Siemens LGB21.130A17 User manual

CC1N7435en
11.01.2007
Building Technologies
HVAC Products
7435
Burner Controls LGB...
Burner controls for the supervision of 1- or 2-stage gas or gas / oil burners of
small to medium capacity (typically up to 350 kW), with or without fan, in intermit-
tent operation.
The LGB... and this Data Sheet are intended for use by OEMs which integrate the
burner controls in their products!
Use The LGB... burner controls are used for the startup and supervision of 1- or 2-stage gas
or gas / oil burners in intermittent operation.
Depending on the type of burner control used, the flame is supervised either by an
ionization probe, a blue-flame detector QRC1... for forced draft gas / oil burners, or a
UV detector QRA... (with auxiliary unit AGQ1...A27).
In connection with the respective adapters, the LGB... burner controls replace their
predecessor types LFI7... and LFM1... (also refer to «Replacement types» under «Or-
dering»).
- Automatic forced draft burners for gaseous fuels to EN 676
- Gas burner controls to EN 298
- Undervoltage detection
- Air pressure supervision with function check of the air pressure switch during
startup and operation
- Electrical remote reset facility
- LGB41... for use with atmospheric gas burners

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Warning notes
To avoid injury to persons, damage to property or the environment, the following
warning notes should be observed!
Do not to open, interfere with or modify the unit!
•All activities (mounting, installation and service work, etc.) must be performed by
qualified staff
•Before performing any wiring changes in the connection area of the LGB..., com-
pletely isolate the burner control from the mains supply (all-polar disconnection)
•Ensure protection against electric shock hazard by providing adequate protection
for the burner control’s connection terminals
•Each time work has been carried out (mounting, installation, service work, etc.),
check to ensure that wiring is in an orderly state and make the safety checks as
described in «Commissioning notes»
•Check to ensure that wiring is in an orderly state
•Press the lockout reset button only manually (apply a force of no more than 10 N),
without using any tools or pointed objects
•Fall or shock can adversely affect the safety functions. Such units must not be put
into operation, even if they do not exhibit any damage
Mounting notes
•Ensure that the relevant national safety regulations are complied with
Installation notes
•Always run the ignition cables separate from the unit and other cables while ob-
serving the greatest possible distance
•Do not mix up live and neutral conductors
•Install switches, fuses, earthing, etc., in compliance with local regulations
•Ensure that the maximum permissible current ratings will not be exceeded (refer to
«Technical data»)
•Do not feed external mains voltage to the control outputs of the unit. When testing
the devices controlled by the burner control (fuel valves, etc.), the LGB... must not
be connected
•To isolate the burner control from the mains supply, use an all-polar switch with a
contact gap of at least 3 mm
•Secure the earthing lug in the base with a metric screw and a lockwasher
•In the case of burners with no fan, the AGK25 must be connected to terminal 3 as
a burden, or else the burner cannot reliably start
•For safety reasons, feed the neutral conductor to the neutral distributor in the plug-
in base, or to terminal 2. Connect the burner components (fan, ignition transformer
and gas valves) as represented in the figure 7435a14, to the neutral distributor as
shown below. The connection between neutral conductor and terminal 2 is pre-
wired in the base
Exam-
ple 23
745
M
N7435a14/0601
ZV1 V2
Legend
V... Fuel valve
M Fan motor
Z Ignition transformer
Correct wiring of neutral conductors!

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Electrical connection of flame detectors
It is important to achieve practically disturbance- and loss-free signal transmission:
•Never run detector cables together with other cables
– Line capacitance reduces the magnitude of the flame signal
– Use a separate cable
•Observe the permissible length of the detector cables (refer to «Technical data»)
•The ionization probe and the ignition electrode are not protected against electric shock
hazard
•Locate the high-voltage ignition electrode and the ionization probe such that the ignition
spark cannot arc over to the ionization probe (risk of electrical overloads) and that it
cannot adversely affect the supervision of ionization
•With both ionization current and UV supervision, the cable length for flame detec-
tion must not exceed 20 m
•Insulation resistance
– Must be a minimum of 50 MΩbetween ionization probe and ground
– Soiled detector holders reduce the insulation resistance, thus supporting cree-
page currents
– Prerequisite is not only high-quality heat-resistant insulation of the probe’s
cable, but also of the ionization probe itself (ceramic holder)
•Earth the burner in compliance with the relevant regulations; earthing the boiler
alone does not suffice
•The connection diagrams show the burner controls with earthed neutral conductor. In
networks with nonearthed neutral conductor and ionization current supervision, terminal
2 must be connected to the earth conductor via an RC unit (type reference
ARC 4 668 9066 0). It must be made certain that local regulations are complied with
(e.g. protection against electric shock hazard) since AC 230 V / 50 Hz mains voltage
produces peak leakage currents of 2.7 mA
Commissioning notes
•When commissioning the plant for the first time or when doing maintenance work,
make the following safety checks:
Safety check to be carried out Anticipated response
a) Burner startup with previously inter-
rupted line to the ionization probe and
flame detector darkened in the case of
QRA... or QRC1...
Lockout at the end of «TSA»
b) Burner operation with simulated loss of
flame. For that purpose, cut off the gas
supply (e.g. disconnect the fuel valve
while ensuring protection against elec-
tric shock hazard)
Immediate lockout
c) Burner operation with simulated air
pressure failure (not with atmospheric
burners)
Immediate lockout

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Standards and certificates
Conformity to EEC directives
- Electromagnetic compatibility EMC (immunity)
- Low-voltage directive
- Directive for gas appliances
89 / 336 / EEC
73 / 23 / EEC
90 / 396 / EEC
ISO 9001: 2000
Cert. 00739 ISO 14001: 2004 Cert. 38233
•Identification code to EN 298
- LGB21... / LGB22... F T L L X N with 2-stage operation
- LGB32... F M L L X N with 2-stage operation
- LGB41... A B L L X N with 2-stage operation
(«BV1 + BV2» or «ZBV + BV2») A M L L X N with 1-stage operation
LGB21.130A17 x x --- ---
LGB21.130A27 x x x x
LGB21.230A27 x x x ---
LGB21.330A27 x x x ---
LGB21.350A17 x x --- ---
LGB21.350A27 x x x x
LGB21.550A27 x x x x
LGB22.130A27 x x x x
LGB22.230B27 x x x ---
LGB22.330A17 x x --- ---
LGB22.330A27 x x x x
LGB22.330A270 x x x ---
LGB32.130A27 x x x x
LGB32.230A17 x x --- ---
LGB32.230A27 x x x ---
LGB32.330A17 x x x ---
LGB32.330A27 x x x ---
LGB32.350A17 x x x ---
LGB32.350A27 x x x x
LGB41.255A27 x x --- x
LGB41.258A17 x x --- ---
LGB41.258A27 x x --- x
Service notes
•Use KF8872 service adapter for short periods of time only
Disposal notes The unit contains electrical and electronic components and must not be disposed of
together with household waste.
Local and currently valid legislation must be observed.

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Mechanical design The housing is made of impact-proof, heat-resistant and flame-retarding plastic.
It is of plug-in design (measuring 91 x 62 x 63 mm, including the base) and engages
audibly in the base.
The housing accommodates the
- programming mechanism with the synchronous motor
- electronic flame signal amplifier (ionization) with the flame relay and the other
switching devices
- lockout reset button with its integrated fault indication lamp
Type summary The type references given below apply to LGB... burner controls without plug-in base
and without flame detector. For ordering information on plug-in bases and other acces-
sories, refer to «Mechanical design», «Ordering», «Flame supervision ...» and «Tech-
nical data».
Flame detector Type reference Approved in: tw/s t1/s TSA/s t3n/s t3/s t4/s t9/s t10/s t11/s t12/s t20/s
6) 3) 3)
ca. min. max. ca. ca. ca. max. min. max. max. ca.
Burner controls for 2-stage burners without control of actuator
Ionization probe (ION) LGB21.130A27 4)7) CH, EU, S, SF 8 7 3 2.4 2 8 --- 5 --- --- 6
LGB21.230A27 5) CH, EU, S, SF 8 15 3 2.4 2 8 --- 5 --- --- 38or UV detector QRA...
with AGQ1...A27 LGB21.330A27 5) CH, EU, H, S, SF 8 30 3 2.4 2 8 --- 5 --- --- 23
LGB21.350A27 5)7) CH, EU, H, S, SF 8 30 5 4 2 10 --- 5 --- --- 21
LGB21.550A27 5) AUS, CH, EU 8 50 5 4 2 10 --- 5 --- --- 2
Burner controls for 2-stage burners with control of actuator
Ionization probe (ION) LGB22.130A27 4) CH, EU, N, S 9 7 3 2.4 3 8 --- 4 12 12 21
or UV detector QRA... LGB22.230B27 5) CH, EU, N, S, SF 9 20 3 2.4 3 8 --- 4 16.5 16.5 2
with AGQ1...A27 LGB22.330A27 5)7) AUS, CH, EU, H, N, S, SF 9 30 3 2.4 3 8 --- 4 12 11 2
LGB22.330A270 5)8) EU 9 30 3 2.4 3 8 --- 4 12 11 2
Blue-flame detector LGB32.130A27 4)1) CH, EU 9 7 3 2.4 3 8 --- 4 12 12 21
QRC1... LGB32.230A27 5)1) CH, EU 9 20 3 2.4 3 8 --- 4 12 12 2
LGB32.330A27 5) CH, EU 9 30 3 2.4 3 8 --- 4 12 11 2
LGB32.350A27 5) CH, EU 9 30 5 4.4 1 10 --- 4 12 9 2
Burner controls for atmospheric burners
Ionization probe (ION) LGB41.255A27 EU 18 --- 5 4 2 10 5 --- --- --- 10
or UV detector QRA...
with AGQ1...A27 LGB41.258A27 2)5)7) CH, EU, H, SF 18 --- 5 4 2 10 8 --- --- --- 10
Legend tw Waiting time 1) On request
t1 Prepurge time 2) For atmospheric burners up to 120 kW
TSA Ignition safety time 3) Maximum running time available for actuator
t3 Preignition time 4) Also suited for flash steam generators
t3n Postignition time 5) Also suited for stationary direct-fired air heaters
t4 Interval «BV1-BV2» or «BV1-LR» 6) «t9» + reaction time of flame relay
t9 Second safety time 7) Also available for AC 100...110 V; in that case, the last 2
t10 Specified time for air pressure signal digits read ...17 in place of ...27
t11 Programmed opening time for actuator «SA» 8) Without internal microfuse; must only be used in connection
t12 Programmed closing time for actuator «SA» with external microfuse 6.3 A (slow)!
t20 Interval up to self-shutdown of programming mechanism

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Ordering
Burner control, without plug-in base refer to «Type summary»
Connection accessories for small burner controls refer to Data Sheet N7201
- Plug-in base AGK11...
- Cable holders AGK65..., AGK66, AGK67...
- Cable strain relief elements for AGK67...
Connection accessories for small burner controls refer to Data Sheet N7203
- Plug-in base AGK13...
- Plug-in housing AGK56
- Accessories AGK68
Flame detectors
- Ionization probe supplied by thirds
- UV- flame detectors QRA2... / QRA10... refer to Data Sheet N7712
- Blue-flame detectors QRC1... refer to Data Sheet N7716
RC unit ARC 4 668 9066 0
For the supervision of ionization currents in networks with nonearthed neutral conductor
PTC resistor (AC 230 V) AGK25
To burden terminal 3 (mandatory when using burners with no fan
motor connected to terminal 3)
Auxiliary unit for UV supervision
- Cable length 500 mm AGQ1.1A27
- Cable length 300 mm AGQ1.2A27
- Can be fitted under the plug-in base (refer to «Dimensions»)
Pedestal (empty housing) AGK21
- For increasing the height of the LGB... to that of the LFM... or LFI7...
Service adapter KF8872
- For checking the functioning of the burner controls on the burner plant
- Functional test with signal lamps
- Detector resistance measurement with a jack of 4 mm diameter
Adapters / replacement types
No rewiring required KF8852
LFI7...
LGB21... with adapter
KF8880
LFM1... ¹)
LFM1...-F ¹)
KF8853-K
LFI7...
LGB22... with adapter
KF8880
LFM1... ¹)
LGB41... with adapter KF8862
LFM1... ¹)
¹) Designed only for ionization

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Technical data Mains voltage AC 220 V –15 % ...AC 240 V +10 %
(LGB2... / LGB4...)
AC 230 V –15 % / +10 % (LGB32...!)
AC 100 V –15 % ...AC 110 V +10 %
Mains frequency 50...60 Hz ±6 %
Input current at terminal 12 max. 5 A
within the permissible voltage range
AC 187...264 V or AC 195...253 V
Current rating
- Terminal 3
- Terminals 4, 5 and 7
- Terminals 9 and 10
- Terminal 12
max. 3 A (15 A for max. 0.5 s)
max. 2 A
max. 1 A
max. 5 A
(at Umax. AC 264 V or AC 253 V)
Cable length terminals 8 and 10 20 m at 100 pF / m
Perm. cable lengths
Detector cable laid separately max. 3 m at 100 pF / m line capacitance 20 m
Power consumption 3 VA
Primary fuse max. 10 A (slow)
Degree of protection IP 40, when built in, with the exception of
the connection area (terminal base)
Mounting position optional
Weight approx. 230 g
Storage DIN EN 60 721-3-1
Climatic conditions class 1K3
Mechanical conditions class 1M2
Temperature range -20...+60 °C
Humidity < 95 % r.h.
Transport DIN EN 60 721-3-2
Climatic conditions class 2K3
Mechanical conditions class 2M2
Temperature range -20...+60 °C
Humidity < 95 % r.h.
Operation DIN EN 60 721-3-3
Climatic conditions class 3K3
Mechanical conditions class 3M2
Temperature range -20...+60 °C
Humidity < 95 % r.h.
Condensation, formation of ice and ingress of water are not permitted!
General unit data
LGB...
Environmental conditions

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Flame supervision
At mains voltage UN= AC 230 V
Detector voltage across terminals 1 and
2 or ground (AC voltmeter Ri ≥10 MΩ)
≤UN
Detector current required for reliable operation min. 3 µA
Possible detector current in operation max. 100 µA
The conductivity and rectifying effect of hot flame gases are used for flame supervision.
For that purpose, AC voltage is applied to the heat-resistant ionization probe which
projects into the flame. The current that flows in the presence of a flame (ionization
current) produces the flame signal which is fed to the input of the flame signal amplifier.
The amplifier is designed such that it only responds to the DC current component of the
flame signal, thereby ensuring that a short-circuit between ionization probe and ground
cannot simulate a flame signal (since in that case AC current would flow).
Basically, the flame supervision circuit is insensitive to adverse effects of the ignition
spark.
However, should the disturbing effects of the ignition spark on the ionization current
exceed a certain level, the electrical connections on the primary side of the ignition
transformer must be changed and / or the location of the ionization probe must be
checked.
Since the ionization current with burner controls operating on AC 110 V is only about
50 % of those operating on AC 230 V, certain applications make it necessary to in-
crease the ionization current with a transformer.
Capacity of transformer: Min. 2 VA
Transforming ratio: Approx. 1.1...1.5
The primary and secondary windings of the transformer must be galvanically sepa-
rated.
LN
AC 115 V
LGB2...
12 2
1AC 115...230 V
7435v01/0504
ION
Flame supervision with
ionization probe
Ionization current su-
pervision with burner
controls operating on
A
C 110 V
Connection of
transformer

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Perm. detector current during the prepurge
time (dark current) max. 5 µA
Detector current required during
operation min. 50 µA
Possible detector current in operation max. 80 µA
Measuring circuit with the QRC1...
M
sw
-+
br
bl
112 2
LGB3...
7435v02/0601
QRC1
Legend
M Microammeter Ri max. 5000 Ω
sw Black wire
br Brown wire
bl Blue wire
The QRC1... has been designed specifically for blue-burning flames. Incidence of light
is from the front and laterally. The flame detector is secured by means of a soft plastic
plug. 3-core connection (preamplifier integrated in the detector casing). For the different
types of flame detectors, engineering notes and technical data, refer to Data Sheet
N7716.
Mains voltage AC 220 V –15 %...AC 240 V +10 %
Mains frequency 50...60 Hz ±6 %
Power consumption 4.5 VA
Degree of protection IP 40
Perm. ambient temperature
- In operation
- During transport and storage
-20...+60 °C
-40...+70 °C
Perm. length of cable from QRA... to
AGQ1...A27 (use separate cable) max. 20 m
Mounting position optional
Perm. length of connecting cable from
AGQ1...A27 to LGB... max. 20 m
Weight of AGQ1...A27 approx. 140 g
At mains voltage UN:
AC 220 V AC 240 V
Detector voltage at QRA... (with no load)
Up to the end of «t10» and after controlled shutdown DC 400 V DC 400 V
From the beginning of «t1» DC 300 V DC 300 V
Detector voltage
Load by DC measuring instrument Ri > 10 MΩ
Up to the end of «t10» and after controlled shutdown DC 380 V DC 380 V
From the beginning of «t1» DC 280 V DC 280 V
DC detector signals with UV detector QRA... Min. required Max. possible
Measurement on the QRA... 200 µA 500 µA
Flame supervision with
blue-flame detector
QRC1...
Flame supervision with
UV detector QRA... and
A
GQ... for LGB21... /
LGB22... / LGB41...

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Flame supervision with UV detector QRA... and auxiliary unit AGQ... for LGB21... / LGB22... / LGB41...
Universal flame detector for use with gas and gas / oil burners. Incidence of light from
the front and laterally, total length 97 mm. Available with normal or, as QRA2M, with
higher sensitivity. Secured with flange and clamp. Also available as a metal encapsu-
lated version in the form of the QRA10... (for details, refer to Data Sheet N7712).
A special UV auxiliary unit AGQ1...A27 is required in connection with LGB... burner
controls.
That unit is to be connected to the mains supply via 2 cables, and to the burner control
via terminals 1, 2 and 11.
Using circuitry (A) or (B), there are 2 ways to make the quench test on aging UV detec-
tors and to detect UV light:
1. (A) Operation with a permanent line:
UV test at a higher supply voltage across the UV cell on startup and after con-
trolled shutdown.
2. (B) Operation with a controlled line:
UV test at a higher supply voltage only on startup, that is, during the interval
between controlled startup and air pressure signal.
– No voltage at the UV cell after controlled shutdown
– No full substitute for mode (A) above, since an aged UV cell can regenerate
itself
Measuring circuit Connection diagram
12 211
*1
7435a19/0301
br bl rt sw AGQ1...A27
sw bl
(B)
LGB...
QRA
12 211
*1
7435a15/0704
GP/SB
R/W
L
L
N
QRA +
-
br bl rt sw AGQ1...A27
sw bl
(B)
(A)
LGB...
Measurement made on the flame detector
GP Gas pressure switch
R Temperature or pressure controller
SB Safety limit thermostat
W Limit thermostat or pressure switch
* With LGB41...: Terminal 3
(A) Operation with permanent line
(B) Operation with controlled line
UV detector QRA...
A
uxiliary unit
A
GQ1...A27
Legend