Siemens LOK16 Series User manual

CC1N7785en
20.11.2017
Building Technologies Division
7785
Burner Controls LOK16...
LGK16...
Burner controls
For gas, oil or dual-fuel forced draft burners of medium to high capacity
For multistage or modulating burners in continuous operation
With air pressure supervision for checked air damper control.
Flame supervision
- LOK16: With silicon detector RAR
- LGK16: With flame detector QRA53/QRA55/ionization probe
Burner control for oil burners or gas burners in accordance with EN 298:2012
Suitable for use with air heaters (WLE)
With self-checking flame signal amplifier
The LOK16.../LGK16... and this Data Sheet are intended for use by OEMs which
integrate the burner controls in their products.

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Use
Burner controls type LOK16.../LGK16... feature a self-checking flame supervision
circuit.
The flame supervision circuit initiates the safety actions in the case of... :
• ... premature or missing flame signal
• ... any kind of fault on the flame detector, the detector cables or the flame signal
amplifier that could simulate a flame signal during burner operation
The burner controls are therefore suited for use in all types of oil- or gas-fired
combustion plant where self-checking flame supervision systems are either mandatory
or recommended.
For example:
-Burners that operate continuously
-Burners in intermittent operation that, in the case of great heat demand, may
operate continuously for more than 14 hours, e.g. in plant using boiler sequencing
-Burners that need to comply with the German TRD 411 and TRD 412 regulations
for steam boilers
-Burners in plant where, for specific safety requirements, supervision of the burner
by a self-checking flame supervision system seems advisable
-The control sequence and connection circuitry of the LOK16…/LGK16… burner
controls are identical to those of the LAL2... and LFL1... respectively (with the
exception of the LFL1.148), so that existing combustion plant can also be equipped
with self-checking burner controls,
provided very good flame detector current values are measured in the plant
supervised so far by the LFL1..., and
provided the following types of flame detectors are either installed or can
subsequently be fitted:
-Photocell detector RAR9
-Flame detector QRA53.../QRA55...
-Ionization probe
-Flame detector QRA53.../QRA55... together with ionization probe, e.g. in the case
of burners using a pilot burner (also see Data Sheet N7712)
Flame supervision
when using LOK16...
Flame supervision
when using LGK16...

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Warning notes
To avoid injury to persons, damage to property or the environment, the following
warning notes must be observed!
Do not open, interfere with or modify the unit!
All activities (mounting, installation and service work, etc.) must be performed by
qualified staff
Before making any wiring changes in the connection area, completely isolate the
plant from mains supply (all-polar disconnection). Ensure that the plant cannot be
inadvertently switched on again and that it is indeed dead. If not observed, there is
a risk of electric shock hazard
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
Press the lockout reset button only manually (applying a force of no more than
10 N) without using any tools or pointed objects
Do not press the lockout reset button on the unit or the remote reset button
(input 21) for more than 10 seconds, since this would damage the lockout
relay inside the unit
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
In the case of flame supervision with flame detectors QRA53 / QRA55, it should be
noted that sources of radiation such as halogen lamps, welding equipment, special
lamps, ignition sparks, as well as X-rays and gamma radiation, can produce
erroneous flame signals
Mounting notes
Ensure that the relevant national safety regulations are complied with.
Connect the earthing lug inside the terminal base to burner ground using a screw
with a lockwasher
An ignited UV tube is a source of UV radiation!
If the flame is monitored by several flame detectors, all detectors must be placed in
a way that ensures there is no direct visual contact between them.
If this is not observed, there is a risk of loss of safety functions
When equipping existing plants with LOK16 or LGK16, the existing plug-in base for LAL
or LFL burner controls must be replaced with the matching plug-in base AGM17 for
LOK16 / LGK16.
By removing link (B) on the underside of the unit, the LOK16... can be switched to start
repetition in the event of loss of flame during operation.
In that case, the wire link must be cut off completely.
However, it must be checked whether this is in compliance with national standards and
regulations.

Note!
In applications involving air heaters (WLE), or in the case of oil burners with a
maximum throughput of > 30 kW/h, removing wire link Bis not permitted.
Upgrading existing plant
Start repetition in the
event of loss of flame

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Installation notes
Always run the high-voltage ignition cables separately while observing the greatest
possible distance to the unit and to other cables
Neutral conductors must not be interchanged
Install switches, fuses, earthing, etc., in compliance with local regulations
Make certain that the maximum permissible current rating of the connection
terminals will not be exceeded
The insulation of internal wiring that is exposed to the mains voltage must
withstand the electrical stress occurring during correct use
Application notes
Note!
For use in applications in dual-fuel burners or oil burners, the oil supply must be
equipped with two shutoff valves connected in series.
Observe the following:
EN 298:2012, Section 7.101.3.3 Prepurge time for oil burner control systems and the
corresponding application standards.
Electrical connection of flame detectors
It is important to achieve practically disturbance- and loss-free signal transmission:
Never run the detector cable together with other cables
– Line capacitance reduces the magnitude of the flame signal
– Use a separate cable
Observe the permissible detector cable lengths (see Technical data)
It is not permitted to connect 2 flame detectors QRA53.../QRA55... in parallel
When using the QRA53.../QRA55..., earthing of terminal 22 is mandatory
The ionization probe is not protected against electric shock hazard
Locate the ignition electrode and 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
Supervision with ionization probe and QRA53/QRA55 flame detector is possible
but, for safety reasons, both must not be active at the same time, with the
exception of the second safety time (t9). At the end of the second safety time, one
of the detected flames must extinguish, e.g. by shutting down the pilot gas valve
connected to terminal 17
Commissioning notes
When commissioning the plant or when doing maintenance work, make the following
safety checks:
Safety check to be carried out Anticipated response
a) Burner startup with flame detector
darkened
Lockout at the end of safety time
b) Burner startup with simulated flame Lockout after no more than 40 seconds
c) Burner operation with simulated loss
of flame; for that purpose, darken the
flame detector in operation and leave
it in that state
LOK16... with wire link cut: Start
repetition followed by lockout at the end
of safety time
LGK16... and LOK16... with wire link
closed: Immediate lockout
d) Burner startup with response of air
pressure switch
Prevention of startup/lockout during
prepurge time
e) Burner operation with simulated air
pressure failure
Immediate lockout

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Commissioning notes
For the connection of valves and other components, the diagram of by the burner
manufacturer is provide.
Standards and certificates
Applied directives:
Low-voltage directive 2014/35/EC
Directive for pressure devices 2014/68/EC
Electromagnetic compatibility EMC (immunity) *) 2014/30/EC
Only LGK16: Directive for gas-fired appliances 2009/142/EC
*) The compliance with EMC emission requirements must be checked after the burner control is
installed in equipment
Compliance with the regulations of the applied directives is verified by the adherence to
the following standards / regulations:
Automatic burner control systems for burners and
appliances burning gaseous or liquid fuels
DIN EN 298
Only LGK16
Safety and control devices for gas burners and gas
burning appliances
DIN EN 13611:
2007-A2:2011
Automatic electrical controls for household and similar use
Part 2-5:
Particular requirements for automatic electrical burner
control systems
DIN EN 60730-2-5
The relevant valid edition of the standards can be found in the declaration of
conformity!
Note on DIN EN 60335-2-102
Household and similar electrical appliances - Safety - Part 2-102:
Particular requirements for gas, oil and solid-fuel burning appliances having electrical
connections.
The electrical connections of the LMV5 and the PLL5 comply with the requirements of
EN 60335-2-102.
EAC Conformity mark (Eurasian Conformity mark)
ISO 9001:2015
ISO 14001:2015
OHSAS 18001:2007
China RoHS
Hazardous substances table:
http://www.siemens.com/download?A6V10883536

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Certified with plug-in base and flame detector:
Type reference
LOK16.140... --- --- ---
LOK16.250... --- --- ---
LOK16.650... --- --- ---
LGK16.122... --- --- 
LGK16.133A17 --- --- --- --- 
LGK16.133A27 --- --- 
LGK16.322... --- --- 
LGK16.333... --- --- 
LGK16.335... --- --- 
LGK16.622... --- --- 
LGK16.635... --- --- 
Service notes
The KF8832 flame detector current measuring device must not be used in continuous
operation.
Life cycle
Burner controls has a designed lifetime* of 250,000 burner startup cycles which, under
normal operating conditions in heating mode, correspond to approx. 10 years of usage
(starting from the production date given on the type field).
This lifetime is based on the endurance tests specified in standard EN 298.
A summary of the conditions has been published by the European Control
Manufacturers Association (Afecor - www.afecor.org).
The designed lifetime is based on use of the burner controls according to the
manufacturer’s Data Sheet. After reaching the designed lifetime in terms of the number
of burner startup cycles, or the respective time of usage, the burner control is to be
replaced by authorized personnel.
* The designed lifetime is not the warranty time specified in the Terms of Delivery
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.
Mechanical design
Plug-in design
Exchangeable unit fuse (including spare fuse)
Made of impact-proof and heat-resistant black plastic
Lockout reset button with viewing window; located behind it are:
- The lockout warning lamp
- The lockout indicator
- coupled to the spindle of the sequence switch
- visible in the transparent lockout reset button
- uses easy-to-remember symbols to indicate the type of fault and the point in
time lockout occurred
LGK16.../LOK16...
Housing

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Type summary
The type references given below apply to the LOK16 without plug-in base and without
flame detector. For ordering information for plug-in bases and other accessories, see
Accessories.
Switching times are given in the order of the startup sequence, valid for 50 Hz mains
frequency. At 60 Hz, the times are about approx. 17% shorter.
The type references apply to burner controls operating on AC 230 V, 50...60 Hz.
* For burner controls operating on AC 100...110 V, 50...60 Hz, the last 2 digits of the type reference read «17» in place of «27».
For flame supervision with a photocell detector RAR9... for oil burners
Preferred use:
Flash-steam
generators
Universal
application
Medium- or
heavy-oil burners
Type LOK16.140A27* LOK16.250A27* LOK16.650A27
Article
no. BPZ:LOK16.140A27 BPZ:LOK16.250A27 BPZ:LOK16.650A27 Legend of times
t1 10 s 22 s 66 s Prepurge time with air damper fully open
TSA 4 s 5 s 5 s Safety time or first safety time
TSA´ --- --- --- Safety time with burners using a pilot burner
t3 2 s 2.5 s 2.5 s Preignition time
t3´ From startup command (with air pressure supervision:
from receipt of air pressure signal)
Long preignition time
t3n 10 s 15 s 15 s Postignition time (ignition transformer connected to
terminal 15)
t4 8 s 7.5 s 7.5 s Interval between start of safety time and release of
valve at terminal 19
t4´ --- --- --- Interval between start of safety time and release of
valve at terminal 19
t5 4 s 7.5 s 7.5 s Interval between end of interval (t4/t4´) and release of
load controller or valve at terminal 20
t6 10 s 15 s 15 s Postpurge time (identical to permissible afterburn time
(t13))
t7 2 s 2.5 s 2.5 s Switch-on delay of fan motor (M2)
t8 30 s 47 s 91 s Duration of startup without «t11» and «t12»
t9 --- --- --- Second safety time with burners using a pilot burner
t10 6 s 10 s 10 s Interval from startup to the beginning of the air
pressure check
t11 Optional Air damper running time to the fully open position
t12 Optional Air damper running time to the low-fire position
t13 10 s 15 s 15 s Permissible afterburn time
t16 4 s 5 s 5 s Interval from startup to the open command for the air
damper
t20 32 s 34.5 s 12.5 s Interval to self-shutdown of the sequence switch
LOK16...

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Type summary (cont’d)
The type references given below apply to the LGK16 without plug-in base and without
flame detector. For ordering information for plug-in bases and other accessories, see
Accessories.
For flame supervision with flame detector QRA53.../QRA55... or ionization probe
Preferred use:
Flash-steam
generators
Flash-steam
generators
Also suited for
direct-fired air
heaters)
Type LGK16.122A27* LGK16.133A27 LGK16.322A27* LGK16.333A27* LGK16.335A27* LGK16.622A27* LGK16.635A27*
Article
no. BPZ:LGK16.122A27 BPZ:LGK16.133A27 BPZ:LGK16.322A27 BPZ:LGK16.333A27 BPZ:LGK16.335A27 BPZ:LGK16.622A27 BPZ:LGK16.635A27
t1 10 s 9 s 35.5 s 31.5 s 37 s 65 s 66 s
TSA 2 s 3 s 2 s 3 s 2.5 s 2 s 2.5 s
TSA´ 2 s 3 s 2 s 3 s 5 s 2 s 5 s
t3 4 s 3 s 4 s 6 s 5 s 4 s 5 s
t3´ 4 s --- 4 s 6 s 2.5 s 4 s 2.5 s
t3n --- --- --- --- --- --- ---
t4 6 s 6 s 10 s 11.5 s 12.5 s 10 s 12.5 s
t4´ 6 s --- 10 s 11.5 s 15 s 10 s 15 s
t5 4 s 3 s 10 s 11.5 s 12.5 s 10 s 12.5 s
t6 10 s 14.5 s 12 s 17 s 15 s 12 s 15 s
t7 2 s 3 s 2 s 3 s 2.5 s 2 s 2.5 s
t8 30 s 29 s 65 s 69 s 74 s 95 s 103 s
t9 2 s 3 s 2 s 3 s 5 s 2 s 5 s
t10 6 s 6 s 8 s 11.5 s 10 s 8 s 10 s
t11 Optional
t12 Optional
t13 10 s 14.5 s 12 s 17 s 15 s 12 s 15 s
t16 4 s 3 s 4 s 6 s 5 s 4 s 5 s
t20 32 s 60 s --- 26 s 22 s --- ---
LGK16...

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Accessories (to be ordered separately)
Oil burner controls, without plug-in base
For AC 230 V* Control sequence and
connection diagram like
Preferred use
LOK16.140A27* LAL2.14 Flash-steam generators
LOK16.250A27* LAL2.25 Universal application
LOK16.650A27 LAL2.65 Heavy-oil burners
* For burner controls operating on AC 100...110 V, 50...60 Hz, the last 2 digits of the
type reference read «17» in place of «27»
Connection accessories
for medium-capacity
burner controls
Plug-in base AGM16
Article no.: BPZ:AGM16
- with Pg11 thread for cable entry glands
Plug-in base AGM16.1
Article no.: BPZ:AGM16.1
- with M16 thread for cable entry glands
see Data Sheet N7230
Flame detectors Photocell detectors RAR9...
see Data Sheet N7713

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Accessories (to be ordered separately) (cont‘d)
Gas burner controls, without plug-in base
For AC 230 V* Control sequence and
connection diagram like
Preferred use
LGK16.122A27* LFL1.122 Flash-steam generators
LGK16.133A27 LFL1.133 Flash-steam generators
LGK16.322A27* LFL1.322 Also suited for direct-fired
air heaters
LGK16.333A27* LFL1.333
LGK16.335A27* LFL1.335
LGK16.622A27* LFL1.622
LGK16.635A27* LFL1.635
* For burner controls operating on AC 100...110 V, 50...60 Hz, the last 2 digits of the
type reference read «17» in place of «27»
Connection accessories
for medium-capacity
burner controls
Plug-in base AGM17
Article no.: BPZ:AGM17
- with Pg11 thread for cable entry glands
Plug-in base AGM17.1
Article no.: BPZ:AGM17.1
- with M16 thread for cable entry glands
see Data Sheet N7230
Flame detectors Flame detectors QRA53.../QRA55...
see Data Sheet N7712
Ionization probe
to be supplied by thirds

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Accessories (to be ordered separately) (cont‘d)
Actuators Actuator SQN7
Refer to Data Sheet N7804
Actuator SQN3/SQN4
Refer to Data Sheet N7808
Actuator SQM40... / SQM41
Refer to Data Sheet N7817
Actuator SQM5...
Refer to Data Sheet N7815
Others Flame detector current measuring device KF8832
Article no.: BPZ:KF8832
For detector current measurements with QRA53...,
QRA55... , recommended up to series C and E
Not suited for continuous operation
Only for measurements of short duration
Notice!
The KF8832 negates the self-supervision function

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Technical data
Mains voltage
A
C 230 V -15% / +10%
A
C 100 V -15%...AC 110 V +10%
Mains frequency 50...60 Hz ±6%
Unit fuse, built-in T6,3H250V to DIN EN 60 127
Primary fuse (external) Max. 16 A (slow)
Weight
A
pprox. 1000 g
Power consumption
A
pprox. 3.5 V
A
Perm. mounting position Optional
Degree of protection IP40, (to be ensured through mounting)
with the exception of the connection area
(terminal base)
Safety class II
Perm. input current at terminal 1 Max. 5 A to VDE 0660 AC3
Perm. current load of control terminals Max. 4 A to VDE 0660 AC3
Required switching capacity of switching
devices
-Between terminals 4 and 5, 4 and 12
-Between terminals 4 and 14
1 A, AC 250 V
depending on loading of terminals 15, 16,
18, 19 (LGK16...: 16...19), min. 1 A,
A
C 250 V
Permissible length of the standard detector
cable (laid separately)
See Technical data, section Flame
supervision
Capacity
-Output on startup (without fan)
-Nominal output
Optional (with ignition < 120 kW)
Optional
Storage DIN EN 60721-3-1
Climatic conditions Class 1K3
Mechanical conditions Class 1M2
Temperature range -20...+60 °C
Humidity <95% r.h.
Transport DIN EN 60721-3-2
Climatic conditions Class 2K3
Mechanical conditions Class 2M2
Temperature range -20...+60 °C
Humidity <95% r.h.
Operation DIN EN 60721-3-3
Climatic conditions Class 3K3
Mechanical conditions Class 3M3
Temperature range -20...+60 °C
Humidity <95% r.h.
Installation altitude Max. 2,000 m above sea level
Caution!
Condensation, formation of ice and ingress of water are not permitted!
If this is not observed, there is a risk of loss of safety functions and a risk of
electric shock
General unit data
LOK16.../LGK16...
Environmental
conditions

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Technical data (cont´d)
LOK16... LGK16...
RAR9... QRA5x.C...
QRA5x.E...
QRA5x.D...
QRA5x.G...
Ionization probe
Operating voltage (Terminal 23 or 24) <DC 1 V
±10%
AC 280 V ¹)
±10%
AC 280 V ¹)
±10%
AC 245 V ¹)
±10%
Minimum detector current required DC 6 µA DC 35 µA DC 120 µA DC 12 µA
Maximum possible detector current DC 38 µA DC 50 µA DC 270 µA DC 100 µA
Short-circuit current --- --- --- Approx. AC 300 µA
Maximum length of detector cable (laid separately) 100 m ²) ²) 60 m ³)
1) AC voltage, measured with no detector current at AC 230 V mains voltage. Internal resistance of measuring instrument 10 M. The
shutter of the flame detector QRA53.../QRA55... is powered by mains voltage
2) Detector cable laid in a minimum distance of 5 cm from other mains carrying cable:
-As a multiple cable
-With 5 single wires
Max. 50 m
Max. 70 m
With a shielded 3-core control cable to terminals 3, 4 and 5 of the flame detector QRA53.../QRA55... and
standard mains cable to terminals 1 and 2
Max. 15 m
With 2 shielded single-core coaxial cables (45 pF/m, e.g. RG 62) to terminals 3 and 4 of the flame detector
QRA53.../QRA55... and standard mains cable to terminals 1, 2 and 5
Max. 60 m
If possible, shielding should be earthed at both ends
3) Longer cable distances are permitted when connecting low-capacitance detector cables to terminal 24 of the burner control
(especially against earthed wires!)
Detector current measurement
The measuring device must be connected between the detector and terminal 22 (+pole
to terminal 22).
With RAR9...
22
24
DC 6...38 µA
+
RAR9...
+A
7785v02/1008
Notice!
Use the KF8832 measuring device (not suited for continuous operation).
There is no self-checking while measurements are made.
The KF8832 is not required when using the QRA5x.D.../QRA5x.G...
With QRA5x.C.../QRA5x.E... With QRA5x.D.../QRA5x.G...
22
DC 35...50 µA
+
A
+
470 µF/25 V
7785v04/1008 22
DC 120...270 µA
+
A
+
470 µF/25 V
7785v01/1008
Flame supervision
Measuring circuit for
detector current
measurement
LOK16.../RAR9...
LGK16.../QRA53.../
QRA55...

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Detector current measurement (cont´d))
The measuring device must be connected between terminal 24 and the detector
electrode (+pole to terminal 24).
With ionization
24 ION
+A
7785v03/1008
DC 12...100 µA
1
2
5
3
4
4
3
5
2
1
4
3
5
2
1
1
2
22
23
15
2
7785g01e/0604
Burner control
LGK16... base
Burner
Terminals in the
burner compartment
QRA5...
Terminals in
the control panel
Mains cable 3 x 1.5 mm
Single-wire coaxial cable
(e.g. RG62)
Shielding
Max. 60 m
Cable AGM19
A Ammeter
RAR9... Silicon photocell detector
ION Ionization probe
LGK16
Legend

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Function
In contrast to conventional amplifiers, the signal delivered by the flame detector is
handled dynamically and not statically. The flame detector signal is converted to a
sequence of control pulses and then fed to the flame relay circuit. The latter is designed
such that the flame relay can only be energized by a flame signal of the described form.
If the pulses change due to a faulty detector or faulty detector cables, the relay will be
deenergized and the burner control triggers the required safety actions. In the case of
UV supervision, it must also be ensured that self-ignition of the UV tube (e.g. due to
aging) does not simulate a flame signal. For that reason, incident radiation at the UV
cell is periodically interrupted by a shutter. In addition to the self-checking facility, the
flame signal circuit is subjected to a functional test during the prepurge time. If it does
not operate correctly, the startup sequence will be aborted or lockout initiated.
Furthermore, if mains voltage drops to a level where safe operation of the burner
control is no longer ensured, the burner will automatically shut down. When mains
voltage returns to the normal level, the burner control repeats the startup sequence. If
the detector signals are only slightly above the minimum levels, such mains voltage
fluctuations can also give rise to burner lockout however.
-The burner control is reset and in the start position (terminals 11 and 12 must
receive power)
-The air damper is closed. The end switch (z) for the CLOSED position must pass
voltage from terminal 11 to terminal 8
-All control contacts between terminals 12 and 5 (limit thermostat, control
thermostat, etc.) must be closed
Principle of
self-supervision
Prerequisites for
burner startup

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Startup program
A Start
When control thermostat or pressurestat closes, the burner control’s sequence switch starts running. At the
same time, the fan motor connected to terminal 6 (only prepurging) receives power and, on completion of
switch-on delay time, the fan motor or flue gas fan at terminal 7 (pre- and postpurging) also receives power.
On completion of interval (t16), the control command to open the air damper is given via terminal 9. During
the running time of the motor, the sequence switch does not operate, as terminal 8, via which the motor of
the sequence switch first receives power, is not live during that period of time. The sequence switch starts
again and begins the prepurge time (t1) only after the air damper is fully open and end switch «a» has
changed over to feed power to terminal 8.
t1 Prepurge time with air damper fully open (nominal amount of combustion air)
Shortly after the start of the prepurge time, air pressure switch must change over, thus interrupting the
current path between terminals 4 and 13. Otherwise, the burner control would go to lockout (start of air
pressure check). At the same time, terminal 14 must be live since this current path is used to power the
ignition transformer and the fuel valves.
t3‘ With the LOK16…, an ignition transformer connected to terminal 15 is therefore switched on at this point in
time (long preignition). If there is no air pressure switch, the ignition transformer receives power already with
the start command. On completion of the prepurge time, the burner control via terminal 10 drives the air
damper into the low-fire position, which is determined by the changeover point of auxiliary switch (m). During
the positioning time, the sequence switch stops again until terminal 8 receives power from «m».
t5 Interval
On completion of interval (t5), terminal 20 receives power. At the same time, control outputs 9 to 11 and
input 8 are galvanically separated from the unit’s control section, so that the latter is protected against
reverse voltages from the load control circuit. The startup sequence of the burner control ends with the
release of load controller at terminal 20. The sequence switch switches itself automatically off, depending on
the time variant used, either immediately or after some so-called idle steps, that is, without changing the
contact positions.
Expanding flame burners with LOK16... or LGK16...
t3 Short preignition time; followed by fuel release via terminal 18.
TSA Safety time (part load)
On completion of the safety time latest, a flame signal must be present at the input of the flame signal
amplifier, or else the burner control will initiate lockout.
Only with LOK16...:
t3n Postignition time (provided the ignition transformer is connected to terminal 15).
t4 Interval until the fuel valve is released via terminal 19.

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Startup program (cont’d)
Interrupted pilot burner with LGK16 (burners using a pilot burner)
t3
t3‘ Short preignition time; followed by release of fuel for the pilot burner via terminal 17.
Note! (Only for LGK)
For use in applications in dual-fuel burners or oil burners, the oil supply must be equipped with two
shutoff valves connected in series.
Observe the following:
EN 298:2012, Section 7.101.3.3 Prepurge time for oil burner control systems and the corresponding
application standards.
TSA
TSA‘ First safety time (ignition load) On completion of the safety time latest, a flame signal must be present at the input of the flame signal
amplifier, or else the burner control will initiate lockout.
t4
t4‘ Interval until the fuel valve at terminal 19 is released (start load of the main burner).Times safety time (TSA´), short preignition time (t3´) and interval (t4´) are only programmed by burner controls type
LGK16.335... and LGK16.635...
t9 Second safety time
On completion of the safety time, the main burner must have been ignited by the pilot burner, since the pilot
gas valve is closed on completion of second safety time (t9).
B Operating position of the burner
B - C Burner operation (generation of heat)
During burner operation, the load controller drives the air damper to the nominal load or low-fire position,
depending on heat demand. Here, the nominal load is released by auxiliary switch (v) in the actuator.
C Controlled shutdown by control thermostat or pressurestat
In the case of controlled shutdown, the fuel valves are immediately closed and, at the same time, the
sequence switch starts again to program the postpurge time (t6).
t6 Postpurge time (postpurging with fan (M2) connected to terminal 7).
Shortly after the start of the postpurge time, voltage at terminal 10 is reinstated, so that the air damper is
driven into the MIN position. The full closing of the air damper starts only shortly before the completion of the
postpurge time initiated by the control signal on terminal 11, which also remains live during the following
burner off period.
t13 Permissible afterburn time
During permissible afterburn time (t13), the flame signal input may still receive a flame signal
No lockout
D - A End of control sequence (= start position)
When, on completion of postpurge time (t6), the sequence switch has reset the control contacts to their start
positions, thereby switching itself off, the detector and flame simulation test is started again. However, during
the burner off period, lockout can occur only if the faulty flame signal lasts a few seconds. Hence, short
ignition pulses of the UV detector caused by cosmic radiation do not initiate lockout.

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Control sequence in the event of fault and indication of lockout
In case of any disturbance, the supply of fuel will immediately be interrupted. At the
same time, the sequence switch stops and thus the lockout indicator also.
The symbol appearing above the reading mark indicates the kind of fault:
No start One of the contacts is not closed (also see Prerequisites for burner startup)
Extraneous light
Lockout during or after completion of the control sequence
Example:
- Flame not extinguished
- Leaking fuel valves
- Faulty flame supervision circuit
=Abortion of startup
sequence
No OPEN signal for end switch (a) at terminal 8
Terminals 6, 7 and 14 and, in case LOK16... is used, terminal 15, also remain live
until the fault is corrected.
P Lockout The air pressure signal has not been received at the start of the air pressure check
Each air pressure failure after this time initiate also lockout.
Lockout Due to a fault in the flame supervision circuit.
>Abortion of startup
sequence,
Auxiliary switch (m) has not delivered the positioning signal for the low-fire position
to terminal 8.
Terminals 6, 7 and 14 and, in case LOK16... is used, terminal 15, also remain live
until the fault is corrected.
1 Lockout No flame signal has been received on completion of the (first) safety time.
2 Lockout Only with LGK16...:
No flame signal has been received on completion of the second safety time (flame
signal of the main flame with interrupted pilot burners).
I Lockout The flame signal has been lost during burner operation
Air pressure failure
After the lockout reset, the burner control sequence switch first returns to the start
position and then initiates a burner restart.
If lockout occurs any other moment in time between start and preignition not indicated
by a symbol, the usual cause is a premature flame signal, that is, a faulty flame signal
caused, for instance, by a self-igniting UV tube.
Only with LOK16...:
If wire link (B) was cut off and the flame is lost during burner operation, the burner
control programs a repetition of the startup sequence with the full program.

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Control sequence in the event of fault and indication of lockout (cont´d)
P
a
b´
b
a
b´
b
2
1
a
2
b
a
b
1
P
P
1
P
1
2
a
b´
b
P
1
2
LOK16.140...
LOK16.250...
LOK16.650...
LGK16.122...
LGK16.133...
LGK16.322...
LGK16.333...
LGK16.622...
LGK16.335... LGK16.635...
7785p02/0296
a-b Startup sequence
b-b´ With certain time variants:
Idle steps of the sequence switch up to the self-shutdown after burner startup
(b´ = operating position of the sequence switch)
b(b´)-a Postpurge sequence after controlled shutdown.
In start position (a), the sequence switch switches itself automatically off or
immediately initiates another burner startup (e.g. after a fault has been
corrected)
Duration of safety time with expanding flame burners
 Duration of safety times with interrupted pilot burners
When lockout has occurred, the burner control can immediately be reset:
Do not press the lockout reset button for more than 10 seconds
The sequence switch always travels to the start position first
After resetting
After rectification of a fault that led to shutdown
After each power failure
During this period of time, power is only fed to terminals 7 and 9...11
After that, the burner control programmed the restarting of the burner
Note!
Do not press the lockout reset button for more than 10 seconds.
Lockout indication

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Connection diagrams (for circuitry variants, see Connection examples)
LOK16...
H
N
C
D
A
L
EK2
AL
21
1
AS
2
1(3)
3
W
R
45 6 7
t6
B
A
t7
BV3BV1Z
SA
15 16 17 18
az
M
2019 9
LR
t4
t3
TSA
t5 t1 t11
az
m
11 10 822
B
1
v
7785a01/0908
LK
Si
LP
+
141213
t10
SB
P
t3´
t3n
24
m
t13
t12 t16
RAR9...
M1 M2
BV2

Note!
In applications involving air heaters (WLE), or in the case of oil burners with a
maximum throughput of > 30 kW/h, removing wire link Bis not permitted.
Caution!
Do not press lockout reset button (EK...) for more than 10 seconds!
Connect the safety valve as specified in the diagram provided by the burner
manufacturer.