Riello RLS 28 Quick start guide

C6505058 - 2915759 (5) - 11/2009
Installation, use and maintenance instructions
Forced draught gas burner
Progressive two-stage or modulating operation
CODE MODEL
C9531000 (3483270) RLS 28
C9532000 (3484170) RLS 38
C9533000 (3484670)
C9533001 (3484670) RLS 50
(3484675) RLS 50

Contents
1 C6505058 - 2915759
1 Information and general instructions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1 Information about the instruction manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.2 General dangers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.3 Safety precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.1.4 Danger: live components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.2 Guarantee and responsibility . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
1.2.1 Owner’s responsibility. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 Safety and prevention . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.1 Introduction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
2.2 Personnel training. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
3 Technical description of the burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1.1 Burner models designation: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
3.1.2 Accessories (optional): . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2 Burner description. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.2.1 Packaging - weight - Approximate measurements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2.2 Max. dimensions - Approximate measurements. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2.3 Standard equipment . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
3.2.4 Firing rates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
3.2.5 Minimum furnace dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9
4 Installation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.1 Notes on safety for the installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.2 Handling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.3 Preliminary checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
4.4 Boiler plate . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.5 Blast tube length. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.6 Securing the burner to the boiler . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
4.7 Choice of nozzles for 1st and 2nd stage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
4.8 Nozzle assembly. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.9 Adjustments before first firing (light-oil operation). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.10 Servomotor. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.11 Pump . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.12 Fuel supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.13 Hydraulic connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.14 Pump priming . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.15 Burner calibration (light-oil operation). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.16 Gas pressure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.17 Gas piping. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.18 Gas train. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
4.19 Adjustments before first firing (gas operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5 Start-up, calibration and operation of the burner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.1 Notes on safety for the first start-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.2 Burner starting (gas operation). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.3 Burner firing (gas operation). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4 Burner calibration (gas operation) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4.1 High fire output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4.2 Low fire output . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
5.4.3 Air pressure switch - CO check . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.4.4 Low gas pressure switch . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

C6505058 - 2915759 2
Contents
6 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.1 Notes on safety for the maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
6.2 Opening the burner. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.2.1 To open the burner: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.2.2 To close the burner: . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.3 Hydraulic system layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.3.1 Oil pressure switch. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
6.3.2 Combustion checks . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
7 Electrical system . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.1 Electrical wiring. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
7.2 Field wiring connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.3 External fuses (see the electrical diagram) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
7.4 Burner firing rates according to air density. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
7.5 Flame signal. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.6 Sequence of operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.7 Firing failure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
7.8 Burner flame goes out during operation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35
8 Spare parts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
8.1 Exploded spare parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 38
8.2 Spare parts list . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39

Information and general instructions
3 C6505058 - 2915759
1.1 Information about the instruction manual
1.1.1 Introduction
The instruction manual supplied with the burner:
³is an integral and essential part of the product and must not be
separated from it; it must therefore be kept carefully for any
necessary consultation and must accompany the burner even
if it is transferred to another owner or user, or to another sys-
tem. If the manual is lost or damaged, another copy must be
requested from the Technical Assistance Service of the area;
³is designed for use by qualified personnel;
³offers important indications and instructions relating to the
installation safety, start-up, use and maintenance of the
burner.
Symbols used in the manual
In some parts of the manual you will see triangular DANGER
signs. Pay great attention to these, as they indicate a situation
of potential danger.
1.1.2 General dangers
The dangers can be of 3 levels, as indicated below.
1.1.3 Safety precautions
Good safety practices must be used when working on burner
equipment. The potential energy in the electrical supply, fuel and
related equipment must be handled with extreme care to prevent
equipment failures, injuries and potential death.
1.1.4 Danger: live components
Other symbols
³This symbol indicates a list.
Abbreviations used
Ch. Chapter
Fig. Figure
Pag. Page
Sec. Section
Tab. Table
Delivery of the system and the instruction manual
When the system is delivered, it is important that:
³The instruction manual is supplied to the user by the system
manufacturer, with the recommendation to keep it in the room
where the heat generator is to be installed.
³The instruction manual shows:
– the serial number of the burner;
– the address and telephone number of the nearest Assis-
tance Centre;
³The system supplier carefully informs the user about:
– the use of the system,
– any further tests that may be necessary before the system is
started up,
– maintenance and the need to have the system checked at
least once a year by the manufacturer or another specialised
technician.
To ensure a periodic check, the manufacturer recommends
the drawing up of a Maintenance Contract.
1 Information and general instructions
DANGER
Maximum danger level!
This symbol indicates operations which, if not car-
ried out correctly, cause serious injury, death or
long-term health risks.
WARNING
This symbol indicates operations which, if not car-
ried out correctly, may cause serious injury, death
or long-term health risks.
CAUTION
This symbol indicates operations which, if not car-
ried out correctly, may cause damage to the ma-
chine and/or injury to people.
WARNING
If you smell gas, open window, extinguish any open
flames, stay away from electrical switches, evacu-
ate the building and immediately call the gas com-
pany.
If this equipment is not installed, operated, operated
and maintained in accordance with the manufactur-
ers intructions, this product could expose you to
substances in fuel or from fuel combustion which
can cause death or serious illness.
Improper servicing of this equipment may create a
potential hazard to equipment and operators.
Servicing must be done by a fully trained and
qualified personnel.
DANGER
This symbol indicates operations which, if not car-
ried out correctly, lead to electric shocks with lethal
consequences.
ENVIRONMENTAL PROTECTION
This symbol gives indications for the use of the ma-
chine with respect for the environment.
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C6505058 - 2915759 4
Information and general instructions
1.2 Guarantee and responsibility
The manufacturer guarantees its new products from the installa-
tion date, in accordance with the regulations in force and/or the
sales contract. At the moment of the first start-up, check that the
burner is integral and complete.
In particular, the rights to the guarantee and the responsibility
will no longer be valid, in the event of damage to things or injury
to people, if such damage/injury was due to any of the following
causes:
³incorrect installation, start-up, use and maintenance of the
burner;
³improper, incorrect or unreasonable use of the burner;
³intervention of unqualified personnel;
³carrying out of non authorised modifications on the equipment;
³use of the burner with safety devices that are faulty, incorrectly
applied and/or not working;
³installation of untested supplementary components on the
burner;
³powering of the burner with unsuitable fuels;
³faults in the fuel power supply system;
³use of the burner even following an error and/or an irregularity;
³repairs and/or overhauls incorrectly carried out;
³modification of the combustion chamber with inserts that pre-
vent the regular development of the flame, as structurally
established;
³insufficient and inappropriate surveillance and care of those
burner components most subject to wear and tear;
³use of non-original components, including spare parts, kits,
accessories and optionals;
³force majeure.
the manufacturer furthermore declines any and every re-
sponsibility for the failure to observe the contents of this
manual.
1.2.1 Owner’s responsibility
Please pay attention to the Safety Warnings contained within
this instruction manual. Keep this manual for your records and
provide it to your quali fi ed service agency for use in profession-
ally setting up and maintaining your burner.
Your burner will provide years of ef fi cient operation if it is pro-
fessionally installed and maintained by a qualifi ed service tech-
nician. If at any time the burner does not appear to be operating
properly, immediately contact your qualifi ed service agency for
consultation.
We recommend annual inspection/service of your gas heating
system by a qualifi ed service agency.
Failure to follow these instructions, misuse, or incorrect adjust-
ment of the burner could lead to equipment malfunction and re-
sult in asphyxiation, explosion or fire.
WARNING
Failure to observe the information given in this man-
ual, operating negligence, incorrect installation and
the carrying out of non authorised modifications will
result in the annulment by the manufacturer of the
guarantee that it supplies with the burner.
WARNING
If you smell gas:
³Do not touch any electrical items.
³Open all windows.
³Close all gas supply valves.
³Contact your local gas authority immediately.
• Do not store flammable or hazardous materials
in the vicinity of fuel burning appliances.
• Improper installation, adjustment, alteration,
service or maintenance can cause property
damage, personal injury or death.
• Refer to this manual for instructional or addition-
al information.
• Consult a certified installer, service representa-
tive or the gas supplier for further assistance.
• Burner shall be installed in accordance with
manufacturers requirements as outlined in this
manual, local codes and authorities having ju-
risdiction.

Safety and prevention
5 C6505058 - 2915759
2.1 Introduction
The burners have been designed and built in compliance with
current regulations and directives, applying the known technical
rules of safety and envisaging all the potential danger situations.
It is necessary, however, to bear in mind that the imprudent and
clumsy use of the equipment may lead to situations of death risk
for the user or third parties, as well as the damaging of the burn-
er or other items. Inattention, thoughtlessness and excessive
confidence often cause accidents; the same applies to tiredness
and sleepiness.
It is a good idea to remember the following:
³The burner must only be used as expressly described.
Any other use should be considered improper and therefore
dangerous.
In particular:
it can be applied to boilers operating with water, steam,
diathermic oil, and to other users expressly named by the
manufacturer;
the type and pressure of the fuel, the voltage and frequency of
the electrical power supply, the minimum and maximum deliv-
eries for which the burner has been regulated, the pressurisa-
tion of the combustion chamber, the dimensions of the
combustion chamber and the room temperature must all be
within the values indicated in the instruction manual.
³Modification of the burner to alter its performance and destina-
tions is not allowed.
³The burner must be used in exemplary technical safety condi-
tions. Any disturbances that could compromise safety must be
quickly eliminated.
³Opening or tampering with the burner components is not
allowed, apart from the parts requiring maintenance.
³Only those parts envisaged by the manufacturer can be
replaced.
2.2 Personnel training
The user is the person, body or company that has acquired the
machine and intends to use it for the specific purpose. He is re-
sponsible for the machine and for the training of the people
working around it.
The user:
³Undertakes to entrust the machine exclusively to suitably
trained and qualified personnel.
³Must take all the measures necessary to prevent unauthorised
people gaining access to the machine.
³Undertakes to inform his personnel in a suitable way about the
application and observance of the safety instructions. With
that aim, he undertakes to ensure that everyone knows the
use and safety instructions for his own duties.
³Must inform the manufacturer if faults or malfunctioning of the
accident prevention systems are noticed, along with any pre-
sumed danger situation.
³Personnel must always use the personal protective equipment
envisaged by legislation and follow the indications given in this
manual.
³Personnel must follow all the danger and caution indications
shown on the machine.
³Personnel must not carry out, on their own initiative, opera-
tions or interventions that are not within their province.
³Personnel are obliged to inform their superiors of every prob-
lem or dangerous situation that may arise.
³The assembly of parts of other makes, or any modifications,
can alter the characteristics of the machine and hence com-
promise operating safety. The manufacturer therefore
declines any and all responsibility for any damage that may
be caused by the use of non-original parts.
2 Safety and prevention

C6505058 - 2915759 6
Technical description of the burner
3.1 Technical data
Tab. A
(1) Reference conditions: Ambient temperature 68 °F (20°C) - Barometric pressure 394” WC - Altitude 329 ft.
(2) Pressure at test point 7) (Fig. 1, page 7) with zero pressure in the combustion chamber and maximum burner output.
(3) Sound pressure measured in manufacturer’s combustion laboratory, with burner operating on test boiler and at maximum rated output.
(4) Equivalent Btu values based on 1 USGPH = 140,000 Btu/hr.
3.1.1 Burner models designation:
Tab. B
3 Technical description of the burner
MODEL RLS 28 RLS 38 RLS 50 RLS 50
Output (1)
Delivery (1)
2nd stage MBtu/hr(4)
kW
GPH
616 - 1232
181 - 361
4.4 - 8.8
882 - 1666
258 - 488
6.3 - 11.9
1092 - 2198
320 - 644
7.8 - 15.7
1092 - 2198
320 - 644
7.8 - 15.7
min. 1st stage MBtu/hr(4)
kW
GPH
378
111
2.7
434
127
3.1
546
160
3.9
546
160
3.9
Fuel #2 Fuel oil
Natural gas / Propane gas
Gas pressure at maximum delivery (2),
Gas: Natural gas ” WC 4.33 5.11 5.51 5.51
Operation low-high
Nozzles number 2
Ambient temperature °F 32 - 104 (0 - 40 °C)
Combustion air temperature °F max 140 (60 °C)
Main power supply (+/- 10%) V/Ph/Hz 120/1/60 208-230/460/
575/3/60 120/1/60
Electric motors rpm 3400
Fan motor
Fan motor capacitor
V
W - HP
A
µF
120
370 - 0.5
5.2
45
120
370 - 0.5
5.2
45
208 - 230 / 460 /
575
550 - 0.75
3.2 - 1.6 - 1.3
n/a
120 - 230
550 - 0.75
9.8 - 4.9
40
Pump motor
Pump motor capacitor
V
W - HP
A
µF
120
90 - 0.12
0,8
12,5
Ignition transformer Oil V1 - V2
I1 - I2 120 V - 2 x 5 kV 3.7 A - 35 mA
Gas V1 - V2
I1 - I2 120 V - 1 x 7 kV 1.6 A - 23 mA
Pump Delivery (at 174 PSI)
Pressure range
Fuel temperature
GPH
PSI
° F max
21.5
58 - 261
140 (60 °C)
Electrical power consumption W max 760 760 910 860
Electrical protection NEMA 1
Noise Levels (3) dBA 68 70 72 72
Model Code Voltage Flame safeguard
RLS 28 C9531000 (3483270) 120/1/60 Burner mounted
RLS 38 C9532000 (3484170) 120/1/60 Burner mounted
RLS 50 C9533000 (3484670)
C9533001 (3484670)
(3484675)
208-230/460/3/60
575/3/60
120/1/60
Burner mounted
Burner mounted
Burner mounted

Technical description of the burner
7 C6505058 - 2915759
3.1.2 Accessories (optional):
• Kit for lengthening the combustion head
L = Standard length
L1 = Length obtainable with the kit
COD. 3010264 L = 7 1/2” L1 = 12 27/32” • RLS 28
COD. 3010265 L = 7 29/32“ L1 = 13 7/32” • RLS 38
COD. 3010266 L = 8 1/2” L1 = 13 13/16” • RLS 50
•Kit for LPG operation - Code 3010304: The kit allows the RLS
28-38-50 burners to operate on LPG.
•Gas train according to UL Standards: see page 18.
NOTE
:
The installer is responsible for the supply and installation of
any required safety device(s) not indicated in this manual.
3.2 Burner description
1 Combustion head
2 Ignition electrodes
3 Screw for combustion head adjustment
4Sleeve
5 Low air pressure switch (differential operating type)
6 Air pressure test point
7 Gas pressure test point and head fixing screw
8 Screw securing fan to sleeve
9 Slide bars for opening the burner and inspecting the combus-
tion head
10 Pump
11 Safety solenoid valve
12 Low and high fire oil valves
13 Servomotor
14 UV scanner
15 Plate with four hole knock-outs for flexible hoses and electri-
cal cable routing.
16 Air inlet to fan
17 Gas input connection
18 Boiler mounting flange
19 Flame stability disk
20 Flame inspection window
21 Oil / gas selector switch
22 Fan motor contactor and thermal overload with reset button
(RLS 50 three-phase)
23 Flame safeguard with lock-out pilot light and lock-out reset
button
24 Power switch for different operations:
automatic - manual - off
Button for:
power increase - power reduction
25 Burner terminal strip
26 Low oil pressure switch
27 Pump motor
28 Protection (for RLS 50 single-phase burner)
Two types of burner failure may occur:
•Flame safeguard lock-out:
if the flame relay 23) (Fig. 1) pushbutton lights up, it indicates
that the burner is in lock-out.
To reset, press the pushbutton.
•Motor trip (RLS 50 three-phase):
Release by pressing the pushbutton on the thermal overload
22)(A).
D7638
D2536
D1118
Fig. 1

C6505058 - 2915759 8
Technical description of the burner
3.2.1 Packaging - weight - Approximate measurements
• The burners are shipped in cardboard boxes with the maximum
dimensions shown in (Tab. C).
• The weight of the burner complete with packaging is indicated
in (Tab. C).
Tab. C
3.2.2 Max. dimensions - Approximate measurements
The maximum dimensions of the burners are given in (Fig. 3).
Note that if you need to examine the combustion head, the burner
must be pulled backward on the slide bars and turned upward.
The maximum dimension of the burner, without the cover, when
open is given by measurement H.
Tab. D
3.2.3 Standard equipment
1 - Gas train flange
1 - Flange gasket
4 - Flange fixing screws
4 - Screws to secure the burner flange to the boiler: 3/8 W x 1”
1 - Adaptor G 1/8“ / 1/8“ NPT
1 - Instruction booklet
1 - Spare parts list
inch ABClbs
RLS 28 39 31/32” 24 13/16” 19 11/16” 95
RLS 38 39 31/32” 24 13/16” 19 11/16” 99
RLS 50 three-phase 39 31/32” 24 13/16” 19 11/16” 101
RLS 50 single-phase 39 31/32” 24 13/16” 21 11/16” 103
D88 Fig. 2
A1
B
E
F
M
L
C
H
I
G D
A
D7639
Fig. 3
inch A A1 B C D E F G H I L M
RLS 28 18 23/32” -18 21/32” 22 13/16” 7 1/2” 5 1/2” 13 27/32” 6 7/16” 31 7/8” 4 1/4” 6 5/8” 1 1/2”
RLS 38 18 23/32” -18 21/32” 22 13/16” 7 29/32” 5 31/32” 13 27/32” 6 7/16” 31 7/8” 4 1/4” 6 5/8” 1 1/2”
RLS 50 three-phase 18 23/32” -18 21/32” 22 13/16” 8 1/2” 5 31/32” 13 27/32” 6 7/16” 31 7/8” 4 1/4” 6 5/8” 1 1/2”
RLS 50 single-phase -21 3/16” 18 21/32” 22 13/16” 8 1/2” 5 31/32” 13 27/32” 6 7/16” 31 7/8” 4 1/4” 6 5/8” 1 1/2”

Technical description of the burner
9 C6505058 - 2915759
3.2.4 Firing rates
The RLS 28 - 38 - 50 Model burners can work in two ways: low and
high fire.
MAXIMUM OUTPUT must be selected in area A.
MINIMUM OUTPUT must not be lower than the minimum limit
shown in the diagram:
RLS 28 = 378 MBtu/hr = 2.7 GPH
RLS 38 = 434 MBtu/hr = 3.1 GPH
RLS 50 = 546 MBtu/hr = 3.9 GPH
NOTE
:
The FIRING RATE areas given in (Fig. 4) have been reduced by
10% with respect to the maximum range that can be reached.
Consult on page 34 for operation at different ambient temperatures
and/or altitudes.
3.2.5 Minimum furnace dimensions
The firing rates were set in relation to certified test boilers.
Figure (Fig. 5) indicates the diameter and length of the test com-
bustion chamber.
Example:
output 1388 MBtu/hr:
diameter 20 inch - length 4.9 ft.
RLS 28
RLS 38
RLS 50
Combustion chamber pressure
“WC
Combustion chamber pressure
“WC
Combustion chamber pressure
“WC
Fig. 4
D2537
WARNING
The firing rate area values have been obtained con-
sidering an ambient temperature of 68 °F (20°C),
and an atmospheric pressure of 394” WC and with
the combustion head adjusted as shown on
page 14.
D2918
Length (ft)
Furnace dimensions
Diameter (inches)
Fig. 5

C6505058 - 2915759 10
Installation
4.1 Notes on safety for the installation
After carefully cleaning all around the area where the burner will
be installed, and arranging the correct lighting of the environ-
ment, proceed with the installation operations.
4.2 Handling
The packaging of the burner includes a wooden platform, so it is
possible to move the burner (still packaged) with a transpallet
truck or fork lift truck.
With regard to the transport in the obligatory passages, refer to
the overall dimensions shown in Fig. 2, page 8.
Check also that the area in which you are working is empty and that
there is an adequate escape area (i.e. a free, safe area to which
you can quickly move if the burner should fall).
During the handling, keep the load at not more than 10” from the
ground.
4.3 Preliminary checks
Checking the consignment
4 Installation
DANGER
All the installation, maintenance and disassembly
operations must be carried out with the electricity
supply disconnected.
WARNING
The installation of the burner must be carried out by
qualified personnel, as indicated in this manual and
in compliance with the standards and regulations of
the laws in force.
WARNING
The handling operations for the burner can be high-
ly dangerous if not carried out with the greatest at-
tention: keep any unauthorised people at a
distance; check the integrity and suitableness of the
available means of handling.
CAUTION
After positioning the burner near the installation
point, correctly dispose of all residual packaging,
separating the various types of material.
Before proceeding with the installation operations,
carefully clean all around the area where the burner
will be installed.
CAUTION
After removing all the packaging, check the integrity
of the contents. In the event of doubt, do not use the
burner; contact the supplier.
The packaging elements (wooden cage or card-
board box, nails, clips, plastic bags, etc.) must not
be abandoned as they are potential sources of dan-
ger and pollution; they should be collected and dis-
posed of in the appropriate places.
WARNING
The output of the burner must be within the boiler's
firing rate;
WARNING
A burner label that has been tampered with, re-
moved or is missing, along with anything else that
prevents the definite identification of the burner
makes any installation or maintenance work diffi-
cult.

Installation
11 C6505058 - 2915759
4.4 Boiler plate
Drill the combustion chamber mounting plate as shown in (Fig. 6).
The position of the threaded holes can be marked using the head
gasket supplied with the burner.
4.5 Blast tube length
The length of the blast tube must be selected according to the indi-
cations provided by the manufacturer of the boiler, and it must be
greater than the thickness of the boiler door complete with its insu-
lation. The range of lengths available, L (inch), is as follows
Blast tube 10): RLS 28 RLS 38 RLS 50
• short 71/2“ 729/32“ 81/2“
• long 1227/32“ 137/32“ 1313/16“
For boilers with front flue passes 13) or flame inversion chambers,
protective insulation 11) must be inserted between the boiler re-
fractory 12) and the blast tube 10).
This protective insulation must not compromise the extraction of
the blast tube.
For boilers having a water-cooled front the insulation 11)-12)
(Fig. 7) is not required unless it is required by the boiler manufac-
turer.
4.6 Securing the burner to the boiler
Detach the combustion head from the burner, (Fig. 7):
- disconnect the oil pipes by unscrewing the two connectors 4).
- remove screw 14) and withdraw the cover 15).
- remove the screws 2) from the slide bars 3).
- remove screw 1) and pull the burner back on slide bars 3) by
about 4”.
Disconnect the electrode wires and then pull the burner com-
pletely off the slide bars, after removing the split pin from the
slide bar 3).
Secure the flange 9) (Fig. 7) to the boiler plate, inserting the gas-
ket 6) (Fig. 7). Use the 4 screws, also supplied with the unit, after
first protecting the thread with an anti-locking product.
The seal between burner and boiler must be airtight.
inch A B C
RLS 28 6 9/32“ 8 13/16“ 3/8W
RLS 38 6 9/32“ 8 13/16“ 3/8W
RLS 50 6 9/32“ 8 13/16“ 3/8W D455 Fig. 6
D2538
Fig. 7

C6505058 - 2915759 12
Installation
4.7 Choice of nozzles for 1st and 2nd stage
The burner complies with the emission requirements of the UL 296
standard.
In order to guarantee that emissions do not vary, recommended
and/or alternative nozzles specified by the manufacturer in the
Instruction and warning booklet should be used.
Both nozzles must be chosen from among those listed in (Tab. E).
The first nozzle determines the delivery of the burner at low fire.
The second nozzle works together with the 1st nozzle to determine
the delivery of the burner at high fire.
The deliveries at low and high fire must be contained within the val-
ue range indicated on page 6.
Use nozzles with a 60° spray angle at the recommended pressure
of 174 PSI.The two nozzles usually have equal deliveries.
Example with the RLS 28 Model
Boiler output = 921 MBtu/hr @ efficiency 80 %
Output required by the burner =
921 / 0.8 = 1151 MBtu/hr
1151 / 2 = 576 MBtu/hr (4.0 USGPH) per nozzle
therefore, two equal, 60°, 174 PSI nozzles are required:
1° = 4.00 GPH with 2° = 4.00 GPH,
or the following two different nozzles:
1° = 4.50 GPH with 2° = 3.50 GPH,
or:
1° = 3.50 GPH with 2° = 4.50 GPH.
Tab. E
WARNING
It is advisable to replace nozzles every year dur-
ing regular maintenance operations.
CAUTION
The use of nozzles other than those specified by
the manufacturer and inadequate regular main-
tenance may result into emission limits non-
conforming to the values set forth by the regu-
lations in force, and in extremely serious cases,
into potential hazards to people and objects.
The manufacturing company shall not be liable
for any such damage arising from nonobser-
vance of the requirements contained in this
manual.
NOZZLE
GPH
GPH MBTU/h
145 PSI 174 PSI 203 PSI 174 PSI
RLS 28
2.00
2.25
2.50
3.00
3.50
2.47
2.75
3.07
3.68
4.32
2.72
3.04
3.39
4.07
4.74
2.95
3.33
3.68
4.42
5.16
381
426
475
570
664
RLS 38
2.50
3.00
3.50
4.00
4.50
5.00
3.07
3.68
4.32
4.93
5.54
6.15
3.39
4.07
4.74
5.44
6.12
6.79
3.68
4.42
5.16
5.89
6.63
7.36
475
570
664
762
857
951
RLS 50
3.00
3.50
4.00
4.50
5.00
5.50
6.00
3.68
4.32
4.93
5.54
6.15
6.76
7.40
4.07
4.74
5.44
6.12
6.79
7.46
8.17
4.42
5.16
5.89
6.63
7.36
8.10
8.87
570
664
762
857
951
1044
1144
60
Fig. 8
D1122

Installation
13 C6505058 - 2915759
4.8 Nozzle assembly
Remove screw 1) (Fig. 8, page 12) and extract the internal part 2)
(Fig. 8, page 12) Install two nozzles with the box wrench 1) (Fig. 9),
after having removed the plastic plugs 2) (Fig. 9), fitting the wrench
through the central hole in the flame stability disk or loosen screws
1) (Fig. 10), remove disk 2) (Fig. 10) and replace the nozzles using
the wrench 3) (Fig. 10).
The nozzle for low fire operation is the one underneath the firing
electrodes (Fig. 11).
Make sure that the electrodes are positioned as shown in (Fig. 11).
Refit the burner 4) (Fig. 12) to the slide bars 3) at approximately 4”
from the sleeve 5) - burner positioned as shown in (Fig. 7, page 11)
- insert the ignition electrode cables and then slide the burner up to
the sleeve so that it is positioned as shown in (Fig. 12).
Refit screws 2) (Fig. 12) on slide bars 3).
Secure the burner to the sleeve by tightening screw 1) and then re-
fit the split pin into one of two slide bars 3).
Connect the oil pipes again by screwing on the two connectors 4)
(Fig. 7, page 11).
NOTE
:
When fitting the burner on the two slide bars, it is advisable to
gently draw out the high tension cables until they are slightly
stretched.
WARNING
³Do not use any sealing products such as gas-
kets, sealing compound, or tape.
³Be careful to avoid damaging the nozzle seal-
ing seat.
³The nozzles must be screwed into place tightly
but carefully.
Fig. 9
D1146
Fig. 10
D1147
D2539
Fig. 11
Fig. 12
D2541

C6505058 - 2915759 14
Installation
4.9 Adjustments before first firing (light-oil operation)
• Combustion head setting
The setting of the combustion head depends exclusively on the
delivery of the burner at high fire. Turn screw 5) (Fig. 13) until
the notch shown in diagram (Fig. 14) is level with the front sur-
face of flange 6) (Fig. 13).
• Example burner RLS 38:
High fire burner delivery = 9.6 GPH.
If diagram (Fig. 14) is consulted it is clear that for this delivery,
the combustion head must be adjusted using notch 4, as
shown in (Fig. 13).
• Pump adjustment
No settings are required for the pump, which is set to 174 PSI
by the manufacturer. This pressure must be checked and ad-
justed (if required) after the burner has been ignited.
The only operation required in this phase is the application of a
pressure gauge on the appropriate pump connection.
• Fan damper adjustment
The first time the burner is fired leave the factory setting un-
changed for both low and high fire operation.
4.10 Servomotor
The servomotor adjusts the air damper.
The servomotor rotates through 90° in 25 seconds.
Do not alter (for the time-being) the factory setting.
Blue cam
Sets the position of the air damper during low fire operation.
Red cam
Sets the position of the air damper during high fire operation.
Orange cam
Establishes when the high fire gas or fuel oil valve opens.
It must always operate (just) before the red cam and after the blue
cam.
Fig. 13
SETTING THE COMBUSTION HEAD
D1149
Fig. 14
N° Notches
Burner output in 2nd stage operation
D2540
Fig. 15
BLUE CAM
RED CAM
ORANGE CAM
D2522
RESET

Installation
15 C6505058 - 2915759
4.11 Pump
1 Suction 1/4” NPT
2 Return 1/4” NPT
3 Pressure gauge attachmentG 1/8”
4 Vacuum gauge attachmentG 1/8”
5 Pressure regulator
A Min. delivery rate at 174 PSI pressure
B Delivery pressure range
C Max. suction pressure
D Viscosity range
E Max fuel oil temperature
F Max. suction and return pressure
G Pressure calibration in the factory
H Filter mesh width
Tab. F
AL 65
A
B
C
D
E
F
G
H
GPH
PSI
“Hg
cSt
°F - °C
PSI
PSI
inch
21.5
58 - 261
13
2 - 12
140 - 60
29
174
0.006
PUMP
SUNTEC AL 65
D2542
Fig. 16

C6505058 - 2915759 16
Installation
4.12 Fuel supply
The burner is equipped with a self-priming pump which is capable
of feeding itself within the limits listed in the table at the side.
The tank higher than the burner A
The distance “P” must not exceed 33 ft in order to avoid subjecting
the pump's seal to excessive strain; the distance "V" must not ex-
ceed 13 ft in order to permit pump self-priming even when the tank
is almost completely empty.
The tank lower than the burner B
Pump suction values higher than 13 “Hg must not be exceeded be-
cause at higher levels gas is released from the fuel, the pump starts
making noise and its working life-span decreases.
It is good practice to ensure that the return and suction lines enter
the burner from the same height; in this way it will be more improb-
able that the suction line fails to prime or stops priming.
Tab. G
Key
H = Pump/Foot valve height difference
L =Piping length
Ø =Inside pipe diameter
1 =Burner
2=Pump
3=Filter
4 =Manual on/off valve
5 =Suction line
6 =Foot valve
7 =Return line
4.13 Hydraulic connections
The pumps are equipped with a by-pass that connects return line
and suction line. The pumps are installed on the burner with the by-
pass closed by screw 6), see diagram Fig. 32, page 23.
It is therefore necessary to connect both hoses to the pump.
The pump seal will be damaged immediately if it is run with the
return line closed and the by-pass screw inserted.
Remove the plugs from the suction and return connections of the
pump.
Insert the hose connectors into the connections and screw them
down.
Take care that the hoses are not stretched or twisted during instal-
lation.
Route the hoses through the holes in the plate, preferably using
those on the right side, (Fig. 18): unscrew the screws 1), now divide
the insert piece into its two parts 2) and 3) and remove the thin plug
blocking the two passages 4). Install the hoses where they cannot
be stepped on or come into contact with hot surfaces of the boiler
and where they do not hamper the opening of the burner.
Now connect the other end of the hoses to the suction and return
lines.
1
2
3
7
5
6
6
75
4
A
B
+ H- H V
P
10 cm
D2543
Fig. 17
+ H
- H
ft
L ft
Ø
inch
5/16” 3/8” 1/2”
+ 13
+ 10
+ 6.6
+ 3.3
+ 1.6
115
99
86
69
63
296
263
227
194
174
500
500
500
428
391
056 158 355
- 1.5
- 3.3
- 6.6
- 10
- 13
49
43
30
13
-
141
122
89
53
20
319
283
211
138
66
D2544
Fig. 18

Installation
17 C6505058 - 2915759
4.14 Pump priming
-Before starting the burner, make sure that the tank return
line is not clogged. Obstructions in the line could cause
the pump seal located on the pump shaft to break. (The
pump leaves the factory with the by-pass closed).
- Also check to make sure that the valves located on the suction
line are open and that there is sufficient fuel in the tank.
- For self-priming to take place, one of the screws 3) of the
pump, see Fig. 16, page 15, must be loosened in order to bleed
off the air contained in the suction line
- Start the burner by closing the control circuit, with switch 1)
(Fig. 19) in the "MAN" position and with switch 21) (Fig. 1,
page 7) in the "OIL" position.
- The pump is primed when the fuel oil starts coming out of the
screw 3) (Fig. 16, page 15). Stop the burner: switch 1) (Fig. 19)
set to "OFF" and tighten the screw 3).
The time required for this operation depends upon the diameter
and length of the suction tubing. If the pump fails to prime at the first
starting of the burner and the burner locks out, reset the burner,
and then repeat the starting operation.
Do not illuminate the UV scanner cell or the burner will lock out.
4.15 Burner calibration (light-oil operation)
NOTE
:
It is advisable to first set the burner for operation on oil and
then for gas.
• FIRING
Set switch 1) (Fig. 19) to "MAN".
During the first firing, and the change from low to high fire, there is
a momentary lowering of the fuel pressure caused by the filling of
the high fire nozzle tubing. This lowering of the fuel pressure can
cause the burner to lock-out.
• OPERATION
The optimum calibration of the burner requires an analysis of the
flue gases at the boiler outlet and adjustments at the following
points:
Low and high fire nozzles
See the information listed on page 12.
Combustion head
The adjustment of the combustion head already carried out
(page 19) need not be altered unless the high fire input of the burn-
er is changed.
Pump pressure
174 PSI: this is the pressure calibrated in the factory which is usu-
ally sufficient for most purposes. Sometimes, this pressure must be
adjusted to:
145 PSI in order to reduce fuel delivery. This adjustment is possible
only if the surrounding temperature remains above 0°C;
203 PSI in order to increase fuel delivery or to ensure firings even
at temperatures of less than 0°C.
In order to adjust pump pressure, use the screw 5) (Fig. 16,
page 15).
Low fire fan air damper
Keep the burner operating at low fire. The fan air damper is adjust-
ed by moving the blue cam of the servomotor, see page 14.
High fire fan air damper
Press switch 2) (Fig. 19) “increase output” and keep it pressed until
the high fire position. The fan air damper is adjusted by moving the
red cam of the servomotor, see page 14.
12
D791 Fig. 19
WARNING
Turn burner off prior to switching fuels

C6505058 - 2915759 18
Installation
4.16 Gas pressure
The adjacent tables are used to calculate manifold pressure taking
into account combustion chamber pressure.
Gas manifold pressure measured at test point 1) (Fig. 20), with:
• Combustion chamber at 0” WC
• Burner operating at high fire
• Natural gas
Calculate the approximate high fire output of the burner as follows:
subtract the combustion chamber pressure from the gas pressure
measured at test point 1) (Fig. 20).
Find the nearest pressure value to your result in the table for the
burner in question.
Read off the corresponding output on the left.
Example - RLS 28
• High fire operation
• Natural gas
• Gas pressure at test point 1) (Fig. 20) = 3.66” WC
• Pressure in combustion chamber = 0.79” WC
3.66 - 0.79 = 2.87” WC
A high fire ouput of 796 MBtu/hr shown in table RLS 28 corre-
sponds to 2.87” WC pressure, natural gas.
This value serves as a rough guide, the effective delivery must be
measured at the gas meter.
Tab. H
Tab. I
Tab. J
4.17 Gas piping
• The gas train must be connected to the gas attachment 1)
(Fig. 21), using flange 2), gasket 3) and screws 4) supplied with
the burner.
• The gas train can enter the burner from the right or left side, de-
pending on which is the most convenient, see (Fig. 21).
• Gas solenoid 6) (Fig. 22, page 19) must be as close as possi-
ble to the burner to ensure gas reaches the combustion head
within the safety time period.
• Make sure that the pressure governor calibration range (colour
of the spring) comprises the pressure required by the burner.
RLS 28 ∆p (“ WC)
MBtu/hr Natural gas
616
700
796
890
985
1079
1174
1232
2.56
2.68
2.87
3.15
3.43
3.78
4.09
4.33
RLS 38 ∆p (“ WC)
MBtu/hr Natural gas
882
985
1098
1212
1325
1440
1553
1666
3.46
3.58
3.70
3.86
4.09
4.37
4.65
5.11
RLS 50 ∆p (“ WC)
MBtu/hr Natural gas
1092
1250
1401
1553
1704
1856
2007
2198
3.94
4.02
4.13
4.25
4.45
4.61
5.00
5.51
Fig. 20
D2545
Fig. 21
D1137