Comtherm PHC Series Instruction Manual

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Installation & Maintenance Manual
PH Burner
Burners, Heaters & Combustion Systems

PH Burner Instruction Manual
Page.1 .............................................GeneralSpecification
Page.2 .............................................GeneralDescription
Page.3 .............................................Installation
Page.4 .............................................Installation
Page.5 .............................................Installation
Page.6 .............................................Initial Light Up (Commissioning guidance)
Page.7 .............................................Initial Light Up (Commissioning guidance)
Page.8 .............................................Initial Light Up (Commissioning guidance)
Page.9 .............................................Initial Light Up (Commissioning guidance)
Page.10 ...........................................Fault Finding Guide
Page.11 ............................................Fault Finding Guide
Page.12 ............................................Fault Finding Guide
Page.13 ............................................Fault Finding Guide
Page.14 ............................................Fault Finding Guide
Page.15 ............................................Fault Finding Guide (Indirect Heaters)
Page.16 ............................................ Parts List (Key)
Page.17 ............................................Suggested Service Program
Page.18 ............................................SuggestedService Program
Page.19 ............................................BurnerService program
Page.20 ............................................Burner Commissioning Record
Additional Commissioning Notes
Index
Comtherm Ltd
Installation & Maintenance Manual
Burners, Heaters & Combustion Systems

The Comtherm and PHC' series of gas burners are designed to fire applications were
fresh or recirculated air is to be heated up to plant requirements. The burners can be installed
in air systems were it is not possible to construct a combustion chamber and install a
conventional type of burner assembly. The burners can be supplied for gap firing or flange
mounted in-line combustion head.
All the air required for combustion can be supplied by an integral combustion air fan mounted
on the burner head or provided that the process air has sufficient oxygen by developing
sufficient pressuredrop through profile plates on an design.
Typical applications; Industrial Dryers, Preheaters, Industrial Spray Booths, Direct Fired ARP
and AHU, Drying and Curing Rooms
The PH and PHC burner is modular with each 300mm section rated at 300kW whilst the PHC
is rated at 600 kW per 300mm section.
The burners are available in and sections which enable the burner to be
constructed to suit the appliance layout and in theory limitless in maximum output.
Typical Flame Lengths at Maximum Duty - 600mm
All valve assemblies on the burners are sized to suit an inlet gas pressure of 17.5 mbar
(natural gas) or 30mbar (LP gases) unless otherwise specified. Burners can be supplied to suit
other gastypes and supply pressures.
Combustion air PressureDrop across burner air wings;
PH 200 Pascals
PHC 300 Pascals
The nozzle mix design of the burner and the progressive air mixing feature of the combustion
head ensure that burners can operate with high turn down capability; turndown ratios up to
40:1 arepossible dependingon burner applicationsand selection.
The PH burner range is designed to always operate with approximately 30% excess
combustion air.
For high - low and modulating gas only burnerswith fixed combustion air.
The PH burner is not availablewith modulating gas and air control.
General Specification
Comtherm Ltd
Installation & Maintenance Manual
Page 01
Burners, Heaters & Combustion Systems

The burner consists of a gas manifold assembly having fuel and air jets designed to produce
effective mixing of the fuel and combustion air hence providing good flame stability.
The manifold assembly is fitted with integral ignition and flame sensor facilities.
The unit comes complete with all the valves and controls required; forming a fully packed, safe
burner assembly.
The valves and controls are pre-piped and mounted on the burner side plate, as illustrated
diagrammatically in document M4. Pressure test points are fitted between valves where
necessary.
The physical arrangement of the burner is shown in diagram form in document M3 (where
applicable).
All the electrical equipment on the unit is pre-wired to a terminal enclosure on the assembly,
as detailed in the burner wiring diagram in document M5.
The electrical operation of the burner is as follows:
When the electrical supply is switched on to the burner and all the control circuits are closed,
the burner light up sequence is initiated.
The burner flame safety sequence control unit (unit A1) receives the electrical start signal and
begins to cycle through an air pre-purgeand light up sequence.
The air pre-purge is for a specified, preset time and allows for dilution of any fuel leakage; to
safeguard against the possibility of explosive fuel/air mixture being present in the burner duct
when the ignition is energized.
After the completion of the pre-purge,the ignition and flame proving period take place.
When the flame signal is proven, the burner sequence control remains in the operating
position until any of the control circuit interlocks are broken or a flame failure (lockout)
condition occurs.
Complete details of the burner light-up sequence including the flame safety control unit (item
A1) will be found in the component data sheet, enclosed. For details on installation and
commissioning, referto pages 3-9.
NOTE: - See pages 16 for key to items referred to throughout this manual. Refer to documents
M!, M3, M4, M5, M9 sent with your contract for specific component manufacturers used on
this equipment.
General Description
Comtherm Ltd
Installation & Maintenance Manual Page 02
Burners, Heaters & Combustion Systems

Before proceeding with the installation of the burner, inspect the burner for any physical
damage that may have occurred during transit, storage or off-loading. Any damage should
be reportedimmediately.
The pipe work or gas valves on the burner should not be used for lifting under any
circumstances, as this tends to pull fittings loose or damage valves, causing leaks during later
operation.
Mount the burner in the firing position, making sure that adequate space is allowed around
the burner for ventilation and that the combustion air inlet is not blocked. Ensure that an
adequate fresh air supply is available for combustion and generalventilation.
Situations where gas from valve and pipe work leaks can collect and form pockets of
combustible gas/air must be avoided.
Ensure that adequate space is allowed around the burner for easy access to all burner
components, pressureswitches, control operatorsetc.
The burner should be securely fixed and the transmission of vibration and heat should be
minimised.
GAS SUPPLY:
Gas piping to the burner should be of sufficient size to provide the correct gas pressure at the
burner valve assembly inlet (see specificationon pageM1).
If in any doubt concerning the size and design of the gas supply pipe work, consult the gas
supply company.
The pressure loss in the gas supply pipe work should be such that the following pipeline
velocities are not exceeded:
Unfiltered supply 20M/s (65.6ft.sec)
Filtered supply (250microns) 45M/s (148ft.sec)
The above stated velocities are based on the avoidance of excessive noise pollution and
erosion.
For low-pressure supplies up to 25 mbar (10 w.c), the pressure drop between the meter and
the burner inlet should normally not exceed 1mbar (0.4 w.c). For high-pressure supplies, this
pressuredropshould not exceed 10%of the available gaspressure.
Installation
Comtherm Ltd
Installation & Maintenance Manual
Page 03
Burners, Heaters & Combustion Systems

A manual shut off valve followed by a union or flangedjoint should beincorporatedin the
Gas supply pipe adjacent to the burner, this valve permits isolation of the supply and removal
of the burner assembly for maintenance purposes.
The manual shut off valve should be easily accessible.
Do not use the burner valve assembly to support the gas supply pipe work. Suitable brackets
or hangersshould be used for this purpose.
Before connecting the gas supply check that the available gas pressure is correct (see
specification in document M1).
Check that the gas supply system has been designed and installed to ensure that during fault
conditions, pressuresin excess of the maximum designratingof the equipmentcan not be
reached.
If the burneris installed in aconfined spaceconsiderationshould be taken forthe fitting of a
vent pipe to the breatherholes of governors.
Vents from governorsmust not be manifoldedand should terminate in a safe place,preferably
above roof level.
Any additional vent pipes that are requiredwill be shown in document M4.
The gas supply pipe will be full of air andwill require purging.
This purging should only be carried out by a suitably qualified gas engineer.
With regardto the soundness (leak) testing and purgingof the supply pipework ensure that a
certificate exists stating that this work has been completed in accordancewith technical
publications EN 746-2.
After completion of the installationwork, the procedurefor testing for gasleaks on the burner
detailed in the manual section pages 10-15, should be completed and any leaks repaired.
The burnershould be left with the manual shut off valve (item V1) in the closed position until
the plant is commissioned by a suitably qualified gas engineer.
Installation (Continued)
Comtherm Ltd
Installation & Maintenance Manual Page 04
Burners, Heaters & Combustion Systems

ELECTRICAL SUPPLY:
Burners can be supplied to suit almost all types of electrical power supply; including all
common industrial three phase (50 or 60Hz) power supplies and with 110/120v or
220/240v control circuits. Burners to suit other electrical supply voltages can be supplied
specially to suit specific application requirements.
All wiring on the burner should comply with the requirements of the local electrical codes of
practice.
All conduits should be kept clearof heat zones.
Local means of electrical isolation should be installed close to the burner.
Ensure that the electrical voltage does not vary from the specified by morethan 6%.
High temperaturewire (tri-rated or better) should beused for all electrical connections.
The electrical connections to the burner shown on diagram M5 should be strictly adheredto.
Gas pipe work should not be used as an electrical earth.
Installation (Continued)
Comtherm Ltd
Installation & Maintenance Manual
Page 05
Burners, Heaters & Combustion Systems

PLEASE NOTE:
Without exception, burners should only be commissioned by suitably qualified
personnel. The following notes are intended as guidance and in no way negate the
need for the equipment to be commissioned by suitably qualified personnel.
1. Examine the burner for physicaldamage.
2. Close all manual fuel valves.
3. Check that the electrical supply is switched off.
4. Check all electrical connections to ensure that the combustion air pressure switch (item P1)
and the safety shut off valve (item S1) are wired to the correct terminals in the burner
safety control unit (see electrical diagram in document M5)
5. Check the incoming gas pressure (at V1) and verify that the inlet gas pressure is as
specified (see document M1).Generally speaking, the inlet gas pressure, without the
burner operating,will be somewhat higher than when the burner is in operation.
6. Ensure that the burner on/off switch is in the position.
7. Switch the electrical supply on.
8. Check for gasleaks on the burneras follows:
(a) Close the manual valve V1 and pilot manual valve V6.
(b) Vent burner pipe work downstream of V1 by opening a suitably positioned test
nipple.
(c) Use a manometer test pressure downstream of V1 for 1.5 minutes. If no pressure
buildsup, valve V1 is not leaking.
(d) Open valve V1.
(e) Check for external leakage using a soap solution or gasdetector on
pipe work and valves, rectifying any leaks before proceeding.
(f) Put temporary electrical supply onto valve S1.This will pressurise the space
between S1 and S2. Open the test point downstream of S2 and connect the
manometer (valve V2 must be closed); if no pressure builds up within 1.5 minutes then
valve S2 is sound.
Initial Light Up (Commissioning)
Comtherm Ltd
Installation & Maintenance Manual Page 06
Burners, Heaters & Combustion Systems

(g) Disconnect the electrical supply to valve S1 and vent the space
between valve S1 and S2, using the pressuretest nipple. Using the
manometer, check that no pressure builds up between the two valves; if no pressure
is detected then valve S1 is sound
(h) Open pilot manual valve V6 and check by using the test nipple downstream of V1
that there is no pressure drop at this point. If no pressure drop is detected in 1.5
minutes then valve S3 is not leaking.
(i) Finally, check downstream of V2 and V3 with soap solution or gas detector (with
burner running).
In cases where burners are fitted with main multi-block / combination safety valve units, the
above procedure will vary; the valve should be energized to check for downstream pipe
leakages and de-energised followed by venting of downstream pipe space to check for valve
seat leakages.
9. Release the spring pressure on the gas governor (item G2).
10.Set the combustion air pressure switch (item P1) 25% below the specified air pressure
required.
11. Start the fan supplying the combustion air and ensure that the fan rotation direction is
correct.
Check the running current of the motor and crosscheck this with the data on the Motor label.
Ensure that the motor overload protection is correctly set.
12.Ensure that valves V2 and V6 areclosed.
13.Check that all pressure switches associated with the burner are in the correct position.
Note that the burner combustion air pressure switch (item P1) should be in the
position and should only switch over after the combustion air fan has started
14. Check that all pressure switches associated with the burner arein the position calling
for and switch the burner on.It may be necessary to reset the burnerlockout fault button.
Initial Light Up (Commissioning)
Comtherm Ltd
Installation & Maintenance Manual
Page 07
Burners, Heaters & Combustion Systems

15.Allow the flame safety control unit (item A1) to cycle through the start up sequence; check
that the pressure switch (P1) has changed over from the `no to the air proved position.
If it adjust the combustion air supply so as to provide satisfactory burner air
pressure. Check that the ignition and pilot solenoid valves are electrically energised at the
correct time and in the correct sequence. The burner flame safety control unit should then
lockout.
16.Open the manual pilot valve (item V6)
17.Fit Micro-ammeter into circuit with the flame sensor.
18.Reset the burner lockout button; the burner will cycle and the pilot flame should light. It
maybe necessary to start the light up sequence (reset) several times so as to remove air
from the pilot line and to adjust the pilot flame to the correct size. Check the pilot flame
signal on the micro-ammeter.
19.Note that the burner will go to lockout after each attempt to light the pilot.
20.Half open the manual test valve (item V2). Reset the burner lockout button. The burner
should cycle and light up onto the main flame.
21.Slowly open up the manual test valve (item V2) to the full position and adjust the main gas
governor (item G2) to produce the required flame size. With the burner on full fire
(temperature control calling heat) check that the gas pressure at the nozzle is as specified
for the required thermal/fuel rating, this will be indicated on the burner data label and
can also be established from the nozzle flow graph included with this manual.
22.Check the main flame signal on the micro-ammeter.
23.Turn the combustion air pressure switch (item P1) upwards so that the burner shuts down.
Note the adjustments in air pressureand reduce the switch setting by 25%.
24.Whilst the burner is operating remove the electrical connections from the flame sensor.
Check that the burner flame safety control locks out immediately and that the gas supply is
automatically shut off.
25. Whilst the burner is operating, block the combustion air supply so that the pressure switch
P1 switches to the position, checking that the burner shuts down.
Initial Light Up (Commissioning)
Comtherm Ltd
Installation & Maintenance Manual Page 08
Burners, Heaters & Combustion Systems