Nu-Way MOL 3400-410 Instruction Manual

Installation & Maintenance Manual
MOL 3400-4100
Oil Burner
Tel:[phone] Fax: [phone] Email: [email protected] Web: www.nu-way.co.uk

CONTENTS
BURNER & COMPONENT IDENTIFICATION FOR MOL 3400 & 4100 BURNERS ……………………………
3
INTRODUCTION …………………………………………………………………………………………………...
7
FEATURES ……………………………………………………………………………………………………………
7
Burner Ca
p
acit
y
…………………………………………………………………………….
7
Controls and Safet
y
S
y
stems …………………………………………………………………………….
7
O
p
eratin
g
Mode …………………………………………………………………………….
7
Fuel …………………………………………………………………………….
7
SITE CONDITIONS AND SERVICES ……………………………………………………………………………….
7
Flue and Chimne
y
Re
q
uirements …………………………………………………………………………….
7
Plant Room Ventilation …………………………………………………………………………….
7
Combustion Chamber Conditions …………………………………………………………………………….
8
Oil S
y
stem …………………………………………………………………………….
8
Oil Stora
g
e Tank …………………………………………………………………………….
8
Oil Su
pp
l
y
to Burner …………………………………………………………………………….
8
Sin
g
le Pi
p
e S
y
stem …………………………………………………………………………….
8
Pum
p
ed Oil Rin
g
Main …………………………………………………………………………….
8
Burner Pum
p
Ca
p
acitor …………………………………………………………………………….
8
Filtration …………………………………………………………………………….
8
Electrical Power Su
pp
l
y
…………………………………………………………………………….
8
UNPACKING AND ASSEMBLY………………………………………………………………………………………
9
MODULATING BURNER OIL SYSTEM …………………………………………………………………………….
10
INSTALLATION ………………………………………………………………………………………………………
11
BURNER CONTROL OPERATION – MODULATING & HIGH/LOW ……………………………………………
12
BURNER CONTROLS ……………………………………………………………………………………………….
13
Oil Pum
p
in
g
Units …………………………………………………………………………….
13
Modulatin
g
Unit …………………………………………………………………………….
13
COMMISSIONING : GENERAL …………………………………………………………………………………….
14
Safet
y
and Emer
g
enc
y
Notes …………………………………………………………………………….
14
Ins
p
ection …………………………………………………………………………….
14
Pre-Firin
g
Checks …………………………………………………………………………….
15
COMMISSIONING : MODULATING …………………………………………………………………………….. 16
Modulating Unit …………………………………………………………………………… 17
COMMISSIONING : HIGH/LOW ..................................................................................................................
19
High/Low Burner Oil System …………………………………………………………………………… 19
FINAL CHECKS - COMMISSIONING ………………………………………………………................................
20
On Com
p
letin
g
Commissionin
g
………………………………………………………………………..
20
ROUTINE MAINTENANCE …………………………………………………………………………………………
21
General ………………………………………….............................................
21
Daily Checks ………………………………………………………...........................
21
Replenishing the Fuel Supply …………………………………………………………………………. 21
Boiler Combustion Services …………………………………………………………………………. 21
Inner Assembly Removal – High/Low ………………………………………………………...........................
21
Inner Assembly Removal - Modulating …………………………………………………………………………. 22
FAULT FINDING ………………………………………………………………….................................................
23
Burner fails to start …………………………………………………………………………..
23
Flame occurs followed by lockout …………………………………………………………………………..
23
Burner starts, no flame appears …………………………………………………………………………..
23
Modulating system …………………………………………………………………………..
23
Burner commissioning sheet …………………………………………………………………………..
23
MOL 3400 & MOL 4100

BURNER HEAD DETAILS & ELECTRODE SETTING ………………………………………………………………
24
FUEL PUMPS - SUNTEC ………………………………………………………………………………………
25
- HP TECHNI
K
…………………………………………………………………………………
26
FLAME FAILURE & SEQUENCE CONTROL & MODULATING CONTROL SYSTEMS …………………………
27
BURNER OIL NOZZLE ……………………………………………………………………………………………..
31
SERVICE & REPLACEMENT ………………………………………………………………………………………….
31
APPENDIX
Burner Performance Graph …………………………………………………………………………………..
32
Commissioning Sheet …………………………………………………………………………………..
33
IMPORTANT – SAFETY
It is essential that the following instructions and adjustments are carried out by qualified en
g
ineers that are
experienced in forced draught gas and pressure jet oil burner commissionin
g
. In the UK it is a le
g
al
requirement that these engineers should also be CORGI registered. Nu-way cannot be held responsible
for any consequential dama
g
e, loss or personal injury as a result of customers failin
g
to follow these
instructions, or as a result of misuse. Your attention is drawn to the Emergency Instructions on Page 14.
EUROPEAN BOILER EFFICIENCY DIRECTIVE (B.E.D.)
All burners and boiler bodies marketed separately should comply with EN 267 (oil burners) or EN676 (
g
as
burners) and EN303-1 (boiler bodies).
Burner adjustments must be made in accordance with boiler manufacturer’s instructions, and these mus
t
include flue gas temperatures, average water temperature, and CO2or O2concentration.
MOL 3400 & MOL 4100 Issue 2 08/08 Page 2

MOL 3400-4100 Issue 2 10 /08 Page 3
BURNER AND COMPONENT IDENTIFICATION FOR HIGH/LOW BURNERS
All dimensions are in mm
* Standard projections
240, 340, 430
Oil pump unit
Note: 545 for MOL 3400-36 only)
These dimensions are intended for general assessment of the overall sizes of the burners and should not be used
without reference to our engineering department for inclusion in drawings for installation purposes. Certified
dimensional drawings are available on receipt of orders.
12
1
3
7
5
4
545 / 640
(See Note)
Item Description
1 Burner Casing
3 Flame Tube
4 Fan Motor
5 Air Inlet
7 Control Panel
12 Fan Inspection Cover
13 Ignition Transformer

MOL 3400-4100 Issue 2 10 /08 Page 4
BURNER AND COMPONENT IDENTIFICATION FOR MODULATING BURNERS
All dimensions are in mm
6
3
4
1
4
9
10
11
13
7
8

MOL 3400-4100 Issue 2 10/08 Page 5
BURNER AND COMPONENT IDENTIFICATION FOR MODULATING BURNERS
Item Description
1 Burner Casing
2 Hinged Extension
3 Flame Tube
4 Fan Motor
5 Air Inlet
6 Modulating Control Motor
7 Control Panel
8 Modulating Cam Unit
9 Oil Spill Control Valve
10 Burner Head Oil Inlet
Quick Release Connection
11 Burner Head Return Oil
Quick Release Connection
12 Fan Inspection Cover
13 Ignition Transformer
Burner Mounting Details
On request, MOL modulating burners can
be supplied in the fully assembled
‘compact’ configuration.
Supply oil connections are made to the Air
Separator Bottle, refer to the Pumping Unit
connections shown on page 13 for
identification.
Standard burners are supplied with a floor-
mounted unit. In this configuration, the
system oil connections 10 & 11 on page 4
refers.

Electrical Data
MOL 3400 & 4100 Modulating and High/Low Burners
Control MCB is 6 Amp in all cases
Control Fan Motor Main
Burner MCB Size Fan Motor MCB Size Overload Cable Size
MOL 3400-36 6 Amp 7.5 kW 3 x 20 Amp 11-16 Amp 4mm2
MOL 3400-41 6 Amp 11.0 kW 3 x 32 Amp 19-27 Amp 6mm2
MOL 3400-44 6 Amp 15.0 kW 3 x 40 Amp 26-35 Amp 6mm2
MOL 4100-36 6 Amp 7.5 kW 3 x 20 Amp 11-16 Amp 4mm2
MOL 4100-41 6 Amp 11.0 kW 3 x 32 Amp 19-27 Amp 6mm2
MOL 4100-44 6 Amp 15.0 kW 3 x 40 Amp 26-35 Amp 6mm2
Pumping Unit details for all sizes of burner
Modulating Pump Motor Main
Pumping Unit Motor MCB Size Overload Cable Size
1.5 kW x 2800 rpm 6 Amp 2.7 – 4.2 Amp 1.5mm2
High/Low Pump Motor Main
Pumping Unit Motor MCB Size Overload Cable Size
1.1 kW x 1425 rpm 4 Amp 1.8 - 2.8 Amp 1mm2
MOL 3400-4100 Issue 2 10/08 Page 6

INTRODUCTION
This manual has been produced to enable users to install, commission and use MOL modulating burners
safely and efficiently. The manual covers two types of burner: High/Low and Modulating (Class D fuel). At
each stage the conditions which should be met and the adjustments and other actions which should be
carried out are detailed and the locations of the various components and adjustment mechanisms are
identified. Where appropriate, this information is supported by tables and graphs. Literature on the
proprietary components used in MOL systems is available on request.
FEATURES
Developed through extensive field experience in the UK and overseas markets, the MOL series meets the
current known test authority requirements in these markets and sets new standards in efficient and reliable
operation. MOL modulating burners are designed for flange mounting to the appliance frontplate and they
are delivered ready to install with a pre-wired packaged control system and oil pumping unit. (See Modes
1, 2 & 3:Page 9)
Burner Nominal Capacities
MOL 3400 3443 kW
MOL 4100 4132 kW
Controls and Safety Systems
MOL burners are fitted with an automatic sequence/flame failure control and photoelectric cell for
continuous flame supervision. A combustion air flow control coupled to an oil nozzle pressure control
system ensures smooth starting and optimum operating efficiency.
Operating Mode
In standard form the MOL Modulating burner can provide a turndown range of up to 3:1.
The High/Low version will be limited to a maximum of 2.5:1.
Fuels
MOL burners covered in this manual are designed to fire distillate fuel.
SITE CONDITIONS AND SERVICES
Flue and Chimney Requirements
It is important that:
The flue pipe from the appliance and the joint between this flue and the chimney are sealed to prevent
leakage of combustion products.
The flue pipe from the appliance does not protrude into the chimney beyond the inside wall.
The top of the flue or chimney shall be higher than any roof within a radius of 10 metres.
Checks are made to ensure that the chimney is suitable for oil fired appliances and that the proposed
installation complies with all Local Authority and other regulations covering such installations.
If more than one appliance is connected to a common flue or chimney the cross-section of this flue or
chimney should be adequate for the total volume of combustion products from the appliances. It is
recommended that each appliance should be exhausted into a separate flue.
Plant Room Ventilation
The burner must be supplied with dust-free air at sufficient rates for all firing conditions, in accordance
with the appropriate standards.
Existing Appliances
The appliance should be prepared for installation of the MOL burner by thorough cleaning, including the
removal of all adhering tar, scale and dirt. An inspection should also be carried out to ensure that the
appliance is in good condition. Any doubt about the appliances suitability for oil firing shall be referred to
the appliance manufacturer.
MOL 3400-4100 Issue 2 10/08 Page 7

Combustion Chamber Conditions
The combustion chamber conditions should not exceed those shown on page 32 of this manual.
Burners working with zero rated combustion chamber conditions can be subjected to a maximum negative
condition of 0.05 kPa (0.5 mbar)
Oil System
Refer to the drawings on page 10 & 19 for details of the burner oil system.
Oil Supply to the Burner
The oil supply from the storage tank to the burner may be provided by:
a. Single pipe gravity feed system
b. Pumped ring main system
Single Pipe System
The height of the main storage tank above the burner and the sizing of the pipe to the burner must be
designed so that the oil pressure at the burner oil pump inlet is not less than 35 kPa (0.34 bar). The
maximum oil pressure at the burner pump inlet must not exceed 500 kPa (5.0 bar) under any operating
conditions.
The pipe must be sized to the full swept volume of the burner oil pump and not the capacity of the burner
nozzles.
Pumped Ring Main System
The pumped ring main is the preferred system of oil supply and is essential for multiple burner installations.
The ring main pumps and supply pipework must be designed to cater for 1.25 times the total swept
volume of the burner oil pumps connected to the supply system.
All oil supply pipes must be constructed and installed to comply with local conditions and appropriate
codes of practice and standards. All pipework must be firmly supported and a Pressure Reducing Valve
(PRV) should be fitted to control the supply pressure.
Burner Pump Capacities
The oil pumps used on Nu-way modulating oil burners are listed in the table on page 26. It is essential
that the full swept volume of the pump be considered when oil supply lines or ring main systems are
calculated.
Filtration
When using fuel oils filtration of the oil is essential. The filtration system should be chosen according to the
individual features of the installation. The ring main system diagram on page 10 gives guidelines. When
the ring main pressure is checked then this should be measured at the burner pump vacuum gauge port to
allow for any pressure drop across the filters.
Failure to provide a good clean oil supply will almost certainly lead to premature wear and rapid failure of
the oil pump unit.
Electrical Power Supply
A three phase 50Hz supply is required (60 Hz Burners are available on request). Power requirements are
tabulated in the Appendix of this handbook. The power supply provided must comply with all relevant
Codes and Standards.
MOL 3400-4100 Issue 2 10/08 Page 8

UNPACKING and ASSEMBLY
To safeguard against damage in transit, MOL modulating burners may be supplied in partly assembled
form in one of three alternative modes:
Mode 1: The complete burner unit fully assembled.
Mode 2: Burner body complete with control panel. Combustion head hinged extension and flame tube
assembly.
To assemble the burner:
Assembly of the burner can be completed after fitting the hinged extension/flame tube
assembly to the appliance.
Alternatively, fit the extension/flame tube assembly to the burner body using the four nuts and
washers provided.
The pumping unit is supplied as a separate component to modes 1 and 2 and is inclusive of flexible pipes
to make all the necessary oil connections.
Mode 3: On request, MOL modulating burners can be supplied in a fully assembled compact
configuration. These burners include the oil pumping and conditioning unit mounted beneath
the burner body and are pre-piped, requiring only the connection of fuel and electrical
supplies to complete the installation. The suitability for installation of compact modulating
burners should be referred to the appliance manufacturer as the addition of the oil pumping
unit adds extra weight to the appliance frontplate.
MOL 3400-4100 Issue 2 10/08 Page 9
HIGH FLAME ADJUSTABLE MICROSWITCH

MOL 3400-4100 Issue 2 10/08 Page 10
BURNER OIL SYSTEM
Pumped Systems – All Modulating Burners
All interconnecting pipework to be minimum 19mm and pressure rated for 42 kg/cm2(600 psi).
All burners require a pump inlet pressure of 0.35 to 0.70 kg/cm2(5 to 10 psi).
If a shut-off valve is fitted in the inlet line, a pressure relief valve set at 0.7 kg/cm2(10 psi) above the
supply pressure must be fitted to prevent damage should the valve be left shut during burner.

INSTALLATION
General
Ensure that the appliance is suitable for the heat input of the burner. If there is any doubt in this area,
reference shall be made to the appliance manufacturer. Detailed burner performance data are presented
in the appendix of this handbook.
Fitting to the Appliance
If the burner is to be fitted to a new appliance refer to the appliance manufacturers recommendations.
If the burner is to be fitted to an existing appliance a mounting flange must be provided as detailed in the
section of Burner & Components Identification. Ensure that the joint between the burner and the mounting
flange is sealed effectively using the gasket provided.
The flame tube should not extend beyond the inner face of the appliance combustion chamber unless the
appliance manufacturer specifies extensions, for example in the case of reverse flame boilers.
Connections
Once the burner is mounted to the appliance, open the hinged extension by removing the two nuts and
washers, connect the HT leads to the ignition electrodes and close and fasten the extension.
Connect the flexible oil pipes between the burner and the pumping unit by referring to the burner
component and pumping unit drawings on pages 4 & 13.
Connect the oil supply to the burner pumping unit with reference to the oil system diagrams and pumping
unit drawings on pages 10 & 19.
Electrical Power Connection
Connect a three-phase, 50 Hz electrical supply to the burner, observing all applicable Codes and
Standards. The electrical connections required are shown in the wiring diagram contained in the
instruction pack attached to the burner. These diagrams also show the auxiliary control connections,
which must be made.
If the burner is supplied as part of a packaged appliance/burner unit, refer to the appliance manufacturers
instructions.
New Wiring Colours
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), Grey (L3) and Blue (N) in three-phase power circuits from
1st June 2006.
Full details of the changes can be found in amendment No.2 9AMD 14905 to BS 7674:2001 – which is a
free download from the IEE website (www.iee.org/cablecolours). They are also within the new version of
BS 7671:2001 (Incorporating Amds 1 & 2) published on 31st March, this new version of the Wiring
Regulations can be identified by its brown cover.
MOL 3400-4100 Issue 2 10/08 Page 11

All personnel concerned with commissioning and/or operation of MOL burners shall
familiarise themselves with the information presented in this section.
BURNER OPERATION - MODULATION
Burner Description
Nu-way MOL modulating series fully automatic oil burner units are of packaged design and meet relevant
National and International standards based on the ISO system of measurement and fastening.
A system of pressure atomisation employing a single spill-back nozzle is used throughout the range. If the
burner is equipped with the Nu-way Electronic Cam Modulating (ECM) system, then reference should
also be made to the supplementary documentation supplied with this handbook. In the case references to
the RWF40 Universal Controller and Modulating Unit within this handbook can be ignored.
The standard method of operation is based on the Siemens RWF40 Universal Controller, which has been
designed for use in oil and gas fired installations, where it provides temperature or pressure control of
modulating burners with continuously adjustable fuel throughput.
The control output of the RWF40 is a potential free 3-position switch, which is used for the control of
reversible motors. The control signals for the Open (Y1) and closed (Y2) are indicated on the controller
face by light emitting diodes.
For further information on the RWF40 and its associated components, please refer to the data provided on
page 29 of this handbook.
When the boiler control calls for heat, the burner modulating unit will travel to the ‘high flame’ position
and interlock the control circuit. An air pre-purge will take place at this position for a pre-determined
period, at the end of which the burner sequence controller will stop until the modulating unit has travelled
to the ‘low flame’ position and interlocked the control circuit again. The sequence control will now
recommence its operational cycle and the burner will light and remain at low flame until the high flame
release signal is given by the sequence control.
The modulating unit will now move to high flame and remain at this position until the desired boiler
temperature/pressure is attained. From this stage the modulating unit will commence to move towards the
low flame position between low and high flame.
BURNER OPERATION – HIGH/LOW
The oil system operates at constant pressure and utilises four nozzles in order to minimise nozzle size, thus
producing the fine atomisation necessary for efficient combustion.
The air regulator is of a rotary type and is hydraulically actuated. Access by removing the top cover from
silencer box and air adjustments by set pins operating against stop on moveable part of regulator.
An adjustable microswitch is actuated by the moving air regulator. The microswitch controls the air/oil
phasing on the change from low to high flame. The switch also proves that the air regulator is moving
before high flame is allowed to spray. The microswitch controls an additional, normally open, solenoid
valve.
MOL 3400-4100 Issue 2 10/08 Page 12

BURNER CONTROLS
Burners are supplied with an integral control panel containing a sequencing control unit and the burner
switchgear. On steam boiler applications an auxiliary control panel containing boiler feed pump controls,
water level interlocks and alarms is available.
Oil Pumping Units
Standard burners are supplied with a floor-mounted pumping unit. Details of which are shown below.
On burners supplied in ‘compact’ configuration, the pumping equipment is mounted on the burner.
Modulating Unit
The modulating unit consists of a reversible servomotor, which is directly coupled to the camshaft of the
modulating unit. Two adjustable cams are mounted on this shaft, one of which is connected to a flexible
cable operating the burner air inlet control damper and is of the variable contour type (see fig 2 on page
17). The second cam is the modulating oil cam and is illustrated in fig. 1.
The Burner Oil System drawing on page 10 shows the hydraulic circuits. Oil for combustion is drawn from
the supply through a fixed displacement pump and supplied direct to the burner nozzle. A return line
from the back of the nozzle is connected to a ‘spill regulating valve’ which regulates the oil pressure at the
nozzle according to the position of an internal piston which is actuated by the oil control cam in the
modulating unit.
There is a well-defined relationship between the delivery of fuel through the nozzle and pressure behind
the nozzle, therefore movement of the oil cam ‘modulates’ the nozzle output and hence the output of the
burner.
The volume of air required for combustion must also be varied as the nozzle output varies, and this is done
by the air control damper, operated by a flexible steel cable connected to a lever system bearing against
the air control cam.
Once the oil has been adjusted as described in the Commissioning procedure section of this handbook, the
profile of the air cam is adjusted to give the desired combustion conditions by turning the thumbscrews
under the cam in or out as the burner is ‘inched’ through its firing range.
The air control damper is spring-loaded ‘open’ for safety in the event of cable failure.
MOL 3400-4100 Issue 2 10/08 Page 13
OIL PUMPING SET
Pipework Connections
Item Description R”
1 Oil Inlet Connection 1
2 Oil Return Connection 1
3 Burner Oil Feed 3/4
4 Burner Oil Return 3/4

COMMISSIONING
IMPORTANT – SAFETY
It is essential that commissioning shall be undertaken only by suitably qualified and experienced personnel.
In the case of MOL modulating burners, commissioning engineers should be experienced in pressure jet oil
burner commissioning. Nu-way can accept no responsibility for consequential loss, damage or personal
injury which results from a failure to follow the commissioning instructions provided or from
commissioning procedures being undertaken by unqualified personnel.
EMERGENCY INSTRUCTIONS
MOL modulating burners are designed and constructed to meet current legislation. When used in
accordance with the instructions provided, MOL modulating burners are unlikely to produce a hazardous
condition. If, however, such a condition should arise in connection with the burner, the appliance or of
any instrument, machine or service in the vicinity of the burner, the OIL AND ELECTRICITY SUPPLIES
SHALL BE ISOLATED IMMEDIATELY and they shall remain isolated until the fault has been identified and
rectified.
Inspection
Before commissioning is begun it is important to:
Check that the electrical wiring is complete and complies with all applicable Codes and Standards.
Ensure that the fuses are fitted and are of the correct rating.
Check electrical earthing.
Verify that the oil supply system is correctly designed and that the supply pipework is correctly sized and
free from leaks.
Ensure that all manual fuel isolation valves are operable, fully closed and leak tight.
Make all personnel involved in the commissioning aware of the location of the emergency fuel and
electricity isolation points.
Check that fittings for bleed and pressure testing are fitted.
Establish that the appliance is in an appropriate and safe condition to be fired: for example, that there is
water in the boiler.
Set the appliance’s ventilation and flueing arrangements.
Ensure that any warning notices appropriate to the commissioning procedure are in position.
Ensure that all tools and test equipment are available and ready for use. Essential items include
temperature measuring instruments for measuring flue gas and appliance water temperatures, and a
means of analysing the flue products for carbon dioxide (CO2), oxygen (O2), carbon monoxide (CO) and
smoke.
Check that all relevant documentation is available including, where appropriate:
- The agreed plant performance specifications
- Plant drawings and pipework diagrams
- Certificates confirming satisfactory completion of procedures such as soundness testing and
electrical safety tests.
- Commissioning, operating and maintenance instructions for the plant.
Establish that the operation of plant other than that being commissioned will not have an adverse effect
on the operation of the plant to be commissioned and similarly, that the operation of the plant to be
commissioned will not have an adverse effect on other plant.
Confirm that the operation of adjacent plant and machinery will not constitute a hazard to the
personnel involved in commissioning.
MOL 3400-4100 Issue 2 10/08 Page 14

Pre-firing Checks and Dry Run
With the oil and power switched off, carry out the following checks:
Check the nozzle size and position relative to the diffuser plate. (The burner head dimensional details
are given in the appendix of this handbook).
Check that the electrode positions and HT leads are correct.
Check all the motor overload settings.
If the appliance is a boiler, check that the water level is correct, the controlling valves are open and that
the water pumps are in working order.
If a flue damper is fitted, check that it is correctly interlocked to the burner or fixed in the fully open
position.
Ensure that there is a good oil supply to the burner pump. Bleed one or two gallons from the flexible to
eliminate any pipe scale and air from the system.
Check that the oil supply is of the recommended temperature and pressure.
Bleed the burner pump manually by removing the right-hand ¼” BSP plug in the top of the pump until
air-free oil flows.
Switch on the electricity supply to the burner and check that the pump motor rotation is correct to the
direction arrows shown on the pump face.
Modulating Burners
Remove the access lid on the modulating cam box unit.
Switch on the burner at the control panel. The modulating unit cam shaft should now rotate to the high
flame setting, and the combustion air motor will start the air pre-purge phase.
Allow the fan motor to run up to speed, switch off the burner and check the fan rotation (anti-clockwise
as viewed from the motor side) as the fan slows down.
Remove and cover the photoelectric cell with a clean lint-free cloth, switch on the burner, and allow it
to run through to lockout. During this run check that the ignition spark is occurring, and note the spill
and line oil pressures at the moment of ignition. Reset the sequence control and repeat the run if
necessary to check these functions. If necessary, adjust the spill pressure to the correct figure according
to the nozzle specification and the line pressure at the burner pump to 27.8 bar (400 psi).
High/Low Burners
Check that the total nozzle size is correct for the particular application. The normal operating pressure
of the burner is 20 atm (20.7 bar : 300 lbf/in2). To obtain nozzle throughput in Imperial gal/h multiply
marking by 1.44. To obtain nozzle throughput in litres per hour multiply by 6.55, and for kg/h multiply
by 6.2.
Check ignition electrodes and leads and the position of the nozzles relative to the face of the diffuser.
When replacing the inner assembly ensure that the ‘O’ rings are correctly in position between the union
blocks.
The works setting of the air regulator is 6mm (¼”) open for low flame and 19mm (¾”) for high flame.
The sequencing microswitch is set to bring in high flame oil after the air regulator has moved from 6mm
(¼”) away from the low position. The air regulator is adjusted by means of set pins acting on a stop
carried on the moving member of the regulator.
Access to the set pins and the sequencing microswitch is obtained by removal of the plate at the top of
the silencer.
Check that all controls and flue dampers are correctly set.
Turn switch on control panel to ‘low flame hold’ and ensure that there is water in the boiler.
Remove and cover the photoelectric cell with a clean lint-free cloth, switch on the burner, and allow it
to run through to lockout. during this run check that the ignition spark is occurring, and note the pump
pressure.
MOL 3400-4100 Issue 2 10/08 Page 15

THE BURNER IS NOW READY TO BE COMMISSIONED
COMMISSIONING - MODULATING BURNER
Hand Auto Selector Switch
This switch must always be in the ‘Auto’ position when the burner is required to start. The ‘Hand’
selection can be made immediately the burner has started to fire.
Should the burner be left in the ‘Hand’ position it will NOT modulate until the ‘Auto’ position is selected.
Commissioning the Burner
New MOL 3400 & 4100 modulating burners are generally supplied against the firing specification of the
appliance. In this case the system and spill pressure may be pre-set and require checking and minor
adjustments only. The following section describes how to set up the modulating cam box unit from a
‘scratch’ situation.
The modulating cam layshaft can be rotated by hand using the gearbox disengagement lever in the drive
servomotor.
Ensuring that the modulating cam arrangement is in the low flame position, adjust the oil cam (see fig 1,
page 17) so that it gives approximately 1.5mm throw (3mm stoke and lock in position).
Check to ensure that the spill valve push rod bears lightly against the oil cam.
Turning to the air cam (fig.2) rotate the thumbscrews in or out so that they give a reasonable amount of
adjustment in each direction. Adjust the flexible cable (at either end if necessary) until the air inlet
damper is fully closed (i.e. until all the slack is taken up on the cable).
Note:
Cams one and two control the high (cam one) and low (cam two) limits of the mechanism. These are
factory set and should not require any adjustment. However, in extreme circumstances the angle of
rotation can be reduced by adjustment of the appropriate cam. Any adjustment made will alter the oil
spill pressure.
Now adjust the thumbscrews to give a small opening of the air damper at low flame.
Uncover and replace the photocell. Reset the sequence control and allow the burner to start.
Immediately the burner starts, switch the hand/auto selector switch to the ‘hand’ position and hold low
flame until the appliance is ready to accept high flame. During this period, check and adjust the low
flame oil throughput.
Check the flame visually. If the flame is dirty, adjust the air cam thumbscrews until the flame becomes
clean.
After a suitable delay, inch the camshaft to the high flame position (i.e. through 180) by means of the
inching switch on the control panel. Adjust the air cam profile by means of the thumbscrews until the
air damper is now fully open. At this stage it will be found that all of the thumbscrews between low and
high position will require adjusting so as to avoid over stressing the cam profile band.
Once this has been done, there should be a fairly smooth profile between low and high positions.
Ensure that the flame is visually clean throughout the modulation range at all times.
MOL 3400-4100 Issue 2 10/08 Page 16

MOL 3400-4100 Issue 2 10/08 Page 17
MODULATING UNIT
(Cams shown in the Low Flame Position)

Check the oil consumption. If this is not correct for the full burner rating, the oil cam must be adjusted as
follows:-
a. Inch the burner to low flame and note the spill pressure
b. To increase the minimum rate, adjust as shown in fig.1.
c. Adjust the cam to give more eccentricity for more oil at high flame, and vice-versa.
d. Return to the minimum setting and compensate for any changes.
e. Inch the burner to high flame and again check the oil flow.
Continue to repeat a. to d. until the high flame oil rate is correct.
When a satisfactory setting has been achieved, lock the air cam thumbscrews with the grubscrews fitted in
the face side of the cam body. Refit the Modulating unit access cover.
Check the function of 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 actual air
pressure against the pressure switch dial setting.
Switch on the electrical supply and allow the burner to establish low flame.
Select ‘Hand’ control and ensure that the burner is at low flame by using the inching switch.
Slowly turn the air pressure switch adjusting dial clockwise until the flame is extinguished. The burner
will go to lockout.
Turn the dial one division anticlockwise and reset the burner lockout. The burner will now continue
through its cycle until flame is established or the burner goes to its lockout position. If the burner goes
to lockout repeat the procedure one division per burner cycle until flame is established. Once
successful turn the dial a further two divisions anticlockwise.
Switch off the burner electrical supply, replace the air pressure switch cover and remove the
manometer.
If the burner control is inclusive of Low, Excess Low and High Water interlocks and alarms, test that these
function correctly. Ensure that the boiler feed pump switchgear provided in the panel is operating
satisfactorily.
Adjust the boiler to attain the correct working pressure/temperature and adjust the on/off and limit
instruments to the desired values.
Switch the Hand/Auto selector switch to ‘Auto’. The plant is now under the control of the
pressure/temperature controllers for modulation and the on/off and high limit instruments for control.
Finally check ancillary controls and equipment such as damper interlocks etc.
MOL 3400-4100 Issue 2 10/08 Page 18

COMMISSIONING - HIGH/LOW BURNER
LOW FLAME
Switch on electricity supply. If controls are correctly set, burner fan will start, followed by oil pump,
providing air pressure switch changes over. Check rotation of each.
Air pressure switch is works set at 50mm wg, but may have to be adjusted to suit installation.
After pre-purge period has elapsed the low flame solenoid valve will open allowing oil to spray through the
low flame nozzle only and be ignited by the HT spark which is already present.
The photo-electric (PE) cell should take over and burner will run.
At this stage adjust the air regulator to give a visibly clean flame.
Do not fire the burner for long periods until warming up of appliance is completed. During warm-up
check lockout period by ‘blacking-out’ PE cell while burner is firing: burner should stop within one second.
Keep PE cell covered: after between 20 and 40 seconds burner should start its cycle again. It should lock
out five seconds after the low flame solenoid valve is energised. The air regulator should now be set to
give a CO2reading of 10-11% with a smoke number of 0-1.
HIGH FLAME
When the appliance is ready to be fired at high flame, move switch on control panel to this position. The
two high flame solenoid valves will be energised. The normally closed valve will open and allow
pressurised oil to pass to the hydraulic cylinder actuating the air regulator. At the same time the other,
normally open, high flame solenoid valve will close to prevent oil reaching the high flame nozzles until the
air regulator has moved and actuated the sequencing microswitch. The micro switch controls this second
high flame valve and should be adjusted to give a clean changeover from low to high flame. (See page 9).
With the burner operating on high flame adjust the air regulator to give a CO2reading of 12-13% and a
smoke number of 0-1.
If silencer has been removed, refit and again check CO2and smoke readings, readjusting the air regulator if
necessary.
MOL 3400-4100 Issue 2 10/08 Page 19