nuway Nu-Way NG15 Gas Burner 1 Phase, Nu-Way NG15 Gas Burner 1 Phase H/L, Nu-Way NG15 Gas Burner 3 Phase, Nu-Way NG15 Gas Burner 3 Phase H/L, Nu-Way NG25 Gas Burner 1 Phase User guide

Installation & Maintenance Manual

Series NG fully automatic gas burner

Models NG15, 25 & 35

Gas Burner

Tel: [phone] Fax: [phone] Email: [e-mail] Web: www.nu-way.co.uk

Contents

IMPORTANT - SAFETY ....................................................................................................... 3

UROPEAN BOILER EFFICIENCY DIRECTIVE (B.E.D.) ............................................................... 3

E
B

URNER & COMPONENT IDENTIFICATION FOR NGN15 O/O................................................. 4

URNER & COMPONENT IDENTIFICATION FOR NGN15 & 25 H/L ......................................... 6

B

URNER & COMPONENT IDENTIFICATION FOR NGN35......................................................... 8

B
F

EATURES .................................................................................................................... 10

Burner Capacity ............................................................................................................................. 10

Air Regulation ................................................................................................................................ 10

Controls......................................................................................................................................... 10

Operation...................................................................................................................................... 10

Fuel ............................................................................................................................................... 10

Weight .......................................................................................................................................... 10

GENERAL ..................................................................................................................... 10

Flue And Chimney Requirements ...................................................................................................10

Plant Room Ventilation .................................................................................................................. 10

Existing Appliances ........................................................................................................................ 10

Combustion Chamber Conditions .................................................................................................. 11

PACKAGING FOR TRANSIT ............................................................................................... 11

Assembly ....................................................................................................................................... 11

SERVICES & SITE CONDITIONS ......................................................................................... 11

Gas Supply .................................................................................................................................... 11

INSTALLATION ............................................................................................................... 11

General ......................................................................................................................................... 11

Fitting To The Appliance ................................................................................................................ 11

Electrical Power Supply.................................................................................................................. 11

Wieland 7 and 4 Pin Connections .................................................................................................. 13

BURNER AIR CONTROLS ................................................................................................. 14

Single Stage (On/Off) Burner Only ................................................................................................. 14

Two Stage (High/Low) Burners........................................................................................................ 14

Air Diffuser .................................................................................................................................... 14

Air Pressure Switch ........................................................................................................................ 14

BURNER GAS CONTROLS ................................................................................................ 14

Gas Nozzle .................................................................................................................................... 14

High Gas Pressure Switch (High/Low Only) .................................................................................... 14

Low Gas Pressure Switch ............................................................................................................... 14

Gas Valve Multibloc - Single Stage (On/Off) NGN15 ....................................................................... 14

Gas Valve Train - Single Stage (On/Off) NGN25 & 35 ..................................................................... 14

Two Stage (High/Low) NGN15, 25 & 35......................................................................................... 14

Air Damper Motors ........................................................................................................................ 15

Valve Adjustment Diagram - Dungs Gas Valve NGN15 On/Off ....................................................... 16

Valve Adjustment Diagram - Landis & Staefa SKP7x Gas Valve High/Low Burners .......................... 17

Valve Adjustment Diagram - SKP2x Gas Valve NGN25 & 35 On/Off.............................................. 18

CONTROLS .................................................................................................................. 18

LAME MONITOR.......................................................................................................... 18

F
B

URNER OPERATING SEQUENCE ....................................................................................... 18

Single Stage (On/Off) Burners ........................................................................................................ 18

Two Stage (High/Low) Burners........................................................................................................ 18

Air/Gas Ratio Controller - Two Stage (High/Low) ............................................................................. 19

Initial Burner Setting - Two Stage (High/Low) .................................................................................. 19

Air/Gas Ratio Controller ................................................................................................................. 19

Model NGN15/25/35Page 2

Start Rate Gas Governor (excluding NGN15 (On/Off)) .................................................................... 20

BURNER DRY RUN ........................................................................................................ 20

B

URNER LIVE RUN - COMMISSIONING ............................................................................... 20

Check For Valve Closure. ............................................................................................................... 20

Natural Gas Supply Pressures ......................................................................................................... 22

ESTABLISHING MAIN FLAME ............................................................................................. 22

Measuring Gas Flow ...................................................................................................................... 22

Dungs Multibloc (NGN15 On/Off) ................................................................................................. 22

Landis & Staefa SKP2x (NGN25 & 35 On/Off) ............................................................................... 22

Landis & Staefa SKP7x High/Low Burners...................................................................................... 23

BURNER START GAS RATE ............................................................................................... 23

Check Flame Signal ....................................................................................................................... 23

Air Pressure Switch Setting ............................................................................................................. 24

High Gas Pressure Switch Setting (High/Low only) .......................................................................... 24

Low Gas Pressure Switch Setting .................................................................................................... 24

FINAL CHECK ............................................................................................................... 24

Commissioning Is Now Complete .................................................................................................. 24

ROUTINE SAFETY CHECKS ............................................................................................... 25

Flame Detection System ................................................................................................................ 25

Flame Probe (Flame Rectification Rod) ...........................................................................................25

UV (Ultra-Violet) Cell ..................................................................................................................... 25

ROUTINE MAINTENANCE................................................................................................. 25

AULT FINDING ............................................................................................................ 25

F
S

PARE PARTS IDENTIFICATION .......................................................................................... 26

Motor & Fan - Removal ................................................................................................................. 26

APPENDIX .................................................................................................................... 27

Combustion Head Details for NGN15 ............................................................................................ 27

Combustion Head Details for NGN15(High/Low) & NGN25 .......................................................... 28

Combustion Head Details for NGN35 ............................................................................................ 29

Gas Supply Pressure Graph for NGN15 with Dungs Control Train ................................................... 30

Gas Supply Pressure Graph for NGN15 with Landis & Staefa Control Train ..................................... 31

Gas Supply Pressure Graph for NGN25 with Landis & Staefa Control Train ..................................... 32

Gas Supply Pressure Graph for NGN35 with Landis & Staefa Control Train ..................................... 33

COMMISSIONING SHEET ................................................................................................. 34

OTES ....................................................................................................................... 35

N

II

MPORTMPORT

I

MPORT

MPORTMPORT

II

It is essential that the following instructions and adjustments are carried out by qualified engineers that
are experienced in blown gas burner commissioning. In the U.K. it is a legal requirement that anyone
working on gas installation, as defined in the “Gas Safety (Installation & Use) Regulations 1994” is
CORGI registered. The manufacturer cannot be held responsible for any consequential damage, loss or
personal injury as a result of failure to follow these instructions, or as a result of misuse. Your attention

is drawn to the Emergency Instructions on Page 20.

EE

UROPEANUROPEAN

E

UROPEAN

UROPEANUROPEAN

EE

All burners and boiler bodies marketed seperately should comply with EN676 - Gas Buirners and EN303

- Heating Boilers. Burner adjustments must be made in accordance with boiler manufacturers’ instruc­tions. and these must include flue gas temperatures, average water temperature, and CO2 or O2 concen­tration.

ANTANT

ANT

ANTANT

- S - S

- S

- S - S

B B

B

B B

AFETYAFETY

AFETY

AFETYAFETY

OILEROILER

OILER

OILEROILER

E E

FFICIENCYFFICIENCY

E

FFICIENCY

FFICIENCYFFICIENCY

E E

D D

IRECTIVEIRECTIVE

D

IRECTIVE

IRECTIVEIRECTIVE

D D

(B.E.D.) (B.E.D.)

(B.E.D.)

(B.E.D.) (B.E.D.)

Model NGN15/25/35

Page 3

BB

URNERURNER

B

URNER

URNERURNER

BB

& C & C

& C

& C & C

OMPONENTOMPONENT

OMPONENT

OMPONENTOMPONENT

I I

DENTIFICDENTIFIC

I

DENTIFIC

DENTIFICDENTIFIC

I I

Standard Burner Arrangement Shown

metInoitpircseD

1 gnisaCrenruB

AA

TIONTION

A

TION

AA

TIONTION

F F

F

F F

NGN15 O/O NGN15 O/O

OROR

OR

NGN15 O/O

OROR

NGN15 O/O NGN15 O/O

2 noisnetxEdegniH

3 ebuTemalF

4 rotoMnaF

5 telnIriA

6

7 slortnoCrenruB

8 lenaplortnoC

9 hctiwSerusserPriA

01 evlaVcolbitluMsaG

BURNER MOUNTING

DETAIL

erusserPsaGwoL

hctiwS

4 OFF M12 x 40

PROJECTION

STUDS

CD

7 P

9

1

45°

HOLE Ø168

240

9

10

6

4

369

200

Model NGN15/25/35Page 4

1

80

1

1.1/4 BSP

8

7

00

305

5

BURNER

740

1

2

PROJ’N

3

100

210

Model NGN15/25/35

Page 5

BB

200

URNERURNER

B

URNER

URNERURNER

BB

& C & C

& C

& C & C

OMPONENTOMPONENT

OMPONENT

OMPONENTOMPONENT

I I

DENTIFICDENTIFIC

I

DENTIFIC

DENTIFICDENTIFIC

I I

AA

TIONTION

A

TION

AA

TIONTION

F F

F

F F

Standard High/Low Burner Arrangement Shown

metInoitpircseD

1 gnisaCrenruB

2 noisnetxEdegniH

3 ebuTemalF

4 rotoMnaF

5 telnIriA

6 rotoMrepmaDriA

7 slortnoCrenruB

8 hctiwSerusserPsaGwoL

9 hctiwSerusserPsaGhgiH

01 ydoBevlaVsaG

11 )x7PKS(evlaVlortnoCsaG

21 )x1PKS(evlaVsaGniaM

NGN15 & 25 H/L NGN15 & 25 H/L

OROR

OR

NGN15 & 25 H/L

OROR

NGN15 & 25 H/L NGN15 & 25 H/L

BURNER MOUNTING

DETAIL

CD

7 P

9

1

45°

31 evlaVsaGdioneloStoliP

41 ronrevoGsaGtoliP

51 lenaPlortnoCrenruB

61 hctiwSerusserPriA

555

4 OFF M12 x 40

PROJECTION

STUDS

HOLE Ø168

16

330

6

4

Model NGN15/25/35Page 6

470

11

1

5

25

480

10

11

12

8

13

7

15

14

NGN15 = 1.1/2” BSP

NGN25 = 2” BSP

9

5

BURNER

765

1

118

305

2

PROJ’N

3

100

226

Model NGN15/25/35

Page 7

BB

1

88

URNERURNER

B

URNER

URNERURNER

BB

& C & C

& C

& C & C

OMPONENTOMPONENT

OMPONENT

OMPONENTOMPONENT

I I

DENTIFICDENTIFIC

I

DENTIFIC

DENTIFICDENTIFIC

I I

AA

TIONTION

A

TION

AA

TIONTION

F F

F

F F

NGN35 NGN35

OROR

OR

NGN35

OROR

NGN35 NGN35

Standard Burner Arrangement Shown

9

3

480

2

5

5

16

1

14

13

15

6

4

32

2” BSP

8

105

BURNER

PROJ’N

140

11

470

811

12

7

260

10

Model NGN15/25/35Page 8

G

metInoitpircseD

1 gnisaCrenruB

2 noisnetxEdegniH

3 ebuTemalF

4 rotoMnaF

5 telnIriA

6 rotoMrepmaDriA

7 slortnoCrenruB

8 hctiwSerusserPsaGwoL

9 hctiwSerusserPsaGhgiH

01 ydoBevlaVsaG

11 )x7PKS(evlaVlortnoCsaG

21 )x1PKS(evlaVsaGniaM

25

BURNER MOUNTIN

DETAIL

CD

P

4

31 evlaVsaGdioneloStoliP

41 ronrevoGsaGtoliP

51 lenaPlortnoCrenruB

61 hctiwSerusserPriA

8 OFF M10 x 35

PROJECTION

STUDS

555

HOLE Ø200

210

Model NGN15/25/35

363

Page 9

FF

EAEA

TURESTURES

F

EA

TURES

EAEA

TURESTURES

FF

Burner Capacity

NGN15 210kW to 450kW
NGN25 400kW to 635kW
NGN35 430kW to 1090kW
Developed from field experiences in the UK and

overseas markets, the NG series sets new stand­ards in efficient and reliable operation, having been
developed to current and future test authority re­quirements in UK and overseas markets. It is deliv­ered ready to install with prewired packaged con­trol system and simple plug in gas train arrange­ments.

Air Regulation

Air for combustion can be adjusted to give maxi­mum efficiency. A patented air control device pro­duces smooth start conditions. A fully closing air
control is fitted as standard on the two stage (high/
low) burner, and is an optional extra on the single
stage (on/off) burner.

Controls

Flame supervision is by ionisation probe or UV cell,
and automatic sequence control.

Operation

Single and two stage operation (on/off and high/
low).

Fuel

Natural Gas at 17.5mbar up to 850kW, 25mbar up
to 1090kW. Special requirements on request - i.e.
Liquid Petroleum Gas / Town Gas.

Weight

NGN15 & 25 70kg approx.
NGN35 80kg approx.

This manual is structured to enable the user to pro­ceed from the delivery of the burner to its commis­sioning and use.

The conditions to be fulfilled and the controls and
adjustments to be used are dealt with in the se­quence that should be followed for the correct as­sembly installation and use. Burner Dry Run and
Burner Live Run - Commissioning are described and
the location of necessary controls and adjustments
to undertake these runs are illustrated and sup­ported by appropriate tabular matter and graphs.

Routine Maintenance, Fault Finding and Spare Parts
Identification complete the manual; literature on

proprietary components is available on request.

Flue And Chimney Requirements

The top of the Chimney/Flue should be above all
roofs within a radius of 10 metres.

Check that it is suitable for use with gas fired appli­ances. Reference should be made to Local Author­ity and other regulations governing such installa­tions. Ensure that the flue pipe from the appliance
does not protrude into the chimney beyond the
wall thickness and is sealed throughout its run.

If more than one appliance is connected to a com­mon flue/chimney, ensure that the cross section of
the flue/chimney is adequate for the total volume
of flue gases from all the appliances.

Plant Room Ventilation

An adequate dust free supply of fresh air is required
for the burner at both high and low level in ac­cordance with the appropriate standards.

Existing Appliances

In preparing the appliance to receive gas burner a
careful inspection should be made of its condition.
If in doubt as to its suitability for gas firing refer to
the appliance manufacturer. In preparing the ap­pliance for gas firing it should be cleaned thoroughly
removing all adhering tars, scale and dirt.

GG

ENERALENERAL

G

ENERAL

ENERALENERAL

GG

The NG15-NG35 burner is supplied for single stage
(On/Off) or two stage (High/Low) operation and
for use with single phase or three phase electrical
supply. Where an instruction or information is ap­plicable to only one of the burner types, single or
two stage, then this is indicated in the text.

Model NGN15/25/35Page 10

Combustion Chamber Conditions

When the burner is fitted to an appliance designed
to work under balanced or negative combustion
chamber conditions, the over-fire draught must not
exceed 0.25 mbar.

PP

ACKACK

ACK

ACKACK

AGINGAGING

AGING

AGINGAGING

P

PP

To safeguard against transit damage and for Export
shipment, the burner may be despatched in partly
assembled form in one of two modes.

F F

F

F F

OROR

OR

OROR

T T

T

T T

RANSITRANSIT

RANSIT

RANSITRANSIT

Mode One: Comprising Two Units

a) Burner body, complete with control package.
b) Gas train complete with hinged extension and
flame tube assembly.

Mode Two: Comprising Three Units

SS

ERVICESERVICES

S

ERVICES

ERVICESERVICES

SS

& S & S

& S

& S & S

ITEITE

ITE

ITEITE

C C

ONDITIONSONDITIONS

C

ONDITIONS

ONDITIONSONDITIONS

C C

Gas Supply

The gas supply to the burner must be constructed
and installed to comply with local conditions and
appropriate Codes and Standards. It should be of
sufficient size to satisfy the pressure/volume require­ments of the burner to ensure its operation.

It is essential that a 90° manual shut-off is fitted
upstream of the burner gas train for the isolation of
the burner during servicing and maintenance.

a) Burner body, complete with control package.
b) Gas train complete with hinged extension and
flame tube assembly.
c) Units are turned through 180° for transit.

Assembly

Mode One (NGN35)

Fit the gas valve train to the hinged extension using
the gasket provided. Ensure the gasket is fitted cor­rectly with all holes corresponding with those on
the burner flange (connect the air inlet/ impulse
pipe from the SKP7x gas valve to left hand side of
the hinged extension (two stage burners only)).

Connect the multi-pin plug from the gas valve train
to the socket located on the rear of the control
package on the left of the burner body.

Mode Two (NGN15 & 25)

Fit the hinged extension and flame tube assembly
to the burner body with the four studs provided.
Ensure the gas inlet flange is at the bottom. Fit the
gas valve train to the hinged extension, with the
four studs using the gasket provided. Ensure that
the gasket is fitted correctly with all holes
corresponding to those on the burner flange.
Connect the air impulse pipe from the SKP7x gas
valve to left hand side of hinged extension (two
stage burners).

The ignition electrode cable, probe (if fitted) and
earth leads are inserted through an aperture in the
base of the casing throat.

Open the hinged extension. Connect the earth lead
under the inner assembly fixing screw, probe lead
(brown) to the flame probe and connect the igni­tion cable to the electrode. Close the extension.

The valve size must not be less than the NG burner
valve train or create restriction to gas flow.

II

NSTNST

ALLALL

AA

ALL

ALLALL

TIONTION

A

TION

AA

TIONTION

I

NST

NSTNST

II

The burner is now completely assembled and ready
for fitting to the appliance.

General

Check that the burner is appropriate for appliance
rating. Detailed burner performance data is given
in the Appendix at the back of this handbook.

Fitting To The Appliance

If the burner is to be fitted to a new packaged unit,
refer to the manufacturers recommendations.

If the burner is to be used with an existing appli­ance prepare the mounting flange as detailed in
the Burner And Components Identification section.
Ensure the joint between appliance and burner is
effectively sealed with the gasket provided.

The flame tube should be flush with the inner face
of the appliance combustion chamber except
where extensions are specified by the appliance
manufacturer (i.e. reverse flame boilers).

Electrical Power Supply

Connect a single or three phase 50Hz electrical
supply to the burner observing all applicable IEE
Regulations. Refer to the connection diagram be­low or the wiring diagram contained in the instruc­tion pack attached to the burners.

If supplied as a packaged appliance/burner unit re­fer to the manufacturers instructions. Connect the
external auxiliary controls by reference to the wir­ing diagram on pages 12 & 13.

Connect the multi-pin plug from the gas valve train
to the socket located on the rear of the control
package on the left of the burner body.

Model NGN15/25/35

Page 11

SS

UPPLEMENTUPPLEMENT

UPPLEMENT

S

UPPLEMENTUPPLEMENT

SS

TOTO

TO

TOTO

H H

ANDBOOKSANDBOOKS

ANDBOOKS

H

ANDBOOKSANDBOOKS

H H

SS

PECIFICPECIFIC

PECIFIC

S

PECIFICPECIFIC

SS

SKP ASKP A

SKP A

SKP ASKP A
WW

W

WW

SKP ASKP A

SKP A

SKP ASKP A

A new range of valve actuators has been introduced by Siemens as an upgrade to the SKP range. The
new actuators SKP15, 25, 55 and 75, are replacements for the SKP10, 20, 50 & 70 which will
become obsolete. The new range of actuators will be introduced into the Nu-way range of Gas and
Duel Fuel Burners as from the 1st of June 2006.

The new range of SKP actuators have plug in connections so Nu-way can no longer use the actuators
as junction boxes and therefore a separate junction box will be introduced to gas trains (Similar to
valve proving configuration).

IRINGIRING

IRING

IRINGIRING

CTUCTU

CTU

CTUCTU

AA

TIONTION

A

TION

AA

TIONTION

AA

TORSTORS

A

TORS

AA

TORSTORS

CTU

C C

C

C C

CTUCTU

CTUCTU

C C

C

C C

HANGESHANGES

HANGES

HANGESHANGES

AA

TORTOR

A

TOR

AA

TORTOR

OLOL

OL

OLOL

OURSOURS

OURS

OURSOURS

UPGRADEUPGRADE

UPGRADE

UPGRADEUPGRADE

ANDAND

AND

ANDAND

N N

N

N N

EWEW

EW

EWEW

Spares supply for the SKP10, 20, 50 & 70 will continue until around January 2007 depending on
stock usage, in future the spares replacement for SKP valve actuators will be an upgrade kit
comprising of the new actuator plus the junction box and wiring harness to enable the fitting of the
SKP15, 25, 55 and 75 to burners originally fitted with the SKP10, 20, 50 & 70.

The new actuators are physically different however the function and adjustment remain the same,
they will fit all existing gas valves (VGD etc.) which are unaffected.

NN

N

NN

In accordance with the Requirements for Electrical Installations BS 7671:2001 Amendment No 2 (the
IEE wiring regulations), wiring colour coding has been amended to Brown (L) and Blue (N) for single
phase power circuits and Brown (L1) Black (L2) and Grey (L3) and Blue (N) in three phase power
circuits from 1 June 2006.

Full details of the changes can be found in Amendment No 2 (AMD 14905) to BS 7671:2001 - which
is a free download from the IEE website (www.iee.org/cablecolours). They are also within the new
version of BS7671:2001 (Incorporating Amds 1& 2) published on 31
Wiring Regulations can be identified by its brown cover.

EWEW

EW

EWEW

W W

W

W W

IRINGIRING

IRING

IRINGIRING

C C

C

C C

OLOL

OL

OLOL

OURSOURS

OURS

OURSOURS

st

March; this new version of the

Supplement SKP & Wiring.PMD

Revision 310506A

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Electrical Data Table

1234

L N

N/O AUXILLARY

CONTACT ON

MOTOR STARTER.

13

14

BR = BURNER RUN.
LO = LOCKOU T.

elbaC

2

)

mm(eziS

elbaC

2

)

mm(eziS

3PH)

LIMIT

INSTRUMENT

CONTROL

INSTRUMENT

1234

L1 N

L2 L3 L

T

p

T

p

*

5

L

6789

T

p

BR

(IF REQUIRED)

1110

12

LO

HIGH/LOW

INSTRUMENT

*

1 PH CONTROL CIRCUIT SUPPLY ON

3 PH BURNERS ONLY

IF NOT REQUIRED FIT 0.75mm (24/.20)
LINK BETWEEN L1 & L

13 14 15 16 1817

MULTI

BOOSTER

START

(IF FITTED) FOR CONNECTION OF

SINGLE

BOOSTER

START

OUTLET INLET

BOOSTER

INTERLOCKS

Wiring diagram for connection of burner to power supply

Model NGN15/25/35Page 12

WW

A

W

WW

IELIEL

IEL

IELIEL

ANDAND

AND

ANDAND

7 7

7

7 7

ANDAND

AND

ANDAND

4 P 4 P

4 P

4 P 4 P

ININ

IN

ININ

C C

ONNECTIONSONNECTIONS

C

ONNECTIONS

ONNECTIONSONNECTIONS

C C

Standard 4 and 7 pin European Packaged Boiler/Burner connections to DIN4791
Single (On/Off) and two stage (High/Low) control

7 PIN WIRING FOR SINGLE

STAGE BURNERS

NPEL

BURNER

B4 S3 T2 T1 N L T8 T7 T6 B5

B4 S3 T2 T1 N L T8 T7 T6 B5

N1 F2 N2

hh

P1 H1

TT T

SOCKET

APPLIANCE

PLUG

DDITIONAL 4 PIN

WIRING FOR TWO

STAGE BURNERS

H3 P2

S1

F1

NPE L

metInoitpircseDmetInoitpircseD

1F esuFylppuS 1N tnemurtsnIffO/nOecnailppA

2F tnemurtsnItimiLecnailppA 2N tnemurtsnIwoL/hgiHecnailppA

1H langiStluaFrenruB 1P retnuoCnuRsruoHgnitarepOrenruB

2H langiSgnitarepOrenruB 2P retnuoCnuRsruoHemalFhgiHrenruB

3H langiSemalFhgiHrenruB 1S hctiwSffO/nOylppuS

Model NGN15/25/35

Page 13

BB

URNERURNER

B

URNER

URNERURNER

BB

The air for combustion is controlled by an adjust­able air flap located inside the air inlet on the right
hand side of the burner viewed from the rear.

Its purpose is to regulate and control the volume of
combustion air flowing through the burner.

A A

A

A A

IRIR

IR

IRIR

C C

C

C C

ONTROLSONTROLS

ONTROLS

ONTROLSONTROLS

Single Stage (On/Off) Burner Only

Adjustable stops for locking the air control damper
in its final position are located beneath the cover
on the rear of the air inlet casing.

Two Stage (High/Low) Burners

Low Gas Pressure Switch

The low gas pressure switch is a requirement of
EN676 (Automatic forced draught burners for
gaseous fuels), and is fitted to all burners carrying
the CE mark. The switch may or may not be fitted
to non CE burners.

The low gas pressure switch is located on the inlet
side of the gas valve block on the left of the burner,
viewed from the rear. It is required to monitor inlet
gas pressure during the burner operating cycle. Gas
pressure failure will result in safe shutdown of the
burner. Final adjustment of this switch is described
in the section Burner Live Run - Commissioning.

Combustion air is controlled by a three position
servo motor. Positions for high and low flame air
are adjustable. A fully closed position is incorpo­rated for when the appliance temperature/pressure
is satisfied.

Air Diffuser

The air diffuser is fitted to the front end of the in­ner assembly and located within the flame tube.

It controls the volume of combustion air and cre­ates a pressure drop over the burner head to en­sure good fuel/air mixing and flame stability.

Air Pressure Switch

Located on the right side of the burner casing
viewed from the rear, it is required to prove ad­equate air flow throughout the burner operating
cycle. Flow failure at any stage following the first
few seconds of pre-purge will lockout the burner

BB

URNERURNER

B

URNER

URNERURNER

BB

G G

G

G G

ASAS

AS

ASAS

C C

ONTROLSONTROLS

C

ONTROLS

ONTROLSONTROLS

C C

Gas Nozzle

The gas nozzle is fitted to the front end of the inner
assembly and located in the flame tube. The holes
in the gas nozzle are designed to suit the output of
the particular burner model and gas type being
used.

Gas Valve Multibloc - Single Stage (On/Off)
NGN15

The gas valve is of the multibloc type incorporating
start rate, safety and main valves and pressure gov­ernor. Valve adjustments are detailed in the Valve
Adjustment Diagram on page 16.

Gas Valve Train - Single Stage (On/Off)
NGN25 & 35

The gas valve train includes start rate valve, main
gas safety shut-off valve, control valve complete
with governor, and start rate gas pressure governor.
Valve adjustments are detailed in the Valve Adjust-
ment Diagram on page 18.

Two Stage (High/Low) NGN15, 25 & 35

The two stage system includes an air/gas ratio con­troller, safety shut-off valve, and gas regulator in
the start rate line. Three factory-supplied impulse
pipes are connected to the ratio controller.

One pipe is connected to the burner hinged ex­tension and supplies air pressure to the ratio con­troller. A second pipe is connected downstream of
the valve set and supplies gas pressure to the ratio
controller. The third pipe is vented to atmosphere.
Valve adjustments are detailed in Valve Adjustment
Diagram on page 17.

High Gas Pressure Switch (High/Low Only)

A high gas pressure switch is fitted and prewired to
the gas train. This is so that if the gas pressure at
the burner head rises above the pressure at maxi­mum continuous running, the burner will lockout,
thus indicating a fault on the air/gas ratio valve.
The switch is factory set to the maximum position.
Final adjustment of this switch is described in the
section Burner Live Run - Commissioning.

Model NGN15/25/35Page 14

Air Damper Motors

Berger Lahr STM30 Q5

rhaLregreB

5Q03MTS

Berger Lahr STM 30 B2

maC

etatS

riAlluF

woL

emalF

riA

hgiH

emalF

riA

ffo-tuhS

maC

1°0

2°51

3°06

rhaLregreB

03MTS

yrotcaF

gnitteS

maC

etatS

riAlluF

ffo-tuhS

woL

emalF

riA

hgiH

emalF

riA

Note: The fully closed cam is factory set, and under normal circumstances

should not require further adjustment. Operation of the low and high flame air

switches is made by manually adjustable cams. A setting scale is provided at the

end of the cam stack for guidance, while adjustments are made using the screw

adjusters situated within the cam disk body (STM30 Q5), or with levers and fine

setting screw adjusters (STM30 B2).

maC

II°0

V°51

I°06

yrotcaF

gnitteS

Model NGN15/25/35

Page 15

Valve Adjustment Diagram - Dungs Gas Valve NGN15 On/Off

tnemtsujdAnoitpircseD

A

B .)revocdetulfevomeR(retsujdatfillaitinitsafevlaVniaM

C

D .hctiwserusserpsaGwoL

E .tnioPtseTerusserpmaertspU

F .tnioPtseTerusserpmaertsnwoD

G .etaresaercniotesiwkcolc-itnanruT.retsujdAetaRtoliP

H .staesevlavneewtebtnioPtseT

.erusserpesaercniotesiwkcolcnruT.tnemtsujdaronrevoG

.rabm02-4=egnaR

nrutdnawercsdaeheseehcnekcalS.tnemtsujdAsaGniaM

.nepootesiwkcolc-itnabonkdetulf

Model NGN15/25/35Page 16

Valve Adjustment Diagram - Siemens SKP7x Gas Valve High/Low Burners

COMBUSTION

ATMOSPHERE

tnemtsujdAnoitpircseD

1

2

3 .erehpsomtaotdetneV

4 .enilsagehtotnoitcennoC

5 .daehrenrubehttaylppusrianoitsubmocehtotnoitcennoC

6 .ekortsevlavehtfonoitacidnI

Model NGN15/25/35

erifhgih(oitarria/sagehtfonoitacidnidnatnemtsujdA

.)gnittes

ehtfotnemecalpsidlellarapehtfonoitacidnidnatnemtsujdA

.)gnitteserifwol(citsiretcarahc

Page 17

Valve Adjustment Diagram - SKP2x Gas Valve NGN25 & 35 On/Off

CC

ONTROLSONTROLS

C

ONTROLS

ONTROLSONTROLS

CC

The control package is fitted on the left of the burner
viewed from the rear. It includes a sequence con­trol box of the cyclic or thermal type depending
upon the application, a transformer and necessary
contactors, terminal strip, motor starter, on/off
switch and two neon lights. The amber light shows
“BURNER ON” and the red light illuminates when
the burner stops as a result of “EXCESS TEMPERA­TURE” in the appliance.

FF

LL

F

L

LL

FF

The flame probe (flame rectification probe) is lo­cated on the burner head and is required to super­vise the safe operation of the burner under all work­ing conditions. An ultraviolet cell is fitted as stand­ard on the NGN25 & 35 burners.

AMEAME

AME

AMEAME

M M

M

M M

ONITORONITOR

ONITOR

ONITORONITOR

Model NGN15/25/35Page 18

BB

URNERURNER

B

URNER

URNERURNER

BB

O O

O

O O

PERAPERA

PERA

PERAPERA

TINGTING

TING

TINGTING

S S

EQUENCEEQUENCE

S

EQUENCE

EQUENCEEQUENCE

S S

Single Stage (On/Off) Burners

The operating sequence begins with an air pre­purge on full air, then start rate gas flame which
when proved allows the burner to operate on main
flame, then to the “OFF” position after the heat
input is satisfied. The operation is determined by
demand of the appliance control instruments.

Two Stage (High/Low) Burners

The sequence begins with an air pre-purge on full
air, followed by start rate gas flame which when
proved allows the burner to operate on High/Low/
Off. The operation is determined by the demand
of the appliance control instruments.

metInoitpircseD

1 evlaVytefaSniaM

2

3 evlaVdioneloStoliP

4 ronrevoGsaGtoliP

rotalugeR&evlaVdenibmoC
ffO/nO=x2PKS
woL/hgiH=x7PKS

5

6 egnalFnoitcennoCrenruB

7 hctiwSerusserPsaGwoL

8 eborPgnisneSsaG

9 )ylnox7PKS(erehpsomtAoTtneV

01

hctiwSsaGerusserPhgiH

)ylnox7PKS(

eborPgnisneSriAnoitsubmoC

)ylnox7PKS(

Typical Gas Valve Arrangement with

Landis & Staefa Control Valves

Air/Gas Ratio Controller - Two Stage (High/Low)

The controller controls the gas pressure related to
the pressure of the combustion air so that the gas
to air ratio remains constant over the entire output
range of the burner. When using the controller, a
separate gas pressure governor is not required.

In installations with negative pressure in the com­bustion chamber, the air impulse pipe from the
burner to air/gas ratio valve must always be under
a positive pressure condition.

Model NGN15/25/35

Initial Burner Setting - Two Stage (High/Low)

Remove the cover from the air damper motor on
the end of the air inlet casing. Check and adjust
the cam positions (refer to settings on page 15).

Air/Gas Ratio Controller

Remove the small plate on top of the regulator and
keep it in a safe place. Set the air/gas ratio at 0.8
on the visual scale by adjusting the screw (1) anti­clockwise to increase, or clockwise to decrease.

Page 19

Set the air/gas ratio on the visual scale, adjusting
screw (2) to half a division on the ‘+‘ side of “0”.
Turn the adjusting screw clockwise to decrease., or
anticlockwise to increase.

Start Rate Gas Governor (excluding NGN15
(On/Off))

Remove the metal cap from the top and turn the
adjusting screw until it is approximately halfway
between maximum and minimum setting, clock­wise to increase, and anticlockwise to decrease.
Never adjust to its maximum limit.

IMPORTIMPORT

IMPORT

IMPORTIMPORT

It is essential that the following instructions and ad­justments are carried out by qualified engineers that
are experienced in blown gas burner commission­ing. In the U.K. it is a legal requirement that anyone
working on gas installation as defined in the “Gas
Safety (Installation & Use) Regulations 1994”, is
CORGI registered. The manufacturer cannot be held
responsible for any consequential damage, loss or
personal injury as a result of failure to follow these
instructions, or as a result of misuse.

EMERGENCY INSTRUCTIONSEMERGENCY INSTRUCTIONS

EMERGENCY INSTRUCTIONS

EMERGENCY INSTRUCTIONSEMERGENCY INSTRUCTIONS

This product has been designed and constructed to
meet all of the essential requirements of the GAS
APPLIANCE DIRECTIVE 90/396/EEC and under
normal circumstances should not give occasion to
any hazardous conditions. If such a condition should
occur during commissioning or subsequent use of
this product, be it a fault of the burner, the appliance
or of any instrument, machine or service in the
proximity of the burner, then the GAS and
ELECTRICITY supply to the burner should be
IMMEDIATELY ISOLATED until such time that the
fault has been investigated and rectified.

ANT - SAFETYANT - SAFETY

ANT - SAFETY

ANT - SAFETYANT - SAFETY

BB

URNERURNER

B

URNER

URNERURNER

BB

Check both gas and electricity supplies to the burner
are turned off. Remove the cover and fit a link be­tween terminals 2 & 3 of the low gas pressure switch.
Remove the control panel cover and open the low
flame hold link (two stage burners). Set the air pres­sure switch to minimum. Replace the control panel
cover. Momentarily switch on the burner and check
the motor rotation, which should be anticlockwise,
viewed from the motor end.

If the direction of rotation is incorrect, please refer
to Fault Finding to correct it. Switch on the burner.
Depending on the type of the control box, the
burner will go through its operating sequence

a) Immediately if it has previously been working
but switched off during a normal operating cycle.

b) On pressing the reset button on the control box.
The burner motor will run. If at this stage the burner

goes to lockout, please refer to page 26, Starting

Flame Failure Without Ignition.

Check that the ignition spark is present. For actual
timings refer to the Sequence Diagram and Timing
Chart on page 21.

If at this stage there is no ignition spark and the
burner goes to lockout, the air pressure switch may
require adjustment. Following the safety lockout
time (T3) the ignition spark should cease and the
burner go to lockout.

Switch off the electrical supply to the Burner. Re­move the Control Panel cover and close the Low
Flame Hold link. Replace the Control Panel cover.
Remove the temporary link between terminals 2 &
3 of the Low Gas pressure switch and refit and
secure the cover.

Safety system proved. Burner commissioning can
proceed. Switch off power to the burner.

D D

D

D D

RYRY

RY

RYRY

R R

R

R R

UNUN

UN

UNUN

Control Panel Links

The following procedures require access to three
links found inside the control panel. Switch off the
electricity supply to the burner and open the con­trol panel cover to access the links, they are marked
as follows.

kniLnoitpircseD

LCPkniLkcehCtoliP

CFLkcehCemalFwoL

CSFkcehClangiSemalF

Model NGN15/25/35Page 20

BB

URNERURNER

B

URNER

URNERURNER

BB

Re-check that the electrical wiring is complete and
complies with all Codes and Standards. Check fuses
are fitted and correctly sized.

Re-check that the gas pipework is correctly installed
and leakproof.

Check that the appliance is in a proper and safe
state to be fired (for instance, is there water in the
boiler?) Set the appliance controls to call for heat.

L L

L

L L

IVEIVE

IVE

IVEIVE

R R

R

R R

UNUN

UN

UNUN

- C - C

OMMISSIONINGOMMISSIONING

- C

OMMISSIONING

OMMISSIONINGOMMISSIONING

- C - C

Start

y

T1 T2

Run

Operation

Off

Read

For

Restart

Burner Motor

Ignition

Start Rate
Gas Valve

Main Gas Valve

(low flame on h/l)

High Flame

(h/l only)

T8

T3

T4

T5

T9

ecneuqeS

esahP

1T 0404030404egrup-erPriAnoitsubmoC

2T 3424 6 noitingi-erP

3T 33333 emiTtuokcoLytefaS

4T 5.21018 emalFniaMotetaRtratS-yaleD

5T 921emalFwoLotetaRtratS-yaleD

GMD

079

IMM

018

epyTrellortnoC

12BGL

-7GMT

3-04

T6

Ttotal

LFL

333.1

T7

noitpircseDecneuqeS

6T 621emalFhgiHotemalFwoL-yaleD

7T 0181egrup-tsoPriAnoitsubmoC

8T 5558 21kcolretnIhctiwSerusserPriA

9T 5.3675650819emiTtratSlatoT

latoTT 5.36756509601rellortnoCfoemiTelcyClatoT

Note: The pre-purge times shown refer to the control box only. The air damper control will extend the total burner

purge time up to 127 seconds depending upon the firing rate and air requirements of the appliance.

Sequence Diagram and Timing Chart

Check For Valve Closure.

The space between the upstream manual valve and
the gas train inlet should now be filled with gas at

All gas train assemblies are fully tested for function
and valve security before despatch. A test of the
gas valves is difficult without specialised testing
equipment. However, the following check can be
performed to test the security of the valve system.

Ensure the gas supply pipework to the burner gas
line inlet is sound and gas is available at the re­quired inlet pressure for the burner. Fit a manom­eter to the test point at the inlet to the upstream
main safety valve. Open the main upstream manual
valve for a few seconds, then close and secure the
gas supply.

inlet pressure. If the pressure remains stable over
one minute then this indicates that the valve train
is secure, but not necessarily in the main valve. If
the pressure decreases then this indicates that the
main and one other valve is leaking or that there is
a leak between the upstream manual valve and
the main gas valve.

Secure the upstream test point and fit the manom­eter to the test point situated between the main
and control valves. Check the reading on the ma­nometer, this should now show near atmospheric
pressure. Open the upstream manual valve and
look for an increase in pressure over one minute. If
no rise is detected, this indicates that the main valve
is closing correctly.

Model NGN15/25/35

Page 21

The next stage of the procedure requires the burner
to be momentarily started. Open the upstream
manual valve and switch the burner on. The burner
will attempt to start and will either establish a flame
(in which case switch the burner off immediately)
or 'lockout'. Isolate the electricity supply.

The space between the main and control valves
should be filled with gas at near inlet pressure. If
the pressure remains stable over one minute, this
indicates that the valve system is secure.

If the pressure decreases, this indicates that there
is a leak in the valve system and the valve train
assembly should be returned to the factory for a
full examination. Remove the manometer and close
the test point.

Natural Gas Supply Pressures

Refer to the gas supply pressure graphs on pages
30-33 of this manual. The supply pressure must
not exceed 100mb on all burners. All pressure
quotes are running pressures, not static.

Fit a manometer or other approved pressure meas­uring instrument at the test point on the upstream
side of the first safety shut-off valve. Open the main
isolating manual gas valve. Check there is adequate
gas pressure to enable commissioning to proceed.

EE

STST

ABLISHINGABLISHING

E

ST

ABLISHING

STST

ABLISHINGABLISHING

EE

M M

M

M M

AINAIN

AIN

AINAIN

F F

F

F F

LL

AMEAME

L

AME

LL

AMEAME

Measuring Gas Flow

These sections refer to the individual commis­sioning procedures for each type of gas valve. Ref­erence is made to checking flow rates at the gas
meter. This is the most accurate way of deter­mining throughputs and should be used when­ever possible.

Information regarding the burner head gas pressures
is shown on pages 30 to 33. These are intended as
a guide to initial burner settings, but should not be
relied upon to offer proof of actual throughputs.

IMPORTANT After each adjustment, gas flow rate
and flue gas analysis should be checked.

ALWAYS use approved test equipment.
NEVER rely on a visual inspection of the flame as a

guide to combustion quality.

Dungs Multibloc (NGN15 On/Off)

Refer to Valve Adjustment Diagram A on page 16.

Set the air control damper in an approximate posi­tion for the firing rate. This can be determined by
setting the damper at the same proportion as the
firing rate lies in relation to the performance graph
on page 30.

With a screwdriver slacken the cheesehead screw
on the main gas adjuster (C) and turn the fluted
knob clockwise to give minimum gas flow rate. Set
the gas inlet pressure switch to minimum.

Note: Should the burner lockout when establish­ing start and main flames then the probable cause
is air or inert gas in the gas line. This can be re­moved by purging the line through the pressure
test points located on the gas multibloc. Alterna­tively, there may be insufficient pressure on the gas
governor.

Switch the burner on and allow it to establish main
flame. Slowly turn the main gas adjuster (C) anti­clockwise to the fully open position. Keep a watch­ful eye on the CO content during this stage and
make adjustments to the air damper setting if the
CO content becomes excessive. It is possible at
this stage that the burner may be overfiring the ap­pliance with a resultant excess of CO.

Check the gas throughput at the gas meter. Ensure
that other appliances served by the same meter
are isolated when gas throughputs are being ad­justed.

With a screwdriver slowly adjust the gas governor
(A) to increase or decrease the gas volume through
the burner to the rate required for the appliance.
The adjuster is turned clockwise to increase
throughput.

With the gas flow rate set and the burner running
with a stable flame, a full flue gas analysis can be
performed.

Make adjustments to the air and gas settings to give
the required combustion analysis whilst the burner
is running on main flame.

Landis & Staefa SKP2x (NGN25 & 35 On/
Off)

Refer to Valve Adjustment Diagram on page 18.
Set the air control damper in an approximate posi-

tion for the firing rate, by setting the damper at the
same proportion as the firing rate lies in relation to
the performance graph on pages 32 & 33.

Close the upstream manual valve until it reaches
an opening of approximately 20%. Set the gas inlet
pressure switch to minimum. Switch the burner on
and allow it to establish main flame.

Model NGN15/25/35Page 22

Gradually open the upstream manual valve fully
keeping watch on the CO level. If the CO content
is excessive, adjust the gas regulator in the face of

the SKP2x or the air damper setting. It is possible
at this stage that the burner may be overfiring the
appliance with a resultant excess of CO.

Check the gas flow rate at the meter. Ensure other
appliances served by the same meter are isolated
during these checks. Gradually alter the gas rate by
turning the gas regulator screw on the face of the
SKP2x governor to satisfy the appliance rating. Ad­just the combustion air damper as necessary to keep
the CO content in check.

With the gas flow rate set and the burner running
with a stable flame, a full flue gas analysis can be
performed.

Make adjustments to the air and gas settings to give
the required combustion analysis whilst the burner
is running on main flame.

Landis & Staefa SKP7x High/Low Burners.

Refer to the Valve Adjustment Diagram on page

17. Set up the air damper for initial firing as fol­lows. Low flame air 15 °: High flame air 60°. Close
the upstream manual valve until it reaches an open­ing of approximately 20%.

Set the gas inlet pressure switch to minimum. Open
the low flame check link. Switch the burner on
and allow it to establish low flame. Gradually open
the upstream manual valve to the fully open posi­tion keeping a watchful eye on the CO level.

If the CO content is excessive, adjust the low fire
adjustment screw (2) on the SKP7x valve to achieve
acceptable figures. In extreme cases it is possible
to run out of adjustment on the low fire screw with­out achieving the desired results. If this happens
adjust the High Fire setting screw (1) to bring the
CO content down to an acceptable level.

Switch the burner off and close the low flame check
link. Restart the burner. Low flame will be estab­lished, expanding to main flame after the expiry of
period T6 on the control box timing chart.

It is important to monitor the flame visually during
the change from low to high. If the flame becomes
more compact, this indicates an excess of com­bustion air. If the flame becomes large and shape­less, this indicates an excess of fuel.

Both conditions are acceptable at this stage pro­viding that the burner remains stable and immedi­ate actions are taken to correct the situation. If in
doubt switch off the burner and adjust the High
Flame screw (1) on the SKP7x in the appropriate
direction.

With the burner stable on high flame, adjust the
High Flame screw (1) to bring the CO2 to an ac­ceptable figure. It is possible at this stage that the
burner may be overfiring the appliance with a re­sultant excess of CO.

With the burner firing at low flame, adjust the Low
Flame screw (2) on the SKP7x valve to bring the
CO2 content to an acceptable figure.

Adjustment of the Low Flame setting will have
marginal effect on High Flame. To achieve optimal
results repeat the above procedures on High and
Low flame several times until acceptable figures
are obtained without any further adjustment.

It should not be necessary to make any further ad­justments to the gas valve.

With the burner now running on high flame, the
gas throughput should be checked at the gas me­ter. Ensure that any other appliances served by the
meter are isolated during the checks. The gas rate
can be altered by adjusting the air damper open­ing in the appropriate direction. Similarly the low
flame throughput can be adjusted by altering the
low flame position of the air damper. Care should
be taken so as not to exceed the limits of the burner
performance envelope as shown on pages 31-33.

With the gas flow rate set for both Low & High flame
a final check should be made on the flue gases to
ensure they remain within acceptable limits.

BB

URNERURNER

B

URNER

URNERURNER

BB

Switch off the electrical supply to the burner, re­move the control panel cover, open the pilot check
link, and replace control panel cover.

Switch on the electrical supply to the burner and
allow the burner to establish start rate flame.

The start gas rate can now be adjusted by turning
the adjusting screw in the start gas pressure gover­nor clockwise to increase and anticlockwise to de­crease (SKP 2x & SKP 7x valve systems). Refer to
Valve Adjustment Diagram on page 16 for Dungs
Multibloc.

A start rate of approximately 25% is required of
Main Flame (On/Off burners) or High Flame (High/
Low burners)

S S

S

S S

TT

ARTART

T

ART

TT

ARTART

G G

G

G G

ASAS

AS

ASAS

R R

R

R R

AA

TETE

A

TE

AA

TETE

Model NGN15/25/35

Page 23

Ensure that the start gas rate does not exceed
30% of the high flame gas rate as measured at
the gas meter.

Too small a start gas rate will result in burner lockout
on changeover during the initial and final running.

Switch off the electrical supply, remove the control
panel cover, close the pilot check link, replace the
control panel cover. Open the main manual gas
valve.

Switch on the electrical supply to the burner.

Check Flame Signal

Switch off the burner. Remove the control panel
cover and open the flame signal check link.

Connect a DC. microammeter with a range of 0­10µA / 0-100µA to the test points either side of the
opened link.

Switch on the burner and observe the flame re­sponse signal on the microammeter. A steady read­ing in excess of 7µA (probe) or 15µA (UV cell) in­dicates that the burner is in a reliable run situation.

If the current recorded is too low, it may be due to
some maladjustment of the flame and intermittent
lockout may occur. Check and reset if necessary.
Refer to the Fault Finding section. Switch off the
burner and disconnect the microammeter. Close
the flame signal check link and control panel cover.

Air Pressure Switch Setting

Switch off the electrical supply to the burner.
Remove the air pressure switch cover. Fit a ma-

nometer to the pressure switch to check the actual
air pressure against the pressure switch dial set­ting.

Remove the control panel cover and disconnect
the low flame hold link to hold the burner in the
low flame position (two stage burners only).

Switch on the electrical supply and allow two stage
burners to establish low flame and single stage burn­ers to establish main flame.

Slowly turn the adjusting dial clockwise until the
flame is extinguished. The burner will go to lock­out.

Turn the dial one division anticlockwise and reset
burner lockout. The burner will then continue
through its cycle until either the start rate flame is
established or the burner goes to its lockout posi­tion.

If the burner goes to lockout repeat the procedure
once per burner cycle until the start rate flame is
established.

Allow the burner to cycle to low flame (two stage)
and main flame (single stage) and then turn the
adjusting dial a further two divisions anticlockwise.

Switch off the electrical supply to the burner, re­connect the low flame hold link, replace the con­trol panel cover and also the air pressure switch
cover, and remove the manometer.

High Gas Pressure Switch Setting (High/Low
only)

When the burner is finally commissioned, the gas
switch must be adjusted with the burner running.
Remove the cover, and move the dial in an anti­clockwise direction until the switch trips and the
pressure switch indicating light is illuminated (the
burner will shut down). Move the pressure switch
dial in a clockwise direction one division, fit the
cover, and reset the pressure switch via the button
situated on the pressure switch cover. The burner
will now restart.

Low Gas Pressure Switch Setting

The low gas pressure switch is wired in series with
the appliance controlling instruments and will cause
the burner to effect a ‘safety shut down’ if a loss of
inlet gas pressure is detected.

Isolate the burner and remove the gas pressure
switch cover. Switch on the electrical supply and
allow the burner to establish main flame.

Slowly turn the adjustment dial on the gas pres­sure switch clockwise until the flame is extinguished
and the burner shuts down. Turn the dial slowly
anticlockwise one division at a time until the burner
restarts and establishes main flame.

Recheck the performance and then turn the dial a
further two divisions anticlockwise. Switch off the
burner and replace the gas pressure switch cover.

FF

F

FF

Check that all the covers to components have been
replaced and that locking devices are properly se­cured. Check that the appliance control instruments
are set to safe limits.

INALINAL

INAL

INALINAL

C C

C

C C

HECKHECK

HECK

HECKHECK

Commissioning Is Now Complete

Switch on the electrical supply.
The burner will now operate until switched off: ­a) by controlling instruments of the appliance
b) manually
c) by power failure.

Model NGN15/25/35Page 24

Upon restoration of power, the burner will restart
automatically and follow sequence.

RR

OUTINEOUTINE

R

OUTINE

OUTINEOUTINE

RR

TO BE CARRIED OUT ONLY BY QUALIFIED AND
EXPERIENCED PERSONNEL.

Check that the plant room is ventilated at all times.
Frequently inspect the air inlet of the burner and

ensure that there are no obstructions to air flow.

S S

S

S S

AFETYAFETY

AFETY

AFETYAFETY

C C

C

C C

HECKSHECKS

HECKS

HECKSHECKS

Flame Detection System

Flame Probe (Flame Rectification Rod)

Switch off the electrical supply to the burner. Re­move control panel cover and open the flame sig­nal check link. Refit the control panel cover.

Switch on the electrical supply. Check that the
burner locks out at the end of the ignition cycle.

Switch off the electrical supply. Remove control
panel cover and close the flame signal check link.
Replace the control panel cover and switch on the
electrical supply. Reset lockout.

UV (Ultra-Violet) Cell

Switch off the power supply to the burner. Remove
the UV cell from the burner casing and cover the
quartz glass envelope to exclude any light. Do not
touch the quartz glass with fingers.

Switch on the power supply. Check that the burner
locks out at the end of the ignition cycle. Switch
off the power supply. Replace UV cell switch on
the power supply. Reset lockout.

Remove the split-pin from the base of hinge-pin
adjacent to the gas train and withdraw the hinge­pin from the hinged extension.

Open the hinged extension, disconnect the igni­tion electrode H.T. lead and if fitted the flame probe
lead.

Remove the cap head screw securing the inner as­sembly gas pipe to its manifold, note that the earth
lead for the ionisation probe is also fitted to this
point. Carefully withdraw the inner assembly from
the hinged extension.

Air Diffuser And Gas Nozzle

Clean using a stiff brush.

Ignition Electrode

Clean and check the electrode is not cracked or
worn. Renew if necessary.

Check the settings of the ignition electrode and
flame rectification probe, and reset if necessary.
Replace all components and covers, and secure all
fittings. The burner is now ready for operation.
Switch on the electricity supply and gas supply to
the burner.

Replacement of Control Valves SKP2x,
SKP7x and Dungs Multibloc

Should any of the above valves require replacing
due to mechanical or electrical failure, then the
burner will require re-commissioning to restore the
proper combustion and performance values. It is
essential that replacement of these components and
re-commissioning of the burner be undertaken only
by qualified combustion engineers.

RR

OUTINEOUTINE

R

OUTINE

OUTINEOUTINE

RR

Switch off electrical supply and gas supply to the
burner.

M M

AINTENANCEAINTENANCE

M

AINTENANCE

AINTENANCEAINTENANCE

M M

Combustion Air Fan

Clean the blades regularly with a stiff brush. Ac­cess is obtained through the burner top cover. Care
should be taken to avoid damaging the fan blades.
Check that the air inlet into the fan is clean.

Inner Assembly

Open the hinged extension as follows:­Remove the gas train multi-pin plug from its socket

on the control package (Landis & Staefa) or the
DlN plugs from the valve block itself (Dungs).

Model NGN15/25/35

FF

F

FF

Any modifications to the installation or component
settings resulting from actions suggested below may
require the re-establishment of the various settings
as indicated earlier in this manual.

F F

AA

ULUL

TT

T

TT

F

F F

INDINGINDING

INDING

INDINGINDING

A

UL

AA

ULUL

Burner Motor Fails To Start

Check:

• that the electrical supply is available and the

burner is correctly wired.

• all fuses for continuity and size.

• all control instruments are “calling for heat”.

• the gas train is electrically connected.

Page 25

• the control box is not locked out (e.g. signal

lamp faulty). (If the control box is locked out,
press the reset button).

• there is sufficient gas pressure.

• the burner probe is not earthed.

• the air pressure switch is in the “start” posi-

tion, as follows: -

a) Switch off the electrical supply. Remove the plug­in assembly from the control box base. Check for
an open circuit between the following terminals:

Satronic MMI / MMG - Terminals 5 & 7
Satronic DMG - Terminals 4 & 7
If there is continuity between terminals, turn the

dial on the air pressure switch fully anticlockwise
to the minimum setting.

If there is now an open circuit, the air pressure
switch is in order, otherwise the air pressure switch
is faulty and must be renewed.

b) Remove the plug-in assembly from the control
box base. Check for continuity between the fol­lowing terminals:

Satronic TMG 740 - Terminals 17 & 16
Landis & Staefa LFL 1.333 - Terminals 4 & 13
Landis & Staefa LGB - Terminals 3 & 6
If the air pressure switch is not in the start position,

turn the setting dial clockwise. If no continuity is
obtained, the air pressure switch is faulty and must
be renewed.

Starting Flame Failure Without Ignition

Check:

• The glass envelope of the U.V. cell is clean

and correctly positioned.

• The U.V. cell and its wiring.

• The air pressure switch is set correctly.

• The electrode is correctly set and the porce-

lain is not cracked.

• The ignition transformer is not faulty.

• The control box is not faulty.

Starting Flame Failure Without Flame

If the start rate flame is not properly established,
the safety circuit of the sequence controller will
cause lockout in one second.

The cause may be insufficient signal to the flame
detection device. Alternatively the flame signal
check link has been removed, or insufficient gas to
allow the flame monitoring device to take over and
signal the sequence controller to continue its cy­cle.

This may be remedied by adjusting the fast initial
lift of the downstream safety valve.

If an Ionisation Probe is fitted in place of the U.V.
cell check:

• The probe is correctly positioned.

• For bad earth continuity/faulty wiring.

• The ignition tranformer for crossed polarity.

• The Test Link has been closed.

Burner Fails To Establish Main Flame

Check:

• The low flame hold link has been closed.

• The gas valves are operating correctly.

• The combustion air is set correctly.

• There is sufficient gas.

• The control box is not faulty.

Burner Motor Only Runs Continuously

Check:

• That the air damper motor is correctly wired.

• That the air damper motor is not faulty.

Incorrect Rotation Of Burner Motor

Motor rotates clockwise viewed from the shaft end.
If the burner motor rotation is incorrect, the single
phase motor should be renewed. On three phase
motors, interchange any two phases. In normal cir­cumstances, this will correct the rotation.

SS

S

SS

Separate illustrated lists, containing an item number,
description and code number, are included in this
Section for the NGN15 - NGN35 Burners. The vari­ations on a component are included and care must
be taken when making any reference to a compo­nent to use the correct description and code
number.

PP

P

PP

AREARE

ARE

AREARE

P P

P

P P

ARTSARTS

ARTS

ARTSARTS

I I

DENTIFICDENTIFIC

I

DENTIFIC

DENTIFICDENTIFIC

I I

AA

TIONTION

A

TION

AA

TIONTION

Model NGN15/25/35Page 26

APPENDIX

Combustion Head Details for NGN15

metInoitpircseD

1 elzzoNsaGrenruB

2 ebuTemalFrenruB

3

4 edortcelEnoitingI

5

6 etalPresuffiD

7

8

9

01

gnitnuoMresuffiD

dutS

ylbmessArennI

woblE

fi(eborPnoitasinoI

)dettif

3.0

3.5

noitalusnIeborP

)dettiffi(eceiP

ylbmessArennI

5

gniRgnilaeS

ylbmessArennI

rotpadA

155 O/D

PROJECTION

115

146 DIA

135 DIA

96

45

U.V. CELL FITTED

OMITTED WHEN

IONISATION PROBE

8 x 4.0 DIA HOLES

2

8 x 8.0 DIA HOLES

6

8

71

6

13

4

7

9

5

10

Model NGN15/25/35

Page 27

Combustion Head Details for NGN15(High/Low) & NGN25

metInoitpircseD

1 elzzoNsaGrenruB

2 ebuTemalFrenruB

3

4 edortcelEnoitingI

5

6 etalPresuffiD

7

8

9

01

gnitnuoMresuffiD

dutS

ylbmessArennI

woblE

fi(eborPnoitasinoI

)dettif

noitalusnIeborP

)dettiffi(eceiP

ylbmessArennI

gniRgnilaeS

40

5

3.0

3.5

TUBE

PILOT

ylbmessArennI

rotpadA

160 O/D NGN25
155 O/D NGN15

PROJECTION

115

146 DIA

135 DIA

U.V. CELL FITTED

OMITTED WHEN

IONISATION PROBE

NGN15 = 8 x 4.0 DIA HOLES

NGN25 = 8 x 6.0 DIA HOLES

2

NGN15 = 8 x 8.0 DIA HOLES

96

45

6

71

NGN25 = 8 x 10.0 DIA HOLES

8

6

13

4

7

9

5

10

Model NGN15/25/35Page 28

Combustion Head Details for NGN35

J

metInoitpircseD

1 elzzoNsaGrenruB

2 ebuTemalFrenruB

3

4 edortcelEnoitingI

5

6 etalPresuffiD

7

8

gnitnuoMresuffiD

dutS

ylbmessArennI

woblE

ylbmessArennI

gniRgnilaeS

ylbmessArennI

rotpadA

40

5

3.0

3.5

TUBE

PILOT

ECTION

PRO

105

181 DIA

172 DIA

9045

12

152 DIA

HOLES IN FACE

12 x 6.4 DIA END

8 x 9.5 DIA HOLES

3

65

4

5

1

7

826

Model NGN15/25/35

Page 29

Gas Supply Pressure Graph for NGN15 with Dungs Control Train

40050

0

Burner Output (kW

)

2

0

CombinedBurnerHeadandLineLoss(mba

r

)

05101

5

C
o

m
b

u

s

t

i

o

n
C

h

a

m
b

e

r

R
e

s

i

s

t

a

n

c

e
(

m
b

a

r

)

4

(1inc

h)412(1

.

n

ch)

tanda

r

Burner PerformanceEnvelop

e

d

e

The total minimum supply pressure is obtained by summing the
combustion chamber resistance and the combined burner head
and line loss. A further 2.5 mbar should be added to allow for
manufacturing tolerances etc.

15

10

The burner output is based on a gross calorific value of natural
gas of 38.56 MJ/m

3

)

d

S

0

1

(

i

5

2

H

s

a

G

r

u

s

s

e

r

P

a

e

5

0

200 300

e

r

u

s

s

e

r

P

d

a

e

H

r

i

A

.

b

m

o

C

Model NGN15/25/35Page 30

Gas Supply Pressure Graph for NGN15 with Landis & Staefa Control Train

40050

0

BurnerOutput(kW

)

4

0

CombinedBurnerHeadandLineLoss(mba

r

)

0102030

C

o

m
b

u

s

t

i

o

n
C

h

a
m

b

e

r
R
e

s

i

s

t

a

n
c

e
(

m
b

a

r

)

BurnerPerformanceEnvelope

1

c

G

a

s

HeadPressur

e

C

omb

.Ai

r

HeadPress

ure

t

T

The total minimum supply pressure is obtained by summing the
combustion chamber resistance and the combined burner head
and line loss. A further 2.5 mbar should be added to allow for
manufacturing tolerances etc.

The burner output is based on a gross calorific value of natural
gas of 38.56 MJ/m

30

3

20

10

0

200 300

n

i

a

r

T

s

a

G

l

a

n

o

i

t

p

O

h

c

n

i

1

n

i

a

r

s

a

G

.

d

S

h

n

i

5

.

Model NGN15/25/35

Page 31

Gas Supply Pressure Graph for NGN25 with Landis & Staefa Control Train

55065

0

BurnerOutput(kW

)

2

0

CombinedBurnerHeadandLineLoss(mba

r

)

05101

5

C
o

m
b

u

s

t

i

o

n
C

h

a

m
b

e

r

R
e

s

i

s

t

a

n

c

e
(

m
b

a

r

)

BurnerPerformanceEnvelope

o

m

essur

The total minimum supply pressure is obtained by summing the
combustion chamber resistance and the combined burner head
and line loss. A further 2.5 mbar should be added to allow for
manufacturing tolerances etc.

The burner output is based on a gross calorific value of natural
gas of 38.56 MJ/m

15

10

3

e

n

i

L

s

a

G

l

a

n

o

i

t

p

O

h

c

n

i

5

.

1

S

h

c

n

i

2

G

C

e

n

i

L

s

a

G

.

d

t

e

H

s

a

r

i

A

.

b

r

u

s

s

e

r

P

d

a

r

P

d

a

e

H

e

e

5

0

350 450

Model NGN15/25/35Page 32

Gas Supply Pressure Graph for NGN35 with Landis & Staefa Control Train

1000120

0

BurnerOutput(kW

)

4

0

CombinedBurnerHeadandLineLoss(mba

r

)

0102030

C
o

m
b

u
s

t

i

o

n
C

h

a

m
b

e

r
R

e

s

i

s

t

a

n

c

e
(

m
b

a

r

)

o

r

P

s

r

The total minimum supply pressure is obtained by summing the
combustion chamber resistance and the combined burner head
and line loss. A further 2.5 mbar should be added to allow for
manufacturing tolerances etc.

The burner output is based on a gross calorific value of natural
gas of 38.56 MJ/m

30

3

20

10

0

400 600 800

n

i

a

r

T

s

a

G

l

a

n

o

i

t

p

O

h

c

n

I

5

.

1

Burner Performance
Envelope

n

i

a

r

T

s

Ga

.

d

t

S

h

c

n

I

2

e

r

u

s

s

e

r

P

d

a

e

H

s

a

G

m

C

a

e

H

i

A

.

b

e

u

s

e

r

d

Model NGN15/25/35

Page 33

COMMISSIONING SHEET

The details below are to be completed by the Commissioning Engineer

Installer’s Name : _________________________________________________________________

Address :________________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

Site Address : ____________________________________________________________________

_______________________________________________________________________________

_______________________________________________________________________________

Appliance : Type : ____________ Size : _____________ Serial No. : _____________

Burner : Type : ____________ Size : _____________ Serial No. : _____________

Commissioning date : _____________________________________

Guarantee Expiry date :____________________________________

Gas type : _______________________________________________

Gas Pressure upstream of main gas governor :

a) Standing : _____________________ mbar b) Running :______________________ mbar

Gas pressure at burner head __________________mbar _______________ in.w.g.

Gas rate __________________ m

3

_______________ ft3/hr

Heat input __________________MJ/hr _______________ Btu/h

CO __________________% _______________ %

CO

2

__________________% _______________ %

Gross flue gas temperature __________________°C _______________ °F

Ambient temperature __________________ °C _______________ °F

Nett flue gas temperature __________________°C _______________ °F

Efficiency __________________% _______________ %

Model NGN15/25/35Page 34

Enertech Limited,
P O Box 1,
Vines Lane
Droitwich,
Worcestershire,
WR9 8NA

Tel: [phone] Fax: [phone]
Email: [e-mail] Web: www.nu-way.co.uk