Honeywell BCU 370 Technical Information

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Page 1

AGA

Burner control unit BCU 370

Technical Information · GB

6 Edition 01.19

• For modulating, forced draught burners for gas of unlimited capacity in intermittent or continuous operation

• Control of fan and butterﬂy valve

• Simple system set-up thanks to optional tightness control and integrated ignition unit

• Easy start-up and maintenance thanks to Manual operating mode

• Optionally available with integrated ﬁeldbus interface for simple wiring

Page 2

Burner control unit BCU 370 ........................1

Contents ............................................2

1 Application ........................................4

1.1 Applications example ..............................6

1.1.1 Modulating-controlled forced draught burner........6

1.1.2 Modulating-controlled forced draught burner with

tightness control ............................................6

1.1.3 Modulating-controlled forced draught burner with

pilot burner and tightness control ..........................7

1.1.4 Controlling the BCU via

PROFIBUS DP ...............................................8

1.1.5 Controlling the BCU and the butterﬂy valve via

PROFIBUS DP ...............................................8

2 Certiﬁcation .......................................9

3 Function ......................................... 10

3.1 Connection diagrams .............................10

3.1.1 BCU 370 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

3.1.2 BCU 370 with actuator IC 20........................ 14

3.1.3 Capacit y control by adjusting the valve between

the Open position and a separate Min position........... 15

3.1.4 BCU 370..B1 with PROFIBUS DP ...................16

3.1.5 Assignment of connection terminals ................17

3.2 BCU 370 program sequence .....................19

3.2.1 Normal start-up ..................................... 19

3.2.2 Quick start, butterﬂy valve waits in the Ignition

position.....................................................21

3.2.3 Quick start, butterﬂy valve waits in the Closed

position....................................................23

3.2.4 Start-up without pre-purge, butterﬂy valve waits

in the Closed position ..................................... 25

3.2.5 Controlled air ﬂow ....................................27

3.3 Tightness control .................................28

3.3.1 Program sequence ..................................30

3.4 PROFIBUS DP ....................................32

3.4.1 Safety-related control signals.......................32

3.4.2 BCSoft ...............................................33

3.4.3 Conﬁguration, master-slave procedure .............33

3.4.4 Addressing...........................................33

3.4.5 Network technology .................................34

3.4.6 Conﬁguration........................................34

3.4.7 Bus communication .................................34

3.5 Program status ...................................36

3.6 Fault message (blinking)..........................37

3.6.1 Reaction to process faults ..........................38

4 Parameters ...................................... 40

4.1 Scanning the parameters .........................42

4.2 Flame control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

4.2.1 Burner ﬂame signal.................................. 42

4.2.2 Burner switch-off threshold......................... 42

4.2.3 UVS check (1× in 24 hours) ..........................43

4.3 Behaviour during star t-up ....................... 44

4.3.1 Minimum burner pause time tBP ....................44

4.3.2 Burner start-up attempts ...........................44

4.3.3 Switch-on delay time t

4.3.4 Pre-ignition time t

4.3.5 1 t

SA1

4.3.6 1

4.3.7 2

4.3.8 2

safety time on start-up, burner/pilot burner

........................................................46

ﬂame proving period, burner/pilot burner t

safety time on start-up, main burner t

ﬂame proving period, main burner t

.............................45

................................45

FS1

.......47

SA2

.........47

FS2

..46

4.4 Behaviour during operation...................... 48

4.4.1 Minimum operating time tB .........................48

4.4.2 Controller enable signal delay time t

4.4.3 Safety time during operation t

.............48

...................48

4.4.4 Restart after ﬂame failure during operation ........49

4.4.5 Last fault signal .....................................49

4.4.6 V2 during burner operation .........................50

4.5 Monitoring/tightness control ....................51

4.5.1 Min. gas pressure monitoring ........................51

4.5.2 Digital input function.................................51

4.5.3 Air monitoring during pre-purge .................... 52

4.5.4 Air monitoring during operation.....................53

4.5.5 Tightness controll, test period t

...................54

BCU 370 · Edition 01.19 2

= To be continued

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Page 3

4.6 Air control .........................................56

4.6.1 Valve control .........................................56

4.6.2 Pre-purge............................................56

4.6.3 Quick start starts in... .................................57

4.6.4 Pre-purge time t

4.6.5 Post-purge time t

4.6.6 Fan run-up time t

. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 58

.................................59

.................................60

4.7 Control using PROFIBUS DP .....................61

4.7.1 Bus control activation ................................61

4.7.2 Bus control limitation.................................61

4.8 Manual mode .....................................63

4.8.1 Operating time in Manual mode ....................63

4.9 Fault messages ...................................64

4.9.1 The last 10 fault messages..........................64

4.10 Password ........................................64

4.10.1 User-deﬁned password . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64

5 Selection ........................................ 65

5.1 Type code .........................................65

6 Project planning information .................... 66

6.1 Cable selection .................................. 66

6.1.1 Ionization cable......................................66

6.1.2 UV cable .............................................66

6.1.3 Ignition cable ........................................66

6.2 Fan control........................................67

6.3 Controlling the butterﬂy valve ....................67

6.4 Safety interlock (limits) ...........................67

6.5 Too many remote resets ..........................67

6.6 Protecting the ignition unit from overload ...... 68

6.7 Wiring ............................................ 68

6.7.1 Single-electrode operation with external ignition

unit.........................................................68

6.8 BCU switched off ................................ 68

6.9 Note on EC type-examination or CSA and FM

approval ...............................................69

6.10 Contact fuses ...................................69

6.11 Installation ......................................69

6.12 Protective circuits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .69

6.13 BCSoft...........................................69

7 Flame control ..................................... 70

7.1 ...with ﬂame rod....................................70

7.2 ...with UV sensor ...................................70

8 Accessories.......................................71

8.1 High-voltage cable ...............................71

8.2 BCSoft ............................................71

8.2.1 Opto-adapter PCO 200 ..............................71

8.3 Radio interference suppressed terminal boots...71

8.4 Connection kit BCU 370..........................71

8.5 Set of stickers BCU 370...........................71

8.6 GSD master data ﬁle for BCU 370..B1 ............72

9 Technical data ....................................73

9.1 PROFIBUS DP ....................................74

9.2 Operating controls and dimensions ..............75

9.3 Converting units ..................................76

10 Legend ..........................................77

11 Glossary .........................................78

11.1 Safety shut-down ................................78

11.2 Fault lock-out....................................78

11.3 Warning signal ...................................78

11.4 Timeout 25 s/250 s .............................78

12 Annex .......................................... 79

12.1 Status and fault messages for PROFIBUS DP ..79

Feedback ...........................................82

Contact.............................................82

BCU 370 · Edition 01.19 3

= To be continued

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Page 4

Application

BCU 370

1 Application

The BCU 370 burner control unit controls, ignites and

monitors industrial forced draught burners of unlimited capacity in intermittent or continuous operation.

It can be used for directly ignited forced draught burn-

ers or forced draught burners ignited with pilot burner.

The BCU 370 activates the fan and sets the connected

butterﬂy valve to Pre-purge and Ignition position. After

pre-purge and burner start, the enable signal is issued to an external controller which positions the butterﬂy valve in accordance with the capacit y demand. Post-

purge occurs after the end of burner operation. The

burner control unit BCU 370 monitors the gas and air

pressure. An optionally integrated tightness control

BCU 370 · Edition 01.19 4

Lower section Upper section

function checks the valves with an external gas pres-

sure switch.

Programmability by means of the optical interface and BCSoft PC software guarantees optimum adaptation to the relevant application. Adjustable start-up attempts and automatic restart which can be activated ensure the high ﬂexibility of the burner equipment.

The quick-start option allows standard-compliant star t-

up of the forced draught burner without pre-purge after controlled shut-down. This avoids unnecessary admission of air into the combustion chamber. The heat output is available as quickly as possible after a temperature demand.

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Page 5

Application

The program status, the unit parameters and the level

of the ﬂame signal can be read directly from the BCU. An integrated Manual mode allows manual start of the

burner and setting of the butterﬂy valve position inde-

pendently of the central control system. The BCSoft

operator-control and setting software provides a pow-

erful tool for commissioning and servicing.

To reduce the installation and wiring costs, Honeywell

Kromschröder offers an optional Proﬁbus DP interface to transfer the activation signals and feedbacks.

BCU 370 · Edition 01.19 5

Page 6

Application

BCU 370..I1

9 3

min

BCU 370..I1..D3

9 3

min

1.1 Applications example

25 28 26

20 19

90° ➔ 0

VG..L

IC 20

pu/2

0 ➔ 90°

5293130 32

BVA

0 ➔ 90°

29 3130

5 32

B VA

GIK

90° ➔ 0

GIK

18 17

UVS

25 28 26

20 19

18 17

UVS

1.1.1

Modulating-controlled forced

draught burner

The BCU 370 controls the fan and

moves the butterﬂy valve to prepurge and ignition position. It issues the enable signal to the control system after start-up of the burner.

Modulating-controlled forced

1.1.2 draught burner with tightness control

In addition to controlling the forced draught burner, the burner control unit also monitors the fail-safe function of the two solenoid valves for gas via the gas pressure switch DG which is set to pu/2.

Parameter 27 = 1: V2 is “ON” during burner operation.

BCU 370 · Edition 01.19 6

Page 7

Application

BCU 370..D3

9 3

min

V1 V2

pu/2

VG..L

IC 20

BVA

90° ➔ 0

0 ➔ 90°

29 3130

632

GIK

1.1.3

28 26

20 19

18 17

Modulating-controlled forced draught burner with pilot burner and tightness control

A pilot burner ignites the main burner and is switched off during the main burner’s safety time.

Parameter 27 = 0: V2 is “OFF”, i.e. interrupted pilot burner, during burner operation.

UVS

BCU 370 · Edition 01.19 7

Page 8

Application

L1,

PLC

BCU 370..B1

L1,

PLC

Profibus DP

BCU 370..B1-3

L1,

0 ➔ 90°

29 31 3230

3PS

29 30 31

BUS

90° ➔ 0

BUS

0 ➔ 90°

Proﬁbus DP

Temperature controller

90° ➔ 0

3PS

Temperature controller

1.1.4 Controlling the BCU via PROFIBUS DP

The BCU 370..B1 issues the enable

signal to the temperature controller for capacity control. The temperature controller then controls the butterﬂy valve directly.

1.1.5 Controlling the BCU and the butterﬂy valve via PROFIBUS DP

The BCU 370..B13 receives posi-

tioning information for the butterﬂy valve from the temperature controller via the PROFIBUS DP and activates the butterﬂy valve following controller enable.

BCU 370 · Edition 01.19 8

Page 9

Certiﬁcation

2 Certiﬁcation

Certiﬁcates – see ww w.docuthek.com

EU certiﬁed pursuant to

Directive:

– Low Voltage Directive (2014/35/EU),

– EMC Directive (2014/30/EU).

Regulation:

– Gas Appliances Regulation (EU) 2016/426

FM approved

Factory Mutual Research Class: 7611 “Combustion Safeguards and Flame Sensing Systems”. Suitable for applications pursuant to NFPA 86.

www.approvalguide.com

ANSI/CSA approved

UL listed

USA and Canada

Underwriters Laboratories – UL 372 “Primary Safety Controls for Gas and Oil-ﬁred Appliances”.

ww w.ul.com ➔ Tools (at the bottom of the page) ➔ Online Certiﬁcations Directory

AGA approved

AGA

Australian Gas Association, Approval No.: 6880

http://ww w.aga.asn.au/product _directory

Eurasian Customs Union

The product BCU 370 meets the technical speciﬁca-

tions of the Eurasian Customs Union.

American National Standards Institute/Canadian

Standards Association – Class number: 333501 and

333581.

BCU 370 · Edition 01.19 9

Page 10

Function

BCU 370..I1

l v1 v2s1v3 cc

31 2 4 5 6 7 8 9 10 11 12 13 14 15 16 1917 18 20 21 22 23 24 25 26 27 28 29 30 31 32

V1 C S1 S L A Z M V2 V3 R

DL DG

ppp

minDGmax

230V~

PE N

3 Function

3.1 Connection diagrams

3.1.1 BCU 370

The drawing shows the BCU 370..I1 with integrated

ignition unit, ionization control and double-electrode operation.

For cable selection and wiring, see page 66 (Project

planning information).

90° ➔ 0

0 ➔ 90°

r1 s

max. 1 A,

253 V

3PS

For the explanation of symbols, see page 77 (Legend).

▼

L1 (L1) N (L2)

BCU 370 · Edition 01.19 10

Page 11

Function

13 14 15 16 PE

3 2

UVS

BCU 370..I1 for 120 V and 230 V, UV control

BCU 370..I2

N13 14 15 16 PE

3 2

UVS

Z Z

BCU 370..I2 for 230 V, ignition by electrode to electrode

BCU 370..I3 for 120 V, ignition by electrode to electrode

BCU 370..I3

N13 14 15 16 PE

with centre tap for secondary grounding

▼

3 2

UVS

BCU 370 · Edition 01.19 11

Z Z

Page 12

Function

BCU 370

BCU 370 with external ignition transformer, e.g. TZI or

N13 14 15 16 PE

TGI

BCU 370 with single-electrode operation, which requires an external ignition transformer TZI or TGI

N13 14 15 16 PE

BCU 370..D3, gas pressure switch DG for tightness

BCU 370..D3

11 12

control

▼

BCU 370 · Edition 01.19 12

Page 13

Function

BCU 370..U1

131141516 PE N

4 3

UVC 1

2 1

BCU 370..U1 with UV ﬂame detector UVC 1 for continuous operation

Use 5-core connection cable including a PE wire and complying with local regulations.

The UVC 1 is grounded using a PE wire connection

which is galvanically connected to the housing.

BCU 370 · Edition 01.19 13

Page 14

Function

BCU 370

90° ➔ 0

0 ➔ 90°

25 26 27 28 29 30 31 32

3PS

90°

3.1.2 BCU 370 with actuator IC 20

The “closed contact” (90° ➔ 0) of the external three-

point step controller (3PS) can be connected to terminal 26 or 27.

Terminal 26: the controller operates between the open

and ignition positions.

Terminal 27: the controller operates between the open

and closed positions.

L1 (L1) N (L2) PE

90° ➔ 0

0 ➔ 90°

321

674812 1115 13

S11

IC 20

S10

S1S2

S3 S4

BCU 370 · Edition 01.19 14

Page 15

Function

90° ➔ 0

0 ➔ 90°

25 26 27 28 29 30 31 32

3.1.3 Capacity control by adjusting the valve between the Open position and a separate Min position

This connection is used if the valve position to be ap-

proached is below the Ignition position.

Standard wiring of BCU 370 and BCU 370..B1 without three-point step control function

Valve position Activation of terminal

Upper end position Open 28 Lower end position Closed 27 Lower end position Min Via separate limit switch Lower end position Ignition 26

–+

3PS

BCU 370 · Edition 01.19 15

Min

Page 16

Function

BCU 370..I1..B1

l v1 v2s1v3 cc

31 2 4 5 6 7 8 9 10 11 12 13 14 15 16 24 25 26 27 28 29 30 31 32

V1 C S1 S L A Z M V2 V3 R

DL DG

ppp

minDGmax

230V~

PE N

3PS

BCU 370..B1

OFF

2B 2A 1B 1A

0 ➔ 90°

90° ➔ 0

L1 (L1) N (L2)

PROFIBUS-DP

3.1.4 BCU 370..B1 with PROFIBUS DP

Function, see page 32 (PROFIBUS DP)

For cable selection and wiring, see page 66 (Project planning information).

For the explanation of symbols, see page 77 (Legend).

BCU 370 · Edition 01.19 16

Page 17

Function

3.1.5 Assignment of connection terminals

Terminal Type Designation Function

1, 2 V AC input Supply voltage

3 V AC output Fan Connection for fan control 4 5 Gas valve V2 Connection of phase for gas valve V2 6 Gas valve V3 Connection of phase for gas valve V3 7 9 Minimum gas pressure Connection for pressure switch to monitor the minimum gas pressure 11 Maximum gas pressure Connection for pressure switch to monitor the maximum gas pressure 8, 10 and

Safety circuit output

Inputs for pressure switches

V AC outputs Mains supply Phase for pressure switch mains supply

13 14 Supply voltage to UV sensor Output for supply voltage to UV sensor 15 Burner ground Burner ground input for UV sensor

Flame control

Gas valve V1 Connection of phase for gas valve V1

Minimum air pressure Connection for pressure switch to monitor the minimum air pressure

Flame ampliﬁer input Input for ﬂame ampliﬁer

16 Ignition transformer output Output for (external) ignition transformer

17, 18

19, 20

1) 2)

Floating contact

1) 2)

V AC input

Signalling contact for operating signals

Signalling contact for faults Contact between terminals 19 and 20 closes in the event of a BCU fault signal Start-up signal Signal applied: BCU start; no signal: BCU stop

Controlled air ﬂow

Remote reset Input for external signal (button) to reset the unit af ter a fault lock-out

24 Controller enable/emergency stop Connection for higher-level safety devices and interlocks (e.g. emergency stop)

26 27 28

Connection for external threepoint step controller

Controller enable

Y (to ignition position) Connection for the signal to activate the ignition position Y (to min. position) Connection for the signal to activate the position for minimum capacity Y+ (to max. position) Connection for the signal to activate the position for maximum capacity

Voltage to operate the BCU, 1 = phase (L1), 2 = neutral conductor (N)

Contact between terminals 17 and 18 closes once the operating signal has been received from the burner

Signal applied: fan is started to supply air to the combustion chamber for cooling, for example. Only functional in standby. The function is deactivated as soon as a signal is received at terminal 1 (BCU star t).

Output signal for controller enable for the three-point step controller. The actuator can be set to various positions.

▼

BCU 370 · Edition 01.19 17

Page 18

Function

Terminal Type Designation Function

29, 30 and 31

32 Safety circuit input

BCU..B1: not ﬁtted/non-functional

BCU..B13: not ﬁtted/non-functional

V AC output Capacity control Connection for capacity control using an actuator

Feedback from actuator/ frequency converter

Connection for the position feedback signal from the actuator

BCU 370 · Edition 01.19 18

Page 19

Function

3.2 BCU 370 program sequence

Switch on BCU 370

In the event of fault signal: reset

Start-up position/standby

Start-up with ϑ signal

Switch-on delay time t

Fan run up time t

Butterﬂy valve moves to Open position

Pre-purge time t

Butterﬂy valve moves to Ignition position

Pre-ignition time t

Ignition activated

Safety time t

burner/pilot burner (P12),

Flame proving period t

running for burner/pilot burner (P13)

SA1

V1 and V2 open

running (P22)

(P20)

running (P18)

running (P21)

running for

FS1

3.2.1 Normal start-up

If a fault from the preceding operating cycle is still being signalled after switching on, it will be necessary to reset this ﬁrst. Once the startup signal (ϑ) has been applied, the switch-on delay tE starts to elapse.

During the fan run-up time t

which follows, the fan starts with the butterﬂy valve being closed. The butterﬂy valve then moves from the Closed to the Open position. After pre-purge, it moves back to the Ignition position.

The running times depend on the

respective actuator. The BCU waits for actuator feedback before continuing the program sequence.

Now the BCU activates pre-ignition t

and then opens valves V1 and

V2 for the pilot burner. The ignition time tZ is constant. After the ﬂame proving period for the pilot burner t to ignite the main burner.

, valve V3 opens

FS1

▼

BCU 370 · Edition 01.19 19

Page 20

Flame proving period t

FS1

running for burner/pilot burner (P13)

Safety time t

SA1

running for

burner/pilot burner (P12),

V1 and V2 open

Pre-ignition time t

running (P21)

Ignition activated

Function

Safety time t

Controller enabler signal delay time t

Butterﬂy valve moves to Closed position

SA2

If parameter P27 = 0:

V2 is switched off

Flame proving period t

running for main burner (P15)

Controller enable signal

Controlled shut-down

Post-purge time t

running for main burner (P14),

V3 opens

FS2

(P29)

via ϑ signal

running (P19)

If parameter 27 = 0, V2 closes at the end of the main burner safety time t

. The pilot burner is switched off.

SA2

Then the ﬂame proving period for

the main burner t

and the con-

FS2

troller enable signal delay time tRF start to elapse. Af terwards, the BCU issues the enable signal to the controller.

If there is no pilot burner, program steps

and

will be omitted.

As soon as the start-up signal (ϑ) is switched off, post-purge starts. The butterﬂy valve moves to the Ignition position during this time, then to the Closed position. Next, the BCU rests in the start-up position/ standby.

BCU 370 · Edition 01.19 20

Start-up position/standby

Page 21

Function

Start-up position/standby

Start-up with ϑ signal

Switch-on delay time t

Fan run up time tGV (P20)

Waiting time t

Pre-ignition time t

Ignition activated

Safety time t

burner/pilot burner (P12),

V1 and V2 open

Flame proving period t

running for burner/pilot burner (P13)

Safety time t

running for main burner (P14),

SA2

V3 opens

running (P22)

running (P21)

running for

SA1

3.2.2 Quick start, butterﬂy valve waits in the Ignition position

Parameter 06 = 0, parameter 28 = 0

Quick start is the same as normal start, except that pre-purge is dispensed with. The burner starts quicker. This results in improved control quality, since there is no dead time, the energy is used better and no cold air is fed to the combustion chamber.

The BCU 370 only carries out a

quick start if the last shut-down was a controlled shut-down. No more than 24 hours may have elapsed and the BCU must have been switched on.

In contrast to the “normal start-up”, in the case of a quick start, program

FS1

steps ted.

and

will be omit-

If there is no pilot burner, program steps

und

will also be omit-

ted.

If parameter P27 = 0:

V2 is switched off

BCU 370 · Edition 01.19 21

▼

Page 22

Flame proving period t

FS1

running for burner/pilot burner (P13)

Safety time t

SA2

running for main burner (P14),

V3 opens

If parameter P27 = 0:

V2 is switched off

Safety time t

SA1

running for

burner/pilot burner (P12),

V1 and V2 open

Pre-ignition time t

running (P21)

Ignition activated

Function

Controller enabler signal delay time t

Flame proving period t

running for main burner (P15)

Controller enable signal

After controlled shut-down, the post-purge time tPN starts to elapse

FS2

and then the butterﬂy valve moves to the Ignition position in preparation for the next start.

(P29)

NOTE: Quick start is not allowed for units with FM or CSA approval.

BCU 370 · Edition 01.19 22

Butterﬂy valve moves to Open position

Butterﬂy valve moves to Ignition position

Controlled shut-down

via ϑ signal

Post-purge time t

Start-up position/standby

running (P19)

Page 23

Function

Start-up position/standby

Start-up with ϑ signal

Switch-on delay time tE running (P22)

Butterﬂy valve moves to Open position

Butterﬂy valve moves to Ignition position

Fan run up time t

Waiting time t

Pre-ignition time t

Ignition activated

Safety time t

for burner/pilot burner (P12),

V1 and V2 open

Flame proving period t

running for burner/pilot burner (P13)

(P20)

running (P21)

running

SA1

FS1

3.2.3 Quick start, butterﬂy valve waits in the Closed position

Parameter 06 = 0, parameter 28 = 1

Pre-purge will also be omitted for this type of quick start. To prevent cold air from entering the combustion chamber while the BCU is in start-up position/standby, the butterﬂy valve waits in the Closed position.

The BCU 370 only carries out a

quick start if the last shut-down was a controlled shut-down. No more than 24 hours may have elapsed and the BCU must have been switched on.

After the switch-on delay time t

the butterﬂy valve moves to the Ignition position. The Ignition position is always approached from the top.

Therefore, the butterﬂy valve moves

to the Open position ﬁrst.

▼

BCU 370 · Edition 01.19 23

Page 24

Flame proving period t

FS1

running for burner/pilot burner (P13)

Safety time t

SA1

running

for burner/pilot burner (P12),

V1 and V2 open

Pre-ignition time t

running (P21)

Ignition activated

Function

Safety time t

Controller enabler signal delay time t

Post-purge time t

SA2

If parameter P27 = 0:

V2 is switched off

Flame proving period t

running for main burner (P15)

Controller enable signal

Controlled shut-down

running for main burner (P14),

V3 opens

FS2

(P29)

via ϑ signal

running (P19)

If there is no pilot burner, program steps

and

will be omitted.

NOTE: Quick start is not allowed for units with FM or CSA approval.

BCU 370 · Edition 01.19 24

Butterﬂy valve moves to Closed position

Start-up position/standby

Page 25

Function

Switch on BCU 370

In the event of fault signal: reset

Start-up position/standby

Start-up with ϑ signal

Switch-on delay time t

Butterﬂy valve moves to Open position

Butterﬂy valve moves to Ignition position

Fan run up time t

Waiting time t

Pre-ignition time t

Ignition activated

Safety time t

burner/pilot burner (P12),

V1 and V2 open

Flame proving period t

running for burner/pilot burner (P13)

running (P22)

running (P21d

running for

SA1

(P20)

FS1

3.2.4 Start-up without pre-purge, butterﬂy valve waits in the Closed position

Parameter 18 = 0, parameter 28 = 1

starts to elapse.

Afterwards, the butterﬂy valve moves from the Closed to the Open position and then to the Ignition position. During the fan run-up time t

which follows, the fan starts

with the butterﬂy valve being set to Ignition position.

After the waiting time t

, the BCU

activates pre-ignition tVZ and then opens valves V1 and V2 for the pilot burner. The ignition time tZ is constant. After the ﬂame proving period for the pilot burner t

FS1

, valve

V3 opens to ignite the main burner.

▼

BCU 370 · Edition 01.19 25

Page 26

Flame proving period t

FS1

running for burner/pilot burner (P13)

Safety time t

SA1

running for

burner/pilot burner (P12),

V1 and V2 open

Pre-ignition time t

running (P21d

Ignition activated

Function

Safety time t

Controller enabler signal delay time t

Butterﬂy valve moves to Closed position

SA2

If parameter P27 = 0:

V2 is switched off

Flame proving period t

running for main burner (P15)

Controller enable signal

Controlled shut-down

Post-purge time t

Start-up position/standby

running for main burner (P14),

V3 opens

FS2

(P29)

via ϑ signal

running (P19)

If parameter 27 = 0, V2 closes at the end of the main burner safety time t

. The pilot burner is switched off.

SA2

Then the ﬂame proving period

for the main burner t

and the

FS2

controller enable signal delay time tRF start to elapse. Af terwards, the BCU issues the enable signal to the controller. If there is no pilot burner, program steps

and

will be

omitted.

NOTE: Quick start is not allowed for units with FM or CSA approval.

BCU 370 · Edition 01.19 26

Page 27

Function

r1 s

1917 18 20 21 22 23 24 25 26 27 28 29 30 31 32

max. 1 A,

253 V

3PS

0 ➔ 90°

3.2.5 Controlled air ﬂow

The controlled air ﬂow function is enabled when the

90° ➔ 0

controlled air ﬂow input, terminal 22 or via Status and fault messages for PROFIBUS DP, is activated. Cold air is fed to the combustion chamber, e.g. for cooling.

Following the air pressure switch DL “no ﬂow” state check, the BCU 370 starts the fan and opens the butterﬂy valve to the Open position. The pressure switch for air DL monitors the air pressure.

If the start-up signal (ϑ) is applied during controlled air

ﬂow, the burner is started. If the elapsed controlled air ﬂow time is at least as long as the set pre-purge time,

the burner starts immediately after the Ignition position

L1 (L1) N (L2)

has been reached. If it is shorter, the total air volume is supplied until the end of the pre-purge time.

Activation of the controlled air ﬂow input is not required

for normal burner start.

Activation of the controlled air ﬂow function during

burner operation will be ignored.

BCU 370 · Edition 01.19 27

Page 28

Function

BCU 370..I1..D3

9 3

min

3.3 Tightness control

On BCU 370..D3, the tightness control monitors the fail-safe function

of the gas solenoid valves if parameter 24 is set to 3.

The aim of the tightness control is

to identify an inadmissible leak on

one of the gas solenoid valves and

25 28 26

20 19

90° ➔ 0

0 ➔ 90°

pu/2

VG..L

29 3130

5 32

IC 20

B VA

GIK

18 17

UVS

to prevent burner start. The other

gas solenoid valve continues working properly and takes over the safe shut-off of the gas supply.

The test takes place during pre-

purge. The fan runs and the air pressure opens the air/gas ratio control GIK.

In the case of quick start (parameter

06 = 0), the test takes place after burner operation during post-purge.

The pre- and post-purge times (pa-

rameters 18 and 19) must be set so

that their duration is at least as long

as the test period t

▼

BCU 370 · Edition 01.19 28

Page 29

Function

BCU 370..D3

9 3

min

Downstream of the gas solenoid valve V2 on the burner side, the pipe to the burner must be open so that the space between valves V1 and V2

can be vented.

The pressure switch DG moni-

tors the pressure between the two

28 26

20 19

90° ➔ 0

V1 V2

0 ➔ 90°

632

29 3130

18 17

valves. It must be set to half of the

inlet pressure p

/2 in order to check

both valves with equal sensitivity.

In pilot/main burner systems with three gas solenoid valves, V2 and V3 are checked simultaneously.

pu/2

VG..L

GIK

UVS

IC 20

BVA

BCU 370 · Edition 01.19 29

Page 30

Function

TEST

tL = 3 s

pZ >

0 ➔ I

I ➔ 0

–

3.3.1 Program sequence

The program ﬂow chart explains the

process during the TEST phase.

V1 V2

After start-up the waiting time t

starts to elapse. Then either the left

or right path is executed.

START

pZ >

–

– If the interspace pressure p

greater than half of the inlet pressure pu/2 after the waiting time tW, V2 is tight. V2 is opened for a duration of 3 seconds to vent the interspace. Then the measure-

ment time tM starts to elapse. If

0 ➔ I

no interspace pressure can be measured after this time, V1 is

tL = 3 s

also tight. Both valves have thus been checked.

I ➔ 0

–

pZ >

V1 V2

– If no interspace pressure p

be measured after the waiting time tW, V1 is tight. Then V1 is opened for 3 seconds to ﬁll the space between the valves. Then the measurement time tM starts to elapse. If a pressure can be

can

measured in the interspace after this time, V2 is also tight. Both valves have thus been checked.

▼

BCU 370 · Edition 01.19 30

Page 31

Function

TEST

0 ➔ I

tL = 3 s

I ➔ 0

START

pZ >

Leakage is indicated by ﬁrst valve and

for the

for the second.

V1 V2

–

0 ➔ I

tL = 3 s

I ➔ 0

pZ >

–

BCU 370 · Edition 01.19 31

V1 V2

pZ >

Page 32

Function

L1, N, PE

SPS PLC API

PROFIBUS DP

BCU..B

BUS1– 6

BCU..B

BUS1– 6

3.4 PROFIBUS DP

The BCU..B1 features the same functions and perfor-

mance of a BCU® without a PROFIBUS connection.

PROFIBUS is a manufacturer-independent, open ﬁeld-

BUS

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 subscribers 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.

BCU..B

3.4.1 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-

cess must be monitored by further measures, e.g. ﬂow monitoring.

BCU 370 · Edition 01.19 32

Page 33

Function

3.4.2 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.

3.4.3 Conﬁguration, master-slave procedure

PROFIBUS DP is structured as a master-slave system.

This allows mono-master or multi-master systems to be

implemented.

A distinction is made between three device types:

– DP Master 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 Master 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 referred to as “slaves”.

This also includes the BCU..B1.

3.4.4 Addressing

A maximum of 126 units (masters and slaves) can be

connected to a PROFIBUS DP system. Each subscriber is assigned an individual PROFIBUS address which can be set between 0 and 126 using two code switches on the BCU..B1 board.

BCU 370 · Edition 01.19 33

Page 34

Function

3.4.5 Network technology

All devices are connected in a bus structure (line). Up to 32 subscribers (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 subscribers are implemented or if there is a need to expand the network area, repeaters (ampli-

ﬁers) must be used to link the individual bus segments.

3.4.6 Conﬁguration

When planning a PROFIBUS DP system, unit-speciﬁc parameters of each subscriber are to be taken into account.

To allow for simple and standardized planning, the param

eters 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 can be downloaded from www.docuthek.

com, once you have registered. The steps required to copy the ﬁle are described in the instructions for the automation system.

3.4.7 Bus communication

Input bytes (BCU ➔ master)

Bit Byte 0 Byte 1 Byte 2 Byte 3

0 Burner operation 1 2 Fault lock-out 3 Controlled air ﬂow

6 ON 7 Manual mode

* Only on BCU 370..B13, three-point step control via PROFIBUS DP

Bit Byte 0

0 Reset 1 Start-up 2 Controlled air ﬂow 3 4 5 6 Open* 7 Close*

* Only on BCU 370..B13, three-point step control via PROFIBUS DP

Open position

reached*

Closed position

reached*

Output by tes (master ➔ BCU)

Reserved

See table on page

for PROFIBUS DP)

79 (Status and fault messages

0–25.5 µA of the burner

▼

255 steps

BCU 370 · Edition 01.19 34

Page 35

Function

I/O bytes: the programmer can choose the data to be transferred.

Inputs Outputs

BCU 370 Basic I/O 1 byte 1 byte BCU 370 Standard I/O 4 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 can 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. 6XV18300EH10, or

Lapp cable unitronic, Order No. 2170220T.

BCU 370 · Edition 01.19 35

Page 36

Function

3.5 Program status

Display Program status

In Manual mode, two dots blink on the display.

Start-up position/standby

Butterﬂy valve moves to Closed position

Air monitor "no ﬂow" state check

Fan run-up time t

Butterﬂy valve moves to Open position

Air monitor operating position check

Pre-purge time t

Butterﬂy valve moves to Ignition position

Waiting time t

Pre-ignition time t

1st safety time on start-up t

1st ﬂame proving period t

2nd safety time on start-up t

2nd ﬂame proving period t

Controller enable signal delay time

Operation/Controller enable

Waits for switch-on delay or min. pause time

Controlled air ﬂow

Post-purge time t

SA1

FS1

SA2

FS2

BCU 370 · Edition 01.19 36

Page 37

Function

3.6 Fault message (blinking)

Fault message (blinking) Display Fault lock-out Safety shut-down Warning signal

Flame simulation

Start-up without ﬂame signal

Flame failure during 1

Flame failure during 2

Flame failure during operation

Too many remote resets

Safety interlock failure

Permanent remote reset

Timing cycle too short

oscillating

min.

Bus module error

Bus fault

Open + Close set simultaneously

Fault Valve feedback

Tightne ss control: V1 leaking

Tightne ss control: V2/V3 leaking

Fault Air monitor break contact check

Fault Air monitor make contact check

Fault Air supply during pre-purge

Fault Air supply in program step X

Fault DG

Butterﬂy valve closed position not reached

Butterﬂy valve open position not reached

Butterﬂy valve ignition position not reached

in program step X

max.

in program step X

min.

ﬂame proving period

safety time

ﬂame proving period

01 04 05 06 07 08 10 50 52 53 55

E P

56 35 36 37 0 1 P X X X A0 A1 A2

      



        

   

BCU 370 · Edition 01.19 37

Page 38

Function

3.6.1 Reaction to process faults

The BCU 370 reacts differently to process faults in different program steps. If, for example, the signal from air

pressure switch DL drops during pre-purge, elapse. If the signal is not applied again, the BCU carries out three further start-up attempts.

Process fault BCU 370’s reaction

ﬂashes on the display and a timeout time of 25 seconds starts to

Signal (terminal)

(11) drops

max.

(9) drops

min.

DL (7) pending

Signal status During program step

not pending after t

not pending

drops

▼

SA1

SA2

All

All except t

SA1

SA2

"no ﬂow" state check

Operating position check

Pre-purge time

Valve moves to Ignition position

Waiting time

Pre-ignition time

SA1

FS1

SA2

FS2

Controller enable waiting time

SA1

+ t

SA2

Controlled shut-down

Timeout 25 s

Immediate fault lock-out



 

Safety shut-down

Start-up attempts1)Restart2)Fault message



 

BCU 370 · Edition 01.19 38

Page 39

Function

Process fault BCU 370’s reaction

Signal (terminal)

DL (7) drops

ϑ (21)

Safety interlock (24) drops

Flame (13) pending

According to parameter 07. If the last start-up at tempt fails, a fault lock-out occurs.

According to parameter 08. If the restar t fails, a fault lock-out occurs.

Safety time elapses completely.

BCU restarts as soon as the signal is applied again.

The program sequence is blocked.

4) and 5)

Signal status During program step

Operation

drops

pending

not pending after t

drops

SA1

Controlled air ﬂow

All except t

SA1

SA2

All

"no ﬂow" state check

Operating position check

Pre-purge time

Valve moves to Ignition position

Waiting time

SA1

FS1

SA2

FS2

Controller enable waiting time

Operation

SA1

+ t

SA2

Controlled shut-down

Timeout 25 s

 



         

Immediate fault lock-out

Safety shut-down

 



           

Start-up attempts1)Restart2)Fault message

8 P

50 01 01 01 01 01 04 05 06 07 08 08

BCU 370 · Edition 01.19 39

Page 40

Parameters

4 Parameters

Description Parameter Value range Default Adjustable1)

Burner ﬂame signal 01 Burner switch-off threshold 02 Last fault signal 03 XX Air monitoring during pre-purge 04 0 = Off; 1 = On 1 Air monitoring during operation 05 0 = Off; 1 = On 1

Pre-purge 06

Burner start-up attempts 07 1–4 1

Restart after ﬂame failure during operation 08

Safety time during operation t Minimum operating time t Minimum burner pause time t

safety time on start-up, burner/pilot burner t

ﬂame proving period, burner/pilot burner t

safety time on start-up, main burner t

ﬂame proving period, main burner t

FS2

SA1

FS1

SA2

09 1; 2 s 1 s 10 0–250 s 0 s 11 0–250 s 0 s 12 2; 3; 5; 10 s 5 s 13 0; 2; 5; 10; 20 s 2 s 14 0; 2; 3; 5; 10 s 3 s 15 0; 2; 5; 10; 20 s 2 s

Operating time in Manual mode 16

UVS check (1× in 24 hours) 17 0 = Off; 1 = On 0 Pre-purge time t Post-purge time t Fan run-up time t

18 0–250 s 30 s 19 0–250 s 0 s 20 0–25 s 2 s

0–25 µA 1–20 µA 1 µA

0 = Quick start;

1 = On each start-up

0 = Fault lock-out;

1 = Restart

0 = Unlimited;

1 = Limited to 5 minutes

 



      



   

▼

BCU 370 · Edition 01.19 40

Page 41

Parameters

Description Parameter Value range Default Adjustable1)

Pre-ignition time t Switch-on delay time t

Min. gas pressure monitoring 23 0 = Of f; 1 = On 1

Digital input function 24

Valve control 25 0 = Of f; 1 = On 1

Tightne ss controll, test period t

V2 during burner operation 27 0 = Off; 1 = On 0

Quick start star ts in... 28

Controller enable signal delay time t

User-deﬁned password 30 0000–9999 XXXX Bus control activation 31 0 = Of f; 1 = On 1

Bus control limitation 32

The last 10 fault messages 81–90 XX

Adjustable using BCSoft soft ware and a PC opto-adapter. Changes using BCSoft must be veriﬁed by scanning the parameters using the

Reset/Information button.

Will not be displayed.

 = Adjustable v = Depends on hardware conﬁguration

21 0–5 s 1 s 22 0–250 s 0 s

0 = –

max.

10; 20;

10 s

1 = DG

3 = Tightne ss control

30–250 s

0 = Ignition position;

1 = Closed position

0; 10; 20;

30–250 s

0 s

0 = Closed position

1 = Low position

2 = Ignition position

  



BCU 370 · Edition 01.19 41

Page 42

Parameters

4.1 Scanning the parameters

During operation, the 7-segment display shows the pro-

gram step/status.

In addition to the ﬂame signal and the fault history, all the parameters of the BCU can be scanned in numerical order by repeatedly pressing the Reset/Information button (for 1 s).

The parameter display is ended 60 seconds after the

last time the button is pressed or by switching off the

BCU.

The BCU displays The parameters cannot be scanned when the BCU is

switched off or when a fault or warning is displayed.

when the mains switch is off.

4.2 Flame control

The BCU is ﬁtted with a ﬂame ampliﬁer which evaluates

whether an adequate ﬂame signal is supplied by the burner using a ﬂame rod or UV sensor.

4.2.1 Burner ﬂame signal

Parameter 01

Displays the ﬂame signal in μA.

The BCU measures the ﬂame signal and assesses

whether there is a ﬂame on the basis of the switch-off threshold.

4.2.2 Burner switch-off threshold

Parameter 02

The sensitivity at which the burner control unit detects

a ﬂame can be set using parameter 02.

As soon as the measured ﬂame signal falls below the

set value (2 to 20 µA), the BCU performs a fault lockout during start-up after the elapse of the safety time or during operation after the elapse of the safety time during operation (parameter 19).

In the case of UV control, this value can be increased, should the burner to be monitored be inﬂuenced by other burners for example.

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.

No switch-off threshold will be displayed on the BCU

370..U1 for use with UVC 1.

BCU 370 · Edition 01.19 42

Page 43

Parameters

4.2.3 UVS check (1× in 24 hours)

Parameter 17

Activates an automatic restart of the burner control unit

after 24 hours operating time.

For ﬂame control using a UV sensor for intermittent op-

eration, parameter P17 = 1 must be set to force a restart after 24 hours of operation to test the UV sensor.

Parameter 17 = 0: unlimited burner operation

Parameter 17 = 1: an automatic restart is activated

once every 24 hours. The restart begins with pre-purge (parameter 06, “Pre-purge on each start-up” = 1) or starting the burner in the Ignition position (parameter 06, “Pre-purge on each start-up” = 0).

The time starts each time the start-up signal (ϑ) is applied.

Since the BCU 370 interrupts burner operation autonomously after 24 hours, it is to be veriﬁed whether the process allows for the resulting break in heat supply.

BCU 370 · Edition 01.19 43

Page 44

Parameters

4.3 Behaviour during start-up

4.3.1 Minimum burner pause time tBP

Parameter 11

Determines the minimum burner pause time.

To stabilize the burner operation, a minimum burner

pause time t control system.

If the start-up signal (ϑ) drops after fan start or if a safety shut-down occurs, a restart is suppressed for the duration of the minimum burner pause time t starts to elapse after expiry of the post-purge time tPN (parameter 19).

4.3.2 Burner start-up attempts

Parameter 07

This deﬁnes the maximum number of possible start-up

attempts of the burner.

For burners which require several start-up attempts

due to longer pipes for example, the BCU can automatically carry out several start-up attempts.

Parameter 07 = 1: one start-up attempt

If a safety shut-down takes place during start-up, e.g. on account of a ﬂame signal failure, a fault lock-out occurs once the time t and shows the cause of the fault.

Parameter 07 = 2 – 4: 2 – 4 start-up attempts

can be set independently of the central

, which

has elapsed. The display blinks

If several start-up attempts are set at the works and if the BCU performs a safety shut-down during start-up, it closes the valves after the safety time t

has expired

and attempts to start up again. Each start-up attempt begins with pre-purge. Once the last programmed start-up attempt has failed, the burner control unit performs a fault lock-out, in case no ﬂame has formed. The display blinks and shows the cause of the fault.

In accordance with EN 7462 and EN 676 a maximum of four start-ups are permitted in speciﬁc cases if the safety of the installation is not impaired. Please note application standards.

NOTE: only 1 start-up attempt is possible for units with FM or CSA approval.

BCU 370 · Edition 01.19 44

Page 45

Parameters

4.3.3 Switch-on delay time tE

Parameter 22

P1 A2

A1 08

03 04

SA1

06 H0 05 00

FS1

SA2

H8 07

FS2

1 24 11 DG 9

90° ➔ 0

0 ➔ 90°

31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

max. min.

Determines the time between applying the start-up sig-

nal (ϑ) and initiating the burner start.

When several burners are activated simultaneously, setting different switch-on delay times t

prevents the

fans from starting at the same time and reduces the

load on the power supply.

4.3.4 Pre-ignition time t

Parameter 21

P1 A2

A1 08

03 04

SA1

06 H0 05 00

FS1

SA2

H8 07

FS2

The ignition unit is activated.

The ignition spark can stabilize in the air ﬂow during the

pre-ignition time t

The valves are still closed during the pre-ignition time

. Following pre-ignition tVZ, the safety time t

starts to elapse. The valves are opened while the ignition unit continues to operate.

1 24 11 DG 9 30 29 31 32 7 DL 21 3 16 13 4 5 V2 6 V3 17-18 19-20

SA1

max.

min.

90° ➔ 0 0 ➔ 90°

BCU 370 · Edition 01.19 45

Page 46

Parameters

4.3.5

1st safety time on start-up, burner/pilot burner t

Parameter 12

P1 A2

A1 08

03 04

SA1

The safety time on start-up t

06 H0 05 00

FS1

SA2

determines when the

SA1

H8 07

FS2

pilot burner or burner valves will be closed in the event of ﬂame signal failure.

V1 and V2 are opened and the ignition unit is activated

as the safety time t

starts to elapse. If no ﬂame

SA1

signal is pending after elapse of the safety time t the BCU performs a safety shut-down. The valves are closed. The BCU carries out up to 3 further start-up attempts, depending on how parameter 07 “Burner startup attempts” has been set.

1 24 11 DG 9

90° ➔ 0

0 ➔ 90°

31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

SA1

max. min.

SA1

The setting of safety time t

is to be determined on

SA1

the basis of the burner capacity, the type of control and the relevant application standard, e.g. EN 7462, EN 676, NFPA 85 or NFPA 86.

1st ﬂame proving period, burner/pilot burner t

4.3.6

Parameter 13

P1 A2

A1 08

03 04

SA1

06 H0 05 00

FS1

SA2

H8 07

FS2

Determines the ﬂame proving period of the burner or pilot burner.

This time elapses before the BCU starts the next pro-

gram step so as to give the ﬂame time to stabilize.

The ﬂame proving period t

safety time t

has expired.

SA1

starts to elapse once

FS1

1 24 11 DG 9

90° ➔ 0

0 ➔ 90°

31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

max. min.

FS1

BCU 370 · Edition 01.19 46

Page 47

Parameters

4.3.7 2nd safety time on start-up, main burner t

SA2

Parameter 14

P1 A2

A1 08

03 04

SA1

The safety time on start-up t

06 H0 05 00

FS1

SA2

determines when the

SA2

H8 07

FS2

1 24 11 DG 9

90° ➔ 0

0 ➔ 90°

31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

max. min.

main burner valves will be closed in the event of ﬂame signal failure.

V3 is opened as the safety time t One second before the end of the safety time t

starts to elapse.

SA2

, V2 is closed (parameter 27 = 0, “Interrupted pilot burner”) or remains open (parameter 27 = 1, “Permanent pilot burner”). If no ﬂame signal is pending after elapse of the safety time t

, the BCU performs a safety shut-

SA2

down. Valves V1, V2 and V3 are closed. The BCU carries out up to 3 further start-up attempts, depending on how parameter 07 “Burner start-up attempts” has been set.

The setting of safety time t

is to be determined on

SA2

the basis of the burner capacity, the type of control and the relevant application standard, e.g. EN 7462, EN 676, NFPA 85 or NFPA 86.

4.3.8 2

ﬂame proving period, main burner t

FS2

Parameter 15

P1 A2

A1 08

03 04

SA1

06 H0 05 00

FS1

SA2

H8 07

FS2

1 24 11 DG 9

90° ➔ 0

0 ➔ 90°

31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

max. min.

Determines the ﬂame proving period of the main burner in pilot/main burner combinations.

This time elapses before the BCU starts the next pro-

gram step so as to give the ﬂame time to stabilize.

The ﬂame proving period t

safety time t

has expired.

SA2

starts to elapse once

FS2

BCU 370 · Edition 01.19 47

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Parameters

SA1

4.4 Behaviour during operation

4.4.1 Minimum operating time tB

Parameter 10

Deﬁnes the minimum burner operating time.

To stabilize the burner operation, a minimum operating

time can be set independently of the central control system.

If the start-up signal (ϑ) drops once the ﬁrst safety time t

has started to elapse, the burner remains in opera-

SA1

tion for at least time tB. The minimum operating time tB starts to elapse following controller enable. If the start-up signal drops before the ﬁrst safety time t e.g. during pre-purge, the control unit reverts directly to standby and the burner is not ignited.

4.4.2 Controller enable signal delay time t

Parameter 29

P1 A2

A1 08

03 04

06 H0 05 00

FS1

SA2

H8 07

FS2

SA1

1 24 11 DG 9

90° ➔ 0

0 ➔ 90°

31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

max. min.

Deﬁnes the time between start-up of the burner and controller enable.

The controller enable signal delay time ensures a stable

combustion process, e.g. through uniform heating of the entire combustion chamber.

The time t

after expiry of if

SA1

FS1

SA2

FS2

The BCU shows program status

starts to elapse

= 0, t

t t

SA2

FS2

SA2

= 0 = 0 > 0, t

= 0

FS1

> 0

FS1

> 0, t

FS1

. After time tRF has elapsed,

the BCU closes the operation signalling contact (terminals

17/18) and activates controller enable (terminal 25).

4.4.3 Safety time during operation t

Parameter 09

Deﬁnes the safety time during operation t

for valves

V1, V2 and V3.

If there is a ﬂame failure while the burner is operating, the BCU closes the valves within the safety time during operation t

. The default in accordance with EN 298 is 1 s.

The safety time during operation tSB can also be set to 2 s.

Prolonging the time increases the installation availability in the case of brief-duration fades of the ﬂame signal.

The safety time of the installation during operation (in-

cluding closing time of the valves) may not exceed 3 s in accordance with EN 7462 or 4 s in accordance with NF PA 85 and NFPA 86. Please note application standards.

BCU 370 · Edition 01.19 48

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Parameters

4.4.4 Restart after ﬂame failure during operation

Parameter 08

Determines whether a restart will be attempted follow-

ing a safety shut-down during operation.

For burners with occasionally unstable ﬂame signals

during operation, a one-off restart can be attempted.

Parameter 08 = 0: Off. A fault lock-out will occur in the

event of a ﬂame failure during operation

In the event of an installation fault (e.g. ﬂame failure or air pressure failure), the burner control unit performs a

fault lock-out within the safety time during operation

. This involves disconnecting the power from the gas

valves. The fault signalling contact closes, the display blinks and shows the current program status, see page

79 (Status and fault messages for PROFIBUS DP).

Parameter 08 = 1: On. A restart will take place after a ﬂame failure during operation.

If the BCU detects an installation fault (e.g. ﬂame failure) after the second ﬂame proving period has elapsed, the valves are closed and the operation signalling contact is opened within time t

. The burner control unit

now attempts to restart the burner once. The restart begins with pre-purge. For further restart attempts, the burner must have been operational for at least 2 seconds.

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 7462 and EN 676, a restart may be attempted under certain conditions. The safety of the system must not be impaired. Please note application standards.

4.4.5 Last fault signal

Parameter 03

The BCU shows the last fault message.

In order to analyze a burner system, the last fault message can be called up. In addition, parameters 81 to 90 show the last 10 messages. Extended diagnostics is possible using the BCSoft software.

BCU 370 · Edition 01.19 49

Page 50

Parameters

4.4.6 V2 during burner operation

Parameter 27

Determines whether valve V2 is switched off 1 s before

the end of the second safety time t

On systems with pilot burners, the pilot burner can be

switched off once the main burner is operational.

Parameter 27 = 0: valve V2 is switched off 1 s before the

end of the second safety time t

SA2

this occurs at the end of the ﬁrst ﬂame proving period t

or at the end of the ﬁrst safety time t

FS1

This setting is required for pilot/main burner systems

where the pilot burner does not ignite the main burner safely in each operating status.

Parameter 27 = 1: valve V2 remains open during the en-

tire burner operation. This setting is valid for directly ignited burners (t

= 0) and pilot/main burner systems

SA2

with permanent pilot burner.

SA2

. (If t

is set to 0,

SA2

SA1

if t

FS1

= 0).

BCU 370 · Edition 01.19 50

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Parameters

4.5 Monitoring/tightness control

4.5.1 Min. gas pressure monitoring

Parameter 23

Determines whether the minimum gas pressure DG

is monitored.

To ensure that there is adequate gas pressure on the

burner, the pressure can be monitored using the gas pressure monitor DG

min.

Monitoring takes place in the start-up position/standby,

during burner start-up or during burner operation. If the signal is not applied, a locking warning signal is triggered and the display shows

, “Fault DG

program step X”. When the signal is applied again, the

BCU 370 attempts to restart the burner, provided the

start-up signal (ϑ) is applied.

The requirement for monitoring of the minimum gas

pressure is stipulated in the relevant application standard.

min

min.

. in

4.5.2 Digital input function

Parameter 24

Deﬁnes the function of the input on terminal 11.

Parameter 24 = 0: input has no function.

Parameter 24 = 1: monitoring of the maximum gas pressure DG

max.

To ensure that the permissible gas pressure on the

burner is not exceeded, the pressure can be monitored using the gas pressure monitor DG

max.

Monitoring takes place in the start-up position/standby, during burner start-up or during burner operation. If the signal is not applied, a fault lock-out occurs and the display shows

, “Fault DG

in program step X”.

max.

Parameter 24 = 3: monitoring of the pressure switch between V1 and V2/V3 for tightness control (only on BCU..D3). See Function – Tightness control.

BCU 370 · Edition 01.19 51

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Parameters

4.5.3 Air monitoring during pre-purge

Parameter 04

This parameter is activated automatically if parameter

05 “Air monitoring during operation” has also been activated. The parameter determines whether the air supply is monitored during pre-purge.

To ensure that there is actually air pressure during pre-

purge, the pressure can be monitored using the air monitoring during pre-purge function.

Parameter 04 = 0: no air monitoring during pre-purge. A

decrease in the air pressure or a failure in air supply will not be detected.

Parameter 04 = 1: air monitoring during pre-purge. Air

pressure switch signal to terminal DL (7). The BCU checks whether the air monitor signal changes:

– Check of the LOW signal (no air monitoring signal)

Before pre-purge, no signal may be present. A LOW

signal must be applied to input DL. If the LOW signal is not applied, the BCU performs a fault lock-out once the delay time of 25 seconds has elapsed. Fault message:

, “no ﬂow” state check.

– Check of the HIGH signal (air monitoring signal acti-

vated)

Once the fan has been activated, the BCU checks

whether the air monitor switches while the actuator moves to the Open position (start-up with pre-purge) or during the waiting time (quick start). The signal to input DL must be switched to HIGH. If the HIGH sig-

nal is not applied, the BCU performs the set number of further start-up attempts (parameter 07) after a delay time of 25 seconds has elapsed. If no further start-up attempts have been parameterized, a fault

lock-out occurs and fault message

, “No air supply

during start-up”, is displayed.

Air pressure must be present and a HIGH signal must

be applied to input DL during the subsequent prepurge. If the HIGH signal is not applied, the BCU performs a safety shut-down once the delay time of 25 seconds has elapsed. If no further start-up attempts have been parameterized (parameter 07), a fault lock-

out occurs and fault message

, “No air supply during

pre-purge”, is displayed.

Depending on the application standard, different air monitoring methods are possible. Along with pressure monitoring, other functions such as fail-safe feedback signals from the actuator or air ﬂow monitoring devices may be required. Please note application standards.

BCU 370 · Edition 01.19 52

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Parameters

4.5.4 Air monitoring during operation

Parameter 05

If this parameter is activated, parameter 04 “Air monitoring during pre-purge” is also activated. This parameter determines whether the air supply is monitored during burner operation.

To ensure that there is actually air pressure during burn-

er operation, the pressure can be monitored using the air monitoring during operation function.

Parameter 05 = 0: no air monitoring during operation. A

decrease in the air pressure or a failure in air supply will not be detected.

Parameter 05 = 1: the air pressure is monitored during

operation. During burner start (after pre-purge until the end of the main burner safety time t

) and during

SA2

burner operation (after the end of main burner ﬂame proving period t

until the end of normal operation),

FS2

the air must ﬂow and a HIGH signal must be applied to input DL. If the HIGH signal drops, the BCU performs a safety shut-down.

– DL signal drops during burner start.

If further start-up attempts have been parameterized

(parameter 07), a further burner start-up attempt is made. If no further start-up attempts have been parameterized, a fault lock-out occurs and fault mes-

sage

, “No air pressure on DL in program step X”, is

displayed.

– DL signal drops during burner operation.

If a restart is parameterized (parameter 08), a one-off

burner restart is attempted. If the restart option is not activated, a fault lock-out occurs and fault message

, “No air pressure on DL in program step X”, is dis-

played.

BCU 370 · Edition 01.19 53

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Parameters

4.5.5 Tightness controll, test period tP

Parameter 26

BCU..D3 only

Deﬁnes the tightness control test period t

solenoid valves. It can be set to 10, 20 or 30 to 250 seconds.

Depending on the burner capacity, the tightness of the

gas solenoid valves must be checked in accordance with the relevant application standard, e.g. EN 676,

EN 746, NFPA 85 and NFPA 86.

The sensitivity of the tightness control can be adjusted

individually by adapting the test period t age rate QL is to be detected, a long test period tP must be set. The test period tP is the sum of the waiting time tW, 3 s opening time tL and measurement time tM.

The test period tP is calculated from the inlet pressure

pu [mbar (psig)], the leakage rate QL [l/h (ft3/h)] and the test volume VP [l (f t3)].

tP = 4 x

[mbar] x V

[l/h]

[l]

+ 1 s

Leakage rate

The tightness test allows a check to be made for a spe-

ciﬁc leakage rate QL. In countries where the standards and Directives of the European Union are applicable, the maximum leakage rate QL is 0.1% of the maximum

ﬂow rate Q

(N) max .

[m3(ft3)/h (n)].

for the gas

. If a low leak-

[m3/h] x 1000 [l/h]

Leakage rate QL [l /h]

Test volume V

(N) max.

1000 x 1 [m

/h]

The test volume VP is calculated from the basic vol-

ume VG (for 2 valves VG), added to the volume of the pipe VM for each additional metre in length L:

VP = VG + L x V

10 0.01 0.011 0.1 0.11 15 0.07 0.0 74 0.2 0.21 20 0.12 0.127 0.3 0.32 25 0.2 0.21 0.5 0.53 40 0.7 0.74 1.3 1.37 50 1.2 1.27 2 2.11 65 2 2.11 3.3 3.49 80 4 4.23 5 5.28 100 8.3 8 .77 7.9 8.35 125 13.6 14.37 12.3 13 150 20 21.13 17.7 18 .7 200 42 44.38 31.4 33.18

Basic volume V

Litres Quarts Litres Quarts

Volume per metre V

BCU 370 · Edition 01.19 54

Page 55

Parameters

BCU 370..I1..D3

Calculation example for test period t

2 valves VG 20,

distance L = 0.5 m (19.68 inch), inlet pressure pu = 50 mbar (0.725 psig), max. ﬂow rate Q

(N) max.

15 m

= 50 mbar

Leakage rate Q

2 x VG 20, distance L = 0.5 m (19.68 inch) Test volume V

15 m

= 0.12 l + 0.5 m x 0.3 l /m = 0.27 l (0.28 qt)

= 15 m3/h (425,6 ft3/h)

(N) max .

VG VG..L

DN 20

/h (425.6 ft3/h) x 0.1% = 15 l/h (0.4256 ft3/h)

0,5 m

VG..

Calculated test period:

tP [s] = 4 ×

Set the next highest value (10 s) using parameter 26.

50 x 0.27

(

s = 7.6 s

)

BCU 370 · Edition 01.19 55

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Parameters

4.6 Air control

4.6.1 Valve control

Parameter 25

Determines whether an actuator connected to termi-

nals 29 to 32 is activated for valve control.

If valve control is deactivated, the BCU 370 can be used to control single-stage-controlled burners.

Parameter 25 = 1: valve control is active. The BCU

activates the outputs on terminals 29, 30 and 31 to move the actuator to the Open (pre-purge), Closed and Ignition positions. When the appropriate position is reached, this information is signalled back by the actuator via the input on terminal 32. The BCU 370 waits for the feedback signal from the actuator once the outputs have been activated. The time required depends on the actuator running time. If the position is not reached within the timeout time of 250 seconds, the BCU displays the fault message “Position not reached”.

Parameter 25 = 0: the BCU 370 runs through all pro-

gram steps without waiting for a feedback signal from the butterﬂy valve. The outputs for valve control are not activated.

4.6.2 Pre-purge

Parameter 06

This parameter determines whether the BCU pre-purg-

es on the next start-up after a controlled shut-down.

Within the scope of the application standard EN 676 pre-purge can be dispensed with under certain conditions. This prevents cold air from entering the combustion chamber and accelerates burner start-up.

Parameter 06 = 1: pre-purge occurs on each start-up.

Parameter 06 = 0: pre-purge is omitted if the last shutdown was a controlled shut-down and occurred within the last 24 hours. After switching on the BCU, after a safety shut-down or a fault lock-out or after a pause of more than 24 hours, the BCU completes an entire prepurge cycle.

For burner capacities as from 70 kW, application standard EN 676 requires that a valve check be carried out if pre-purge has been omitted.

For burner capacities as from 117 kW, application standards NFPA 85 and NFPA 86 require a valve check before pre-purge and a pre-purge before each system start.

The valves can be checked using a tightness control.

See “Function – Tightness control”. Please note application standards.

BCU 370 · Edition 01.19 56

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Parameters

4.6.3 Quick start starts in...

Parameter 28

Only active if parameter 06 = 0 (Pre-purge) and param-

eter 25 = 1 (Valve control) are set.

Determines whether on quick start, the butterﬂy valve

rests in the Ignition position or in the Closed position during standby.

In the Closed position, the amount of combustion air which enters the combustion chamber is minimized.

Parameter 28 = 0: the BCU sets the butterﬂy valve to

the Ignition position for quick start after controlled shut-down. Once the start-up signal (ϑ) has been applied, the BCU initiates burner ignition immediately after the fan run-up time (parameter 20) and the waiting time.

Parameter 28 = 1: the BCU sets the butterﬂy valve to

the Closed position for quick start after controlled shutdown. Once the start-up signal (ϑ) has been applied, the BCU moves the actuator to the Ignition position via the Open position and ignites the burner after the fan run-up time (parameter 20) and the waiting time. The time between activating the start-up signal (ϑ) and burner start is determined by the running time of the actuator of the butterﬂy valve.

BCU 370 · Edition 01.19 57

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Parameters

4.6.4 Pre-purge time tPV

Parameter 18

P1 A2

A1 08

03 04

SA1

06 H0 05 00

FS1

SA2

H8 07

FS2

1 24 11 DG 9

90° ➔ 0

0 ➔ 90°

31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

max. min.

Determines how long the full air ﬂow will be supplied to

the combustion chamber before burner start.

Pre-purge removes non-combusted gases from the

combustion chamber.

The pre-purge time t

starts once the actuator has sig-

nalled the Open position and the air pressure switch DL contact has closed.

If “Pre-purge on each start-up” is deactivated (parameter 06 = 0), pre-purge is omitted on burner start after a controlled shut-down within the last 24 hours.

If the pre-purge time t

is set to 0 s, pre-purge is al-

ways omitted, e.g. even on restart after a safety shutdown. The BCU carries out a quick start on each burner

start. The butterﬂy valve is moved to the Ignition position via the Open position after controlled shut-down.

If tightness control is activated (BCU..D3, parameter

24 = 3), the pre-purge time t

must be set to at least

the value of the test period (parameter 26).

The pre-purge time t

is to be set on the basis of the

relevant application standard (e.g. EN 676, EN 7462, NFPA 85 or NFPA 86).

BCU 370 · Edition 01.19 58

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Parameters

4.6.5 Post-purge time tPN

Parameter 19

08 P9 A0

1 24 11 DG 9

29 31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

max. min.

➔ 0

➔ 90

Determines how long air will be supplied to the com-

bustion chamber after burner operation has been terminated.

To remove combustion gas residues from the burner,

this can be purged with air after operation.

The post-purge time t

starts to elapse once the start-

up signal (ϑ) has been deactivated or once the ﬁrst safety time has elapsed in case of a safety shut-down. If the actuator is located above the Ignition position at this time, it moves to the Ignition position. If it is below the Ignition position, the actuator stays in its current position.

Pre-purge on each start-up (parameter 06 = 1):

The actuator moves to the Closed position after the end

of the post-purge time t

Quick start (parameter 06 = 0) or pre-purge time = 0 (parameter 18 = 0):

After the post-purge time t

has elapsed, the actuator

moves to the Open position and then to the Ignition position (parameter 28 = 0) or the Min position (parameter

28 = 1).

If tightness control is activated (BCU..D3, parameter

24 = 3) and quick start is activated (parameter 06 = 0),

the post-purge time must be set to at least the value of the test period (parameter 26).

BCU 370 · Edition 01.19 59

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Parameters

4.6.6 Fan run-up time tGV

Parameter 20

P1 A2

A1 08

03 04

SA1

06 H0 05 00

FS1

SA2

H8 07

FS2

1 24 11 DG 9

90° ➔ 0

0 ➔ 90°

31 32 7 DL

21 3 16 13 4 5 V2 6 V3 17-18 19-20

max. min.

This parameter deﬁnes the time between the activation

of the fan output (terminal 3) and the opening of the butterﬂy valve or burner start.

Fan start with the butterﬂy valve being closed reduces

the start-up current of the fan motor.

BCU 370 · Edition 01.19 60

Page 61

Parameters

4.7 Control using PROFIBUS DP

4.7.1 Bus control activation

Parameter 31

Only on BCU 370..B13

Activates three-point step control via Proﬁbus DP.

The activation signals for capacity control using the

butterﬂy valve can be transferred via the Proﬁbus DP.

Once bit 7 of the output byte has been set, the valve

moves in the direction of the Closed position. When bit 6 is set, the valve moves to the Open position. If both bits are set, the valve stops. The BCU 370 displays fault message

The lower limit of the modulation range is deﬁned using

parameter 32.

, “Open + Close set simultaneously”.

4.7.2 Bus control limitation

Parameter 32

Only on BCU 370..B13

Deﬁnes the lower limit of the modulation range of the butterﬂy valve.

Parameter 32 = 0: when bit 7 is activated, the butterﬂy valve moves to the Closed position. This is deﬁned by the limit switch in the actuator.

Parameter 32 = 2: when bit 7 is activated, the butterﬂy valve moves to the Ignition position. This is deﬁned by the limit switch in the actuator.

90° ➔ 0

0 ➔ 90°

25 26 27 28 29 30 31 32

▼

BCU 370 · Edition 01.19 61

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Parameters

Parameter 32 = 1: when bit 7 is activated, the butterﬂy

valve moves to the Low position. For this purpose, terminal 25 is wired to a fourth limit switch in the actuator.

90° ➔ 0

0 ➔ 90°

25 26 27 28 29 30 31 32

Min

Deﬁnition of the modulation range following controller enable

BCU..B13 with three-point step control function

Valve position Output byte

Upper end position Open Bit 6 Lower end position Closed Bit 7, parameter 32 = 0

Lower end position Low

Lower end position Ignition Bit 7, parameter 32 = 2

Bit 7, parameter 32 = 1,

terminal 25 wired to separate limit

switch

BCU 370 · Edition 01.19 62

Page 63

Parameters

4.8 Manual mode

For convenient setting of the burner or analyzing faults.

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 Start-up signal (ϑ) (terminal 21), Controlled air ﬂow (terminal

22) and Remote reset (terminal 23) as well as the bus inputs on BCU..B1. The functions of the safety interlock (terminal 24) are retained.

Each time after the button is pressed again, the BCU

moves to the next section of the program sequence and stops there. After approx. 3 seconds, the ﬂame signal is indicated instead of the operating status. In the event of ﬂame simulation, the ﬂame signal will be displayed immediately.

Following controller enable (status display

nected butterﬂy valve can be opened and closed as required. By holding the button, the motor is ﬁrst opened

further. The BCU indicates

the button has been released, the butterﬂy valve stops in the relevant position. If the button is pressed again, the butterﬂy valve is closed (Closed position). The BCU indicates tion takes place each time the button is released and pressed again.

A.0.

, with blinking dots. A change of direc-

A .1.

, with blinking dots. Once

), a con-

When the butterﬂy valve has reached its ﬁnal position, the dots disappear.

4.8.1 Operating time in Manual mode

Parameter 16

Determines whether the BCU in Manual mode is reset to the standby position for Manual mode.

Parameter 16 = 0: Manual mode is not limited in time.

If this function has been selected, operation of the burner may be continued manually in the event of failure of the control system or the bus.

Parameter 16 = 1: ﬁve minutes after the last time the button is pressed, the BCU ends burner operation and moves abruptly back to the standby position for Manual mode. The burner can be restarted manually.

Manual mode is terminated by switching off the BCU or in the event of a power failure.

BCU 370 · Edition 01.19 63

Page 64

Parameters

4.9 Fault messages

4.9.1 The last 10 fault messages

Parameters 81 – 90

The BCU shows the last 10 fault messages.

In order to analyze a burner system, the last fault messages can be called up in the order in which they occurred. Extended diagnostics is possible using the

BCSoft software.

The BCU records the last 10 fault messages internally.

Parameter 81 shows the most recent fault message,

parameter 82 the one before and so on.

4.10 Password

4.10.1 User-deﬁned password

Parameter 30

Password saved to protect parameter settings.

To prevent unauthorized changes to parameter settings,

a password is stored in parameter 30. The parameter settings can be modiﬁed after the password (4 numbers) has been entered. The password can be changed using BCSoft. Note the effect of parameter settings on the safe functioning of your system.

The password set at the factory can be found in the de-

livery note supplied.

BCU 370 · Edition 01.19 64

Page 65

Selection



* If “none”, this speciﬁ cation is omit ted.

Order example

* I2 only for 230 V, I3 only for 120 V Please quote the required settings of all parameters when ordering, see “Parameters”.

5 Selection

BCU 370: for modulating-controlled forced draught burners

W Q I1 I2 I3 F E U0 U1 D1 D3 B1* 3*

BC U 370

= standard, v = available

BC U 370WI1FEU0D1

5.1 Type code

Code Description

BCU Burner control unit

W Q

I1 I2* I3* no speciﬁ cation

F Fan control E Valve control

U0 U1

D1 D3

B1 For PROFIBUS DP 3 Three-point step control via PROFIBU S DP

   v v    v  v v v

Mains voltage 230 V AC, 50/60 Hz 120 V AC, 50/60 Hz

Electronic ignition, single-pole

Electronic ignition, double-pole

Electronic ignition, double-pole with neutral conductor

Ionization control (continuous or intermittent op.) or UV control (intermittent op. with UVS)

UV (continuous operation with UVD 1)

Integrated tightness control

Ignition

Without ignition

Flame control

monitoring

max.

BCU 370 · Edition 01.19 65

Page 66

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. 1.5 mm

Control line for UVC 1 wiring: 1 mm

Cable for burner ground: 4 mm

Do not route BCU cables in the same cable duct as frequency converter cables or cables emitting strong ﬁelds.

6.1.1 Ionization cable

Use an unscreened high voltage cable for the ignition cable, see page 71 (Accessories).

Recommended cable length: max. 50 m (164 ft).

Lay cables individually, 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 UV cable

Cable length: max. 50 m (164 ft).

Install well away from mains cables and interference

from electro-magnetic sources.

Do not lay together with ignition cable.

6.1.3 Ignition cable

(BCU 370..I1, BCU 370..I2 with integrated electronic ignition unit)

Use an unscreened high voltage cable, see page 71 (Accessories).

Cable length: max. 1 m (3.2 ft).

Avoid external electrical interference.

Permanently connect the ignition cable(s) to the integrated ignition unit using plug connectors, see page

71 (Accessories).

Lay cables individually, not in a metal conduit.

Do not lay UV/ionization cable and ignition cable(s) together and lay them as far apart as possible.

Feed out of the BCU on the shortest possible route (no loops). Push through corresponding knock-out hole(s) in the housing and use enclosed M16 cable gland(s).

Only use radio interference suppressed terminal boots (with 1 kΩ resistor), see page 71 (Accessories).

For units with external ignition, e.g. ignition transformer

TGI, please note the corresponding unit instructions.

BCU 370 · Edition 01.19 66

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Project planning information

6.2 Fan control

The BCU features an output for fan control. The max.

start-up current for the fan motor must not exceed the permitted contact rating of this output, see page 73 (Technical data). If necessary, an external contactor must be used.

6.3 Controlling the butterﬂy valve

The required burner commissioning time depends on

the running time of the butterﬂy valve actuator.

The BCU 370 waits for the feedback signal to indicate

that the actuator has reached the Open position, for instance, before the pre-purge time is started.

The Ignition position is always approached via the Open

position.

Once the butterﬂy valve has been set to the relevant

position, a plausibility check takes place. The related control output is switched off brieﬂy. The feedback signal must drop accordingly.

6.4 Safety interlock (limits)

The limiters in the safety interlock (linking of all the rel-

evant safety control and switching equipment for the use of the application, for example STL [safety temperature limiter]) must isolate terminal 24 from the voltage supply. If the safety interlock is interrupted, the display shows a blinking sequence is interrupted. All of the BCU 370’s outputs are disconnected from the electrical power supply. The burner control unit restarts when the safety interlock is switched on again and the start-up signal (ϑ) activated.

as a warning signal. The program

6.5 Too many remote resets

If a remote reset is made 5 times in 15 minutes (terminal 23 or by bus signal), the BCU is locked, shows fault message be reset by pressing the Reset /Information button.

, “Too many remote resets”, and can only

BCU 370 · Edition 01.19 67

Page 68

Project planning information

6.6 Protecting the ignition unit from overload

The BCU protects the integrated ignition unit and the

electronic switch from overload. Excessive switching triggers a warning signal (blinking

). After the mini-

mum cycle time has elapsed, the BCU starts.

The minimum cycle time saved in the BCU can be cal-

culated using the formula:

Minimum cycle time = (t

+ t

SA1

- 1) x 6

Example: Pre-ignition time t

1st safety time on start-up t

= 2 s,

SA1

= 3 s

(2 s + 3 s - 1) x 6 = 24 s

In this example, the BCU 370 may not be started more often than every 24 s.

If an external ignition unit/transformer is being used, the formula is as follows:

Minimum cycle time = (t

Adjust the minimum burner pause time t

+ t

SA1

- 1) x 2

(parameter

11) correspondingly, if required.

6.7 Wiring

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 inputs. Do not connect voltage to the outputs.

On BCU 370..B1 for PROFIBUS DP, no voltage may be connected to terminals 17 to 23. Otherwise, the BCU may be damaged.

6.7.1 Single-electrode operation with external ignition unit

BCU 370

N13 14 15 16 PE

If a burner only has one electrode, which is used for ignition and ionization control, an external ignition transformer must be used, e.g. TZI or TGI.

6.8 BCU switched off

The BCU indicates

when no mains voltage is applied or the burner control unit is switched off. The fault signalling contact is only closed when the BCU is supplied with voltage and switched on.

BCU 370..B1

The bus interface is still operational to maintain the

function of the communications system. The control outputs of the BCU (valves, ignition unit) are electrically isolated from the mains voltage.

––

. In general, it cannot be activated

BCU 370 · Edition 01.19 68

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Project planning information

6.9 Note on EC type-examination or CSA and FM approval

Since EN 298 (1993) or NFPA 85 and NFPA 86 does not describe all functions of the BCU 370, the operator is responsible for ensuring that all parameters and

functions are matched to the respective application.

6.10 Contact fuses

The safety-related switching contacts on the BCU 370

(V1, V2, V3, Ignition, Controller enable, Open butterﬂy valve, Close butterﬂy valve and Butterﬂy valve ignition) are protected by an internal fuse (3.15 A, slow-acting).

This fuse cannot be replaced, since safe opening of

the contacts is not guaranteed following overload or a short-circuit, e.g. due to a wiring fault. The BCU must be returned to the manufacturer for repair.

6.11 Installation

Recommended installation position: vertical (cable

glands pointing downwards).

Detach the upper section of the BCU, remove and screw

on lower section with four screws Ø 4 mm. Replace upper section and screw into place.

6.12 Protective circuits

Connected control elements must be equipped with protective circuits in accordance with the manufacturer’s instructions. This prevents high voltage peaks which can cause malfunction of the BCU.

6.13 BCSoft

Changes using BCSoft must be veriﬁed by scanning the parameters using the Reset/Information button.

BCU 370 · Edition 01.19 69

Page 70

Flame control

7 Flame control ...

7.1 ...with ﬂame rod

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 are possible if an external ignition transformer is used.

The requirements for continuous operation are satisﬁed

in the event of ﬂame control using a ﬂame rod.

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 17 = 1.

Further information can be found in Technical Information bulletins UVS 5 and UVS 10 at ww w.docuthek.com.

The burner control unit BCU..U1 is prepared for UV ﬂame detector UVC 1. This enables continuous opera-

tion.

Further information can be found in TI UVC at ww w.docuthek.com.

BCU 370 · Edition 01.19 70

Page 71

Accessories

8 Accessories

8.1 High-voltage cable

FZLSi 1/7 up to 180°C (356°F), Order No.: 04250410,

FZLK 1/7 up to 80°C (176°F), Order No.: 04250409.

8.2 BCSoft

The current software can be downloaded from our In-

ternet site at www.docuthek.com. To do so, you need to register in the DOCUTHEK.

8.2.1 Opto-adapter PCO 200

BCSoft CDROM included, Order No.: 74960625.

8.3 Radio interference suppressed terminal boots

Right-angle terminal boot, 4 mm, interference-suppressed, Order No.: 04115308.

Straight terminal boot, 4 mm, interference-suppressed, Order No.: 04115307.

Straight terminal boot, 6 mm, interference-suppressed, Order No.: 04115306.

8.4 Connection kit BCU 370

2 M16 cables glands,

2 plug connectors for ignition cable,

2 seal inserts for M20 cable glands.

The connection kit is included in the scope of delivery

for the lower section. Order No.: 74960479

8.5 Set of stickers BCU 370

Various stickers with information in the following lan-

guages: D, F, I, NL and E,

sticker: “Important, changed parameters”.

The set of stickers is included in the scope of delivery for

the upper section. Order No.: 74960480

BCU 370 · Edition 01.19 71

Page 72

Accessories

8.6 GSD master data ﬁle for BCU 370..B1

The GSD ﬁle can be downloaded from our Internet site at

ww w.docuthek.com.

Log on to the Docuthek and then choose document

type “Software”.

GSD ﬁle on CD, Order No.: 74960460.

BCU 370 · Edition 01.19 72

Page 73

Technical data

9 Technical data

Mains voltage: BCU..W: 230 V AC, 15/+10%, 50/60 Hz, or

BCU..Q: 120 V AC, 15/+10%, 50/60 Hz, for grounded or ungrounded mains.

Flame control with UV sensor or ﬂame rod.

Flame signal for:

Ionization control: 1 – 28 μA, UV control: 1 – 35 μA.

For intermittent or continuous operation.

Air pressure check during pre-purge and operation by

external air pressure switch DL.

Maximum length of ignition cable with integrated elec-

tronic ignition: 1 m (3.2 ft).

Electronic ignitions: BCU 370W..I1:

Ignition voltage: 22 kVpp, ignition current: 40 mA , spark gap: 3 mm, secondary connection diameter: 1 × 4 mm to grounding connection.

BCU 370W..I2:

Ignition voltage: 22 kVpp, ignition current: 40 mA , spark gap: 3 mm, secondary connection diameter: 2 × 4 mm.

BCU 370Q..I1: Ignition voltage: 12 kV amplitude, ignition current: 40 mA , spark gap: 3 mm, secondary connection diameter: 1 × 4 mm to grounding connection.

BCU 370Q..I3: Ignition voltage: 2 × 6.5 kV amplitude, ignition current: 40 mA , spark gap: 3 mm, secondary connection diameter: 2 × 4 mm plug to grounding connection.

Maximum length of ionization/UV cable: 50 m (164 ft).

Max. number of operating cycles: 250,000.

Ambient temperature:

BCU 370: 20 to +60°C (4 to +140°F), BCU 370..I: 10 to +60°C (14 to 140°F), no condensation permitted.

Enclosure: IP 54 pursuant to IEC 529.

Permitted operating altitude: < 2000 m AMSL.

▼

BCU 370 · Edition 01.19 73

Page 74

Technical data

Housing made of impact-resistant and heat-resistant

plastic. Plug-in upper section with operating controls and indicators.

Lower section with connection terminals, grounding

strip and pre-wired neutral bus with spacious wiring chamber.

1x M25 multiple cable gland, 4x 7 mm cable grommets,

2x M20 multiple cable gland, 2x 7 mm cable grommets,

and loosely enclosed

1x or 2x M16 plastic cable glandr(s) for the ignition

cable (s).

Voltage to inputs, valves, fan, controller enable, actuator

and ignition unit = mains voltage.

Power consumption: approx. 9 VA plus approx. 50 VA for

integrated ignition.

Input voltage of signal inputs:

Rated value 120 V AC 230 V AC

Signal “1” 80–126.5 V 160–253 V Signal “0” 0–20 V 0–40 V

Input current signal “1”: typ. 2 mA

Output to ignition transformer:

no-switch contacts via semi-conductor.

Contact rating: Valves: max. 1 A, cos j = 1, Butterﬂy valves: max. 1 A, cos j = 1,

Ignition: max. 1 A, cos j = 0.3,

Controller enable signal: max. 1 A, cos j = 1,

the contacts may be loaded with a max. total of 2.5 A, Fan: max. 3 A, start-up current: max. 6.5 A < 1 s.

The outputs may be loaded with a max. total of 4 A.

Operation and fault signalling contacts:

Dry contact, max. 1 A, 253 V, not internally fused (does not satisfy the requirements for safe isolation, therefore not ﬂoating).

Reset/Information button: max. number of operating cycles: 1000.

Fuse in BCU, replaceable, F1: T 5A H, pursuant to IEC 601272/5.

Fuse for protecting the safety-relevant outputs V1, V2, V3, Ignition, Controller enable, Open valve, Close valve and

Valve ignition position: 3.15 A, slow-acting, not replaceable.

Permissible UV sensors: Honeywell Kromschröder models UVS 1, 5, 10 and UVC 1.

Weight: approx. 1.8 kg.

9.1 PROFIBUS DP

Manufacturer ID: 0x08EC.

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 370 · Edition 01.19 74

Page 75

185

154

138

ø 5

Technical data

200

170

154

9.2 Operating controls and dimensions

A: 2-digit 7-segment display

B: Off switch, deactivates the BCU, outputs are discon-

nected from the electrical power supply

C: Reset /Information button to reset the system after

a fault, to scan parameters on the display or to control manual operation

D: Optical interface

E: BCU label with the most important status messages

in English Additional stickers in D, F, I, NL and E enclosed

185

ø 5

BCU 370 · Edition 01.19 75

138

Page 76

Technical data

9.3 Converting units

See www.adlatus.org

BCU 370 · Edition 01.19 76

Page 77

Legend

10 Legend

Display

Blinking display

Ready

Safety interlocks (limits)

Start-up signal

Controlled air ﬂow

Ignition transformer

Gas valve

Flame signal

Operating signal

Fault signal

Reset

Input signal Output signal Flame simulation check

Pressure switch

(DL for air, DG for gas)

Ignition/Ignition position

Three-point step controller

Actuator (in connection diagram)

BCU 370 · Edition 01.19 77

Page 78

Glossary

11 Glossary

11.1 Safety shut-down

The burner control unit performs a safety shut-down

immediately after receiving a signal from a safety device or after a fault is detected (e.g. ﬂame or air pressure

failure). The safety shut-down prevents operation of the

burner by closing the fuel shut-off valves and deactivating the ignition device.

For this, the BCU disconnects the gas valves and the ig-

nition transformer from the electrical power supply. The operation signalling contact and the controller enable signal are deactivated. The fault signalling contact remains open. The display blinks and displays the current program step, see page 37 (Fault message (blinking)).

After a safety shut-down, the BCU can restart auto-

matically.

11.2 Fault lock-out

A fault lock-out is a safety shut-down with subsequent

lock-out. The system can only be restarted following manual reset. The protective system cannot be reset by mains failure.

In the event of a fault lock-out of the BCU, the fault signalling contact closes, the display blinks and shows the current program step, see page 37 (Fault message (blinking)). The gas valves are disconnected from

the electrical power supply. The fault signalling contact opens if the mains voltage fails.

In order to restart, the BCU can only be reset manually using the button on the front panel, the OCU or the remote reset input (terminal 3).

11.3 Warning signal

The BCU reacts to operating faults, e.g. in the case of

permanent remote resets, with a warning signal. The display blinks and shows the corresponding warning message. The warning signal ends once the cause has been eliminated.

The program sequence continues. No fault signal is ac-

tivated.

11.4 Timeout 25 s/250 s

For some process faults, a timeout phase elapses before the BCU reacts to the fault. The phase starts as soon as the BCU detects the process fault and ends after 25 to 250 s. A safety shut-down or fault lock-out is then performed. If the process fault ends during the timeout phase, the process continues as before.

BCU 370 · Edition 01.19 78

Page 79

Annex

12 Annex

12.1 Status and fault messages for PROFIBUS DP

This table can be used to program the master.

Input bytes (BCU ➔ master)

Byte 2 Byte 0, Bit 2 = 0 (Status message) Byte 0, Bit 2 = 1 (Fault message)

0 0 Star t-up position/standby 1 A0 Valve moves to Closed position 01 Flame simulation 2 01 Fan run up time 3 A1 Butter ﬂy valve moves to Open position 4 P1 Pre-purge time 04 Start-up without ﬂame signal 5 A2 Butter ﬂy valve moves to Ignition position 05 Flame failure during 1 6 03 Pre-ignition time 06 Flame failure during 2

7 04 1 8 05 1 9 06 2 10 07 2

safety time on start-up 07 Flame failure during 2nd ﬂame proving period

ﬂame proving period 08 Flame failure during operation

safety time on start-up

ﬂame proving period d0 Fault Air monitor break contact check 11 08 Controller enable signal d1 Fault Air monitor make contact check 12 P9 Post-purge time d2 Fault Air supply while butterﬂy valve moves to Ignition position 13 d3 Fault Air supply during pre -ignition time 14 d4 Fault Air supply during 1 15 d5 Fault Air supply during 1 16 d6 Fault Air supply during 2 17 d7 Fault Air supply during 2 18 d8 Fault Air supply during operation 19 dP Fault Air supply during pre-purge time

ﬂame proving period

safety time

safety time on start-up

ﬂame proving period

safety time on start-up

ﬂame proving period

▼

BCU 370 · Edition 01.19 79

Page 80

Annex

Input bytes (BCU ➔ master)

Byte 2 Byte 0, Bit 2 = 0 (Status message) Byte 0, Bit 2 = 1 (Fault message)

20 u0 Fault DG 21 u1 Fault Dg 22 u2 Fault DG 23 u3 Fault DG 24 u4 Fault DG 25 u5 Fault DG 26 u6 Fault DG 27 u7 Fault DG 28 u8 Fault DG 29 u9 Fault DG 30 o0 Fault DG 31 o1 Fault DG 32 o2 Fault DG 33 o3 Fault DG 34 o4 Fault DG 35 o5 Fault DG 36 o6 Fault DG 37 o7 Fault DG 38 o8 Fault DG

during standby

min

while butterﬂy valve move s to Open position

min

while butterﬂy valve move s to Closed position

min

during pre-ignition time

min

during 1st safety time on start-up

min

during 1st ﬂame proving period

min

during 2nd safety time

min

during 2nd ﬂame proving period

min

during operation

min

during post-purge time

min

in start-up position/standby

max

while butterﬂy valve move s to Open position

max

while butterﬂy valve move s to Closed position

max

during pre-ignition time

max

during 1st safety time during operation

max

during 1st ﬂame proving period

max

during 2nd safety time during operation

max

during 2nd ﬂame proving period

max

during operation

max

▼

BCU 370 · Edition 01.19 80

Page 81

Annex

Input bytes (BCU ➔ master)

Byte 2 Byte 0, Bit 2 = 0 (Status message) Byte 0, Bit 2 = 1 (Fault message)

max

39 o9 Fault DG 40 A0 Butterﬂy valve closed position not reached 41 A1 Butterﬂy valve open position not reached 42 A2 Butterﬂy valve ignition position not reached 50 10 Too many remote resets 58 bE Bus module error 61 31 CRC error: Parameter 62 32 Undervoltage 63 33 EEProm parameter exceeds limit valvue 65 35 Fault Valve feedback 66 36 Tightness control: V1 leaking 67 37 Tightness control: V2/ V3 leaking 80 50 Safety interlock failure 82 52 Permanent remote reset 83 53 Timing cycle too short

min

85 55 DG

oscillating 86 56 Open + Close set simultaneously 99 99 Internal error 100 H0 Switch-on delay time/pause time 104 C1 Controlled air ﬂow 108 H8 Controller enable signal delay time

during post-purge time

BCU 370 · Edition 01.19 81

Page 82

Feedback

ascas

ascasc

Kromschröder AG

Michael Rehkamp

m.rehkamp@kromschroeder.com

Osnabrüc

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Contact

Elster GmbH Postfach 2809 · 49018 Osnabrück Strotheweg 1 · 49504 Lotte (Büren)

Germany Tel. +49 541 12140

Fax +49 541 1214370 hts.lotte@honeywell.com

ww w.kromschroeder.com

BCU 370 · Edition 01.19

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The current addresses of our international agents

are available on the Internet: https://thermalsolutions.honeywell.com ➔ contact us

We reserve the right to make technical modiﬁcations in the interests of progress.

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