Bentone STG 120/2 Technical specifications

Providing sustainable energy solutions worldwide
178 064 25-4 P93783 2022-11-23
Installation- and maintenance instruction
STG 120/2
LME21.550C2
MD-DLE 407
Translation of the original instructions.

2Bentone
example Beispielexempel
352011030141
Designation
Type
Model
Serial no.
Motor supply
Main supply
MADE IN SWEDEN BY
LIGHT OIL 35-90kW 1,25-6,0 cSt 7-14bar
BF 1 KS 76-24
BF 1
BF 1 KS 76-24
1234567
1~230V 1,0A 50Hz IP 20
Man.Year 2019
Cap. Min-Max
3
?
1
-sv
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2. www.bentone.com\
nedladdning eller scanna
QR-koden.
3. Skriv in brännarens
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din typskylt (se bild) och välj
ditt språk.
Detaljerad ecodesign
information kan laddas ner
på: www.bentone.com/
ecodesign.
-en
1. Manuals in other languages
2. www.bentone.com\
download or scan QR-code.
3. Enter the burner`s article
number on your data plate
(see picture) and select
language.
Detailed ecodesign
information can be
downloaded at:
www.bentone.com/
ecodesign.
-da
1. Manualer på andre sprog
2. www.bentone.com\
download eller scan
QR-koden.
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-fr
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2. www.bentone.com\
download ou scannez le
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-de
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download oder scannen Sie
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(siehe Bild) und wählen Sie
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Detaillierte Informationen
zum Ecodesign können unter
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heruntergeladen werden.
2

3Bentone
Table of contents
1. General Information............................................................4
1.1 Delivery inspection........................................................................ 4
1.2 Safety ............................................................................................... 4
1.3 What to do if you smell gas......................................................... 5
2. Technical data.......................................................................6
2.1 Dimensions STG 120/2................................................................. 6
2.2 Output range ................................................................................. 7
2.3 Gas categories, approved gases................................................ 7
2.5 Workingeld.................................................................................. 8
2.4 Technicalspecication ................................................................. 8
2.6 Components................................................................................... 9
2.7 Skeleton diagram CPi................................................................. 10
3. Installation..........................................................................11
3.1 General instructions................................................................... 11
3.2 Instructions .................................................................................. 11
3.3 Inspection and maintenance.................................................... 11
3.4 Preparation for assembly ......................................................... 11
3.5 Gas supply .................................................................................... 11
3.6 Electric connection ..................................................................... 11
4. Electric equipment.............................................................12
4.1 Safety system .............................................................................. 12
4.2 Function LME... ............................................................................ 13
4.3 Control program when disruption; ......................................... 14
5. Mounting ............................................................................16
5.1 Gas nozzle..................................................................................... 17
5.3 Tightness control ........................................................................ 18
5.2 De-aerating................................................................................... 18
5.4 Calculationofgasow.............................................................. 19
6. Settings ...............................................................................20
6.1 Air setting .................................................................................... 20
6.2 Nozzle assembly adjustment.................................................... 20
6.3 Startup........................................................................................... 21
6.4 Control of combustion .............................................................. 21
6.5 Setting the air pressure switch ................................................ 22
6.6 Setting the gas pressure switch, min...................................... 23
7. Gas valve .............................................................................24
7.1 Overview ....................................................................................... 24
7.2 Mounting closed position indicator (CPi)............................... 25
7.3 Adjustment of governor ............................................................ 26
7.4 AdjustmentofstartgasowvalveV3..................................... 26
7.5 FlowadjustmentmainvalveV2................................................ 26
7.6 Skeleton diagrams ...................................................................... 27
8. Service .................................................................................29
8.1 Burner Service Schedule, Gas .................................................. 29
8.2 Component replacement intervals.......................................... 29
8.3 Combustion device ..................................................................... 30
8.4 Fan motor and fan wheel .......................................................... 31
8.5 Air intake and suction cone ...................................................... 32
8.6 Replacement of electrical components.................................. 33
8.7 Vibrations...................................................................................... 34
8.8 Controlofamemonitoringandionizationcurrent ........... 35
9. Handing over of the installation
10. Troubleshooting
11. Service- and inspection protocol

4Bentone
172 515 01-2 2021-10-05
1. General Information
The burner may only be used for its intended purpose in accordance with the
product’s technical data.
We reserve the right to make design changes and cannot be held liable for any
misprints or typographical errors.
Modifying the design or using accessories or components that have not been
approved by Enertech in writing is strictly prohibited.
This Installation and Maintenance manual:
• is to be regarded as part of the burner and must always be kept near
the installation site.
• must be read prior to installation.
• is intended for use by authorised personnel.
1.1 Delivery inspection
• Make sure everything is delivered and the goods have not been
damaged during transit. Transport damage should be reported to the
shipping company.
• If something is wrong with a delivery, report it to the supplier.
1.2 Safety
- before installation:
• Installation and work on the burner and associated system
components may only be carried out by persons who have undergone
relevant training.
• The product is packaged to prevent damage from occurring when
handled – Handle the product with care! Lifting equipment must be
used to lift larger packages.
• The products must be transported/stored on a level surface in a dry
environment, max. 80% relative humidity, no condensation.
Temperature -20 to +60 °C.
- installation:
• The burner must be installed in accordance with local regulations for
 re safety, electrical safety, and fuel distribution.
• The premises must comply with local regulations pertaining to use of
the burner and must have adequate air supply.
• The installation site must be free of chemicals.
• Fire extinguisher with Class BE recommended.
• Make sure when installing the burner that there is enough space to
service the burner.
• The electrical installation must be professionally carried out in
accordance with current mains electricity regulations and in a
professional manner.
• Make sure that the burner is suitable for the application (see Technical
Data).
• All components must be installed without being bent, twisted or
subjected to mechanical or thermal forces that affect components.

5Bentone
• Care must be taken by the installer to ensure that no electrical cables
or fuel lines are pinched or otherwise damaged during installation or
service.
• Sharp edges can occur on, for example:  ame tube, fan wheel and air
damper.
• The gas outlet from the pressure regulator must be con gured in
accordance with applicable regulations and lead to a safe area.
- before  rst start:
• The burner must not be put into operation without proper safety and
protection devices.
• Permitted ambient temperature during operation -10 to +60 °C. Max.
80% relative humidity, no condensation.
• The surface temperature of the burner’s components may exceed
60 °C.
• Handle with caution – the burner has moving parts, and there is risk
of crushing injuries.
• Seal inspections must be performed during installation and servicing
to prevent leakage.
• Fitting and installation work has been completed and approved.
• Electrical installation has been correctly performed.
• Flue gas ducts and combustion air ducts are not blocked.
• All actuators and control and safety devices are in working order and
correctly set.
• If the boiler is equipped with an access hatch, this must be equipped
with a hatch opening switch connected to the burner’s safety system.
• When in operation, the burner’s noise level can exceed 85 dBA – use
hearing protection!
- Operation:
• Carry out all stipulated settings, service and inspection work within
the set time.
1.3 What to do if you smell gas
• Turn off the fuel supply.
• Turn off the device and remove the boiler from operation.
• Open windows and doors.
• Prevent open  ames or sparking, e.g. do not turn lights on or off, do
not use any electrical appliances or mobile phones.
• Evacuate the building.
• Notify the installer or gas supplier of the problem so that it can be
recti ed.

6Bentone
172 535 40-1 2022-11-22
KM
L
J
2. Technical data
The burner is intended for:
• Operation in installations according to EN 303 and EN 676.
Fuels:
• Natural gas H, E, L, LL.
• LPG, Butane and Propane.
2.1 Dimensions STG 120/2
Length of
 ame tube
Flame tube
Measure A
Flame tube
Measure B
115 88 Ø 89
147 120 Ø 89
C
A
Ø B
D
E
G
F
C D E F G
224 226 110 130 273
* Dimensions may vary depending on the components used.
2.1.1 Measurements for connection to the boiler
J K L M
Flange 1 10 Ø 90 Ø 125 5
Flange 2 10 Ø 90 Ø 125 21
Flange 1 Flange 2
K
L
M
J

7Bentone
2.2 Output range
Capacity kW Gas volume at a min.
output Nm3/h 1)
Gas volume at a max
output Nm3/h 1)
Max. inlet
pressure mbar
Rated inlet pressures
mbar
STG 120/2
G20 15 - 50 1,45 5,0 360 10
G25 15 - 50 1,8 6,25 360 15
G30 18 - 70 0,5 2,7 360 10
G31 18 - 70 0,7 2,0 360 10
Gas quantity and capacity vary according to grade of gas and connection pressure.
2.3 Gas categories, approved gases
Only dry gas is permitted for use.
Category Country of destination Supply pressure
II2R3R AT, BE, BG, CH, CY, CZ, DE, DK, EE, ES, FI, FR, GB, GR,
HR, HU, IE, IS, IT, LT, LU, LV, MK, MT, NL, NO, PL, PT, RO,
RS, SE, SI, SK, TR
20 mbar
II2H3B/P AT, CH, CY, DK, FI, LT, RO, SE, SK 20 mbar
II2H3P GB, IE 20 mbar
II2L3B/P NL, RO 20 mbar
II2E3B/P PL 20 mbar
I2E(R)B BE 20 mbar
I3P BE 20 mbar
160302-264-3

8Bentone
2.5 Working eld
!Do not exceed working
eld
-0,2
0,0
0,2
0,4
0,6
0,8
1,0
1,2
1,4
10 20 30 40 50 60 70
mbar
kW
G20,G25 15-50 kW
G30,G31 18-70 kW
160302-296-2
2.4 Technical specication
Measurements according to EN 15036-1:2006
Alt.1 The noise level of the burner can be reduced by equipping the burner
with silencer. Installation must be done so it does not prevent air supply
to the burner.
Alt.2 The burner’s noise level can be reduced by connecting the burner’s air
intake to the air duct that opens into an appropriate location. Installation
must be done so it does not prevent air supply to the burner.
STG 120/2
Main supply 230V, 1~, 1.4A, 50/60Hz, IP20
Max fuse rating 8A
NOX-class 2
Noise level 74dBA

9Bentone
2.6 Components
1. Reset button
2. Control box
3. Transformer
4. Fixing  ange
5. Connection, gas valve
6. Ionisation electrode
7. Gas nozzle
8. Brake plate
9. Flame tube
10. Ignition electrode
11. Air damper
12. Fan housing, front
13. Fan housing, rear
14. Air pressure switch
15. Shielding wall, fan housing
16. Fan wheel
17. Air settings
18. Nozzle assembly adjustment
19. Motor
20. Electrical connection
21. Gas valve (MultiBloc)
22. Gas pressure switch, min
1
2
21
11
10
6
9
12
16
13
14
1517
18
19
20
22
4
3
5
8
7

10 Bentone
172 525 13 2020-10-08
2.7 Skeleton diagram CPi
1. Ball valve
2. Filter
3. Governor
4. Pressure gauge with shut-off cock
5a. Gas pressure switch, mini
5b. Gas pressure switch, maxi
6a. Main valve
6b. Safety valve
7. 1) Valve proving system
9. Air pressure switch
10. Electrical connection
11. Solenoid V3
Pos. 5b, 7: Components not required according to EN 676.
1) Required over 1200 kW according to EN 676.

11Bentone
172 535 09-2
3. Installation
3.1 General instructions
Installation must be carried out in accordance with current regulations and
instructions.
The supplier/installer of the facility is obliged to familiarize himself with
all regulations so that the installation meets the requirements of the local
authorities.
Installation, assembly and settings must be performed to obtain the best
possible function. Only gas intended for the gas burner may be used.
3.2 Instructions
It is the installer’s responsibility to instruct the user in detail in the functions of
the gas burner and the entire system.
3.3 Inspection and maintenance
The system must be maintained at the interval specied in the service
schedule. If the burner is in a dirty environment, service should be done at
more frequent intervals.
3.4 Preparation for assembly
Check that the burner’s dimensions and capacity range match the current
boiler. The power information on the type plate refers to the burner model’s
min. and max. effect.
3.5 Gas supply
In order to obtain good operational safety, it is important that the installation
of the gas distribution system is carried out correctly, considering the
following:
• Check that the burner is approved for the gas quality of the
installation.
• Check that the burner gas components are approved for the specied
gas pressure, see type plate.
• Installation must be carried out in accordance with current standards.
• Pipe lines should be assembled so that service can easily be
performed on the boiler and burner.
• Pipe lines should be assembled so that any contaminants do not come
into contact with the gas components.
3.6 Electric connection
• Before work on the electrical connection, the current must be
disconnected so that the installation is isolated.
• Connection must be done in accordance with the applicable
regulations.
• Connection must conform to the wiring diagram.
!If any electrical connection other than that recommended
by Enertech is used, there is a risk of property damage and
personal injury.

12 Bentone
172 615 76-4 2022-11-16
4. Electric equipment
4.1 Safety system
The safety system (safety switch for hatches, doors, water level, pressure, temperature
and other safety devices) must be installed in the safety circuit in accordance with
current regulations for the system. If these safety requirements are met by other
means, safety circuits must be bypassed/jumpered. This can differ between different
systems in which the burner is installed, see rules and regulations that apply.
The cables of the safety system must be separated so that the outgoing signal is not
placed in the same cable as the incoming signal.
Wiring diagram LME...
Bn Brown
Bu Blue
Gn Green
Ye Yellow
Gn/Ye Green/Yellow
Bk Black
Gy Grey
Rd Red
Wh White
Og Orange
Vt Violet
E106359

13Bentone
4.1.1 List of components
A1 Gas burner control
S9 Gas pressure switch
A2 Twin thermostat
S29 CPI
B1 Ionization electrode
T1 Ignition transformer
F1 Fuse
X1 Plug-in contact, burne
H1 Alarm, 230V
X2 Plug-in contact, boiler
M1 Motor
X50 Pilot test link
S3 Main switch
Y1 Gas solenoid valve
S8 Air pressure switch
Y1S Safety solenoid valve
4.1.2 Technical data
4.2 Function LME...
1. Operating switch ON-Thermostat ON-Gas pressure switch ON
A check that the air pressure switch does not indicate fan pressure is
carried out.
2. Burner motor starts
A check that the air pressure switch indicates sucient fan pressure is
carried out.
3. The ignition spark is created
4. The gas solenoid valve is open
The gas is ignited. The ionisation electrode now indicates a ame.
5. The safety time expires
The ignition spark ceases. The safety period ceases. If the spark is missing
or it disappears after this time limit, the gas burner control is blocked.
6. Operating position
7. Stop
The operation of the burner can now be stopped with the control switch or
thermostat.
If the gas burner control is blocked
Red light in the gas burner control is lit. The burner is restarted by pushing
the reset button.
!Mains connection and fuse
in accordance with local
regulations.
LME21.130C2 LME21.550C2
2 s 2 s
7 s 50 s
2.5 s 4.5 s
< 3 s < 5 s
< 1 s < 1 s
< 1 s < 1 s
5 µA 5 µA
20 µA 20 µA
160303-317
Preiginition time
Prepurge time
Postignition time
Safety lockout time
Reset time after lockout
Reaction time on  ame failure
Min. ionisation current at  ame
Max. ionisation current

14 Bentone
AL
FS
lights red Light period
(waiting time 10 s) Flash code Paus Flash code
c:a 3 s
Press reset-
button > 3 s
4.3 Control program when disruption;
Disruption display, Gas burner control: LME....
Colour codes
Diagnostics alarm trigger
The red alarm signal lamp lights continuously after the alarm is disconnected.
Diagnostics for alarm triggers can be read as specied by the following
sequence:
Limiting of starting repetitions
LME11 ... has a function with start repetition if the ame is not created at start
ord disappears during operation.. LME11 ... allows max. three repetitions
during coninuous starting cycle
Table colour codes for multi-coloured signal light (LED)
Status Colour codes Colours
Waiting period «tw», other waiting periods ○………………… O
Ignition phase, ignition controlled ●○●○●○●○●○● Blinking yellow
Normal operation □………………… Green
Operation, poor ame signal □○□○□○□○□○ Blinking green
Illegal ame signal during start-up □▲□▲□▲□▲□▲ Green-Red
Undervoltage ●▲●▲●▲●▲●▲ Yellow-Red
Fault, alarm ▲………………… Red
Blinking code for fault codes ▲○ ▲○ ▲○ ▲○ Blinking red
Interface diagnostics ▲▲▲▲▲▲▲▲ Red icking
…… Continuous
○Off
▲Red
●Yellow
□Green

15Bentone
Alarm code table
Red blinking code on
signal lamp (LED)
Possible causes
Blinking 2 x
••
No ame creation at End of “TSA”
–defective or fouled ame monitoring.
–defective or fouled fuel valves.
–poor burner setting.
–defective ring device.
Blinking 3 x
•••
“LP” defective
–No air pressure switch signal after “t10”.
–“LP” is welded in open position.
Blinking 4 x
••••
Illegal ame signal during start-up.
Blinking 5 x
•••••
Time out “LP”
–“LP” is welded in open position.
Blinking 6 x
••••••
Free
Blinking 7 x
•••••••
Too many ame disappearances during operation.
–poor burner setting.
–defective or fouled fuel valves.
–defective or fouled ame monitoring.
Blinking 8 x
••••••••
Free
Blinking 9 x
•••••••••
Free
Blinking 10 x
••••••••••
Connection fault or internal fault, outgoing contacts or
other faults.
Blinking 14 x
••••••••••••••
CPI contact not closed.
During the diagnosing of the alarm cause, the control outputs are voltage-
free.
• The burner is disconnected.
• Exception, alarm signal «AL» at board 10.
• Reconnection of the burner happens after resetting only.
• Press the reset button 0.5...3 s.
Interface diagnostics
To change to interface mode, press and hold the reset button longer than 3 s.
To go back to the normal position, press and hold the reset button longer than
3 s. If the gas burner control is in the alarm position, it is reset by pressing the
reset button 0.5...3 s.

16 Bentone
172 515 20-2 2022-09-07
!Before obtaining access to electrical and fuel line
components all supply circuits must be disconnected.
5. Mounting
The burner is mounted on the boiler with bolts according to the hole
pattern on the xing ange.
Mount the xing ange and the supplied gasket on the boiler. If new
mounting holes must be drilled, use the xing ange as a template and
fasten with M8-M10 screws.

17Bentone
5.1 Gas nozzle
Check that the ignition and ionization electrodes are correctly set before
mounting on the boiler.
Natural gas, LPG
Natural gasLPG
2,5
8

18 Bentone
5.2 De-aerating
De-aerating the gas line by closing the tap to the gas connection and
unscrewing the screw on the measuring nipple for the connection pressure.
Connect a plastic hose, open the tap and drain the gas in a safe place. When
the de-aerating is completed, be sure to ret the screw on the measuring
nipple.
5.3 Tightness control
When checking for leakage, the solenoid valve must be closed. A pressure
gauge is connected to the measuring nipple ”Pa”, see picture. The test
pressure in the system must not be higher than max. connection pressure,
see data plate. If leaks are found during measurement, locate the source
using soapy water or leak detection spray. After sealing: check the tightness
of the gas xture again.
!Check the gas tightness.
Pa

19Bentone
5.4 Calculation of gas ow
Formula symbol
Description
Example values
VNStandard gas volume [Nm3/h]
Gas volume at normal condition 15 °C 1013 mbar
-
QBoiler output [kW] 35 kW
HiLower caloric value of gas [kWh/m3]
Natural gas under normal conditions 15 °C 1013 mbar, EN 676
9.45 kWh/m3
ηBoiler eciency (e. g. 90%) 0.9
fConversion factor (pressure and temperature compensation) -
tGas Gas temperature at gas meter [°C] 15 °C
PBaro Barometric air pressure [mbar] 945 mbar
PGas Pressure of gas at the gas meter [mbar] 20 mbar
VOperating volume [m3/h] -
VGGas ow measured at the gas meter [m3]0.12 m3
TMeasuring time for consumed gas quantity [s] 93 s
VN=
Q
VN =
35 kW
=4.1 m3/h
η · Hi0.9 · 9.45 kW/m3
Calculate standard volume using the following formula:
f=
273
x
PBaro + PGas
f=
273
·
945 + 20
= 0.90
273 + tGas 1013 273 + 15 1013
Calculate conversion factor using the following formula:
V=VNV=
4.1 m3/h =4.6 m3/h
f0.90
Calculate gas volume using the following formula:
V=
3600 · VGV= 3600 · 0.12 m3
=4.6 m3/h
T93 sek
Determine operating volume with the following formula:
Gas quality kWh/Nm3MJ/Nm3
Natural gas G20 9.5 34.02
Natural gas G25 8.2 29.25
Caloric value of the gas
Lower caloric value Hi at normal conditions 15 °C and 1013 mbar, EN 676.
For exact caloric value of the gas, contact the gas distributor.
172 535 28
Height above
sea level [m] 0 100 200 300 400 500 600 700 800 900 1000 1100 1200
PBaro [mbar] 1013 1001 989 977 966 954 943 932 921 910 899 888 877
Gas quality kWh/Nm3MJ/Nm3
Butan G30 32.25 116.09
Propan G31 24.44 88.00

20 Bentone
172 515 22-2
6. Settings
6.1 Air setting
Prior to commissioning, adjust the burner setting for air damper according to
diagram, see Technical data. After the rst start, the burner must be adjusted
again for good function and combustion.
6.2 Nozzle assembly adjustment
The burner is equipped with a nozzle assembly adjustment that changes the
position of the nozzle assembly in the burner head. The position of the nozzle
assembly must be adjusted to achieve as favorable pressure drop across the
brake plate as possible.
Which position to use depends on gas ow and overpressure in the boiler. At
lower capacities, the opening should be smaller between the brake plate and
the combustion device. Turn the screw in the desired direction with an allen
key.
• Turn screw to the left to reduce opening.
• Turn screw to the right to increase opening.
Air setting
Nozzle assembly
adjustment