7 781

Flame Safeguards LAE10

LFE10
 Flame safeguards for burners with intermittent operation
 The LAE10 is used for the supervision and indication of oil flames
 The LFE10 is used for the supervision and indication of gas and oil flames
 Supplementary Data Sheets for flame detectors, refer to N7712 and N7713
 For control units LEC1 for continuous operation, refer to Data Sheet N7761

The LAE10 / LFE10 and this Data Sheet are intended for use by OEMs which
integrate the flame safeguards in their products!

Use
LAE10 - For the supervision of oil flames
- Flame supervision with silicon photocell detector RAR9...

LFE10 - For supervision of gas flames and luminous or blue-burning oil flames
- Flame supervision with flame detector QRA... or ionization probe

General Both types of flame safeguards are used primarily in conjunction with LEC1 control
units on the following applications:
- Dual-supervision of burners / supervision of the main flame or of the ignition and
main flame by 2 identical or different types of detectors
- Supervision of forced draft oil / gas burners / supervision of the flame with
different types of detectors, depending on the operating mode
- Multiflame supervision / plants with several burners whose flames must be
supervised individually by one or several detectors, whose startup and supervision,
however, should or must be carried out centrally and simultaneously by only 1
burner control
- The flame safeguards can also be used in connection with other types of burner
controls provided the given combination and selected connection circuit do not
impair the burner control’s safety functions
- The flame safeguards are also used as flame indication units in combustion plant
with manual startup

CC1N7781en
Building Technologies Division
15.10.2012 Infrastructure & Cities Sector
Warning notes
The avoid injury to persons, damage to property or the environment, the
following warning notes must be observed!

It is not permitted to open, interfere with or modify the units!

 All activities (mounting, installation and service work, etc.) must be performed by
qualified staff. If this is not observed, there is a risk of loss of safety functions or
a risk of electric shock
 For safety reasons – self-test of flame supervision circuit, etc. – at least one
controlled shutdown is required every 24 hours. If this is not observed, there is a
risk of loss of safety functions
 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 flame safeguard´s connection terminals. If this is not observed, there is a
risk of electric shock
 Each time work has been carried out (mounting, installation, service work, etc.),
check to ensure that wiring is in an orderly state. If this is not observed, there is a
risk of loss of safety functions or a risk of electric shock
 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
 The ionization probe does not offer protection against electrical shock hazard. The
mains-operated ionization probe must be protected against accidental contact. If
this is not observed, there is a risk of electric shock
 An ignited UV tube is a source of UV radiation! In case of flame supervision by
means of flame detectors, the detectors must be placed such that there is no
direct visual contact between them. If this is not observed, there is a risk of
loss of safety functions

Engineering notes
Ensure that the drop out delay time of relay «d» does not exceed 50 ms (also refer to
«Connection examples», 7781a02).

Mounting notes
 The relevant national safety regulations must be complied with
 The flame safeguards can be mounted in any position directly on the burner, in
control panels, or on the front of a panel
 There are 2 types of plug-in bases available, designed for cable entry from the
front, the side or below. 2 earth terminals provide looping facilities for the earth
connections of other burner plant components such as ignition transformers (the
flame safeguards themselves are double-insulated!)

Installation notes
 Always run the high-voltage ignition cables separately while observing the greatest
possible distances to the unit and to other cables
 Do not mix up live and neutral conductors

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Electrical connection of the 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
 Ionization probe does not provide protection against electrical 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)
 Observe the maximum permissible lengths and shielding of the detector cables
(refer to «Technical data»)
 Locate and adjust the detector such that only the flame to be supervised will be
detected
 Protect the UV cell adequately against UV sources emitted by halogen lamps,
welding equipments, special lamps, ignition sparks, high energy x-rays and gamma
rays

Standards and certificates

ISO 9001: 2008 ISO 14001: 2004

Cert. 00739 Cert. 38233

Only in combination Conformity to EEC directives

with the flame detector - Electromagnetic compatibility EMC (immunity) 2004/108/EC
- Directive for gas appliances 2009/142/EC
- Directive for pressure devices 97/23/EC

With LEC1…
LAE10 x x x x x --- x ---
LFE10 x x x x --- x x x

Life cycle
Flame safeguards 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 EN230 / EN298 and the table containing
the relevant test documentation as published by the European Association of
Component Manufacturers (Afecor) (www.afecor.org).

The designed lifetime is based on use of the flame safeguards 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 flame safeguards is to be
replaced by authorized personnel.

* The designed lifetime is not the warranty time specified in the Terms of Delivery

Disposal notes
The flame safeguards contain 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 flame safeguards are of plug-in design and consist of power supply section, flame
signal amplifier, flame relay, an auxiliary relay for controlling the flame detector or the
flame simulation test, and a flame indication lamp located in the unit cover behind a
viewing window.

The electrical circuit is intrinsically safe in connection with LEC1 control unit – is tested
in respect of proper functioning each time the burner is started up. The plug-in bases –
like the housing – are made of impact-proof and heat-resistant plastic. For illustrations
of the plug-in bases and other notes, refer to «Dimensions».

Special features LAE10 Automatic light simulation test by increasing the sensitivity of the amplifier during the
burner off and the purging times of the LEC1 control unit control.

Special features LFE10 Automatic testing of the flame detector by increasing the operating voltage of the UV
tube during the burner off and the purging times of the LEC1 control unit.

Flame Flame detector Data Sheet

supervision QRA2..., QRA10... N7712
QRA4.U N7711
RAR9... N7713

Ionization probe Flame supervision by making use of the electrical conductivity of the flame in
conjunction with the rectifying effect is only possible with gas and blue-flame burners.
Since the flame signal amplifier responds only to the DC component of the flame signal
(ionization current), a short-circuit between flame detector and functional earth cannot
simulate a flame signal.

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Type summary
Flame safeguard
- For the supervision of oil flames with silicon photocell detectors RAR9...
- AC 220…240 V LAE10
- AC 110 V LAE10-110V

Flame safeguard
- For the supervision of gas / oil flames with flame detector QRA... or ionization probe
- AC 220…240 V LFE10
- AC 110 V LFE10-110V

Ordering
When ordering, please give complete type reference.

Flame safeguard is delivered without plug-in base; order these separately (refer to
«Accessories»).

Accessories
Silicon photocell detectors RAR9... refer to Data Sheet N7713

UV flame detector QRA2..., QRA10... refer to Data Sheet N7712

UV flame detector QRA4.U refer to Data Sheet N7711

Ionization probe supplied by thirds

Low plug-in base (refer to «Dimensions») AGK410413450

- 10-pole screw terminals
- 5 cable entries

High plug-in base (refer to «Dimensions») AGK410490250

- 10-pole screw terminals
- With removable front
- 6 cable entries, 4 of which with Pg11 thread

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Technical data
General unit data Mains voltage AC 220 V –15 %...AC 240 V +10 %
AC 100 V –15 %...AC 110 V +10 %
Mains frequency 50...60 Hz ±6 %
Prefuse (external) Max. 10 A (slow)
Power consumption 4.5 VA
Perm. contact rating Max. 2 A
Degree of protection IP40, with appropriate cable entry
Mounting position Optional
Cross sectional areas that can be
connected to AGK4...
- Terminal 1...10 Min. 0,75 mm²
Max. 1,5 mm²
Solid wire or stranded wire with ferrule
- Auxiliary terminals N, PE, 11 and 12 Min. 0,75 mm²
Max. 1,5 mm²
Solid wire or stranded wire with ferrule (when
connecting 2 solid wires or stranded wires per
terminal, same cross-sectional areas must be
used)

Weight LAE10 LFE10

Without plug-in base Approx. 305 g Approx. 395 g
With normal plug-in base Approx. 380 g Approx. 470 g
With high plug-in base Approx. 415 g Approx. 505 g

LAE10 LFE10
Flame supervision with... ...RAR9... ...Ionization probe ...QRA...
Required detector current
- At AC 100 V / AC 220 V Min. 8 µA Min. 8 µA Min. 150 µA
- At AC 110 V / AC 240 V Min. 8 µA Min. 9 µA Min. 200 µA
Possible detector current
- At AC 100...110 V / AC 220...240 V Max. 38 µA Max. 100 µA Max. 650 µA

Perm. length of connecting cables 20 m ²) 20 m ¹) 20 m ¹)

¹) In case of greater distances, use low-capacitance cable (total max. 2 nF)

Example: Single-core RG62
²) Run detector cables separately, at least 5 cm away from other cables

Environmental Storage DIN EN 60721-3-1

conditions 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 2K2
Mechanical conditions Class 2M2
Temperature range -20...+60 °C
Humidity <95 % r.h.
Operation DIN EN 60721-3-3
Climatic conditions Class 3K5
Mechanical conditions Class 3M2
Temperature range -20...+60 °C
Humidity <95 % r.h.

Caution!
Condensation, formation of ice and ingress of water are not permitted!

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Technical data (cont´d)

Measuring circuits Ionization probe QRA... RAR9…

LFE10 LFE10 A LAE10

A
8 10 9 10 9 10
ION M - +
M
- +
- M - +
- + C
+
QRA... + 7781a07/0908

Legend A Illumination of flame ION Ionization probe

C Electrolytic capacitor 100 µF, M Microammeter
DC 10 V QRA... Flame detector

Caution!
Ignition may affect the ionization current!
Remedy: Exchange the connections on the primary side of the ignition
transformer.

Function
Basic mode of operation of the flame safeguards in connection with the LEC1 control
unit:

When used with the LEC1, the flame safeguard feeds the flame signal into the burner
control’s control program the same way as if the flame safeguard was a component of
the burner control (same as with an oil or gas burner control). In the event of non-
ignition, loss of flame during burner operation or faulty flame signal during burner off or
purging times, the burner will always be shut down and the burner control will initiate
lockout. The switching functions needed to feed the flame signal into the burner
control’s control circuit are provided by flame relay «FR» of the flame safeguard and
the 2 auxiliary relays «HR1» and «HR2» of the LEC1 control unit. The LEC1 control
unit also delivers the sequence control for the flame simulation test in connection with
the LAE10 flame safeguard, and the flame detector test with the LFE10. The test is
controlled via the connecting line between terminal 15 of the burner control and
terminal 6 of the respective flame safeguard.

Both tests
 start about 7 seconds after a controlled shutdown
 are continued during burner off times
 Are continued during the ensuing prepurge time
 end 3 seconds before start of the safety time

Following flame signals during this test time lead to lockout with interlocking of the
LEC1 control unit:
- Extraneous light
- Ageing flame detectors
- Other defects of the flame supervision equipment

In the flame safeguard, the switching functions required are performed by auxiliary
relay «HR3».
Since in the case of flame supervision with an ionization probe, it is not necessary to
carry out a test, the connecting line between terminal 15 of the burner control and
terminal 6 of the flame safeguard is not required here.

Information!
Instead, terminal 6 must be connected to the live wire.
Example: By making a connection to terminal 1, 5 or 7.

Any flame signal – be it a normal flame signal during operation or a faulty signal – is
indicated by the indication lamp at housing of flame safeguard.

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Mode of operation of the flame safeguards when used for dual-supervision (detailed connection diagram, e.g.
for oil burners)

LEC1 With this type of supervision, 1 flame is supervised by 2

1 2 6 5 7 13 14 15 independently operating flame safeguards, aimed at
reducing the possibility of loss of flame during operation
in case of a simultaneous failure of both flame
3 4 1 6 safeguards to an «improbable coincidence».
8 With dual-supervision, the control contacts of the flame
FR RAR9...
9 + relays of both flame safeguards are connected in series
10 so that loss of the flame signal of either of the flame
L1
safeguards is sufficient to cause lockout of the burner.
7 5 2 LAE10
A faulty flame signal by only 1 of the 2 flame safeguards
during burner off times or purging times also leads to
lockout.

3 4 1 6
8
FR RAR9...
9 +
10
Z OV1 OV2 L1
7 5 2 LAE10

P(R) N(Mp) 7781a01/0908

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Building Technologies Division CC1N7781en

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Mode of operation of the flame safeguards when used for the supervision of 2 manually controlled burners
With this type of supervision, too, the burner can be
started only if the flame detector or flame simulation test
has been successful. This means that neither of the 2
flame safeguards may detect a flame signal during burner
off times. When the burner is started up, the detector test
will automatically be interrupted.
When pressing button «I», relay «d» is energized via
circuit path 4-5 of the flame relays, which is still closed,
thus switching on the ignition of both burners.
At the same time, fuel is released.
The duration of the start pulse given by pressing button
«I» should be limited by a time relay – in the sense of a
safety time.
If the flame is established on both burners - indicated by
the signal lamps at housing of flame safeguards – relay
«d» is now maintained in its energized condition via
circuit path 3-7 of the 2 flame relays.
When releasing button «I», ignition will be switched off,
thus completing the startup sequence.
If the event of loss of flame on 1 of the burners, the
respective flame relay is deenergized, thereby
neutralizing the holding circuit for relay «d». This means
that the fuel valves of both burners will immediately be
shut.
The burners are switched off manually be pressing button
«0», or – automatically – by the control / limit thermostat
or pressurestat / pressure switch in the phase wire
connection.
In case of flame supervision with ionization probes,
terminal 6 of the flame safeguards must be connected
directly to the phase wire since no detector test is
required here.
Example: During connection with terminal 1!

Note!
 Ensure that the drop out delay time of relay «d» does not exceed 50 ms (also refer to
«Connection examples», 7781a02).

Caution!
An ignited UV tube is a source of UV radiation! In case of flame supervision by
means of flame detectors, the detectors must be placed such that there is no direct
visual contact between them. If this is not observed, there is a risk of loss of safety
functions

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Mode of operation of the flame safeguards with multi-flame supervision (detailed connection diagram, e.g. for
gas burners)

LEC1 Like with dual-supervision, the control contacts

1 2 6 5 7 13 14 15 of the flame relays of all flame safeguards must
be connected in series when using multi-flame
3 4 1 6 supervision.
8
FR ION
9 +
10 QRA...
A burner causes all other burners to go to
0 I L1
BS
Z lockout if:
7 5 2 LFE10
- the flame is not established during the
GV1 GV2
safety time, or
- the flame is lost during operation.
3 4 1 6
8
FR ION Correctly operating burners can be restarted
9 +

0 I L1
10 QRA... only – after the burner control has been reset –
Z
BS 7 5 2 LFE10
when the faulty burner has been shut down.
GV1 GV2 In that case, the operating switch must not only
bridge the control contacts of the respective
flame safeguards, thus closing the control chain
3 4 1 6
8 again, but must also break the phase wire
FR ION
9 + connection to the ignition transformer and the
10 QRA...
0 I Z L1 fuel valves.
BS 7 5 2 LFE10 Likewise, after rectification of the fault, the
GV1 GV2 burner can only be restarted in connection with
the other burners, that is, only after all burners
P(R) N(Mp) 7781a03/0903
have previously been shut down.

Caution!
Terminal 10 must be connected to
earth also when using the flame
detector QRA...!

Legend BS Operating switch OFF / ON  per burner

ION Ionization probe for ionization supervision
FR Flame relay
GV1 / GV2 Gas valve for 1st and 2nd stage
L1 Built-in signal lamp  indication of flame
QRA... Flame detector
Z Ignition transformer

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Basic circuit diagrams
LFE10 with flame detector QRA

P(R)

H 15 LEC1

7 5 1 6

FR
HR3

8
QRA...
hr3 9 +
10
L1

3 4 2 7781a05/0199
N(Mp)
13 14 LEC1

Caution!
Terminal 10 must be connected to earth!

LFE10 with ionization supervision

P(R)

7 5 1 6

FR HR3

8
ION
hr3 9
10
L1

3 4 2 7781a06/0903
N(Mp)
13 14 LEC1

LAE10 with silicon photocell detector RAR9...

Legend
P(R)

15 LEC1
FR Flame relay
H
H Main switch
7 5 1 6 HR3 Auxiliary relay for UV detector or
flame simulation test
FR ION Ionization probe for ionization
HR3
supervision
8 L1 Built-in signal lamp
RAR9...
hr3 9 +  Indication of flame
L1 10 QRA... Flame detector
RAR9... Silicon photocell detector

3 4 2
7781a04/0908
N(Mp)
13 14 LEC1
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Dimensions
Dimensions in mm

Base versions

Low plug-in base, Design features:

AGK 4 104 1345 0 10-pole (screw terminals), with additional earth terminals. Cable entry either through
the bottom of the base (2 knockout holes), the front, from the right or left side (total of 5
cable entries).

13

4,6
1 2 3 4 5 6 7 8 9 10 31
4

1 2 3 4 5 6 7 8 9 10
13
16
31

90 4

22 22 16,2
25 25 7781m02/1198

30 30
42,5 42,5

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Dimensions (cont´d)
Dimensions in mm

Base versions

High plug-in base, Design features:

AGK 4 104 9025 0 With removable front (shaded area in the drawing).

10-pole (screw terminals), and:

- 2 auxiliary terminals with markings 11 and 12
- 2 neutral terminals, wired to terminal 2 (neutral input)
- 2 earth terminals, with earthing lug for the burner

For cable entry:

- 2 cable entries in the bottom of the base
- 4 threaded knockout holes for cable glands Pg11, 1 on the right, 1 on the left, and
in the removable front

13

4,5
31,5

1 2 3 4 5 6 7 8 9 10
4

N
11 12
13
16
23,5
34

16 10,5 110 4
22 22 4,5
25 25
30 30 7781m01/1198
45 45

2012 Siemens AG Infrastructure & Cities Sector Building Technologies Division

Subject to change!
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