Nu-Way XGN Series User manual

Page 1
XGN Handbook
HANDBOOK
Series XGN fully automatic burners
Models XGN450 to XGN3000
Natural Gas
®

XGN HandbookPage 2
Contents
IMPORTANT - SAFETY ....................................................................................................... 5
EMERGENCY INSTRUCTIONS .............................................................................................. 5
EUROPEAN BOILER EFFICIENCY DIRECTIVE (B.E.D.) ............................................................... 5
IMPORTANT NOTICE ....................................................................................................... 5
BURNER & COMPONENT IDENTIFICATION ............................................................................ 6
COMBUSTION HEAD DETAILS ........................................................................................... 7
CONTROL PANEL & ELECTRICAL DATA................................................................................ 8
CONNECTING THE ELECTRICAL SUPPLY................................................................................ 9
FEATURES ................................................................................................................... 10
Air Regulation ......................................................................................................................................... 10
Controls & Operation .............................................................................................................................. 10
Fuel ......................................................................................................................................................... 10
GENERAL.................................................................................................................... 10
SERVICES & SITE CONDITIONS ....................................................................................... 10
Gas Supply .............................................................................................................................................. 10
Flue and Chimney Requirements ............................................................................................................ 10
Plant Room Ventilation ............................................................................................................................ 10
Existing Appliances .................................................................................................................................. 10
Combustion Chamber Conditions ........................................................................................................... 10
PACKAGING FOR TRANSIT .............................................................................................. 10
ASSEMBLY................................................................................................................... 10
INSTALLATION .............................................................................................................. 11
General ................................................................................................................................................... 11
Fitting to the Appliance ............................................................................................................................ 11
Electrical .................................................................................................................................................. 11
BURNER AIR CONTROLS ................................................................................................ 11
Air Diffuser .............................................................................................................................................. 11
Air Pressure Switch .................................................................................................................................. 11
BURNER GAS CONTROLS ............................................................................................... 11
Gas Nozzle .............................................................................................................................................. 11
Gas Pressure Switch ................................................................................................................................ 11
INTEGRATED VALVE PROVING SYSTEM ............................................................................... 11
Functional sequence ................................................................................................................................ 11
OPERATION ................................................................................................................ 12
COMMISSIONING THE BURNER ........................................................................................ 12
Check for Valve Closure .......................................................................................................................... 12
Gas Supply Pressures ............................................................................................................................... 12
Adjust IR Detector ................................................................................................................................... 12
ESTABLISHING MAIN FLAME ............................................................................................ 12
Measuring Gas Flow ................................................................................................................................ 12
MULTI-FUNCTIONAL DISPLAY.......................................................................................... 13
Microprocessor Burner Control Unit (MBC) ............................................................................................ 13
Entering the pass code. ............................................................................................................................ 13
Commissioning Procedure ...................................................................................................................... 14
Firing the burner ..................................................................................................................................... 14
FINAL ADJUSTMENTS ..................................................................................................... 15

Page 3
XGN Handbook
Setting the Air Pressure Switch ................................................................................................................ 15
Setting the Flame Signal ........................................................................................................................... 15
Setting the Low Gas Pressure Switch ....................................................................................................... 16
FINAL CHECK .............................................................................................................. 16
THE RWF40 MODULATION CONTROL ............................................................................ 16
Basic display ............................................................................................................................................ 16
To change the working set point. ............................................................................................................. 16
RWF40 Recommended Parameters ......................................................................................................... 17
To enter a new parameter ....................................................................................................................... 17
Configuration Values ............................................................................................................................... 17
MBC DISPLAYS .......................................................................................................... 18
Standby Display ....................................................................................................................................... 18
Operating Display ................................................................................................................................... 18
Information Display ................................................................................................................................. 18
Service Display ........................................................................................................................................ 18
ROUTINE SAFETY CHECKS .............................................................................................. 19
Flame Detection System (IRD Cell) .......................................................................................................... 19
ROUTINE MAINTENANCE ............................................................................................... 19
Combustion Air Fan ................................................................................................................................. 19
Inner Assembly ........................................................................................................................................ 19
Air Diffuser and Gas Nozzle .................................................................................................................... 20
Ignition Electrode .................................................................................................................................... 20
Replacement of Control Valve SKP2x ...................................................................................................... 20
FAULTFINDING............................................................................................................ 20
MBC Error Codes .................................................................................................................................... 20
Incorrect Rotation of Burner Motor ......................................................................................................... 21
Motor & Fan – Removal .......................................................................................................................... 21
Burner Motor Fails to Start ....................................................................................................................... 21
Starting Flame Failure Without Ignition .................................................................................................... 21
Starting Flame Failure Without Flame ...................................................................................................... 21
Burner Fails to Establish Main Flame ........................................................................................................ 21
IR Detector Possible faults ........................................................................................................................ 21
6FH Error - Failure of the air servo motor ................................................................................................ 21
6FH Error - Failure of the gas servo motor ................................................................................................ 22
SPARE PARTS ............................................................................................................... 22
BURNER PERFORMANCE CURVES ..................................................................................... 22
XGN650-23 ............................................................................................................................................. 23
XGN450-23 ............................................................................................................................................. 23
XGN1150-38 ........................................................................................................................................... 24
XGN1000-25 ........................................................................................................................................... 24
XGN1750-38 ........................................................................................................................................... 25
XGN1250-34 ........................................................................................................................................... 25
XGN2350-38 ........................................................................................................................................... 26
XGN2100-34 ........................................................................................................................................... 26
XGN3000-38 ........................................................................................................................................... 27
XGN2400-34 ........................................................................................................................................... 27
COMMISSIONING SHEET ................................................................................................ 28
BURNER SERVICE RECORD ............................................................................................. 29
NOTES ...................................................................................................................... 30

XGN HandbookPage 4

Page 5
XGN Handbook
IMPORTANT - SAFETY
It is essential that the following instructions and adjustments are carried out by qualified engineers that
are experienced in forced draught gas burner commissioning. In the UK 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 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.
EUROPEAN BOILER EFFICIENCY DIRECTIVE (B.E.D.)
All burners and boiler bodies marketed seperately within the European Union must comply with EN676
- Gas Burners, and EN303 - Heating Boilers. Burner adjustments must be made in accordance with
boiler manufactures instructions, and these must include flue gas temperatures, average water
temperature, and CO2or O2concentration.
IMPORTANT NOTICE
To protect the microprocessor fitted in the burner control unit, any action such as the fitting or removal
of plugs, valves or any other wiring should be carried out with the MBC isolated. Failure to comply with
this notice may result in damage to the MBC unit.

XGN HandbookPage 6
Burner
Projection
A
B
CDEF
G
H
K
J
L
M
N
8 off M10 x 35 Studs
Equispaced on P PCD
XGN1000 to XGN3000
4 off M12 x 40 Studs
Equispaced on P PCD
XGN450 & XGN650
123
13
12
11
10
4 5
6
7
89
16
15
14
Ø
Ø
N
Ø
Burner Weight Kg ABCDEFGHJKLMNP
XGN450-23 70 740 193 155 100 246 104 207 300 580 271 200 1½" 168 197
XGN650-23 70 740 193 160 100 246 104 207 300 583 271 200 2" 168 197
XGN1000-25 80 810 236 181 140 273 104 197 312 583 291 225 2" 200 254
XGN1150-38 133 1014 265 223 165 287 104 227 429 583 394 289 2" 230 305
XGN1250-34 107 957 265 223 165 287 104 227 385 583 333 269 2" 230 305
XGN1750-38 136 1014 265 255 165 287 104 227 429 583 394 289 2" 265 305
XGN2100-34 118 957 265 223 165 287 104 227 385 583 394 269 2" 230 305
XGN2350-38 171 1014 265 255 165 287 163 227 429 794 457 289 DN65 265 305
XGN2400-34 149 957 265 255 165 287 163 227 385 794 394 269 DN65 265 305
XGN3000-38 198 1014 265 255 165 287 163 227 429 859 457 289 DN65 265 305
BURNER & COMPONENT IDENTIFICATION
Item Description Item Description
1Flame Tube 9Electrical Panel
2Hinged Extension 10 Combined Gas Valve & Governor
3Burner Fan Casing 11 Gas Pressure Switch
4Differential Air Pressure Switch 12 Gas Safety Shut Off Valve
5Air Inlet Casting 13 Gas Control Valve & Motor
6Inspection Window 14 Ignition Transformer
7Multi-functionalDisplay Unit 15 Electrical Connection Plugs
8Burner Fan Motor 16 Air Inlet Control Motor

Page 7
XGN Handbook
COMBUSTION HEAD DETAILS
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Item Description Item Description
1Inner Assembly Elbow 7Inner Assy Fixing Screw
2Hinged Extension 8Gas Train Adaptor
3Ignition Electrode 9Diffuser Mounting Stud
4Gas Nozzle 10 Inner Assy Centralising Rail
5Flame Tube 11 Diffuser Plate
6Pilot Gas Tube
Burner ABCDEFGNozzle Side
Ports
Nozzle End
Ports
XGN450-23 71 96 135 155 146 168 19 8 x Ø8.0 8 x Ø4.0
XGN650-23 71 96 135 160 151 168 19 8 x Ø10.0 8 x Ø6.0
XGN1000-25 77 90 152 181 172 200 15 8 x Ø9.5 12 x Ø6.4
XGN1150-38 77 90 190 223 206 230 45 8 x Ø9.5 12 x Ø6.4
XGN1250-34 77 90 190 223 206 230 45 8 x Ø9.5 12 x Ø6.4
XGN1750-38 77 90 204 255 234 265 45 8 x Ø11.0 12 x Ø7.0
XGN2100-34 77 90 178 223 206 230 45 8 x Ø11.0 12 x Ø7.0
XGN2350-38 77 90 204 255 234 265 45 8 x Ø12.7 12 x Ø8.0
XGN2400-34 77 90 204 255 234 265 45 8 x Ø12.7 12 x Ø8.0
XGN3000-38 77 90 204 255 234 265 45 8 x Ø14.0 12 x Ø8.0

XGN HandbookPage 8
CONTROL PANEL & ELECTRICAL DATA
1
2
3
4
5
6
7
8
9
10
11
12
13
Item Description
1Microprocessor Burner Control Unit (MBC)
2Conduit Entry Comb
3Multifunctional Display Unit
4Motor Starter
5Control Circuit Fuses
6Terminals
7Power On Indicator
8Modulating Controller (Optional)
9Burner On/Off Switch
10 Voltage Free Contacts (Optional)
11 Wieland Plugs
12 Motor Overload
13 3 Phase Entry Point
3 Phase 400V/50Hz
Burner
Model
Motor
(kW/rpm)
Start
Current (A)
Full Load
Current (A)
Main
Fuse (A)
Cable
Size (mm2)
XGN450-23 0.75/2800 8.0 2.0 10 1.0
XGN650-23 0.75/2800 8.0 2.0 10 1.0
XGN1000-25 1.1/2800 9.0 2.7 10 1.0
XGN1150-38 3.0/2800 35 6.6 20 1.5
XGN1250-34 2.2/2800 25 5.0 16 1.5
XGN1750-38 4.0/2800 45 8.5 25 2.5
XGN2100-34 3.0/2800 35 6.6 20 1.5
XGN2350-38 5.5/2800 40 11.3 32 2.5
XGN2400-34 4.0/2800 45 8.5 25 2.5
XGN3000-38 7.5/2800 57 15.2 40 4.0
1 Phase 230V/50Hz
Burner
Model
Motor
(kW/rpm)
Start
Current (A)
Full Load
Current (A)
Main
Fuse (A)
Cable
Size (mm2)
XGN450-23 0.75/2800 18.0 4.6 20 1.5
XGN650-23 0.75/2800 18.0 4.6 20 1.5
XGN1000-25 1.1/2800 20.0 6.2 25 1.5

Page 9
XGN Handbook
CONNECTING THE ELECTRICAL SUPPLY
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I.E.AOTCPANEL,BMS,
TIMECLOCK.
(IFNOTREQUIREDLINK1&2)

XGN HandbookPage 10
The XGN series sets new standards in efficient and
reliable operation, having been developed to the
current requirements of the UK and overseas markets.
Delivered ready to install with a pre-wired packaged
control system and plug-in gas train, this can be
arranged for left or right-hand entry.
Air Regulation
Air for combustion can be adjusted to give
maximum efficiency. A closed position air control
is incorporated as standard.
Controls & Operation
XGN burners are supplied for two-stage (high-low)
or modulating operation which is automatic, via
the burner controller. Flame supervision is by U V
cell.
Fuel
This handbook covers natural gas only. For other
requirements, refer to Nu-way Ltd.
GENERAL
This handbook is structured to enable the user to
proceed from the delivery of the burner to its use.
The conditions to be fulfilled and the controls and
adjustments to be used are dealt with in the
sequence that should be followed. The location
of all the necessary controls and adjustments to
undertake commissioning are illustrated and
supported by appropriate tabular matter and
graphs.
Routine maintenance, fault finding and spare parts
identification complete the handbook.
SERVICES & SITE CONDITIONS
Gas Supply
The gas supply pipework must be constructed and
installed in compliance with the appropriate Codes
and Standards, and comply with all local
conditions. It shall be of sufficient size to satisfy
the pressure and volume flow requirements of the
burner under all firing conditions.
A 90° manual isolation valve must be fitted
upstream of the gas control train to allow the
burner to be isolated for maintenance.
To avoid any restriction in gas flow the size of this
valve should not be less than that of the gas train.
FEATURES Flue and Chimney Requirements
The flue and chimney must be constructed and
installed in compliance with appropriate Codes
and Standards, and comply with all local
conditions. It shall be of sufficient size to satisfy
the volume of flue gases at all firing conditions.
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 the XGN
burner, a careful inspection should be made of its
condition after it has been cleaned thoroughly to
remove all adhering tars, scale and dirt.
Combustion Chamber Conditions
The combustion chamber draught must not exceed
0.25 mbar. If this figure is exceeded, then steps
should be taken to reduce it to this level.
PACKAGING FOR TRANSIT
To safeguard against transit damage the burner may
be despatched partly assembled in either two or
three units.
ASSEMBLY
If not already fitted, fit the hinged extension / flame
tube assembly to the burner body using the studs
provided, and ensure the gas inlet flange is at the
bottom.
Open the hinged extension and connect the
ignition cable to the electrode. Close hinged
extension.
Fit the 90° flanged elbow to the gas train mounting
flange, then the gas train to the elbow, using the
gaskets nuts and washers provided.
Ensure that the gaskets are seated correctly when
tightening the assembly.
Connect the four number-coded plugs from the
gas valves V1 and V2, the gas pressure switch and
the gas butterfly valve to the MBC sockets 2,3,8 &
14 respectively.
Do not force the plugs into the sockets. If difficulty
is encountered, check the coding to ensure correct
location.

Page 11
XGN Handbook
INSTALLATION
General
Check that the burner is appropriate for the
appliance rating. Detailed burner performance
data is given on pages 23 to 27.
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 on page
6.
Ensure the joint between appliance and burner is
effectively sealed with the gasket provided.
Unless the appliance manufacturer specifies
extensions, the flame tube should be flush with
the inner face of the appliance combustion
chamber.
Electrical
The main Electrical supplies to the burner must
have a means of disconnection which has a contact
separation of at least 3mm in all poles.
Connect the electrical supply to the burner
observing all applicable IEE Regulations.
Connect all of the applicable external auxiliary
controls.
Refer to the electrical supply specifications and
connection diagrams shown on page 8.
Ensure that adequate earthing is provided for
motor supply.
If supplied as a packaged appliance/burner unit
refer to the manufacturers instructions.
BURNER AIR CONTROLS
A motorised air flap controls the air for combustion.
It is located inside the air inlet, see page 6.
Air Diffuser
The air diffuser creates a pressure drop over the
burner head to ensure good fuel/air mixing and
flame stability.
Air Pressure Switch
The air pressure switch is required to prove
adequate air flow throughout the burner operating
cycle. Air flow failure at any stage after pre-purge
will result in a lockout, failure during pre-purge will
result in four restarts before a lockout.
BURNER GAS CONTROLS
Gas Nozzle
The holes in the gas nozzle are designed to suit
the output of the particular burner model and gas
type being used.
Gas Pressure Switch
The low gas pressure switch is located between
the two gas valves and has two functions: -
•To monitor the gas pressure during the burner
operating cycle. A low gas pressure will result
in the safe shutdown of the burner.
•The check the gas leak integrity of the valves.
INTEGRATED VALVE PROVING SYSTEM
The XGN burner comes complete with an
integrated Valve Proving System.
A leakage test is performed after every controlled
shutdown.
A leakage test is performed before the burner is
started after a power failure or fault reset.
Functional sequence
After a controlled shutdown, the second main valve
is closed after a 2-second delay. The pressure in
the test section is thus evacuated and the gas
pressure switch opens. A test of the first main valve
(V1) commences and during the first preset test
period. The gas pressure switch must remain in
the open position, otherwise the burner will
lockout and a fault code for ‘valve 1 leaking’ will
be displayed
At the completion of the first test period the first
gas valve is momentarily opened and the test
section is pressurised with gas, the gas pressure
switch closes. A test of the second main valve (V2)
commences during the second preset test period.
The gas pressure switch must remain closed,
otherwise the burner will lockout and a fault code
for ‘valve 2 leaking’ will be displayed.
At the end of the second test period the valve
proving is complete.

XGN HandbookPage 12
OPERATION
When the burner is switched on the start procedure
begins: -
The MBC completes a series of internal tests.
Both the air and gas motors check their reference
positions.
The air damper moves to the high fire position.
Air pressure switch is checked to ensure that it is
in the open position.
The flame monitor checks if flame is present.
If the above is successful, the fan begins the pre-
purge.
During the pre-purge and thereafter the air
pressure switch monitors the air pressure.
The gas servo motor opens fully, above 90° and
then closes to the ignition position.
After the pre-purge period, the air damper moves
to the ignition position.
At the start of the ignition and thereafter the gas
pressure switch checks the gas pressure.
Ignition takes place and the burner starts to fire.
COMMISSIONING THE BURNER
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 there are no leaks.
Set the low gas pressure switch to just above the
minimum and the air pressure switch to minimum.
Check that the appliance is in a proper and safe
state to be fired.
Set the appliance controls to call for heat.
Check for Valve Closure
All gas train assemblies are fully leak tested before
despatch. A test of the individual gas valves is
difficult without specialised testing equipment.
However, the following check can be performed
to test the security of the valve system.
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.
The manometer will detect any gas leakage and
will prove that gas is not leaking past the gas train.
If no drop in pressure is recorded then
commissioning can continue until a full valve
proving test is completed by the integrated proving
system.
Gas Supply Pressures
Refer to the gas supply pressure graphs on pages
23 to 27 of this handbook. The supply pressure
must not exceed 100mbar. All pressures shown are
measured when the burner is at full firing rate.
Fit a manometer or other approved pressure
measuring instrument at the test point on the
upstream main safety valve. Open the main
isolating manual gas valve. Check there is adequate
gas pressure to enable commissioning to proceed.
Adjust IR Detector
Adjust the IRD to maximum sensitivity before start-
ing the burner. If the LED indicator is lit during the
start sequence, carefully adjust the sensitivity con-
trol until LED 1 extinguishes. No LED should light
up during the pre-purge phase.
Note:
Burner operating normally = both LED’s on
Burner in pre-purge phase = both LED’s off
For safety reasons the sensitivity must not be set
higher than necessary
ESTABLISHING MAIN FLAME
Measuring Gas Flow
In the following sections, reference is
made to checking gas flow rates at the
gas meter. This is the most accurate
method of determining throughputs and
should always be used whenever
possible. Information regarding the burner head
gas pressures is shown on pages 23 to 27. 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.

Page 13
XGN Handbook
Microprocessor Burner Control Unit (MBC)
Engineers who are not experienced with this unit
should read all the notes and procedures before
attempting to commission the burner.
The MBC System is attached to a display unit, as
shown on page 13. This unit is used to program
the MBC, and to retrieve information from it.
The system has many functions; several of them
need a pass-code before the user can obtain access
to them. Entering this code is described in the
following text.
When using the keys on the display unit, the best
results are achieved by using a slow deliberate
pressure of about ½ to 1 second in duration.
When the burner is first switched on , the MBC
performs a startup test and then displays
“OFFUPr”. This means that commissioning has not
been completed and the MBC only contains ini-
tial settings. A full commissioning procedure must
be competed.
Entering the pass code.
Press key numbers (1&2) together for a full
commissioning or keys (+&-) together for a part
commissioning.
The display will show seven short lines, the first
flashing and is ready to accept the code.
The default pass-code is 8904236.
To enter the first number (eight) press the plus (+)
key eight times, or the minus (-) key twice
(10-8=2).
Each press of either key, plus or minus (+/-) will
result in flashing line dropping down indicating that
the press has been recorded.
The MBC is controlled by means of 5 keys on the touch sensitive display. The individual
parameters are displayed on the liquid crystal display.
The individual display elements and control buttons are explained below.
Start-up
Lights up during
the run-up phase,
OFF during
operation.
On when
setup mode
is selected
12
+
PSGL/A
h
l,m
3
i
_
On when
information
mode is active
Acknowledge-
ment Key Key 1
Actuation of gas
flow control flap
in conjunction
with +/- buttons
Key 2
Actuation of air
flow control flap
in conjunction
with +/- buttons
Key +/ Key -
In conjunction
with button 1 or 2
Lights up when the
gas flow control
flap is active
Symbols for
Open/Close flaps
Liquid-crystal
display
H = Operating hours indicator
I,m = Oil or gas consumption
3
Lights up when
service mode
is active
Fault
Flame established,
burner run
Lights up when the
air flow control
flap is active
MULTI-FUNCTIONAL DISPLAY

XGN HandbookPage 14
Use the (-) key to move the display backwards from
P0.
To alter the value of any gas setting, move to the
required display point (P9,P1 or P0) and use the
(1) key in conjunction with the (+) or (-) keys.
To alter the value of any air setting, repeat the
above procedure but using the (2) key in
conjunction with the (+) or (-) keys.
The Low Flame point P1 cannot be set at a higher
value than the High Flame point P9.
The initial burner setup is now complete.
Table of Available Gas and Air Settings.
Firing the burner
Scroll through to the GAS EL display by pressing
(+), close the burner control circuit. The burner
will now start.
The display will show a number scrolling down
whilst pre-purge takes place, eventually the burner
will fire at position P0 and will remain at this
position until further actions take place.
Switch the burner off and check the fan motor
rotation, which should be anticlockwise, viewed
from the motor end. If the rotation is incorrect,
please refer to ‘Fault Finding’ to correct it.
Restart a fresh from entering the pass code and
allow the burner to fire at position P0.
•Press (+) to move the control point to P1,
the Low Fire position.
•Check that the gas pressure is not excessive.
•Visually check for a clean, safe and stable
flame, adjusting the air damper to suit if
necessary.
Press key (2) to move to the next number, the
second line will start to flash. To enter this number,
(nine) in this illustration, press (+) key nine times,
or the (-) key once (10-9)=1. Again the flashing
line will drop to indicate it has been recorded.
Press key (2) to move to the next number, zero,
the third line will start to flash. Zero requires no
action therefore move to the next number, (four).
Continue this procedure until all the numbers have
been entered.
When the last number has been recorded, press
the acknowledgement key. The procedure is
complete.
If required, pressing key number (1) will return the
flashing line to the previous position.
Commissioning Procedure
The Nu-way XGN burner has been delivered with
initial gas and air settings. These have been applied
to the burner during the test and inspection phase
of its manufacture. Whilst these settings may
enable the burner to operate, they are not
intended to be final settings.
The commissioning procedure consists of the
following: -
•Entering the pass code.
•Reviewing the air and gas set points.
•Firing the burner.
•Commissioning the burner.
•Completing the procedure.
Refer to page 13 for a functional description of the
Display unit.
Enter the pass code.
Initial settings for air and gas.
The MBC will calculate values for the intermediate
points P2 to P8.
Use the (+) key to move the display forwards from
P9 through P1 to P0.
Point Maximum Angle Minimum Angle
P0 P1+25.5° 0 or P1-25.5°
P1 P0+25.5° or P2 0 or P0-25.5°
P2 P1+25.5° or P3 P1
The same formlula applies to points P3 to P8
P9 P8+25.5° or 90° P8
Bu P1 Bo
Bo P9 Bu
Set
Point
Combus-
tion Air Gas Firing Rate
P9 65° 90° High Fire
P1 15° 10° Low Fire
P0 10° 5° Ignition Position

Page 15
XGN Handbook
•Press (+) to move the control point to P2,
again making any adjustments to keep the
flame safe and stable.
•Follow the above procedure through P3, P4
etc. until position P9, the high fire position,
is obtained.
•With the gas butterfly set at 90°, adjust the
governor on the SKP2x valve to give the
required high flame gas flow.
•Adjust the air damper position to give the
required combustion analysis. Note the air
damper position.
•Switch off the burner and restart the
procedure from entering the pass code.
•Adjust the value of the air damper at P9 to
that noted above.
•Scroll through to the GAS EL display and start
the burner.
•At the ignition point P0, adjust the air and
start gas values to give a good light up.
Ensure that the start rate gas flow
does not exceed 30% of the high
flame gas rate as measured at the
Gas Meter Note the gas and air posi-
tions.
•Move to point P1 and adjust the gas butterfly
to give the required low flame gas flow. Adjust
the air damper to give the required
combustion analysis. Note the gas and air
positions.
•Switch off the burner and restart the
procedure from entering the pass-code.
•Adjust the value of the gas and air settings to
those noted at points P0, P1 and P9.
•Scroll through to the GAS EL display and start
the burner.
•Move to point P2, the firing rate will increase.
•Adjust the air damper to give the correct
combustion analysis.
•Repeat the above procedure for points P3
through P8, fine tuning the combustion
analysis as required.
•When the burner is firing satisfactorily, return
the burner to set point P9.
Two further points Bu and Bo, which correspond
to the minimum and maximum firing rates can now
be set using the air damper angles that were set at
P1 and P9 respectively.
•Press keys (1) and (2) together to access the
display point Bu. Wait until the display is
steady. Adjust the value to reflect the air
damper angle at P1.
•Press keys (1) and (2) again to access the
display point bo. Wait until the display is
steady. Adjust the value to reflect the air
damper angle at P9.
•Finally, press keys (1) and (2) again to enter
the information into memory.
The procedure is now complete.
FINAL ADJUSTMENTS
Setting the Air Pressure Switch
Switch off the electrical supply to the burner.
Remove the air pressure switch cover. Fit a
manometer to the pressure switch to check the
accuracy of the dial.
Re-establish the electrical supply.
Enter the pass-code as described on page 13 for a
part commissioning. The default settings will not
be displayed. Switch on and the burner will purge
then fire at point PO. Slowly turn the adjusting
dial clockwise until the flame is extinguished; the
burner may go to lockout. Turn the dial one
division anticlockwise and let the burner restart, if
the burner fails to start, turn the dial another
division anticlockwise. Repeat the above
procedure at one division per cycle until the
burner operates. Adjust the dial a further two
divisions anticlockwise.
Switch off the burner, isolate the electrical supply,
fit the cover and remove the manometer.
Setting the Flame Signal
When the burner is operating normally, carefully
turn back the sensitivity control until LED 1 begins
to flicker. Increase the setting again by one or two
increments until both LED’s are lit. If LED 1 does
not flicker even at position 1: Leave potentiometer
at position 1-2. This adjustment should be carried
out when the flame signal current is weakest (at a
cold-start, shortly after flame establishment or af-
ter stabilisation).
The flame signal can be checked by using a
microammeter.
The minimum signal required is 15 µA
The MBC display is designed to give an indication
of the signal, the screen gives a 0 to 4 readout.
See service display screen 18.

XGN HandbookPage 16
Setting the Low Gas Pressure Switch
Loss of gas pressure will cause the burner to switch
off. After a 2 minute delay the burner will reststart.
After two restarts the delay is increased to 1 hour.
This delay can be removed by electrically isolating
the burner and then reestablishing the power.
Remove the gas pressure switch cover 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. Turn
the dial a further two divisions anticlockwise.
Replace the gas pressure switch cover.
FINAL CHECK
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. On modulating
burner check and set the RWF40.
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. Upon restoration of power,
the burner will restart automatically and
follow the normal sequence.
THE RWF40 MODULATION
CONTROL
Basic display
The diagram below shows the RWF40 after
switching on the supply voltage. This condition is
called the basic display. The actual value and the
currently active set-point are shown here. Manual
operation, self-optimization, the operating
parameter and configuration levels can be activated
from here.
To change the working set point.
The operating display shows the actual pressure/
temperature of the boiler in red and the required
set point pressure/temperature beneath in smaller
green digits.
One quick press of the PGM button, the display
changes to show the set point as the larger red
digits and the SPI in the lower small green digits.
Alter the red display using the up/down buttons
to show the new required set point, press exit or
let the unit time out to return to the basic display
which should be the new set point figure.
K6
PGM
EXIT
SIEMENS
Landis & Staefa RWF40
Burner enable
Reduce output
Increase output
Manual
operation
Limit
comparator
Increase
value
Exit key
Process value
display (red)
Setpoint
value (green)
Reduce
value
PGM key

Page 17
XGN Handbook
RWF40 Recommended Parameters
To enter a new parameter
The parameters dictate the way in which the burner
firing rate alters in response to changes in the
pressure/temperature of the boiler.
A major factor that determines the need to change
the parameters is if the burner is fitted to a steam
or hot water boiler. The table below indicates the
parameter and it’s setting for steam and hot water
boilers. It must be emphasised that it is only an
indication and any departure from these settings
should be made in small increments, with time
given to see how the burner is reacting to the
changed parameter.
Press and hold the PGM button down until the
green set point figure changes to an AL, the larger
upper figures show the value.
Use the up/down buttons to set the new value,
press the PGM button to enter the value and
change to the next screen. To cancel an entry press
exit. Scroll through the screens, (PGM button)
modifying any value found to be in error (up/down
buttons). At the last screen the PGM button will
return the controller to the original operating
display.
Parameter Display Hot
Water Steam
Proportional
band Pb1 10 1
Derivative
time Dt 10 5
Reset time Rt 50 20
Actuator time Tt
Damper running
time between low &
high flame
Switch on
threshold Hys 1 0-0.2
Upper off
threshold Hyst 3 999.9 0.2
Detector:
range start SCL 0 0
Detector:
range end SCH 100 25
RWF40 CONFIGURATIONVALUES
Display Hot Water Steam
C111 9031 G000
C112 5010 0000
C113 0110 0110
At any point in the procedure the original
operating display can be obtained by letting the
unit time out, the value in the display at the time
out will be accepted.
A value can only be altered within the permitted
range of that parameter. All other parameters must
remain as supplied.
Note: The detector range parameters SCL & SCH
are given as °C for Hot Water (temperature) and
bar for Steam (pressure).
Configuration Values
The configuration values are factory set specific to
the installation, they therefore rarely need to be
altered and are provided for reference only.
The codes control measurement acquisition, con-
troller type etc.

Information Display
The information display can be accessed only from
the operating display, and can be obtained
irrespective of burner status or fuel.
To gain access, press the enter or
acknowledgement key and hold for about 1
second, a small iwill be highlighted. If the key is
continued to be pressed the display will change to
service mode, indicated by a spanner symbol.
Should this occur, take no action and the display
will revert to the original after about twenty
seconds.
Start afresh, but release the key while the small iis
highlighted.
When in the information mode, the display will
move to the next screen and finally back to the
operating display with each press of the
acknowledgement key.
Service Display
The service display can be accessed only from the
operating display, and can be obtained irrespec-
tive of burner status.
To gain access, press the acknowledgement key
and hold for about 2 seconds, a spanner symbol
will be highlighted. When in the service mode, the
display will move to the next screen and finally
back to the operating display with each press of
the acknowledgement key.
MBC DISPLAYS
Standby Display
Operating Display
Screen Information
0Total cubic meters of fuel consumed
1Total hours of operation
2Not applicable
3Not applicable
4Number of successful starts
5The software version number
6The software creation date
7The serial number of the controller
8The production date of the
controller
Screen Information
OFF After shutdown
OFF U Due to low voltage
OFF S Safety circuit open
OFF E Due to eBUS
OFFUPr Un-programmed
TEST Internal tests
LAir stepper motor check
6Gas stepper motor check
1Safety and control circuit check
2Air stepper motor driving to P9
3Burner fan start
4Pre-purge period
5Pre-purge period
6Pre-purge period, gas stepper
motor driving to P0
7Air stepper motor driving to P0
8Pre-ignition
9Safety period
10 Stabilisation time
11 Stepper motors driving to P1
12 Operating position
13 Valve test, phase 1
14 Valve test, phase 2
15 Valve test, phase 3
16 Valve test, phase 4
17 Post-ventilation
18 Waiting time
OFF Standby

ROUTINE SAFETY CHECKS
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.
Flame Detection System (IRD Cell)
•With the system set for normal operation, pull
out the detector probe and cover it up to cut
off light. Both LED indicators must extinguish.
The control box should switch to lockout or
attempt to re-start the sequence.
•Attempt to re-start with the flame detector
covered. There must be no indication from
the LED’s after the start impulse. The burner
control box must switch to lockout at the end
of the safety interval.
•Attempt to start the burner with the detec-
tor exposed to stray light e.g. from fluores-
cent lighting, a cigarette lighter or light bulb
(not daylight or an electric torch): The con-
trol box should switch to lockout either im-
mediately or at the end of the pre-purge, as
a result of stray light.
ROUTINE MAINTENANCE
Switch off electrical supply and gas supply to the
burner.
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: -
XGN450 to XGN1000. Remove the split pin from
the hinge pin adjacent the gas train and withdraw
the hinge pin form the hinged extension.
XGN1150 to XGN3000. Remove the 2 locking
nuts and washers securing the hinged extension.
Screen Information
0Air and gas setting point P0
1Air and gas setting point P1
2Air and gas setting point P2
3Air and gas setting point P3
4Air and gas setting point P4
5Air and gas setting point P5
6Air and gas setting point P6
7Air and gas setting point P7
8Air and gas setting point P8
9Air and gas setting point P9
10 Most recent fault code
11 Second last fault code
12 Third last fault code
13 Fourth last fault code
14 Fifth last fault code
15 Sixth last fault code
16 Testing time Y2
17 Testing time Y3
18 Flame quality indication (1-4)
19 eBus address
21 Integrated valve test, on/off
22 Lower limit of modulation
23 Upper limit of modulation
24 Controller address
25 Motor speed
26 Motor rotation and reference

XGN HandbookPage 20
Open the hinged extension, disconnect the
ignition electrode H.T. lead and remove the cap
head screw securing the inner assembly gas pipe
to its manifold. 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
reset if necessary, details are shown on page 6.
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 Valve SKP2x
Should the SKP2x valve require replacing due to
mechanical or electrical failure, then the governed
gas pressure will have to be reset. It is essential
that only qualified combustion engineers
undertake replacement of these components.
FAULTFINDING
Any modifications to the installation or component
settings resulting from actions suggested below may
require the re-establishment of the various settings.
During the purges and firing cycles the MBC control
checks for both internal and external faults. Should
a fault be found the control causes a safety
shutdown and flashes an error code on the display.
The last six error codes are kept and can be
obtained from the service mode screen ten
onwards.
MBC Error Codes
Code Error Description
20H Air pressure switch not in rest
position
21H Air pressure switch failure
22H Gas pressure switch failure
25H No flame after safety period
26H Extraneous light
27H Flame failure during operation
2BH Short circuit in photoresistor
43H First valve leaking
44H Second valve leaking
66H Gas servomotor or coding plug
68H Air servomotor acknowledgement
69H Gas servomotor acknowledgement
6AH Air motor position out of tolerance
6BH Gas motor position out of tolerance
6EH Motors have been interchanged or
incorrectly connected
6FH Either gas or air servo motor unable
to find reference positions
All
others Internal device fault