Robur M Series User manual

Installation, use and maintenance manual
Powered by natural gas/LPG
Gas unit heaters for use in industrial and commercial
installations
M

This Installation, use and maintenance manual has been drawn up and printed by Robur S.p.A.; whole or partial
reproduction of this Installation, use and maintenance manual is prohibited.
The original is led at Robur S.p.A.
Any use of this Installation, use and maintenance manual other than for personal consultation must be previously
authorised by Robur S.p.A.
The rights of those who have legitimately led the registered trademarks contained within this publication are not
aected.
With the aim of continuously improving the quality of its products, Robur S.p.A. reserves the right to modify the
data and contents of this Installation, use and maintenance manual without prior notice.
Revision: F
Code: D-LBR153
DISPOSAL
The appliance and all its accessories must be disposed of separately in accordance with the regulations in force.
Use of the WEEE symbol (Waste Electrical and Electronic Equipment) indicates that this product cannot be disposed of as household waste.
Proper disposal of this product helps to prevent potential negative consequences for the environment and human health.

Installation, use and maintenance manual – M gas unit heater 3
I Introduction............................................................................. p.4
I.1 Recipients .......................................................................... p.4
I.2 Control device.................................................................. p.4
II Symbols and denitions............................................... p.4
II.1 Key to symbols................................................................. p.4
II.2 Terms and denitions.................................................... p.4
III Warnings...................................................................................... p.4
III.1 General and safety warnings...................................... p.4
III.2 Conformity ........................................................................ p.5
III.3 Exclusions of liability and warranty.......................... p.6
1 Features and technical data ...................................... p.7
1.1 Features.............................................................................. p.7
1.2 Dimensions ....................................................................... p.8
1.3 Electrical wiring diagram ............................................. p.9
1.4 Controls ............................................................................ p.11
1.5 Electrical panel............................................................... p.13
1.6 Technical characteristics............................................. p.13
2 Transport and positioning........................................ p.15
2.1 Warnings .......................................................................... p.15
2.2 Handling........................................................................... p.15
2.3 Appliance positioning................................................. p.15
2.4 Minimum clearance distances.................................. p.16
2.5 Support bracket............................................................. p.16
3 Heating engineer............................................................... p.17
3.1 Warnings .......................................................................... p.17
3.2 Fuel gas supply .............................................................. p.17
3.3 Combustion products exhaust ................................ p.18
3.4 Air ducting....................................................................... p.21
4 Electrical installer.............................................................. p.22
4.1 Warnings .......................................................................... p.22
4.2 Electrical systems.......................................................... p.22
4.3 Electrical power supply............................................... p.22
4.4 Control system............................................................... p.22
5 First start-up .......................................................................... p.24
5.1 Preliminary checks........................................................ p.24
5.2 Burner pressure adjustment ..................................... p.25
5.3 Gas changeover............................................................. p.27
6 Normal operation.............................................................. p.27
6.1 Warnings .......................................................................... p.27
6.2 Switch on and o.......................................................... p.27
7 Maintenance.......................................................................... p.28
7.1 Warnings .......................................................................... p.28
7.2 Scheduled routine maintenance............................. p.29
7.3 Resetting the temperature limit thermostat....... p.29
7.4 Periods of inactivity...................................................... p.29
7.5 Troubleshooting............................................................ p.29
INDEX OF CONTENTS

Introduction
4
I
I INTRODUCTION
Manual
This Manual is an integral part of the M unit and must
be handed to the end user together with the appliance.
I.1 RECIPIENTS
This Manual is intended for:
▶ End user, for appropriate and safe use of the appliance.
▶ Qualied installer, for correct appliance installation.
▶ Planner, for specic information on the appliance.
I.2 CONTROL DEVICE
In order to work, the M unit requires a control device to be con-
nected by the installer (see Paragraph 1.4 p.11 ).
II SYMBOLS AND DEFINITIONS
II.1 KEY TO SYMBOLS
DANGER
WARNING
NOTE
PROCEDURE
REFERENCE (to other document)
II.2 TERMS AND DEFINITIONS
Appliance / Unit = equivalent terms, both used to refer to the
gas unit heater.
TAC = Technical Assistance Centre authorised by Robur.
External request = generic control device (e.g. thermostat, tim-
er or any other system) equipped with a voltage-free NO contact
and used as control to start/stop the unit.
Chronothermostat = control device that integrates the func-
tions of room thermostat and clock programmer.
First start-up = appliance commissioning operation which may
only and exclusively be carried out by a TAC.
III WARNINGS
III.1 GENERAL AND SAFETY WARNINGS
Installer's qualications
Installation must exclusively be performed by a quali-
ed rm and by skilled personnel, with specic knowl-
edge on heating, electrical systems and gas appliances,
in compliance with the laws in force in the Country of
installation.
Declaration of conformity
Upon completing installation, the installing rm shall
issue to the owner/client the appliance's workmanlike
conformity declaration, according to national/local reg-
ulations in force and the manufacturer's instructions/
provisions.
Misuse
The appliance must only be used for the purposes for
which it has been designed. Any other use is deemed
hazardous. Incorrect use may aect operation, duration
and safety of the appliance. Adhere to the manufactur-
er's instructions.
Use of the appliance by children
The device can be used by children over 8 years old,
and by people with reduced physical, sensory or mental
capabilities, or lack of experience or knowledge, only if
they are under surveillance or after they have received
instructions regarding safe use of the appliance and un-
derstanding the dangers inherent in it. Children should
not play with the appliance.
Hazardous situations
Do not start the appliance in hazardous conditions, such
as: gas smell, problems with the electrical/gas system,
parts of the appliance under water or damaged, mal-
functioning, disabling or bypassing control and safety
devices.
In case of danger, request intervention by qualied per-
sonnel.
In case of danger, switch o the electrical power and gas
supplies only if this can be done in total safety.
Do not entrust children, persons with physical, sensory
or mental disabilities or persons with poor knowledge
and experience with use of the appliance.

Warnings
Installation, use and maintenance manual – M gas unit heater 5
III
Gas component tightness
Before performing any operation on gas ducting compo-
nents, close the gas valve.
Upon completing any procedure, perform the tightness
test according to regulations in force.
Gas smell
If you smell gas:
Do not use electrical devices such as telephones, mul-
timeters or other equipment that may cause sparks next
to the appliance.
Shut o the gas supply by turning the valve o.
Open immediately doors and windows to create a
cross-current of air to purify the room.
Switch o the power supply via the external disconnect
switch in the power supply electrical panel.
Use a telephone away from the appliance to ask for inter-
vention from qualied personnel.
Poisoning
Ensure the ue gas ducts are tightness and compliant
with the regulations in force.
Upon completing any procedure, ensure components
are tightness.
Moving parts
The appliance contains moving parts.
Do not remove guards during operation, and in any case
prior to disconnecting the power supply.
Burn hazard
The appliance contains very hot parts.
Do not open the appliance and do not touch internal
components before the appliance has cooled down.
Do not touch the ue gas exhaust before it has cooled
down.
Electrocution hazard
Disconnect the electrical power supply before any oper-
ation on appliance components.
For electrical connections exclusively use compliant
components and according to the specications provid-
ed by the manufacturer.
Ensure the appliance cannot be accidentally switched
back on.
Earthing
Electrical safety depends on an eective earthing sys-
tem, correctly connected to the appliance and carried
out in accordance with the regulations in force. Do not
use gas pipes to ground electrical equipment.
Air ow
Do not obstruct the fan intake or the hot air outlet.
Distance from combustible or ammable materials
Do not deposit ammable materials (paper, diluents,
paints, etc.) near the appliance.
Comply with current regulations.
Aggressive substances in the air
The air of the installation site must be free from aggres-
sive substances.
Acid ue gas condensate
Discharge the acid condensate of combustion ue gas,
as indicated in Paragraph 3.3.4 p. 19 , in compliance
with current exhaust regulations.
Switching the appliance o
Disconnecting the power supply while the appliance
is running may cause permanent damage to internal
components.
Except in the event of danger, do not disconnect the
power supply to switch o the appliance, but always and
exclusively act through the provided control device.
In the event of failure
Operations on internal components and repairs may
exclusively be carried out by a TAC, using only original
parts.
In the event of failure of the appliance and/or breakage
of any component, do not attempt to repair and/or re-
store and immediately contact the TAC.
Routine maintenance
Proper maintenance assures the eciency and good op-
eration of the appliance over time.
Maintenance must be performed according to the man-
ufacturer's instructions (see Chapter 7 p. 28 ) and in
compliance with current regulations.
Appliance maintenance and repairs may only be entrust-
ed to rms legally authorised to work on gas appliances
and systems.
Enter into a maintenance contract with an authorised
specialised rm for routine maintenance and for servic-
ing in case of need.
Use only original parts.
Keep the Manual
This Installation, use and maintenance manual must al-
ways accompany the appliance and must be handed to
the new owner or installer in the event of sale or removal.
III.2 CONFORMITY
EU directives and standards
The M series gas unit heaters meet the essential requirements of
the following Directives:
▶ 2014/30/EC "Electromagnetic Compatibility Directive" as
amended and added.
▶ 2014/35/EC "Low Voltage Directive" as amended and added.
▶ 2006/42/EC "Machine Directive" as amended and added.
Furthermore, they comply with the requirements of the follow-
ing standards:
▶ EN 1020 Non-domestic forced convection gas-red air heat-
ers for space heating not exceeding a net heat input of 300
kW incorporating a fan to assist transportation of combus-
tion air or combustion products.
▶ prEN 17082 Domestic and non-domestic gas-red forced

Warnings
6
III
convection air heaters for space heating not exceeding a net
heat input of 300 kW.
Other applicable provisions and standards
The design, installation, operation and maintenance of the sys-
tems shall be carried out in compliance with current applicable
regulations, depending on the Country and location, and in ac-
cordance with the manufacturer's instructions. In particular, reg-
ulations regarding the following shall be complied with:
▶ Gas systems and equipment.
▶ Electrical systems and equipment.
▶ Heating systems.
▶ Environmental protection and combustion products ex-
haust.
▶ Fire safety and prevention.
▶ Any other applicable law, standard and regulation.
III.3 EXCLUSIONS OF LIABILITY AND
WARRANTY
Any contractual or extra-contractual liability of the man-
ufacturer for any damage caused by incorrect installation
and/or improper use and/or failure to comply with reg-
ulations and with the manufacturer's directions/instruc-
tions shall be disclaimed.
In particular, the warranty on the appliance may be ren-
dered void by the following conditions:
Incorrect installation.
Misuse.
Failure to comply with the manufacturer's indications on
installation, use and maintenance.
Alteration or modication of the product or any part
thereof.
Extreme operational conditions or however outside of
the operational ranges set forth by the manufacturer.
Damages caused by external agents such as salts, chlo-
rine, sulphur or other chemical substances present in the
air of the installation site.
Abnormal actions transmitted to the appliance by the
plant or installation (mechanical stresses, pressure, vi-
brations, thermal expansion, electrical surges...).
Accidental damages or due to force majeure.

Features and technical data
Installation, use and maintenance manual – M gas unit heater 7
1
1 FEATURES AND TECHNICAL DATA
1.1 FEATURES
1.1.1 Available range
M gas unit heater gas unit heaters are available in two versions:
▶ with horizontal ow, with axial fan (M gas unit heater series)
▶ with horizontal ow, ductables, with centrifugal fan
(M gas unit heater C series)
1.1.2 Operation
The M series gas unit heater is an independent heating appli-
ance with airtight combustion circuit and forced air draft.
It has been designed to be installed inside the room to be
heated.
The combustion circuit is room sealed and meets the require-
ments for type C appliances: combustion air supply and ue
gas exhaust discharge take place outdoors and are ensured by
the functioning of an extractor fan inserted in the combustion
circuit.
The appliance is also approved for type B for installations where
it is allowed to take the combustion air directly from the room
to be heated.
The operation of the gas unit heater is controlled by a control
device (not supplied).
The generator works on/o, on or o, at the heat output and the
ventilation speed of the license plate.
Products of gas combustion (natural gas or LPG) ow internally
through the heat exchangers, which are invested externally by
the air current produced by the fan, delivering hot air ow into
the room.
The fan operates automatically only when it receives the ena-
bling signal from the fan thermostat, i.e. with hot heat exchang-
ers, in order to avoid the introduction of cold air into the room,
and it will switch o with cold exchangers.
The air ow direction is adjustable vertically by means of the re-
volving louvres of the grille.
A‘vertical vane kit’is also available on request for horizontal reg-
ulation of the air ow.
If heat exchangers overheat due to malfunction, a temperature
limit thermostat cuts o the supply to the gas valve, thus inter-
rupting fuel ow and turning o the burner.
In case of obstruction of the suction or exhaust duct, or in case
of malfunction of the extractor fan, the dierential pressure
switch intervenes, causing the gas valve to stop and the heater
to switch o.
The winter operation of the gas unit heater can be automatic or
manual.
In summer it is possible to operate the fan only in order to pro-
vide a pleasant air ow within the room.
1.1.3 Mechanical components
▶ Stainless steel atmospheric burner.
▶ Flue gas extractor for forced draft of combustion products.
▶ Cylindrical stainless steel combustion chamber.
▶ Robur patented heat exchangers, made out of a special alu-
minium die-cast alloy, with horizontal nning on the air side
and vertical nning on the ue gas exhaust side, with a very
high heat exchange capacity.
▶ External steel panelling with epoxy powder enamel nish.
▶ External panels made of stainless steel (available on request).
▶ Axial fan(s) with high ow rate.
▶ Centrifugal fan (for the M gas unit heater C series).
▶ Flange for duct connection (for series M gas unit heater C).
▶ Ground control with lock signal and reset button.
1.1.4 Control and safety devices
▶ Electronic control unit, which provides the following func-
tions:
burner ignition
ame monitoring
▶ 100 °C limit thermostat with manual reset against heat ex-
changers overheating.
▶ Thermostat to protect the internal components from over-
heating, with manual reset.
▶ Dierential pressure switch.
▶ Fan thermostat.
▶ Gas solenoid valve.

Features and technical data
8
1
1.2 DIMENSIONS
Figure1.1M series generators size
1 Flue gas exhaust
2 Combustion air inlet
3 Power supply cables input
4 Gas connection
H
L
E
G
A
Z
T
S
S
R
N
J
P
X
Y
V
N
T
S
R
J
P
W
4
2
3
X
Y
1
Z
V
F
D
Q
C
B max
4
M20, M25, M30, M35, M36, M40 M50, M60
Figure1.2M C series generators size
1 Flue gas exhaust
2 Combustion air inlet
3 Power supply cables input
4 Gas connection
F
D
B
M
U
Q
C
G
E
A
HL
YX
321
P
J
N
Z
R
S
T
YX
321
R
S
T
Z
V
W
P
J
N
M20 C, M30 C M60 C
V
4
4

Features and technical data
Installation, use and maintenance manual – M gas unit heater 9
1
Table1.1Dimensions
M20 M20 C M25 M30 M30 C M35 /M36 M40 M50 M60 M60 C
A630 630 630 770 770 880 880 1070 1270 1270
B631 947 590 624 988 624 643 590 624 988
C800 800 800 800 800 800 800 800 800 800
D490 490 490 490 490 490 490 490 490 490
E370 370 370 510 510 620 620 810 1010 1010
F405 405 405 405 405 405 405 405 405 405
G440 438 440 580 578 690 690 880 1080 1078
H430 431 430 430 431 430 430 430 430 431
J215 215 215 215 215 215 215 215 215 215
L285 284 285 285 284 285 285 285 285 284
M- 393 - - 393 - - - - 393
N95 95 95 95 95 95 95 95 95 95
P390 390 390 460 460 515 515 398 468 468
Q435 435 435 435 435 435 435 435 435 435
R340 340 340 340 340 340 340 340 340 340
S600 600 600 600 600 600 600 600 600 600
T715 715 715 715 715 715 715 715 715 715
U- 563 - - 580 - - - - 580
V1/2” 1/2” 1/2” 1/2” 1/2” 1/2” 3/4” 3/4” 3/4” 3/4”
W- - - - - - - 432 495 495
X113 113 113 113 113 113 113 113 113 113
Y133 133 133 133 133 133 133 133 133 133
Z355 300 355 410 324 410 410 355 410 324
1.3 ELECTRICAL WIRING DIAGRAM
Figure1.3Operating wiring diagram
CM Fan condenser
CS Extractor fan condenser
L1 Lockout lamp
M Fan motor (2 motors for M50 and M60 models)
M1 Limit thermostat
M10 Internal component protection thermostat
M12 Pressure switch control relay
M2 Fan thermostat
M4 Controller for ignition, adjustment and ame control
M9 Fuse 4,0 A
NP Dierential pressure switch
P1 Reset button
Q1 Gas electrovalve
Q2 Soft opening coil (for M50 and M60 models)
RD Rectier bridge (for M50 and M60 models)
RP7 Ignition electrode
RP8 Detection electrode
S Extractor fan motor
Z1 Summer/winter diverter (not supplied)
Z9 External request (not supplied)
M9 Z1 Z9 M10M1
RP8 RP7
NP
M12
S
CS
M
CM
M
CM
GND
230V-50HZ
M2 L1
Q2
Q1
RD
M12
P1
123 4 5 6 7 13
14 15
16
17
18 19 J6
JT1 J5 JT 2
M4

Features and technical data
10
1
Figure1.4Wiring plan for mounting the M20/M25/M30/M35/M36/M40 devices
(see legend Figure 1.3 p.9 )
BLA Black
BRO Brown
BLU Blue
WIN Winter
SUM Summer
BLA BRO
BLU
WIN
SUM

Features and technical data
Installation, use and maintenance manual – M gas unit heater 11
1
Figure1.5Mounting electrical diagram for M50/M60 units
(see legend Figure 1.3 p.9 )
BLA Black
BRO Brown
BLU Blue
WIN Winter
SUM Summer
6
7
5
1
20
23
24
21
22
230 V - 50 Hz
BLA BRO
BLU
WIN
SUM
1.4 CONTROLS
1.4.1 Control device
The appliance may only work if it is connected to a control de-
vice, selected from:
1. 1 button basic control OCDS012 (supplied)
2. OCTR000 2-key basic control
3. OTRG005 thermoregulator
4. OCDS008 digital chronothermostat (in association with
OTRG005 thermoregulator)
5. OSWR000 Genius software for remote management of gas
unit heaters (in association with OTRG005 thermoregulator)
6. External request

Features and technical data
12
1
1.4.2 OCDS012 1-key basic control
Figure1.6OCDS012 1-key basic control
OCDS012 1-key basic control signals the ame lockout and al-
lows its resetting.
It does not allow to control the switching on and o of the unit
for space heating, nor for the summer ventilation.
Its functions are:
▶ Light signalling the status of the ame lockout.
▶ Reset of the ame lockout.
For additional details and diagrams see Paragraph 4.4.1 p.22 .
1.4.3 OCTR000 2-key basic control
Figure1.7OCTR000 2-key basic control
OCTR000 2-key basic control signals the ame lockout and al-
lows its resetting. In addition, it allows activating the summer
ventilation mode.
It does not allow to control the switching on and o of the unit
for space heating.
Its functions are:
▶ Light signalling the status of the ame lockout.
▶ Reset of the ame lockout.
▶ Summer ventilation mode activation.
1.4.4 OTRG005 thermoregulator
Figure1.8OTRG005 thermoregulator
Thethermoregulatoris a device that can directly manage gas unit
heaters: the simple and intuitive display interface allows the user
to change the control parameters, manage the power on/o and
change the operating mode (heating or summer ventilation); a
serial interface also allows to create cascading systems managed
by a single chronothermostat (optional OCDS008, described in
Paragraph 1.4.5 p. 12 ), with considerable advantages in terms
of temperature control, especially in large spaces.
The main functions are:
▶ Turning the gas unit heater on/o.
▶ Ambient temperature measurement by NTC probe.
▶ Diagnostics.
▶ Reset of the ame lockout.
▶ Gas unit heater data display and parameters setting.
▶ Space heating and summer ventilation setpoint setting.
▶ Summer ventilation mode activation.
▶ Possibility of creating cascaded systems.
▶ Modbus interfacing for remote control.
For further details and diagrams see the OTRG005 temperature
controller instruction sheet.
1.4.5 OCDS008 digital chronothermostat
Figure1.9OCDS008 digital chronothermostat
OCDS008 digital chronothermostat integrates the functions of
room temperature control and remote control of the gas unit
heaters heating system in a single interface, specically de-
signed to make all functions available to the user in a clear and
intuitive way.
It may be used only in association with the OTRG005
thermoregulator.
The remote control of the heating system allows managing the
operational parameters of more than one gas unit heater with
the relative control boards connected in cascade and also reset-
ting any locking.
The weekly programming includes 3 adjustable temperature
levels and daily times bands.
The main functions are:
▶ Multilingual interface.
▶ Gas unit heaters cascade system management (up to 10).
▶ Hourly programming on a weekly basis on 3 temperature
levels.
▶ Diagnostics.
▶ Reset.
▶ Gas unit heater data display and parameters setting.
▶ Space heating and summer ventilation setpoint setting.
▶ Summer ventilation mode activation.
For further details and diagrams see the instruction sheet of the
digital chronothermostat OCDS008.
1.4.6 OSWR000 Genius software for remote
management of gas unit heaters
This is a software that allows, through the OTRG005 thermoreg-
ulators, to centralize the management of up to 100 gas unit
heaters, allowing them to be freely divided into zones, for an
even more personalized heating management.
If the PC on which the software is installed is accessible remotely,
the software allows remote management of the whole heating
system from multiple devices, as well as sending emails to report

Features and technical data
Installation, use and maintenance manual – M gas unit heater 13
1
any anomalies to the gas unit heaters or to the heating system.
The main functions are:
▶ Centralized system to control up to 100 gas unit heaters.
▶ Division of gas unit heaters into zones, up to 10 dierent
zones.
▶ Independent or centralized gas unit heaters control.
▶ Remote control of the system from multiple devices.
▶ Diagnostics, also by email.
▶ Reset.
▶ Gas unit heater data display and parameters setting.
▶ Space heating and summer ventilation setpoint setting.
▶ Summer ventilation mode activation.
For further details and diagrams see the Genius software instruc-
tion sheet for remote control of the OSWR000 generators.
1.4.7 External request
The appliance may also be controlled via generic enable
devices (e.g. thermostat, timer, button, contactor...) tted with
voltage-free NO contact.
For managing the request signal (Z9 contact), Robur provides as
optionaldierentmodelsofthermostatsandchronothermostats.
For a list of thermostats and chronothermostats available as op-
tional, see Paragraph 1.4.8 p.13 .
For additional details and diagrams see Paragraph 4.4.2 p.23 .
1.4.8 Other optional thermostats and
chronothermostats
For managing the request signal (Z9 contact), Robur provides
as optional dierent models of thermostats and chronothermo-
stats, listed below.
▶ Room thermostat with ON/OFF switch (optional O12301035)
▶ Sealed room thermostat IP55 (optional O12301025)
▶ Programmable chronothermostat (optional OCDS005)
1.5 ELECTRICAL PANEL
Figure1.10Electrical panel
A Internal components protection thermostat
B Limit thermostat
C Dierential pressure switch
D Controller for ignition, adjustment and ame control
E Pressure switch control relay
B
E
C
D
A
1.6 TECHNICAL CHARACTERISTICS
Table1.2Technical characteristics
Axial fan models
M20 M25 M30 M35 M36 M40 M50 M60
Heating mode
Heat input nominal (1013 mbar - 15 °C) (1) kW 20,6 28,8 34,8 42,2 39,4 48,2 57,3 72,5
Heat output nominal kW 18,3 25,5 30,7 37,4 34,9 42,5 50,7 63,8
Eciency nominal heat input % 88,8 88,5 88,2 88,6 88,5 88,2 88,5 88,0
useful at 100% heat input % 88,5 88,2 87,9 88,3 88,2 87,8 88,0 87,5
(1) Relative to NCV (net caloric value).
(2) Values measured in an open area; in a real installation, the thermal ow may reach greater distances than those given here (depending on the height of the ceiling and its thermal insulation).

Features and technical data
14
1
M20 M25 M30 M35 M36 M40 M50 M60
Heat loss
to ue in operation % 11,20 11,50 11,80 11,40 11,50 11,80 11,50 12,00
to jacket in operation % 0,30 0,40 0,50
with burner o % 0,25
Temperature rise nominal heat input K 20,5 29,4 23,8 28,6 26,6 27,8 29,8 27,3
lenght of throw (residual speed < 0,5 m/s) (2) m 12,0 15,0 18,0 20,0 21,0 23,0 25,0
Ambient air temperature (dry bulb) maximum °C 35
minimum °C 0
Electrical specications
Power supply
voltage V 230
type - single-phase
frequency Hz 50
Electrical power absorption nominal kW 0,25 0,24 0,34 0,40 0,50 0,61
fuse A 4,0
Installation data
Gas consumption
G20 natural gas (nominal) m³/h 2,18 3,05 3,68 4,47 4,17 5,10 6,06 7,67
G25 (nominal) m³/h 2,54 3,54 4,28 5,19 4,85 5,93 7,05 8,92
G25.1 (nominal) m³/h 2,53 3,54 4,28 5,19 4,84 5,92 7,04 8,91
G25.3 (nominal) m³/h 2,48 3,47 4,19 5,08 4,74 5,80 6,89 8,72
G27 (nominal) m³/h 2,66 3,72 4,49 5,45 5,09 6,22 7,40 9,36
G2.350 (nominal) m³/h 3,03 4,23 5,12 6,20 5,79 7,09 8,42 10,66
G30 (nominal) kg/h 1,63 2,27 2,74 3,33 3,11 3,80 4,52 5,72
G31 (nominal) kg/h 1,60 2,24 2,70 3,28 3,06 3,75 4,45 5,63
Air ow nominal m³/h 2630 2550 3800 3850 4500 5000 6875
Gas connection type - M
thread “ 1/2 3/4
Flue gas exhaust
diameter (Ø) mm 110
residual head Pa 40 30 35 42 30 27 69
type of installation - B22, C12, C32, C62
Combustion air intake connection diameter (Ø) mm 130
recommended height m 2,5 2,5 ÷
3,0 3,0 ÷ 3,5
sound power Lw(max) dB(A) 67,5 70,5 72,5 72,0 74,5 71,5 76,5
sound pressure Lpat 5 metres (max) dB(A) 45,5 48,5 50,5 50,0 52,5 49,5 54,5
Dimensions
width mm 630 770 880 1070 1270
depth mm 631 590 624 643 590 624
height mm 800
Weight in operation kg 55 59 68 80 90 108
(1) Relative to NCV (net caloric value).
(2) Values measured in an open area; in a real installation, the thermal ow may reach greater distances than those given here (depending on the height of the ceiling and its thermal insulation).
Centrifugal fan models
M20 C M30 C M60 C
Heating mode
Temperature rise nominal heat input K 19,2 22,6 23,5
Electrical specications
Electrical power absorption nominal kW 0,41 0,75 1,30
fuse A 6,3
Installation data
Air ow at maximum available head m³/h 1900 3100 6400
free blowing m³/h 2800 4000 8000
maximum useful pressure head Pa 110
minimum pressure drop on heat ow delivery Pa 0 50 30
sound power Lw(max) dB(A) 74,0 78,0 81,0
sound pressure Lpat 5 metres (max) dB(A) 52,0 56,0 59,0
Dimensions
width mm 632 772 1272
depth mm 948 992
height mm 800
Weight in operation kg 66 82 133
The M36 model is only available for the French market.

Transport and positioning
Installation, use and maintenance manual – M gas unit heater 15
2
2 TRANSPORT AND POSITIONING
2.1 WARNINGS
Damage from transport or installation
The manufacturer shall not be liable for any damage dur-
ing appliance transport and installation.
On-site inspection
Upon arrival at the site, ensure there is no transport dam-
age on packing or metal panels.
After removing the packing materials, ensure the appli-
ance is intact and complete.
Packing
Only remove the packing after placing the appliance on
site.
Do not leave parts of the packing within the reach of
children (plastic, polystyrene, nails...) since they are po-
tentially dangerous.
Weight
The lifting equipment must be suitable for the load.
Lift up the unit and secure it to its support bracket
(Paragraph 2.5 p.16 ).
2.2 HANDLING
2.2.1 Handling and lifting
▶ Always handle the appliance in its packing, as delivered by
the factory.
▶ Comply with safety regulations at the installation site.
2.3 APPLIANCE POSITIONING
The unit must be installed in the room to be heated.
2.3.1 Where to install the appliance
The wall or structure on which the unit is to be installed
must be load-bearing or, in any case, suitable for sup-
porting its weight.
Installation must not be made on walls with poor
strength that do not guarantee adequate resistance to
the stresses produced by the unit. The manufacturer
does not assume any responsibility if the appliance is in-
stalled on surfaces or walls that are not suitable for sup-
porting its weight.
The appliance's ue gas exhaust must not be immedi-
ately close to openings or air intakes of buildings, and
must comply with safety and environmental regulations.
To obtain the maximum system eciency it is advisable to com-
ply with the following rules:
▶ Make sure that the air ow does not directly impinge on the
sta (by tilting the grille louvres appropriately).
▶ Take any obstacles into account (pillars or other).
▶ Consider length of throw of the unit (Table 1.2 p.13 ).
▶ For better heat distribution in the case of multiple unit in-
stallations, create alternate ows of hot air (see Figure
2.1 p.15 ).
▶ In some cases it may also be suitable to place the units close
to the main doors, so that they can also operate as air barri-
ers when doors are opened.
Figure2.1Airow distribution

Transport and positioning
16
2
2.4 MINIMUM CLEARANCE DISTANCES
2.4.1 Distances from combustible or ammable
materials
▶ Keep the appliance away from combustible or ammable
materials or components, in compliance with applicable
regulations.
2.4.2 Clearances around the appliance
Axial gas unit heaters
The minimum clearance distances are required for safety,
operation and maintenance.
Figure2.2Clearances
A Gas unit heater width B Object or structure underneath the gas unit heater
B
> 350 mm
> 400 mm
< 3,5 m
> 2,5 m
> 200 mm A A
> 500 mm
The recommended height from the oor to the gas unit
heater base is 2,5 to 3,5 m (see Figure 2.2 p.16 ). We do
not recommend installing the gas unit heaters at heights
below 2,5 m from the oor.
The minimum distance from the wall must be at least 35
cm.
2.4.2.1 Centrifugal gas unit heaters
The position of gas unit heaters with centrifugal fan must con-
sider the position of the hot air duct. This must be suitably sized
and veried in relation to the air ow rate and the head of the
centrifugal fan (Paragraph 3.4 p.21 ).
The recommended height from the oor to the gas unit
heater base is 2,5 to 3,5 m (see Figure 2.2 p.16 ). We do
not recommend installing the gas unit heaters at heights
below 2,5 m from the oor.
2.5 SUPPORT BRACKET
Robur provides easy mounting support brackets as an option-
al, suitably designed for M series gas unit heaters, which allow
simplifying the wall xing.
If you do not want to use these options, refer to Figure 2.3 p.16 .
When xing the unit to the support brackets, use 4 M10 bolts.
Figure2.3Installation with support bracket
A Gas unit heater xing points centre distance
B Support bracket length
40405
B
A

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Installation, use and maintenance manual – M gas unit heater 17
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Table2.1Support bracket dimensions for axial gas unit heaters
M20 M25 M30 M35/M36 M40 M50 M60
A370 370 510 620 620 810 1010
B840
Table2.2Support bracket dimensions for centrifugal gas unit heaters
M20 C M30 C M60 C
A370 510 1010
B1400
2.5.1 Axial gas unit heaters
For axial gas unit heaters the following support brackets are
available as optional:
▶ O19800020 revolving wall support bracket (M20, M25 mod-
els)
▶ O19800024 revolving wall support bracket (M30 model)
▶ OKMN000 swivel bracket (models M35, M36, M40)
▶ O19800026 revolving wall support bracket (M50 model)
▶ O19800028 revolving wall support bracket (M60 model)
▶ OSTF009 support bracket 1,4 m length
▶ Tubular bracket OSTF005
All support brackets are supplied with bolts and the rear support
plate.
For mounting instructions of the brackets, refer to the relevant
instruction sheets.
2.5.2 Centrifugal gas unit heaters
For centrifugal gas unit heaters, the following mounting brack-
ets are available as optional:
▶ OSTF009 support bracket 1,4 m length
All support brackets are supplied with bolts and the rear support
plate.
For mounting instructions of the brackets, refer to the relevant
instruction sheets.
3 HEATING ENGINEER
3.1 WARNINGS
3.1.1 General warnings
Read the warnings in Chapter III.1 p. 4 , providing im-
portant information on regulations and on safety.
Compliance with installation standards
Installation must comply with applicable regulations in
force, based on the installation Country and site, in mat-
ters of safety, design, implementation and maintenance
of:
heating systems
gas systems
ue gas exhaust
ue gas condensate discharge
Installation must also comply with the manufacturer's
provisions.
3.2 FUEL GAS SUPPLY
3.2.1 Gas connection
▶ 1/2" M (models M20, M25, M30, M35, M36, M40)
▶ 3/4" M (M50, M60 models)
on the rear, to the left (see dimensional diagrams, Paragraph
1.2 p.8 ).
▶ Install an anti-vibration connection between the appliance
and the gas piping.
3.2.2 Mandatory shut-o valve
▶ Provide a gas shut-o valve (manual) on the gas supply line,
next to the appliance, to isolate it when required.
▶ Provide a three-piece pipe union.
▶ Perform connection in compliance with applicable regula-
tions.
3.2.3 Gas pipes sizing
The gas pipes must not cause excessive pressure drops and, con-
sequently, insucient gas pressure for the appliance.
3.2.4 Supply gas pressure
This appliance is equipped for a maximum gas supply
pressure of 50 mbar.
The appliance's gas supply pressure, both static and dynamic,
must comply with Table 3.1 p.17 , with tolerance ± 15%.
Non compliant gas pressure (Table 3.1 p. 17 ) may
damage the appliance and be hazardous.
Table3.1Network gas pressure
Gas supply pressure [mbar]
Product
category Countries of destination G20 G25 G25.1 G25.3 G2.350 G27 G30 G31
II2H3B/P
AL, BG, CH, CY, CZ, DK, EE, FI, GR, HR, IT, LT, LV, MK, NO, RO, SE,
SI, SK, TR 20 30 30
AT, CH 20 50 50
II2H3P
AL, BG, CH, CZ, ES, GB, GR, HR, IE, IT, LT, LV, MK, PT, SI, SK, TR 20 37
RO 20 30
AT 20 50
II2ELL3B/P DE 20 20 50 50

Heating engineer
18
3
II2Esi3P FR 20 25 37
II2Er3P 20 25 37
II2H3B/P HU 25 30 30
II2HS3B/P 25 25 30 30
II2E3P LU 20 50
II2L3B/P
NL
25 30 30
II2L3P 25 37
II2EK3B/P 20 25 30 30
II2EK3P 20 25 30
II2E3B/P
PL
20 37 37
I2E 20
II2ELwLs3B/P 20 13 20 37 37
II2ELwLs3P 20 13 20 37
I2E(R)
BE
20 25
I2E(S) 20 25
I3P 37
I3P IS 30
I2H LV 20
I3B/P MT 30 30
I3B 30
The appliance gas supply pressure, both static and dynamic, must comply with the values in the Table, with a tolerance of ± 15%.
3.2.5 Vertical pipes and condensate
▶ Vertical gas pipes must be tted with siphon and discharge
of the condensate that may form inside the pipe.
▶ If necessary, insulate the piping.
3.2.6 LPG pressure reducers
With LPG the following must be installed:
▶ A rst stage pressure reducer, close to the liquid gas tank.
▶ A second stage pressure reducer, close to the appliance.
3.3 COMBUSTION PRODUCTS EXHAUST
Compliance with standards
The appliance is approved for connection to a combus-
tion products exhaust duct for the types shown in Table
1.2 p.13 .
3.3.1 Flue gas exhaust connection
▶ Ø 110 mm, on the rear side, at the top (see dimensional
drawings in the 1.2 p.8 Section).
3.3.2 Combustion air intake tting
▶ Ø 130 mm, on the rear side, at the top (see dimensional
drawings in the 1.2 p.8 Section).
3.3.3 Installation types
If ducts other than those supplied by the manufacturer
are used, make sure that they are suitable for the unit on
which they are installed. In particular, the temperature
class of the duct must be appropriate for the operating
characteristics of the unit, and must also respect the
chemical-physical stability of the system itself.
In any case, use approved ducts according to the type of
installation to be made. Upon request, Robur can supply
rigid pipes, coaxial ducts and terminals, all of approved
type.
Gas unit heaters of the M series can be installed to one of the
following options.
3.3.3.1 B22 type installation with wall ue gas exhaust pipe
Figure3.1B22 type installation with wall ue gas exhaust pipe
A View from above
A
3.3.3.2 B22 type installation with roof ue gas exhaust pipe
Figure3.2B22 type installation with roof ue gas exhaust pipe

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Installation, use and maintenance manual – M gas unit heater 19
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3.3.3.3 C12 type installation with separate ducts
Figure3.3C12 type installation with separate ducts
A View from above
1 Flue gas exhaust
2 Combustion air inlet
A
1 2
3.3.3.4 C12 type installation with wall coaxial terminal
Figure3.4C12 type installation with wall coaxial terminal
A View from above
A
3.3.3.5 C32 type installation with roof coaxial terminal
Figure3.5C32 type installation with roof coaxial terminal
3.3.3.6 C62 type installation with separate ducts
Figure3.6C62 type installation with separate ducts
3.3.4 Sizing and installing combustion air/exhaust
fumes ducts
In order to dimension the duct system, the total pressure drop of
the system must be calculated.
The total permissible pressure drop in the pipe system depends
on the model of the instrument and any diaphragm tted (Table
3.2 p.20 ).
The pressure drops of the ue and air pipes available as Robur
optional are shown in Table 3.3 p.20 .
The pressure drops of the coaxial pipes available as Robur op-
tional are shown in Table 3.3 p.20 .
Resistance from the separate terminals are negligible since they
are very low.
In the design phase it is necessary to verify that the sum of the
pressure drops of the pipe system used is lower than the max-
imum pressure drop allowed by the device (Table 3.2 p. 20 ).
The 3.3.5 p. 21 Section provides an example of how to calcu-
late the pressure drop.

Heating engineer
20
3
Table3.2Permissible pressure drop depending on model and mounted diaphragm
Air diaphragm Fumes diaphragm Admissible pressure drop (Pa)
Height (mm) Code Height (mm) Code maximum Minimum
M20, M20 C ----- ----- 60 019 40 -----
M25 ----- ----- ----- ----- 30 12
----- ----- 45 012 16 -----
M30, M30 C 84 007 ----- ----- 35 23
84 007 55 013 25 -----
M35, M36
----- ----- ----- ------ 42 25
----- ----- 40 014 24 10
----- ----- 50 020 12 -----
M40 ----- ----- ----- ----- 30 19
----- ----- 35 026 19 -----
M50 ----- ----- ----- ----- 27 8
----- ----- 35 026 8 -----
M60, M60 C
----- ----- ----- ----- 69 45
----- ----- 45 012 46 22
----- ----- 55 013 21 -----
Table3.3Pressure drop for air and ue pipes and coaxial exhausts
M20 M20 C M25 M30 M30 C M35 M36 M40 M50 M60 M60 C
Flue gas exhaust pressure drop
Ø 110 mm
Pipe 1 m Pa 0,4 0,6 0,7 1,7 1,3 1,7 2,3 3,8
Elbow 90° Pa 0,7 1,3 1,4 3,7 2,8 3,7 5,1 8,6
Tee Pa 1,1 1,9 2,0 5,1 4,0 5,1 6,9 11,3
Ø 130 mm
Pipe 1 m Pa 0,2 0,3 0,8 0,6 0,8 1,0 1,7
Elbow 90° Pa 0,4 0,6 0,7 1,9 1,5 1,9 2,6 4,3
Tee Pa 0,5 0,8 0,9 2,3 1,8 2,3 3,1 5,0
Air intake pressure drop
Ø 130 mm
Pipe 1 m Pa 0,1 0,2 0,4 0,2 0,4 0,5 0,7
Elbow 90° Pa 0,2 0,3 0,4 0,9 0,5 0,9 1,2 1,8
Tee Pa 0,3 0,4 0,5 1,1 0,7 1,2 1,5 2,2
Coaxial exhaust pipe pressure drop
Ø 130/180 mm wall (1) Pa 2,0 3,7 4,4 9,3 7,4 9,3 13,2 24,9
Ø 130/210 mm roof Pa 2,2 4,3 4,9 10,6 8,2 10,6 14,5 29,4
(1) Can be used only with OSTF009 support bracket
If horizontal ue gas exhaust pipes having lengths above
1 m are installed, the ue gas exhaust pipe must be
mounted with a downward slope of 2 to 3 cm each 1-m
length (Figure 3.7 p. 20 ), to prevent condensate drops
entering the unit.
In the case of installations of vertical ue pipes longer
than 1.5 m, to prevent any drops of condensation en-
tering the generator, it is necessary to provide a Tee ele-
ment on the base of the vertical ue pipe to collect any
condensation (Figure 3.2 p.18 ).
Figure3.7Slope of horizontal pipes
2 -3 cm/m
For proper installation of the wall external terminals for the ue
gas exhaust and combustion air intake, follow the details given
in Figure 3.8 p.21 .