. 2 A,
253 V
1
2
UVS
3
(BCU 480..C)
BCU 480..E1
40 41 42 43 44 45 46 47
2
l
24
22
23
30 31 32 33 34 35 36 37DI50 51
F3
l
38
A
ϑ
2
P
L1 (L1)
N (L2)
PE
3 Function
3.1 Connection diagrams
3.1.1 BCU 480..E1
For cable selection and wiring, see page 57 (Project
planning information).
For the explanation of symbols, see page 78 (Leg-
end).
BCU 480 · Edition 03.16l 13
Page 14
Function
F1
V1 V2 C N S M L
O
I
4
1 2 PE
5 6 7 8 119 10 12 13 14 15 25 26 2718 19 20
3
s1
µC
88
N1 N1
c1
c2
230V~
N1
v1
V1
ϑ
1
PE 7 8 9 10 24 25PE 7 8 9 24
I
Z
3.1.2 BCU 480
For cable selection and wiring, see page 57 (Project
planning information).
For the explanation of symbols, see page 78 (Leg-
end).
Test
1
N1
v2
16 17 28 2921
V2
1
2
UVS
3
s
max. 2 A,
253 V
(BCU 480..C)
BCU 480
40 41 42 43 44 45 46 47
2
l
24
22
23
30 31 32 33 34 35 36 37DI50 51
F3
l
38
A
ϑ
2
P
L1 (L1)
N (L2)
PE
BCU 480 · Edition 03.16l 14
Page 15
Function
F1
V1 V2 C N S M L
O
N1
I
1 2 PE
5 6 7 8 119 10 12 13 14 15 25 26 2718 19 20
s1
µC
88
N1 N1
c1
c2
230V~
N1
v1
V1
PE 7 8 9 10 24 25PE 7 8 9 24
I
Z
3.1.3 BCU 480..B1..E1
For cable selection and wiring, see page 57 (Project
planning information).
For the explanation of symbols, see page 78 (Leg-
end).
Test
(BCU 480..C)
BCU 480..B1..E1
40 41 42 43 44 45 46 47
F3
N1
v2
V2
s
max. 2 A,
253 V
l
24
22
30 31 32 33 34 35 36 37DI50 51
P
38
L1 (L1)
N (L2)
l
PE
BCU..B1/1
1B1A2B2A
UVS
ON
OFF
1
2
3
PROFIBUS-DP
ON
OFF
BCU 480 · Edition 03.16l 15
Page 16
Function
F1
V1 V2 C N S M L
O
N1
I
1 2 PE
5 6 7 8 119 10 12 13 14 15 25 26 2718 19 20
s1
µC
88
N1 N1
c1
c2
230V~
N1
v1
V1
PE 7 8 9 10 24 25PE 7 8 9 24
I
Z
3.1.4 BCU 480..B1
For cable selection and wiring, see page 57 (Project
planning information).
For the explanation of symbols, see page 78 (Leg-
end).
Test
(BCU 480..C)
BCU 480..B1
40 41 42 43 44 45 46 47
F3
N1
v2
V2
s
max. 2 A,
253 V
l
24
22
30 31 32 33 34 35 36 37DI50 51
P
38
L1 (L1)
N (L2)
l
PE
BCU..B1/1
1B1A2B2A
UVS
ON
OFF
1
2
3
PROFIBUS-DP
ON
OFF
BCU 480 · Edition 03.16l 16
Page 17
Function
F1
V1 V2 C N S M L
N1
O
I
4
1 2 PE
5 6 7 8 119 10 12 13 14 15 25 26 27
3
16 15 14 8 7 12 511 10 4 39 2 16
s1
µC
88
N1 N1
c1
c2
230V~
N1
v1
v2
V1
V2
PE 7 8 9 10 24 25PE 7 8 9 24
I
Z
UVS
3.1.5 BCU 460..P..E1 with industrial plug connector
For cable selection and wiring, see page 57 (Project
planning information).
For the explanation of symbols, see page 78 (Leg-
end).
(BCU 480..P..C)
BCU 480..P..E1
40 41 42 43 44 45 46 47
max. 2 A,
253 V
1
N1
1
2
3
s
19 20
1716
18
24
21
22
23
2
l
30 31 32 33 34 35 36 37 50 51
28 29
ϑ1
8 7 6 5 4 3 2 1
16 15 14 12 11 10
F3
l
38
DI
P A
ϑ2
2
9
L1 (L1)
N (L2)
PE
1
BCU 480 · Edition 03.16l 17
Page 18
Function
F1
V1 V2 C N S M L
O
I
4
1 2 PE
5 6 7 8 119 10 12 13 14 15 25 26 27
3
16 15 14 8 7 12 511 10 4 39 2 16
s1
µC
88
N1 N1
c1
c2
230V~
N1
v1
V1
PE 7 8 9 10 24 25PE 7 8 9 24
I
Z
3.1.6 BCU 460..P with industrial plug connector
For cable selection and wiring, see page 57 (Project
planning information).
For the explanation of symbols, see page 78 (Leg-
end).
UVS
(BCU 480..P..C)
BCU 480..P
40 41 42 43 44 45 46 47
max. 2 A,
253 V
1
N1
v2
s
19 20
1716
18
24
21
22
23
2
l
30 31 32 33 34 35 36 37 50 51
28 29
F3
l
38
V2
DI
ϑ1
8 7 6 5 4 3 2 1
16 15 14 12 11 10
1
2
3
P A
ϑ2
2
9
L1 (L1)
N (L2)
PE
1
BCU 480 · Edition 03.16l 18
Page 19
Function
3.2 BCU..P with 16-pin industrial plug connector
The burner control unit BCU 480..P can be supplied
with an industrial plug connector (pursuant to VDE
0627). This 16-pin plug connector ensures fast connecting or disconnecting of units without any additional wiring required. This simplifies replacing the unit and
reduces standstill times.
All signals to the higher-level control system, the mains
supply and the safety interlocks are routed via this plug,
see page 71 (Accessories).
BCU 480 · Edition 03.16l 19
Page 20
Function
L1, N, PE
DI
SPS
PLC
API
PROFIBUS DP
BCU..B
BUS1– 6
BCU..B
BUS1– 6
3.3 PROFIBUS DP
BCU..B1 features the same scope of functions and performance of a BCU® without a PROFIBUS connection.
PROFIBUS is a manufacturer-independent, open field-
P
BUS
1
bus standard for diverse applications.
PROFIBUS DP is a bus variant for communication between automation systems and distributed peripherals
at the field level, optimized for speed and low connection costs.
On PROFIBUS DP, the individual bus stations are connected via a 2-core shielded cable as standard.
The bus system transfers the control signals for start-
ing, resetting and for controlling the air valve to purge
the furnace or kiln or for cooling in start-up position
and heating during operation from the control system
(PLC) to the BCU..B1. In the opposite direction, it sends
operating status, the level of the flame signal and the
current program status.
2
BCU..B
3.3.1 Safety-related control signals
Signals from the safety interlocks and digital input are
transferred independently of the bus communication
by separate cables. The air valve used to purge the fur-
BUS1– 6
nace or kiln can either be activated via the PROFIBUS
or via a separate cable to terminal 22. The purging pro-
3
cess must be monitored by further measures, e.g. flow
monitoring.
BCU 480 · Edition 03.16l 20
Page 21
Function
3.3.2 BCSoft
The Windows software BCSoft allows extended access
to individual statistics, protocol functions, line recorders and the parameterization of the burner control unit
via an optical interface. Unit parameters which are not
relevant to safety can be set and adjusted to the specific application.
3.3.3 Configuration, MasterSlave procedure
PROFIBUS DP is structured as a MasterSlave system.
This allows mono-master or multi-master systems to be
implemented.
A distinction is made between three device types:
– DP Masters Class 1 (DPM1)
DPM1 devices are central controllers which exchange
data with the distributed stations (slaves) on the basis of a defined cycle. This includes, for instance, the
PLC, PC, CNC or VME systems with which the PROFI
BUS DP is operated.
– DP Masters Class 2 (DPM2)
DPM2 devices are programming, project planning or
operator-control devices. They are used for configuration and commissioning of the system or for system
operation and visualization in ongoing operation.
– DP Slaves
The devices which transmit input information from
the periphery to the master and which issue output
information from the master to the peripher y are re-
ferred to as “slaves”.
This also includes the BCU..B1.
3.3.4 Addressing
A maximum of 126 units (masters and slaves) can be
connected to a PROFIBUS DP system. Each station is
assigned an individual PROFIBUS address which can
be set between 0 and 126 using two code switches on
the BCU..B1 board.
BCU 480 · Edition 03.16l 21
Page 22
Function
1
1
2
A
P
ϑ
1
A
P
ϑ
▼
3.3.5 Network technology
All devices are connected in a bus structure (line). Up
to 32 stations (masters or slaves) can be connected in
a single segment. The beginning and end of each segment is fitted with an active bus terminator. Both bus
terminators must have a permanent power supply to
ensure error-free operation. The power supply for the
bus terminator is provided by the BCU. The bus terminator can be connected in the bus connection plug.
If more than 32 stations are implemented or if there is a
need to expand the network area, repeaters (amplifiers)
must be used to link the individual bus segments.
3.3.6 Configuration
When planning a PROFIBUS DP system, unit-specific
parameters of each station are to be taken into account.
To allow for simple and standardized planning, the pa-
rameters of the BCU..B1 have been summarized in a
so-called device master data file (GSD). The file structure is standardized so that it can be read by the planning devices of different manufacturers.
The GSD file is supplied on the BCSoft CD which is in-
cluded in the delivery of BCU..B1. The GSD file can also
be ordered at www.docuthek.com. The steps required
to copy the file are described in the instructions for the
automation system.
3.3.7 Bus communication
Input bytes (BCU ➔ master)
Bit Byte 0 Byte 1 Byte 2 Byte 3 Byte 4
0
1
2
3
4
5
6
7
Output by tes (master ➔ BCU)
Bit Byte 0
0
1
2
3
4
5 Reserved
6 Reserved
7 Reserved
on
Reserved
on
DI
on
BCU 480 basic I/O
2
messages)
See table on page
27 (Program status and fault
BCU 480 standard I/O
0–25.5 µA
2
255 steps
255 steps
0–25.5 µA
BCU 480 · Edition 03.16l 22
Page 23
Function
I/O bytes: the programmer can choose the data to be
transferred.
Inputs Outputs
480 basic I/O 1 byte 1 byte
480 standard I/O 5 bytes 1 byte
Baud rate: up to 1500 kbit/s.
The max. range per segment depends on the baud rate:
Baud rate [kbit/s] Range [m]
93.75 1200
18 7.5 1000
500 400
1500 200
The specified ranges may be increased by using repeat-
ers. No more than three repeaters should be connected
in series.
The specified ranges relate to bus cable type A (two-
core, shielded and twisted), e.g.
Siemens, Order No.: 6XV18300EH10, or
Lapp cable unitronic, Order No.: 2170220T.
BCU 480 · Edition 03.16l 23
Page 24
Function
A
▼
Switch on BCU 480
In the event of fault signal:
Safety interlocks (Limits)
00
01
02
Start-up position/standby
If parameter P15 = 1:
flame simulation check
Pilot burner start-up
with ϑ1 signal
min. burner pause time t
If parameter P15 = 0:
flame simulation check
Safety time t
running (P22),
ignition in process,
V1 opens and min.
burner on time t
starts to elapse (P20)
If no flame detected:
max. 3 start-up attempts
or fault lock-out
reset
Wait until
has elapsed
SA1
BCU 480
If the air valve control is used,
the unit offers the following additional functions:
3.4 BCU 480 program sequence
Normal start-up
If an “old” fault is still being signalled after
switching on, it will be necessary to reset this
first.
The safety interlocks (terminal 5) must be
In start-up position, the air
valve can be opened for cool-
(display A0).
ing
closed and the burner control unit must be
switched on.
The BCU 480 conducts a self-test when in
the start-up position (the burner is switched
off). If it does not determine a malfunction
Using parameter 31, it can be
determined whether the air
valve can be activated externally during start-up (display
w
A1
).
of the internal electronic circuitry or of the
flame sensors, the burner can be started.
The pilot burner start-up is activated via the
signal input “Start-up signal ϑ1” (terminal 4).
Once the start-up signal ϑ1 has been applied,
the BCU 480 opens valve V1 and ignites the
burner. The ignition time t
flame is detected during the safety time t
The air valve can be set to open
together with V1 (display
via parameter 30.
B
A2
)
the flame proving period t
safety time t
has elapsed.
SA1
If the pilot burner has been started successfully and its flame has stabilized, the burner
is constant. If a
Z
starts after the
FS1
SA1
,
control unit issues the Enable signal for main
burner operation. The operation signalling
contact for the pilot burner (terminals 16/17)
closes.
BCU 480 · Edition 03.16l 24
Page 25
If no flame detected:
max. 3 start-up attempts
or fault lock-out
▼
Function
03
04
05
06
Flame proving period t
running (P23)
In the event of flame failure:
fault lock-out
Operating signal
Pilot burner closes
In the event of flame failure:
restart or fault lock-out
Main burner start-up
with ϑ2 signal
min. burner pause time t
has elapsed (P21)
If parameter P15 = 0:
flame simulation check
Safety time t
V2 opens and
min. burner on time t
starts to elapse (P20)
If no flame detected:
max. 3 start-up attempts
or fault lock-out
Wait until
running (P22),
SA2
FS1
B
The BCU coordinates the correct pro-
The air valve can be set to open
together with V1 (display
via parameter 30.
A3
)
gram run for the pilot and main burners. The main burner can be started
via the signal input “Start-up signal
ϑ2” (terminal 21) if required.
Once the start-up signal ϑ2 has been
The air valve can be set to open
together with V1 (display A4)
via parameter 30.
applied (terminal 21), the BCU 480
opens valve V2. The main burner is
ignited by the pilot burner.
If a flame is detected during the safety time t
t
starts after the safety time t
FS2
, the flame proving period
SA2
SA2
has elapsed.
The air valve can be set to open
A5
together with V1 (display
via parameter 30.
)
If the main burner has been started
successfully and its flame has stabilized, the operation signalling contact
BP
(terminals 28/29) closes.
Start-up of the pilot burner
without flame signal
If no flame is detected during the
The air valve can be set to open
with V2 or to be activated externally (display
parameter 30.
A6
) via
safety time t
out occurs or up to two further startup attempts occur. The required
functions and, if applicable, the
, either a fault lock-
SA1
number of start-up attempts must be
specified when ordering (parameter
10, “Pilot burner start-up attempts”).
BCU 480 · Edition 03.16l 25
Page 26
If no flame detected:
max. 3 start-up attempts
or fault lock-out
Function
07
08
08
00
Flame proving period
t
FS2
In the event of flame failure:
fault lock-out
Operating signal
Main burner closes
In the event of flame failure:
restart or fault lock-out
Controlled shut-down
via ϑ signal for
pilot and main burners
If min. burner on time t
operation signalling contact
V1 and V2 close,
min. burner pause time t
starts to elapse (P21)
running (P24)
elapsed:
opens,
has
B
Behaviour of the pilot burner in
The air valve can be set to open
with V2 or to be activated externally (display A7) via parameter 30.
the event of flame failure during
operation
If the flame fails during operation,
either an immediate fault lock-out or
a restart occurs. This procedure can
be set via the optical interface (pa-
The air valve can be set to open
with the operating signal or to
be activated externally (display
A8
) via parameter 30.
rameter 12, “Pilot burner restart”).
Start-up of the main burner
without flame signal
If no flame is detected during the
safety time t
, either a fault lock-
SA2
out occurs or up to two further
start-up attempts occur. The required functions and, if applicable,
the number of start-up attempts
must be specified when ordering
(parameter 11, “Main burner startup attempts”).
Behaviour of the main burner in
the event of flame failure during
BP
operation
If the flame fails during operation,
either an immediate fault lock-out or
a restart occurs. This procedure can
be set via the optical interface
(pa-
rameter 13, “Main burner restart”).
BCU 480 · Edition 03.16l 26
Page 27
Function
▼
3.5 Program status and fault messages
BCU 480
BCU 480..B1
Program status
BCU switched off
Start-up position/Standby
Purge
Waiting time/Pause time
Safety time on start-up, pilot burner
Flame proving period, pilot burner
Operation, pilot burner
Waiting time, main burner
Safety time on start-up, main burner
Flame proving period, main burner
Operation, main burner
Air valve
Pre-ventilation
Post-ventilation
Cooling
High temperature operation
DISPLAY
– –
00
P0
1
2
3
4
5
6
7
8
10
A
A1
A0
A0
0
P
X
. .
P
Fault message (flashing)
Flame simulation
Start-up without fl ame signal, pilot burner
Flame failure during flame proving period, pilot burner
Flame failure during operation, pilot burner
Flame simulation, main burner
Start-up without fl ame signal, main burner
Flame failure during flame proving period, main burner
Flame failure during operation, main burner
Too many remote resets
Air pressure switch “no flow” state
No air flow during purge
No air flow in position X
Bus fault
BCU 480 · Edition 03.16l 27
Page 28
Function
Program status
DISPLAY
30
31
32
33
51
52
53
In Manual mode, two dots will blink on the display in program status 01–08.
= standard, = option.
* FS = input /output, safety circuit, NFS = input/output, control system.
Fault message (flashing)
EEPROM data change, NF S*
EEPROM data change, FS*
Undervoltage in power pack
Faulty parameterization
Bus module fault
Safety interlock failure
Permanent remote reset
Timing cycle too shor t
BCU 480
BCU 480..B1
BCU 480 · Edition 03.16l 28
Page 29
Parameters
▼
4 Parameters
Description Parameter Value range
Flame signal, pilot burner 01
Flame signal, main burner 02
0–99 μA
0–99 μA
Program status when the most recent fault occurred 03 x0–x8
Switch-off threshold, pilot burner 04
Switch-off threshold, main burner 05
1–20 µA 1 µA
1–20 µA 1 µA
Start-up attempts, pilot burner** 10 1–4 1
Start-up attempts, main burner** 11 1–4 1
Restart, pilot burner 12 0; 1 0
Restart, main burner 13 0; 1 0
Safety time during operation for V1 and V2 t
SB
14 1; 2 s 1 s
Flame simulation check in star t-up position/standby 15 0; 1 1
Permanent pilot burner 16 0; 1 1
Minimum burner on time t
Minimum burner pause time t
B
BP
Pilot burner safety time on star t-up t
Pilot burner flame proving period t
FS1
Main burner safety time on start-up t
Main burner flame proving period t
** 22 3; 5; 10 s
SA1
** 24 3; 5 s
SA2
FS2
20 25 s t
21 0–250 s 0 s
23 0–25 s 0 s
25 0–25 s 0 s
Air valve control 30 0; 1; 2; 3 0
Air valve c an be activated ex ternally on star t-up 31 0; 1 0
Air valve closed/can be activated in the event of malfunction 32 0; 1 1
Factory
default setting
Adjustable*
SA
BCU 480 · Edition 03.16l 29
Page 30
Parameters
Description Parameter Value range
High temperature operation** 33 2; 3
Manual mode limited to 5 minute s 34 0; 1 1
UVS check (1 x in 24 hours) 35 0; 1 0
Low fire over-run time** 36 0; 5; 15; 25 s 0 s
* Adjustable using BCSoft software and a PC opto-adapter
** Please quote in your order.
0 = Function inactive,
1 = Function active.
default setting
On parameterization, ensure that the program se-
quence started matches the application. This parameter may be set in this way only if the burner can restart
as intended in all operating phases.
4.1 Scanning the parameters
During operation, the 7-segment display shows the pro-
gram status, see page 27 (Program status and fault
messages).
The flame signal and all following parameters of the
BCU can be scanned one after the other by repeatedly
pressing the Reset/Information button (for 2 s).
In the event of a fault, the BCU halts the program run,
the display blinks and it then displays the cause of the
fault in coded form.
Factory
Adjustable*
BCU 480 · Edition 03.16l 30
Page 31
Parameters
4.2 Flame control
4.2.1 Flame signal, pilot burner
Parameter 01
Flame signal of the pilot burner, display in μA , measur-
ing range: 0–30 μA.
4.2.2 Flame signal, main burner
Parameter 02
Flame signal of the main burner, display in μA, measur-
ing range: 0–30 μA.
4.2.3 Program status when the most recent fault occurred
Parameter 03
This indicates the program status in which the last
burner fault occurred (e.g. the unit indicates that a
flame simulation has been detected with a blinking
).
In parameter 03, it is now shown which program posi-
tion the unit was in when the fault was detected (wait-
ing time
Result: a flame simulation was detected during the
waiting time or standby.
01
or standby
00
).
01
4.2.4 Switch-off threshold of the flame amplifier
Parameter 04, pilot burner switch-off threshold
Parameter 05, main burner switch-off threshold
The sensitivity at which the burner control unit still de-
tects a flame can be set between 1 and 20 μA.
Example: in the case of UV control with the UV sensor
UVS, the signal of the burner to be monitored is influenced by other burners.
The set value can be incremented in parameter 04 so
that only the flame of the system’s “own” burner is detected.
The measured flame signal of the system’s “own” burner
should be at least 3 μA (empirical value) higher than the
set switch-off threshold.
BCU 480 · Edition 03.16l 31
Page 32
Parameters
▼
4.2.5 High temperature operation in the case of
BCU..D2 or BCU..D3
Parameter 33
Operation of firing systems at temperatures above
750°C. The BCU features a safety-relevant DI input
(Digital Input). This input supports the “High tempera-
ture operation” function. If firing systems are operated
above 750°C, the system is considered to be an item
of high temperature equipment (see EN 7462). Flame
control must be in operation until the furnace wall tem-
perature has exceeded 750°C. Note the requirements
of the Standards!
Frequently, flame control is dispensed with so as to
achieve a particularly high flexibility of the installation.
This means that no incorrect flame signals, e.g. signals
from a UV sensor which are interpreted as extraneous
signals due to reflection of UV radiation, may lead to
faults.
When the DI input is activated, the burner control unit
reverts to high temperature operation. This means: the
BCU operates without evaluation of the flame signal.
The safety function of the device-internal flame con-
trol system is placed out of operation.
In High temperature mode, the gas valves are opened
without flame control.
The precondition for high temperature operation is that
an external flame safeguard ensures the presence of
the flame in fail-safe manner indirectly via the tempera-
ture. For this purpose, we recommend a safety temperature monitor with double thermocouple (DIN 3440).
Sensor discontinuity, sensor short-circuit, failure of a
component or mains failure must set the installation to
a safe state.
The voltage may be applied to the DI input (terminal
6) so as to activate high temperature operation only
when the temperature at the furnace wall has exceeded
750°C. The BCU starts the burner as usual, without
monitoring the presence of the flame.
88 04 02 03 00
1
5
ϑ1
4
DI
6
7
9
V1
12
14 V2
1
16-17
18-19
t
Z
t
SA
t
FS
t
If the temperature in the furnace chamber drops below
750°C, the DI input must be disconnected from the
electrical power supply and the furnace must be operated with the internal flame control system.
BCU 480 · Edition 03.16l 32
Page 33
Parameters
▼
The BCU then responds, depending on setting:
Parameter 33 = 2 (BCU..D2)
04 02 03 01
06 07 08 08
Z
t
SA1
t
FS1
t
t
W
t
SA2 tFS2
88
1
5
ϑ1
4
7
DI
6
12
9
16-17
ϑ2
21
14
24
28-29
18-19
V1
1
V2
2
1
2
t
The BCU switches off the burner once the DI input has
been disconnected from the electrical power supply
and restarts with flame simulation check (recommend-
ed in the case of UV control with UVS).
Parameter 33 = 3 (BCU..D3)
08
08
88
30a
26e
10e
28c
22a
16c
26a
2c–4c
14a
18e
18a
6a–6e
2e–4e
ϑ1
DI
V1
1
1
ϑ2
V2
2
2
t
The burner remains in operation and the BCU performs
flame control again (recommended in the case of ionization control or UV control with UVD).
BCU 480 · Edition 03.16l 33
Page 34
Parameters
If no flame signal is present when high temperature operation is deactivated, the burner control unit performs
a fault lock-out, regardless of parameter 33.
Fault, pilot burner
04 04
Fault, main burner
08
08
88
1
5
ϑ1
4
7
DI
6
12
9
16-17
ϑ2
21
14
24
28-29
18-19
88
1
5
ϑ1
4
7
DI
6
12
9
16-17
ϑ2
21
14
24
28-29
18-19
V1
1
V2
2
V1
1
V2
2
1
2
t
1
2
t
BCU 480 · Edition 03.16l 34
Page 35
Parameters
4.2.6 UVS check
Parameter 35
An automatic restart of the burner control unit can be
activated every 24 hours via this parameter. The time
starts each time the start-up signal (ϑ) is applied.
Parameter 35 = 0: Unlimited burner operation.
Parameter 35 = 1: An automatic restart is activated
once every 24 hours.
It must be ensured in this case that the program sequence started matches the application. This parameter may be set in this way only if the burner can restart
as intended in all operating phases.
UV sensor for intermittent operation
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 automatically after
an operating time of 24 hours. The restart does not
meet the requirements of EN 298 for UV sensor continuous 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. 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.
BCU 480 · Edition 03.16l 35
Page 36
Parameters
t
4.3 Pilot and main burner monitoring
Automatic burner control unit BCU 480 for pilot and
main burner combination of unlimited capacity.
Pilot burner: single-stage-controlled.
Main burner: modulating or stage-controlled.
The burner control unit BCU 480 has separate start-up
signal inputs for the pilot burner (terminal 4) and the
main burner (terminal 21). The burner control unit coordinates the program run (the interplay) of both burners.
If required, the main burner can be started once the
pilot burner has reached its operating position. Benefit:
the time for starting up the main burner can be reduced
as low as its safety time. By using two flame amplifiers,
the pilot and main burners can be monitored separately.
The BCU 480 can also be used on indirectly ignited surface burners with end point monitoring.
Three different operating modes are possible:
Permanent pilot burner
88 02–04 06–08 04 06–08 04
ϑ1
1
ϑ2
2
Intermittent pilot burner
88 02–04 06–08 00 02–04 06–08 00
ϑ
1
2
t
Pilot and main burners are controlled with one start-up
signal (terminals 4 and 21 in parallel). The main burner
starts automatically after the operating signal from the
pilot burner has been detected. Operation is terminated
simultaneously for both burners.
Interrupted pilot burner
88 02–04 06–08 02–04 06–08
ϑ1
1
ϑ2
2
t
The pilot burner is switched off during the main burner
safety time t
. This type of flame control is required if
SA2
no distinction can be made between the flame signals
of the pilot and main burners (e.g. if both burners can
be monitored with a single UV sensor). If the start-up
signal for the pilot burner is applied continually, the
pilot burner restarts immediately after the main burner
has been switched off.
For applications which require a high system availabil-
ity or where a continuously burning flame is necessary.
The pilot burner is ignited once and remains constantly
in operation. The main burner is controlled separately.
BCU 480 · Edition 03.16l 36
Page 37
Parameters
4.3.1 Permanent pilot burner
Parameter 16 = 1
04 06 07 08 02 03 00
t
Z
t
SA1
t
FS1
t
SA2
t
FS2
88
2
5
4
7
12
9
16-17
21
14
24
28-29
18-19
ϑ
1
V1
1
1
ϑ
2
V2
2
2
t
Operating mode: Permanent pilot burner
In the “Permanent pilot burner” operating mode, the pilot burner remains in operation until its start-up signal
drops.
If this parameter is activated (P16 = 1), both flames are
controlled independently in the case of pilot and main
burner monitoring.
Operating mode: Intermittent pilot burner
Start-up as in the illustration “Permanent pilot burner”
with the difference being that the start-up signal for pilot and main burners is applied synchronously and that
immediately after the flame proving period t
FS1
, the
main burner is started.
4.3.2 Interrupted pilot burner
Parameter 16 = 0
04 06 07 08 02 03 00
t
Z
t
SA1
t
FS1
t
SA2
t
FS2
88
2
5
4
7
12
9
16-17
21
14
24
28-29
18-19
ϑ
1
V1
1
1
ϑ
2
V2
2
2
t
Operating mode: Interrupted pilot burner
If parameter 16 = 0, the pilot burner is switched off once
the safety time t
has elapsed. In this setting, the
SA2
flame signal can be connected to terminals 24 or 9.
The pilot burner is switched off after the main burner
safety time t
has elapsed.
SA2
BCU 480 · Edition 03.16l 37
Page 38
Parameters
4.4 Behaviour in start-up position/standby
4.4.1 Flame simulation check in start-up position/ standby
Parameter 15
This defines the instant for the flame simulation check.
00
t
LV
If the BCU notices an extraneous signal during the flame
simulation check, it starts the flame simulation delay time
tLV (25 s). If the extraneous signal is discontinued during this period, the burner can start up. Otherwise, a fault
lock-out occurs. 1 blinks on the display if an extraneous
signal is detected by the pilot burner and 5 blinks if an
extraneous signal is detected by the main burner.
Parameter 15 = 0: The flame simulation check is conduct-
ed after applying the start-up signal (ϑ) during the waiting
time t
.
W
Parameter 15 = 1: The flame simulation check is con-
ducted provided no start-up signal (ϑ) is applied (during
the so-called start-up position/standby). This allows fast
start-up of the burner since there is no waiting time t
The burner must have been switched off for at least 4 s be-
01
88
1
5
ϑ
1
4
7
9
V1
12
14 V2
16-17
18-19
t
.
W
fore start-up in order for the flame simulation check to be
conducted correctly.
Flame simulation check depending on parameter 16, see
page 37 (Permanent pilot burner) and (Interrupted pilot
burner):
Parameter 15 = 1, parameter 16 = 1
88 00 02 06
ϑ1
V1
ϑ2
V2
t
Parameter 15 = 0, parameter 16 = 1
02
t
W1
06
t
W2
88 00 01 05
ϑ1
ϑ2
V1
V2
t
Parameter 15 = 1, parameter 16 = 0
88 00 02 06
ϑ1
V1
ϑ2
V2
t
Parameter 15 = 0, parameter 16 = 0
02
t
W1
06
t
W2
88 00 01 05
ϑ1
ϑ2
V1
V2
t
BCU 480 · Edition 03.16l 38
Page 39
Parameters
4.4.2 Minimum burner pause time tBP
Parameter 21
Programmable time between 0 and 250 s
05 04
t
BP
t
SA2
t
FS2
88 08 06 07 08
1
5
ϑ
1
4
7
1
9
V1
12
16-17
ϑ
2
21
2
9
14 V2
28-29
26
18-19
1
2
t
An immediate restart of the burner after a controlled
shut-down, a start-up attempt, restart, cooling or purging is prevented by the pause time. The pause time
starts when the air valve is switched off. If a start-up
signal (ϑ) is applied before expiry of this time, start-up
is delayed until the end of the pause time.
After the pause time, the burner is started if the start-
up signal (ϑ) is applied.
The minimum burner pause time t
serves to adapt the
BP
program sequence to the requirements of the application.
The time should be set such that the system can be
moved to ignition position, i.e. butterfly valves can be
closed and, possibly, gas can be flared off, before a restart occurs.
Example of application
L1, N, PE
DI
P
SPS
PLC
API
BCU 480
26
14
DI
5
6
3
12
VAG
VR..R
A
ϑ1 ϑ
22 4
µC
24
1
2
2
21
18
19
16
1
17
28
2
29
04 02–04 06–08 06–08
04
P
23
VBY
The pause time has an effect on the behaviour of the
main burner only. Reason: the pilot burner is only used
in single-stage operation.
ϑ
1
1
ϑ
2
2
t
BCU 480 · Edition 03.16l 39
Page 40
Parameters
4.5 Behaviour during start-up
4.5.1 Safety time on start-up tSA
Pilot burner
Parameter 22
88 04 02 03 00
1
5
ϑ
4
7
9
12
16-17
18-19
t
Z
t
SA1
This indicates the safety time on start-up t
pilot burner.
t
FS1
1
1
V1
1
t
SA1
for the
Main burner
Parameter 24
04 06 07 08 02 03 00
t
Z
t
SA1
t
FS1
t
SA2
t
FS2
This indicates the safety time on start-up t
main burner.
SA2
88
2
5
ϑ
1
4
7
V1
12
1
9
1
16-17
ϑ
2
21
14
V2
24
2
28-29
18-19
for the
2
t
BCU 480 · Edition 03.16l 40
Page 41
Parameters
4.5.2 Flame proving period tFS
Pilot burner
Parameter 23
t
Z
t
SA1
t
FS1
Main burner
Parameter 25
04 06 07 08 02 03 00
t
Z
t
SA1
t
FS1
t
SA2
1
5
4
7
9
12
16-17
18-19
t
FS2
4.5.3 Minimum burner on time t
B
Parameter 20
Programmable time in the range from minimum safety
time on start-up t
88 04 02 03 00
ϑ
1
1
V1
1
t
88
2
5
ϑ
1
4
7
V1
12
1
9
1
16-17
ϑ
2
21
14
V2
2
24
2
28-29
18-19
t
the main burner remains in operation. In the case of
brief activation of the start-up signal input (ϑ2) (e.g.
with a pulse), the burner on time tB is started, and the
main burner remains in operation for at least this period.
04 06 07 08
to maximum 25 s during which
SA2
88
2
5
4
12
9
16-17
21
14
24
28-29
18-19
t
SA2
t
B
ϑ
1
V1
1
1
ϑ
2
V2
2
2
t
Programmable time between 0 and 25 s.
This time elapses before the BCU starts the next pro-
gram step so as to give the flame time to stabilize.
BCU 480 · Edition 03.16l 41
Page 42
Parameters
▼
4.5.4 Burner start-up attempts
Pilot burner
Parameter 10
This indicates the number of possible start-up attempts
of the burner.
In accordance with EN 7462, three start-ups are permitted in specific cases if the safety of the installation
is not impaired (note the requirements of the Standards).
If no flame is detected or if the air flow on the BCU fails
during start-up, either a fault lock-out occurs or up
to two further start-up attempts occur. The required
functions and, if applicable, the number of start-up at-
tempts must be specified when ordering.
1 start-up attempt
Parameter 10 = 1
02
t
Z
t
SA
88 02 00
1
5
ϑ
1
4
7
9
V1
12
14 V2
16-17
18-19
t
2 or 3 start-up attempts
Parameter 10 = 2, 3
01 02
t
Z
t
SA
t
Z
t
t
SA
W
880200
1
5
ϑ
1
4
7
9
V1
12
14 V2
16-17
18-19
t
If several start-up attempts are set at the works and if
the BCU detects a flame failure during start-up, it closes valve V1 after the safety time t
has expired and
SA1
attempts to start up again. After the last programmed
start-up attempt has been completed, the burner control unit conducts a fault lock-out. The display blinks
and shows the cause of the fault.
If no flame forms during start-up, a fault lock-out is
performed after expiry of time tSA. The display blinks
and shows the cause of the fault.
BCU 480 · Edition 03.16l 42
Page 43
Parameters
Main burner
Parameter 11
This indicates the number of possible start-up attempts
of the main burner.
In accordance with EN 7462, three start-ups are permitted in specific cases if the safety of the installation
is not impaired (note the requirements of the Standards).
If no flame is detected during start-up, either a fault
lock-out occurs or up to two further start-up attempts
occur. The required functions and, if applicable, the
number of start-up attempts must be specified when
ordering.
1 start-up attempt
Parameter 11 = 1
04 06 02 03 00
t
Z
t
SA1
t
FS1
t
06
SA2
88
1
5
ϑ
4
7
12
9
16-17
ϑ
21
14
24
28-29
18-19
1
V1
1
1
2
V2
2
2
t
2 or 3 start-up attempts
Parameter 11 = 2, 3
04 06 02 03 00
t
Z
t
SA1
t
FS1
t
SA2
05
t
06
t
W
SA2
05
t
06
06
t
W
SA2
88
1
5
ϑ
4
7
12
9
16-17
ϑ
21
14
24
28-29
18-19
1
V1
1
1
2
V2
2
2
t
If several start-up attempts are set at the works and if
the BCU does not detect a flame signal during startup, it closes valve V2 after the safety time t
SA2
has
expired and attempts to start up again. After the last
programmed start-up attempt has been completed, the
burner control unit conducts a fault lock-out. The display blinks and shows the cause of the fault.
If no flame forms during the start-up of the main burner,
a fault lock-out is performed after expiry of time t
SA2
.
The display blinks and shows the cause of the fault.
BCU 480 · Edition 03.16l 43
Page 44
Parameters
▼
4.6 Behaviour during operation
4.6.1 Safety time during operation tSB for pilot and main burners
Parameter 14
This indicates the safety time during operation t
valves V1 and V2.
The default in accordance with EN 298 is 1 s.
The BCU has also the available option of a safety time
during operation t
of 2 s. Prolonging the time in-
SB
creases the installation availability in the case of briefduration signal fades (e.g. fades of the flame signal).
In accordance with EN 7462, the safety time of the
installation during operation (including closing time of
the valves) may not exceed 3 s. (Note the requirements
of the Standards!)
4.6.2 Fault lock-out or restart, pilot burner
Parameter 12
This parameter determines whether the BCU initiates a
one-off restart or performs an immediate fault lock-out
for the burner after a flame failure (see also page 57
(Project planning information)).
SB
for
04
04
t
SB
88
1
5
ϑ
1
4
7
9
1
V1
12
14 V2
16-17
18-19
1
t
After a fault lock-out, the burner control unit can be
reset, either with the button on the front panel or using
an external button. Several burner control units can be
reset in parallel using the external button.
The BCU cannot be reset by mains failure. The fault
signalling contact does, however, open as soon as the
mains voltage fails.
See also parameter 32, page 54 (Behaviour of the air
valve in the event of a fault lock-out).
Immediate fault lock-out in the event of flame
failure
Parameter 12 = 0: Pilot burner fault lock-out.
BCU 480 · Edition 03.16l 44
Page 45
Parameters
Restart in the event of flame failure
Parameter 12 = 1: Restart in the event of flame failure.
1x
04 04 03 01
88
1
5
ϑ
1
4
7
9
1
V1
>2 s
t
t
SB
t
Z
t
t
W
SA1
FS1
If the BCU detects a flame failure after a minimum operating time of 2 s, the valves are closed and the operation signalling contact is opened within time tSB.
The burner control unit now attempts to restart the
burner once. If the burner does not function, a fault
lock-out occurs. The display blinks and shows the
cause of the fault.
In accordance with EN 7462, a restart may be conducted only if the safety of the installation is not impaired. Restart is recommended for burners which occasionally display unstable behaviour during operation.
The precondition for a restart is that activation of the
restart allows the burner to 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.
12
16-17
18-19
1
t
BCU 480 · Edition 03.16l 45
Page 46
Parameters
S
▼
4.6.3 Fault lock-out or restart, main burner
This parameter determines whether the BCU starts a
one-off restart or performs an immediate fault lock-out
for the main burner after a flame failure (see also Pro-
ject planning information).
Immediate fault lock-out in the event of flame
failure
Parameter 13 = 0: Main burner fault lock-out.
08
08
t
B
88
1
5
ϑ
4
7
12
9
16-17
ϑ
21
14
24
28-29
18-19
1
V1
1
1
2
V2
2
2
t
After a flame failure, the burner control unit performs
a fault lock-out within the safety time during operation
tSB. This involves disconnecting the power from the gas
valves and the ignition transformer. The fault signalling
contact closes, the display blinks and shows the current
program status, see table on page 27 (Program status and fault messages).
After a fault lock-out, the burner control unit can be
reset, either with the button on the front panel or using
an external button. Several burner control units can be
reset in parallel using the external button.
The BCU cannot be reset by mains failure. The fault
signalling contact does, however, open as soon as the
mains voltage fails.
See also page 54 (Behaviour of the air valve in the
event of a fault lock-out).
BCU 480 · Edition 03.16l 46
Page 47
Parameters
Restart in the event of flame failure
Parameter 13 = 1: Restart in the event of flame failure.
1x
08
>2 s
06
05
t
t
W2
t
SB
SA2
07
08
t
FS2
88
1
5
ϑ
4
7
12
9
16-17
ϑ
21
14
24
28-29
18-19
1
V1
1
1
2
V2
2
2
t
If the BCU detects a flame failure after a minimum operating time of 2 s, valve V2 is closed and the operation
signalling contact is opened within time tSB.
The burner control unit now attempts to restart the
main burner once. If the burner does not function, a
fault lock-out occurs. The display blinks and shows the
cause of the fault.
In accordance with EN 7462, a restart may be conducted only if the safety of the installation is not impaired. Restart is recommended for burners which occasionally display unstable behaviour during operation.
The precondition for a restart is that activation of the
restart allows the burner to 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.
4.6.4 Program status on last fault
Parameter 03
This indicates the program status in which the last
burner fault occurred.
Example: the unit indicates that the safety interlocks
have been interrupted with a blinking
51
.
Parameter 03 can now be used to scan in what program
status the BCU was when the fault was detected.
BCU 480 · Edition 03.16l 47
Page 48
Parameters
4.7 Air valve control on BCU..L
Parameter 30, Behaviour of the air valve during opera-
tion.
Parameter 31, Behaviour of the air valve during start-up.
Parameter 32, Behaviour of the air valve in the event of
a fault lock-out.
The BCU..L features an adjustable air valve control. The
display shows that purging is currently being carried
out with
tivated for cooling or heating.
The BCU..L supports the following functions:
– Purge
– Cooling in start-up position/standby
– Switching of the burner between low and high burner
capacity during operation via the air valve
– To start up the burner as intended, external activation
of the air valve can be blocked during start-up (prevents synchronization problems between the BCU
and the central control system).
– Setting the air valve parameters, so that it
– opens with valve V1
– opens with valve V2
– opens once the main burner has reached its operat-
– Low fire over-run time t
down
P 0. A
ing position
indicates that the air valve is being ac-
after a controlled shut-
KN
4.7.1 Purge
In the case of multiple burner applications, burners with
mechanical combustion air supply are used. The air for
combustion and pre-purge is supplied by a central fan
controlled by a separate logic. This logic determines the
purging time.
The BCU..L..E1 with adapted power management sup-
ports centrally-controlled pre-purge or post-purge.
The BCU..L is informed that purging is currently being
performed by input 22. It then opens the air valve, regardless of the status of the other inputs (purging has
priority). The display indicates
On BCUs without power management, input 22 and input 5 (safety interlocks) must be activated for purging,
see connection diagrams on pages 14 (BCU 480), 16
(BCU 480..B1) and 18 (BCU 480..P with industrial plug
connector).
4.7.2 Cooling in start-up position/standby
The air valve can be activated externally via input 23 for
cooling in the start-up position. During activation of the
air valve the display shows
currently being carried out.
4.7.3 Burner start
Parameters 30 and 31 determine the behaviour of the
air valve during burner start.
P 0
.
A 0
, indicating that cooling is
BCU 480 · Edition 03.16l 48
Page 49
Parameters
ϑ
4.7.4 Air valve opens in the case of external activation (not during start-up)
00 A0
00
02
03
t
t
Z
t
SA1
L1
A
P
06 88
04
FS1
BCU 480..L
VAG
t
VAS 1
SA2
A807
2
5
ϑ
4
7
12
9
16-17
ϑ
21
14
24
28-29
23
26
18-19
t
FS2
1
SPS
2
PLC
CPE
UV
Parameter 30 = 0: The air valve opens if it is activated
externally via input 23.
Parameter 31 = 0: The air valve remains closed during
start-up even if it is activated externally.
1
V1
1
1
2
V2
2
2
A
t
These settings are required on burners on which the
gas/air ratio is controlled via a pneumatic ratio control
system and which also need to be started at low fire,
e.g. on two-stage-controlled burners. In this case, activation of the air valve during burner start via input 23
must be prevented.
External control allows switchover between low fire and
high fire during operation.
VR..R
BCU 480 · Edition 03.16l 49
Page 50
Parameters
SA1
ϑ
4.7.5 Air valve opens in the case of external activation (even during start-up)
88
A8 A7
2
5
4
7
12
9
16-17
21
14
24
28-29
23
26
18-19
UV
FS1
A4
VAS 1
A6
t
SA2
t
FS2
1
2
A3
A2
A0
00 A0 00
t
t
Z
t
BCU 480..L
L1
A
P
VAS..L
Parameter 30 = 0: The air valve opens if it is activated
externally via input 23.
Parameter 31 = 1: The air valve can be activated even
during start-up.
ϑ
1
V1
1
1
ϑ
2
V2
2
2
A
t
These settings may be selected only if the burner can
start with full air capacity.
VAS
BCU 480 · Edition 03.16l 50
Page 51
Parameters
SA1
ϑ
4.7.6 Air valve opens with valve V2
00 A0
00
02
03
t
t
Z
t
L1
A
P
04
FS1
BCU 480..L
VAS
VR..R
A6
VAS 1
t
SA2
t
FS2
1
2
1
2
A8 A7
SPS
PLC
CPE
88
2
5
4
7
12
9
16-17
21
14
24
28-29
23
26
18-19
Parameter 30 = 2: The air valve opens simultaneously
with valve V2.
Application: single-stage-controlled main burner is
ϑ
1
V1
1
1
ϑ
2
V2
2
2
A
t
switched ON/OFF via the ϑ input.
The air valve can be activated externally via input 23 for
cooling the burner in the start-up position/standby.
BCU 480 · Edition 03.16l 51
Page 52
Parameters
ϑ
4.7.7 Air valve opens with operating signal
04
06
t
SA
L1
A
P
BCU 480..L
VAS 1
VAG
VR..R
t
FS
88
A8 07
2
5
ϑ
1
4
7
V1
12
1
9
1
16-17
ϑ
2
21
14
V2
2
24
2
28-29
A
23
26
18-19
1
SPS
2
PLC
CPE
1
2
Parameter 30 = 3: The air valve opens simultaneously
with the operating signal.
Application: two-stage-controlled main burner is
switched ON/OFF via the ϑ input.
The air valve can be activated externally via input 23 for
cooling the burner in the start-up position/standby.
t
BCU 480 · Edition 03.16l 52
Page 53
Parameters
ϑ
4.7.8 Low fire over-run time tKN after a controlled
shut-down
A8
t
KN
BCU 480..L
L1
A
P
VAS 1
GIK..B
VG..N
VR..R
88 00
1
5
ϑ
1
4
7
V1
12
1
9
1
16-17
ϑ
2
21
14
V2
2
24
2
28-29
A
23
26
18-19
t
1
SPS
2
PLC
CPE
1
2
Parameter 36
Settings: 0; 5; 15 or 25 (low fire over-run time in seconds)
This parameter is applicable to systems with a pneu-
matic
air/gas ratio control system and On/Off control.
Parameter 36 = 0 (low fire over-run time t
= 0 s):
KN
Without low fire over-run, the gas circuit is closed immediately owing to the quick-closing gas valve in the
case of On/Off control. The air circuit closes more slowly. The air flowing in during the closing time increases
the O2 content in the combustion chamber.
Parameter 36 = 5; 15 or 25 (low fire over-run time
t
= 5, 15 or 25 s):
KN
The air valve closes slowly after the activation signal has
been switched off. The gas valve remains open for tKN.
This means that the burner, after deactivation of the
start-up signal (ϑ), is initially adjusted down to low fire
and then switched off completely.
Using the low fire over-run function reduces the O
2
content in the furnace atmosphere.
Flame control is still operational. Can be used only in
the case of a pneumatic air/gas ratio control system
and On/Off control. It must be ensured that no excess
gas occurs.
The low fire over-run time has an effect on the behav-
iour of the main burner only.
Background: the pilot burner is only used in singlestage operation.
BCU 480 · Edition 03.16l 53
Page 54
Parameters
4.7.9 Behaviour of the air valve in the event of a fault lock-out
Parameter 32
This determines whether the air valve can be activated
in the event of a fault lock-out.
Parameter 32 = 0: The air valve is closed in the event of
a fault. It cannot be activated externally via terminal 23.
Parameter 32 = 1: The air valve can be activated exter-
nally via input 23 even during a fault, e.g. for cooling.
BCU 480 · Edition 03.16l 54
Page 55
Parameters
4.8 Manual mode
For convenient setting of the burner or analyzing faults.
The parameter display is not available in Manual mode.
Manual mode can be accessed only if the unit was not
in Fault state before switching off. The following times/
functions are not active in Manual mode: start-up at-
tempts, restart, minimum burner on time and cycle lock.
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.
In this operating mode, the burner control unit operates
independently of the status of the inputs (apart from
the pre-purge input and the safety interlocks. These are
of higher priority and will be processed first).
Each time after the button is pressed again, the BCU
moves to the next section of the program sequence
and stops there. Briefly pressing the Reset/Information
button (< 1 s) displays the relevant Manual mode step.
When the operating position is reached (program sta-
4
tus
burner)), the flame signal is indicated instead of the
program parameter after approx. 3 s. If there is flame
simulation during start-up, the flame signal is displayed
immediately.
On units with air valve control, the air valve can be
opened and closed repeatedly by pressing the button
during operation.
(Operation, pilot burner) or 8 (Operation, main
Manual mode can be terminated by switching off the
BCU (On/Off button).
4.8.1 Manual mode limited to 5 minutes
Parameter 34
Parameter 34 determines when Manual mode is terminated.
Parameter 34 = 0: Manual mode is not limited in time.
If this function has been selected, operation of the furnace may be continued manually in the event of failure
of the central control system.
Parameter 34 = 1: Manual mode ends automatically
five minutes after the last time the button was pressed.
The BCU then moves abruptly back to start-up position/
standby.
BCU 480 · Edition 03.16l 55
Page 56
Selection
5 Selection
T 3 5 10 /3 /5 /1 /2 L 5 15 25 W R 1 2 3 8 GB1)P2)D2 D3 S2 S3 /2 /3 U C B1 /1 E1
BCU 480
= standard, = available. 1) Not available for BCU..T. 2) Not in conjunction with PROFIBUS DP (BCU..B1).
5.1 Type code
Code Description
BCU Burner control unit
4 Series 4
80 Version for pilot and main burners
3; 5; 10 1
/3; /5 2
/1; /2 Safety time during operation t
L* Air valve control
5*; 15*; 25* Low fi re over-run time [s]
W
R
1*
2*
3*
8*
GB* Front fi lm in English with additional stickers in D, F, I, NL, E
P* Industrial plug connector
D2*
D3*
S2*; S3* Number of start-up attempts, pilot burner
/2*; /3* Number of start-up attempts, main burner
U*
C*
B1* For PROFIBUS DP
/1* 9-pin DSub bus plug connector
E1* Power management via phase (L1)
* If “none”, this specifi cation is omitted. Please quote the default parameter settings when ordering.
Preparation for UV sensor for continuous operation UVD 1
Mains voltage: 230 V AC, 15/+10%, 50/60 Hz
High temperature operation in conjunction with: … UVS
Order example
BCU 4805/3/1LW3GBCE1
st
safety time on start-up tSA [s]
nd
safety time on start-up tSA [s]
SB
115 V AC, 15/+10%, 50/60 Hz
Ignition transformer: TZI 515/100
... ionization sensor or UVD
Additional signal distribution
T ZI 725 /20
T ZI 7,5 12 /1 00
TZI 7,520/33
[s]
BCU 480 · Edition 03.16l 56
Page 57
Project planning information
6 Project planning information
6.1 Cable selection
Use mains cable suitable for the type of operation and
complying with local regulations. Signal and control
line: max. 2.5 mm2. Cable for burner ground/PE wire: 4
mm2. Do not route BCU cables in the same cable duct
as frequency converter cables or cables emitting strong
fields.
The connection cables are fed into the BCU housing via
cable glands. The cable glands are equipped with multiple seal inserts for cable diameters of up to 7 mm. For
two cable glands, there is one seal insert each for cable
diameters between 7 and 12 mm.
6.1.1 Ionization cable
Use unscreened high-voltage cable, see page 71
(Accessories).
Recommended cable length: max. 50 m.
Lay cable individually and, if possible, not in a metal
conduit.
Install well away from mains cables and interference
from electro-magnetic sources.
Do not lay together with ignition cable.
6.1.2 Ignition cable
Use unscreened high-voltage cable, see page 71
(Accessories).
Cable length for integrated ignition. max. 5 m (16.4 ft).
Avoid external electrical interference. The longer the ig-
nition cable, the lower the ignition capacity.
Lay cable individually and, if possible, not in a metal
conduit.
Do not lay UV/ionization cable and ignition cable together and lay them as far apart as possible.
Screw the ignition cable securely into the ignition transformer and feed it out of the unit on the shortest possible route (no loops) – use the left-hand M20 plastic
cable gland.
Only use radio interference suppressed electrode plugs
(with 1 kΩ resistor) for ignition electrodes, see page
71 (Accessories).
6.1.3 UV cable
Recommended cable length: max. 50 m.
Install well away from mains cables and interference
from electro-magnetic sources.
Do not lay together with ignition cable.
6.2 Ignition electrode
6.2.1 Electrode gap
Gap between electrode and burner ground:
2 mm ± 0.5 mm.
6.2.2 Star electrodes
We recommend using 7.5 kV ignition transformers on
burners with star electrodes.
BCU 480 · Edition 03.16l 57
Page 58
Project planning information
6.3 Calculating the safety time tSA
BCU 480 · Edition 03.16l 58
Page 59
Project planning information
6.4 Minimum burner on time
Even if the start-up signal (ϑ) is applied only briefly, the
time set under parameter 20 elapses. The minimum
burner on time tB can be extended beyond the safety
time tSA to max. 25 s.
The signal inputs for the pilot /main burner start-up sig-
nal cannot be used for a safety shut-down because the
unit controls the valves until the minimum burner on
time has elapsed.
04 06 07 08
t
SA2
t
B
In the case of pilot/main burner monitoring, the minimum burner on time only has an effect on the behaviour of the main burner. The minimum burner on time
for the pilot burner is limited to the safety time on start-
SA
).
up (t
Background: the pilot burner is only used in single-
stage operation.
88
2
5
4
12
9
16-17
21
14
24
28-29
18-19
ϑ
1
V1
1
1
ϑ
2
V2
2
2
t
of the application, e.g. safety temperature limiter, minimum and maximum gas pressure, tightness control)
must isolate terminal 5 from the voltage supply. If the
safety interlock is interrupted or if fuse F1 has tripped,
the display shows a blinking
51
to indicate a fault.
If the safety interlocks fail, an immediate program abort
with switch-off of all outputs occurs (even during the
safety time). If the safety interlocks are operational
again or the unit is switched back on, the program run is
restarted in standby.
6.6 Protection of safety-relevant outputs
When commissioning, do not switch the safety-relevant
outputs to a short-circuit.
Before switching on, ensure that outputs 7, 12 and 14
are not overloaded (> 3 A), using an ohmmeter, for example.
All safety-relevant outputs of the BCU are fused with
an internal, non-replaceable fuse, see page 13
(Connection diagrams). This affects the outputs for ignition, gas valve V1 and gas valve V2. In the event that
the internal fuse for these outputs blows, the unit must
be sent to the manufacturer for repair.
6.5 Safety interlocks (Limits)
The limiters in the safety interlock (linking of all the rele-
vant safety control and switching equipment for the use
BCU 480 · Edition 03.16l 59
Page 60
Project planning information
6.7 Emergency off
6.7.1 In the event of fire or electric shock
If there is a risk of fire, electric shock or similar, inputs
L1, N and 5 (safety interlocks) of the BCU should be
disconnected from the electrical power supply–this
should be reflected in the wiring on site.
6.7.2 Via the safety interlocks (limits)
The safety interlock turns off the power to the input 5,
such as in the event of low air pressure or similar.Reset
6.8 Reset
6.8.1 Parallel reset
Several automatic burner control units can be reset in
parallel using the external button. The BCU cannot be
reset by mains failure.
6.8.2 Permanent remote reset
Permanent remote reset gives rise to a malfunction. If a
remote reset signal is permanently applied to terminal
52
flashes on the display to indicate a fault.
3,
Reset with a pulse < 1 s.
6.8.3 Automatic remote reset (PLC)
In the case of automatic remote reset (PLC), the reset
pulse duration should not exceed 1 second. Check
compliance with standards.
If a fault is acknowledged by remote reset too often, er-
10
ror
(Too many remote resets) is displayed. The error
can only be acknowledged with the Reset/Information
button on the unit.
The burner malfunction must be remedied. The mal-
function cannot be remedied by changing the method
of activation.
6.9 Burner start
A furnace start may only be initiated, if it has been ensured
using an appropriate procedure that there is no combustible mixture in the combustion/processing chamber, in
the connected areas or in the exhaust gas system (heat
exchanger, dust collector). This can be achieved by prepurge, which occurs immediately before ignition or within
the period specified in the operating instructions.
In the case of multiple burner applications, pre-purge is
not necessary after a controlled burner shut-down.
Note the requirements of the Standards. For exceptions,
see Standards.
6.10 Restart and start-up attempts
The precondition for a restart/start-up attempt is that
activation of the restart allows the burner to 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.
In accordance with EN 7462, up to three start-ups are
permitted in specific cases if the safety of the installation is not impaired (note the requirements of the
Standards).
BCU 480 · Edition 03.16l 60
Page 61
Project planning information
6.11 Fault signalling
The fault signalling contact opens, as soon as the mains
voltage fails.
6.12
Protecting the pilot burner from overload
To protect the unit against overload by too frequent cy-
cling of the pilot burner, the number of start-ups within
one minute is limited for the BCU. Excessive cycling of
the pilot burner triggers a fault message (blinking
). The max. number of start-ups per minute depends on
the safety time t
t
[s] Ignition transformer TZI Max. s tart-ups/min.
SA
3 51 5/100 6
5 51 5/100 6
10 515 /100 3
3 725 /20 3
5 725 /20 2
10 725/ 20 1
3 7,512/1 00 6
5 7,512/1 00 4
10 7, 512 /1 00 2
3 7,520/33 4
5 7,520/33 3
10 7,520/33 2
and the ignition transformer used.
SA1
53
6.13 Installation
Recommended installation position: vertical (cable
glands pointing downwards).
When installing, ensure that there is suf ficient space to
open the BCU.
From inside
Open BCU and screw on with four screws (Ø 4 mm, min.
length 15 mm).
From outside
185 mm
7.28"
6.42"
163 mm
Screw on the closed unit to the rear with 4 self-tapping
screws (enclosed).
Otherwise, mount with external securing bars or the
fastening set, see page 71 (Accessories).
BCU 480 · Edition 03.16l 61
Page 62
Project planning information
6.14 Wiring
Electrical connection via plug-in connection terminals
(2.5 mm²) and plug-in cable glands. The latter can be
removed in order to facilitate installation.
The BCU is suitable for hard wiring only. Do not reverse
phase and neutral conductor. Different phases of a
three-phase current system must not be installed at
the BCU.
No voltage may be connected to the valve and ignition
outputs.
No gas valve may be connected to the air valve output
(terminal 26).
See page 13 (Connection diagrams) onwards.
6.15 BCU and BCU..E1 (with and without adapted power management)
The BCU is available as a replacement unit for existing
systems in which a BCU is already in operation.
We recommend using a BCU with power management
(BCU..E1) when planning new systems. It features a
new power management scheme for simplified installation and control. The power for the ignition transformer
and valves is supplied via the phase (terminal 1) and
must no longer be supplied by the safety interlocks. No
effort and expenditure is thus required for coupling
contactors and their safety devices.
Unit replacement
A BCU without power management may not be re-
placed with a BCU with power management (BCU..E1).
The reverse also applies, i.e. a BCU..E1 may not be re-
placed with a BCU without power management.
6.16 Signal distributor board
An additional signal distributor board (terminals
30–38) can be ordered for wiring additional relays, etc.
(BCU..C).
BCU 480..C
M L
40 41 42 43 44 45 46 47
1
s
max. 2 A,
253 V
21
ϑ
2
17
25 26 2718 19 20
24
22
23
A
P
2
N1
l
30 31 32 33 34 35 36 37
28 29
F3
l
50 51
38
L1 (L1)
N (L2)
PE
BCU 480 · Edition 03.16l 62
Page 63
Project planning information
6.17 PROFIBUS DP
6.17.1 Safety-related control signals
Signals from the safety interlocks and digital input are
transferred independently of the bus communication
by separate cables.
The purge signals can be transferred via the bus com-
munication or by a separate cable.
6. 17. 2 Wiring the PROFIBUS plug connector
BCU..B1/1
1B1A2B2A
ON
OFF
PROFIBUS DP
The PROFIBUS plug connector must be ordered sepa-
rately, see page 71 (Accessories).
Data cables A and B must not be reversed.
The power supply for the bus terminator is provided by
the BCU. The bus terminator can be connected in the
PROFIBUS plug connector.
Ensure an equipotential bond between the different
slaves and masters.
ON
OFF
cable must be used. The shield must be connected to
protective earth on both sides using wide-area shield
clips that ensure good conductivity.
In addition, it must be ensured that all cables leading to
and from the BCU
®
be installed as far away as possible
from cables emitting strong fields (e.g. frequency converter cables).
6. 17. 4 Unit replacement
A BCU..B1 (for PROFIBUS) may only be replaced by a
BCU..B1. BCUs without a PROFIBUS connection may
not be replaced by a BCU..B1.
6. 17. 3 EMC
To achieve a high immunity of the system against elec-
tromagnetic interference radiation, a shielded data
BCU 480 · Edition 03.16l 63
Page 64
Project planning information
▼
6. 17. 5 Status and fault messages for PROFIBUS DP
This table can be used to program the master.
Input bytes (BCU ➔ master)
Byte 2 Display
0
0
1
2
3
4
5
6
7
8
9
10
30
31
33
00
A0
01
A1
02
A2
03
A3
04
A4
05
A5
06
A6
07
A7
08
A8
P0
10
30
31
33
Status signal
Byte 0, Bit 2 = 0
Start-up position/standby
Cooling
*
*
*
*
*
*
*
*
Waiting time/Pause time Flame simulation
Safety time on start-up Start-up without flame signal
Flame proving period Flame failure during flame proving period
Operation Flame failure during operation
Waiting time, main burner Flame simulation, main burner
Safety time on start-up, main burner Start-up without flame signal, main burner
Flame proving period, main burner Flame failure during fl ame proving period, main burner
Operation, main burner Flame failure during main burner operation
Purge
EEPROM data change, NF S**
EEPROM data change, FS**
Faulty parameterization
Fault signal
Byte 0, Bit 2 = 1
Too many remote resets
BCU 480 · Edition 03.16l 64
Page 65
Project planning information
Input bytes (BCU ➔ master)
Byte 2 Display
51
52
53
99
* Display on BCU..L upon activation of the air valve during program step x
** FS = input /output, safety circuit, NFS = input /output, control system
51
52
53
88
Fuse F1 defective or safety interlocks
Status signal
Byte 0, Bit 2 = 0
discontinuit y
Permanent remote reset
Timing cycle too shor t
Fault signal
Byte 0, Bit 2 = 1
Internal error/negative flame current
BCU 480 · Edition 03.16l 65
Page 66
BCU 480
12
23
SPS
PLC
API
DI
L1, N, PE
P
22 4
21
18
19
16
17
28
29
24
2
1
A
P
5
3
DI
6
VBY
µC
ϑ1 ϑ
2
t
1
2
04 02–04 06–08 06–08
04
ϑ
1
ϑ
2
2
1
BV
IC 40
4
7
M
14
26
50 51
VAG
VAS
Project planning information
13
N
14 15
50 51
V3 V2
6.18 Third gas valve (can be shut down) on BCU..L
Units with air valve control have an
additional contact (terminal), which
closes at the same time as the air
valve.
This can be used to activate a third
gas valve (V3). To do this, the output
of valve V1 or V2 must be used as
auxiliary energy (as a result of the
required flame control).
The opposite application describes
a two-stage-controlled burner
without a pneumatic air/gas ratio
control system. The third gas valve
BCU 480 · Edition 03.16l 66
(V3) and the air valve are activated
simultaneously. During purging/
cooling, the gas valve (V3) is not
activated.
Page 67
Project planning information
6.19 BCU switched off
In general, the BCU cannot be activated when no mains
voltage is applied or the burner control unit is switched
off. The fault signalling contact is only closed when the
unit is supplied with voltage and switched on.
If the unit is switched off, an immediate program abort
with switch-off of all outputs occurs (even during the
safety time). When the unit is switched on, the program
run is restarted in standby.
6.20 Furnace control
Switch on the system to start up the furnace, then
release the burner start via the safety interlocks and
afterwards start the burner control so that the burner
control unit may monitor the burners as intended. To
shut down the furnace, first disconnect the burner
control unit from the temperature control (burner ON
signal), then disconnect the safety interlocks and finally
switch off the system.
6.21 Mains switch
The mains switch in the unit isolates the BCU on two
poles from the mains. It does not meet the requirements of EN 501561:2004 (5.2.2 Switch disconnectors) set out in chapter 5 for a device to disconnect the
power supply.
Although the mains switch cannot be used for discon-
necting from the electrical power supply in accordance
with EN 50156, it does allow the burner to be isolated
functionally from the central control system. This function is required for manual operation and, in the case of
PROFIBUS units, to switch off the unit without causing
bus errors.
Disconnection for electrical maintenance work is to be
implemented with an external switch per unit or group
only, in accordance with Standard EN 50156.
6.22 Note on EC type-examination
Since EN 298 (1993) does not describe all functions of
the BCU, the operator is responsible for ensuring that
all parameters and functions are matched to the respective application.
6.23 SIL/PL level for thermoprocessing equipment
Since thermoprocessing installations include different
safety functions, it is not possible to determine a single
SIL/PL level for an entire installation, but this must be
determined separately for every safety function of the
installation.
See also page 76 (Safety-specific characteristic values).
BCU 480 · Edition 03.16l 67
Page 68
Project planning information
6.24 Changing parameters
In certain cases, it may be necessary to change the
default settings. Using a separate software package
and a PC opto-adapter, it is possible to modify certain
parameters on the BCU, such as the switch-off threshold of the flame amplifier, the behaviour in the event
of a flame failure or whether the pilot burner is to burn
permanently in the case of pilot and main burner monitoring.
The software package with PC opto-adapter, as well as
“Changed parameters” stickers, are available as acces-
sories, see page 71 (Accessories).
The unit parameters set at the factory are specified in
the enclosed delivery note.
Document changed parameters in BCSoft using the
protocol function and enclose the protocol with the
plant documentation.
If a replacement is ordered for a BCU with changed parameters, refer to the protocol for details.
BCU 480 · Edition 03.16l 68
Page 69
Flame control
7 Flame control
7.1 With ionization sensor
The BCU generates an alternating voltage (230 V AC)
between the sensing electrode and burner ground. The
flame rectifies this voltage. Only the DC signal (> 1 μA) is
detected by the burner control unit.
A flame cannot be simulated.
Ignition and monitoring with a single electrode is possible.
For ionization control, the BCU is suitable for Safety
Integrity Level SIL 3, see page 76 (Safety-specific
characteristic values).
7. 2 With UV sensor
A UV tube inside the UV sensor detects the ultraviolet
light of a flame. It does not respond to sunlight, incandescent bulb light or infrared radiation emitted by hot
workpieces or red-hot furnace walls.
In the event of incident UV radiation, the UV sensor rectifies the supplied alternating voltage. As with ionization control, the burner control unit only detects this DC
signal.
When using UV sensors of Type UVS, the burner control
unit may be used for intermittent operation only. This
means that operation must be interrupted at least once
every 24 hours. This can be programmed using parameter 35.
Further information can be found in brochure UVS at
ww w.docuthek.com.
The burner control unit BCU..U is prepared for UV sen-
sor UVD 1. This enables continuous operation.
No safety-specific characteristic values are available for
flame control with UVS sensor.
For flame control with UVD sensor, safety-specific characteristic values are available for the Safety Integrity
Level SIL.
Further information can be found in TI UVD 1 at www.
docuthek.com.
BCU 480 · Edition 03.16l 69
Page 70
Flame control
7.3 Via the temperature in high temperature equipment
High temperature equipment is defined as a thermo-
processing installation, in which the wall temperature of
the combustion chamber and/or the processing chamber exceeds 750°C.
Burner control units BCU..D feature a special “High
temperature operation” function, see page 32 (High
temperature operation in the case of BCU..D2 or BCU..
D3).
During heating up, standard monitoring methods (ionization or UV) must be used for flame control. When
the working temperature has exceeded 750°C, indirect
flame control can be taken over by a central monitoring
device. When the DI input (terminal 6) is activated, the
burner control unit reverts to this operating mode.
Important: in “High temperature operation” (HT operation), i.e. with the DI input being activated, burner control units BCU..D do not evaluate the flame signal. The
safety function of the burner control unit’s flame control is deactivated during this operating phase.
BCU 480 · Edition 03.16l 70
Page 71
Accessories
8 Accessories
8.1 High-voltage cable
FZLSi 1/7 up to 180°C,
Order No.: 04250410.
FZLK 1/7 up to 80°C,
Order No.: 04250409.
8.2 Industrial plug connector, 16-pin
Order No.: 74919469
8.3 PROFIBUS plug connector
Variosub PROFIBUS plug connector, 9-pin, with deacti-
vatable bus terminator, Order No.: 74960431
GSD files for BCU Profibus DP on BCSoft CDROM, Order No. 74960436, or at www.docuthek.com
Bibliography
– PROFIBUS Specification, EN 50170 Vol. 2 (version
1.0).
– Installation Guideline for PROFIBUS DP/FMS, avail-
able from the Profibus User Organization (PUO).
– PROFIBUS Technology and Application, Order No.:
4.001, available from the PUO.
– M. Popp, The New Rapid Way to PROFIBUS DP, a text-
book for system operators.
– M. Popp, PROFIBUS DP Principles, Tips and Tricks for
Users.
– www.profibus.com
BCU 480 · Edition 03.16l 71
Page 72
Accessories
D-49018 Osnabrück, Germany
Achtung, geänderte Parameter!
Die Angaben auf dem Typenschild
gelten nicht mehr in vollem Umfang.
Aktuelle Parameter direkt auslesen.
Important, changed parameters!
The details on the type label are no
longer completely accurate. Read the
current parameters direct from the
unit.
Attention, paramètres modifiés !
Les informations figurant sur la plaque
signalétique ne sont plus valables
dans leur intégralité. Veuillez vous
référer directement aux paramètres
actualisés.
8.4 BCSoft
The current software can be downloaded from our In-
ternet site at http://www.docuthek.com. To do so, you
need to register in the DOCUTHEK.
8.4.1 Opto-adapter PCO 200
With USB interface, cable length 3 m,
including BCSoft CDROM.
Order No.: 74960437.
8.4.2 Bluetooth adapter PCO 300
8.5 “Changed parameters” stickers
Affix on the connection dia-
gram of the BCU following
changes to unit parameters set
at the factory.
100 pcs,
Order No.: 74921492.
BCSoft CDROM included
Order No.: 74960617.
BCU 480 · Edition 03.16l 72
Page 73
Accessories
225 mm
12 mm
7 mm
8.6 External securing bar
212 mm
185 mm
200 mm
Order No.: 74960414
ø 4mm
8.7 Fastening set
22 mm
16.5 mm
263 mm
20 mm
Order No.: 74960422
8.8 Radio interference suppressed electrode plugs
Angle plug, 4 mm, interference-suppressed,
Order No. 04115308.
Straight plug, 4 mm, interference-suppressed,
Order No. 04115307.
Straight plug, 6 mm, interference-suppressed,
Order No. 04115306.
BCU 480 · Edition 03.16l 73
Page 74
Technical data
▼
9 Technical data
Mains voltage:
230 V AC, 15/+10%, 50/60 Hz,
115 V AC, 15/+10%, 50/60 Hz,
for grounded and ungrounded mains.
Inherent consumption: approx. 9 VA plus inherent consumption of the integrated ignition transformer [50/60
Hz].
Voltage to inputs and valves = mains voltage.
Signal and control line: max. 2.5 mm
Cable for burner ground/PE wire: 4 mm
Cable gland:5 cable glands with multiple seal inserts for
2 cable diameters of up to 7 mm,
BCU..P: with 2 cable glands with multiple seal inserts
for 4 cables of up to 7 mm in diameter and an industrial
chassis plug.
Each BCU is supplied for two cable glands with one seal
insert each for cable diameters between 7 and 12 mm.
Input voltage of signal inputs:
2
(AWG 14).
2
(AWG 12).
puts),
but total current for valves and ignition transformer:
max. 2.5 A
Fail-safe inputs and outputs:
All the inputs and outputs marked “
” (see connection
diagrams) may be used for safety tasks.
Flame control with UV sensor or ionization sensor.
Flame signal for
ionization control: 1 – 28 μA,
UV control: 1 – 35 μA.
For intermittent or continuous operation.
Maximum length of ignition cable with integrated electronic ignition: 5 m (16.4 ft).
Maximum length of ionization/UV cable: 50 m (164 ft).
Rated value 115 V AC 230 V AC
Signal “1” 80–126.5 160–253
Signal “0” 0–20 0–40
Frequency 50/60 Hz 50/60 Hz
Input current of signal inputs:
Signal “1”: typ. 2 mA
Output current:
max. 1 A, cos ϕ = 1, for the valve outputs (or SRC out-
BCU 480 · Edition 03.16l 74
Page 75
Technical data
* Values in ( ) apply to 60 Hz.
Fuses in unit:
F1: 3.15 A, slow-acting, H, pursuant to IEC 1272/5.
Fuse for protecting the safety-relevant ignition, valve
1, valve 2 and air valve outputs (terminals 7, 12, 14 and
26): 5 A, slow-acting, not replaceable.
F3 (only for BCU.. A, BCU..C and BCU..U):
3.15 A, slow-acting, H, pursuant to IEC 1272/5.
Operation and fault signalling contacts:
Signalling contact for mains voltage, max. 2 A, 253 V,
not internally fused.
Number of operating cycles:
Relay outputs: 250,000 pursuant to EN 298,
Mains switch: 1,000,
Reset/Information button: 1,000.
Ambient temperature: 20 to +60°C (4 to +140°F),
climate: no condensation permitted.
Enclosure: IP 54 pursuant to IEC 529.
Weight: approx. 5 kg (11 lb) depending on version.
Ignition
transformer
TZI 515/100W 230 50 (60) 0.45 (0.35) 5000 15 (11)
T ZI 725 /20 W 230 5 0 (60) 1.1 (0.8) 7000 25 (18)
TZI 7,512/100W 230 50 (60) 0.6 (0.45) 7500 12 (9)
TZI 7,520/33W 230 50 (60) 0.9 (0.7) 7500 20 (15)
T ZI 51 5/100R 115 50 (60) 0.9 (0.7) 5000 15 (11)
T ZI 725 /20 R 115 50 (60) 2.2 (1.6) 7000 25 (18)
T ZI 7,5 12 /1 00 R 115 50 (60) 1.2 (0.9) 7500 12 (9)
TZI 7,520/33R 115 50 (60) 1.8 (1.35) 75 00 20 (15)
V AC Hz* A* V mA*
Input Output
9.1 BCU..B1
External fuse: 12 A per zone.
9.2 PROFIBUS DP
Manufacturer ID: 0x05DB.
ASIC type: SPC3.
SYNC and FREEZE-capable.
Baud rate detection: automatic.
Min. cycle time: 0.1 ms.
Diagnostic bytes: 6 (DP Standard).
Parameter bytes: 7 (DP Standard).
BCU 480 · Edition 03.16l 75
Page 76
Technical data
9.3 Safety-specific characteristic values
In the case of ionization control,
suitable for Safety Integrit y Level
Diagnostic coverage DC 92.7%
Type of subsystem Type B to EN 615082, 7.4.3.1.4
Mode of operation
Mean probability of dangerous
failure PFH
Mean time to dangerous failure
MTTF
Safe failure fraction SFF 98.8%
D
d
The specified values apply for the combination with
ionization electrode (sensor) and a unit of the BCU 400
series. No characteristic values are available for flame
control with UVS sensor.
For flame control with UVD sensor, safety-specific
characteristic values are available for the Safety Integrity Level SIL. Further information can be found in
TI UVD 1 at ww w.docuthek.com.
SIL 3
High demand mode pursuant to EN
615084, 3.5.12
1.92 x 108 1/h
MTTFd = 1 / PFH
D
Relationship between the Performance Level (PL)
and the Safety Integrity Level (SIL)
PL SIL
a –
b 1
c 1
d 2
e 3
Pursuant to EN ISO 138491:2006, Table 4, the BCU
can be used up to PL e.
Max. ser vice life under operating conditions: 20 years
after date of production.
For a glossary of terms, see page 79 (Glossary).
For further information on SIL /PL, see w ww.k-sil.de
BCU 480 · Edition 03.16l 76
Page 77
Technical data
A
200 mm (7.87")
50
mm
(1.97")
200 mm (7.87")
55
mm
(2.17")
185 mm
7.28"
4,5 mm
0.177"
88
B
C
D
E
6.42"
163 mm
9.4 Housing dimensions
Die-cast aluminium housing with plug-in terminal
blocks and plug-in M20 cable glands or (16-pin) industrial plug connector for input signals and optionally preassembled cables for output signals.
9.5 Operating controls
A: Optical interface.
B: Labelling field for individual labelling of the system
components.
C: 2-digit 7-segment display.
D: Mains switch to isolate the BCU on two poles from
the mains.
E: Reset/Information button to reset the system after a
fault or to scan parameters on the display.
9.6 Installation
Recommended installation position: vertical (cable
glands pointing downwards).
Open the BCU and attach with four screws Ø 4 mm or
screw on the closed unit using the external securing bar,
see page 71 (Accessories).
Electrical connection via plug-in connection terminals
(2.5 mm²) and plug-in cable glands. The latter can be
removed in order to facilitate installation. When installing, ensure that there is sufficient space to open the
BCU.
BCU 480 · Edition 03.16l 77
Page 78
Legend
88
ϑ
1
ϑ
2
P
A
1
2
10 Legend
Display
Blinking displ ay
88
Ready
Safety interlocks (Limits)
Start-up signal, pilot burner
Start-up signal, main burner
DI
Digital input
Ignition transformer
Gas valve
Air valve
Purge
Ext. air valve control
Flame signal
Operating signal, pilot burner
Operating signal, main burner
Fault signal
Reset
Input signal
Output signal
Flame simulation check
Waiting time ≥ 2 s
t
W
Safety time on start-up 3 s, 5 s or 10 s
t
SA
Safety time during operation < 1 s or < 2 s
t
SB
Ignition time 2 s, 3 s or 6 s
t
Z
Flame simulation delay time 25 s
t
LV
Flame proving period 0–25 s
t
FS
tBMinimum burner on time tSA up to max. 25 s
Minimum burner pause time 0–250 s
t
BP
Low fire over-run time 0 s, 5 s, 15 s or 25 s
t
KN
Input/Output, safety circuit
BCU 480 · Edition 03.16l 78
Page 79
Glossary
11 Glossary
11.1 Waiting time tW
02 02
01 88
t
t
W
Z
t
SA
Once the start-up signal ϑ has been applied, the wait-
ing time tW starts to elapse. During this time, a self-test
is conducted to detect errors in internal and external
circuit components. If no malfunction is detected, the
burner will start up.
11.2 Safety time on start-up tSA
This refers to the period of time between switching on
and switching off of the pilot gas valve V1, when no
flame signal is detected. The safety time on start-up
tSA (3, 5 or 10 s) is the minimum operating time of the
burner and automatic burner control unit.
22-23
24-25
L1
1
14
ϑ
4
5
V1
9
V2
6
t
ignition time is either 2, 3 or 7 seconds depending on
safety time t
selected.
SA
11.4 Flame simulation/Flame simulation delay time tLV
01 88
t
W
t
LV
An extraneous signal (flame simulation) is a flame sig-
nal that is detected, although there should be no flame
according to the program sequence. If such an extraneous signal is detected, the flame simulation delay time
tLV starts to elapse. If the flame simulation is discontinued during the flame simulation delay time tLV, star t-up
can be initiated or operation continued. Otherwise, a
fault lock-out occurs.
01
14
22-23
24-25
L1
1
ϑ
4
5
V1
9
V2
6
t
11.3 Ignition time tZ
If no malfunction is detected during the waiting time
tW, the ignition time tZ then starts to elapse. Voltage is
supplied to the pilot gas valve V1 and the ignition trans-
former and the burner is ignited. The duration of the
BCU 480 · Edition 03.16l 79
Page 80
Glossary
S
11.5 Safety time during operation tSB
08
08
t
B
If the flame fails during operation, the valve outputs are
disconnected within the safety time tSB.
The default safety time during operation t
ance with EN 298 is 1 second. In accordance with
EN 7462, the safety time of the installation during
operation (including closing time of the valves) may not
exceed 3 s.
Note the requirements of the Standards!
88
1
5
4
7
12
9
16-17
21
14
24
28-29
18-19
in accord-
SB
ϑ
1
V1
1
1
ϑ
2
V2
2
2
t
11.6 Flame signal
If a flame is detected, the flame detector will supply a
flame signal.
11.8 Safety interlocks (Limits)
The limiters in the safety interlock (linking of all the rel-
evant safety control and switching equipment for the
use of the application, e.g. safety temperature limiter,
minimum/maximum gas pressure) must isolate input
from the voltage supply.
11.9 Pilot gas valve V1
The start fuel flow rate for the pilot burner is released
by pilot gas valve V1. It opens when the safety time on
start-up t
burner is switched off again by a controlled shut-down
or fault lock-out.
starts to elapse. It remains open until the
SA1
11.7 Fault lock-out
In the event of a fault lock-out, all valves and the ignition transformer are disconnected from the electrical
power supply, and a fault is signalled. Resetting must
take place manually following a fault lock-out.
BCU 480 · Edition 03.16l 80
Page 81
Glossary
N1
s1
V1 V2 C N S M L
µC
l
88
F1
30 31 32 33 34 35 36 37DI50 51
l
38
F3
(BCU 480..C)
40 41 42 43 44 45 46 47
P
25 26 27
20
22
24
Test
BCU 480
ϑ
2
A
23
2
28 2921
11.10 Main gas valve V2
The start fuel flow rate for the main burner is released
by main gas valve V2. It opens when the safety time on
start-up t
starts to elapse. It remains open until the
SA2
burner is switched off again by a controlled shut-down
or fault lock-out.
1
N1
c1
c2
5 6 7 8 119 10 12 13 14 15
PE
230V~
N1
v1
v2
V1
V2
N1
16 17
s
18 19
max. 2 A,
253 V
11.11 Continuous operation
The gas burner runs continuously for more than 24
hours.
11.12 Air valve
The air valve can be used
– for cooling,
– for purging,
– to control the burner capacity in ON/OFF mode and
in High/Low mode when using a pneumatic air/gas
ratio control system.
11.13 Diagnostic coverage DC
Measure of the effectiveness of diagnostics, which may
be determined as the ratio between the failure rate of
detected dangerous failures and the failure rate of total
dangerous failures
NOTE: Diagnostic coverage can exist for the whole or
parts of a safety-related system. For example, diagnostic coverage could exist for sensors and/or logic system
and/or final elements. Unit: %.
from EN ISO 138491:2008
11.14 Mode of operation
High demand mode or continuous mode
Operating mode, where the frequency of demands for
operation made on a safety-related system is greater
than one per year or greater than twice the proof-test
frequency
from EN 615084:2001
11.15 Safe failure fraction SFF
Fraction of safe failures related to all failures, which are
assumed to appear
from EN 13611/A2:2011
BCU 480 · Edition 03.16l 81
Page 82
Glossary
11.16 Probability of dangerous failure PFHD
Value describing the likelihood of dangerous failure per
hour of a component for high demand mode or con-
tinuous mode. Unit: 1/h.
from EN 13611/A2:2011
11 .17 Mean time to dangerous failure
MTTFd
Expectation of the mean time to dangerous failure
from EN ISO 138491:2008
BCU 480 · Edition 03.16l 82
Page 83
Feedback
Kromschröder AG
Michael Rehkamp
m.rehkamp@kromschroeder.com
Osnabrüc
k
Feedback
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