Siemens LAE10, LFE10 Quick Manual

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Page 1

Landis & Staefa Division CC1N7781E June 01, 1999 1/8

781

Flame Safeguards

LAE10

LFE10

Series 02

Supplementary data sheets 7712 and 7713

Flame safeguards for burners with intermittent operation.

For safety reasons - self-test of flame supervision circuit, etc. - at least one controlled shutdown is required every 24 hours. For flame supervision systems for continuous operation, refer to data sheet 7783.

The LAE10 is used for the supervision and indication of oil flames, the LFE10 for gas and oil flames.

The LAE10 / LFE10 and this data sheet are intended for use by OEMs which integrate the flame safeguards in their products.

The LAE10 is designed for the supervision of oil flames in connection with selenium photocell detectors RAR... The LFE10 is suited for the supervision of gas flames and luminous or blue-burning oil flames in connection with UV detectors QRA... or a flame rectification probe.

Both types of flame safeguards are used primarily in conjunction with the LEC1 burner control on the following applications:

– Dual-supervision of burners

Supervision of the main flame or of the pilot and main flame by two identical or different types of flame detectors

– Supervision of forced draught oil / gas burners

Supervision of the flame with different types of detectors, depending on the operating mode

– Multi-flame 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 one burner control

– The flame safeguards can also be used in connection with other types of burner

controls provided the given combination and selected circuitry 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

ISO 9001

Use

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2/8 CC1N7781E June 01, 1999 Landis & Staefa Division

To avoid injury to persons, damage to property or the environment, the following warning notes should be observed!

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

• Before performing any wiring changes in the connection area of the LAE10 / LFE10, the flame safeguard must be completely isolated from the mains supply!

• Check the wiring and all safety functions!

• Ensure that the drop out delay time of relay «d» does not exceed 50 ms (also refer

to «Connection examples»)!

• The relevant national safety regulations must be complied with!

• Locate the ignition and detector electrodes such that the ignition spark cannot arc

over to the detector electrode! → Risk of electric overloads

• Locate and adjust the flame detector such that only the flame to be supervised will be detected

• Protect the UV cell adequately against UV radiation emitted by – halogen lamps – welding equipment – special lamps – ignition sparks – high energy x-rays and gamma rays

• Installation and commissioning work may only be carried out by qualified staff!

• Observe the permissible lengths and shielding of the detector cables! → Refer to «Technical data»!

• Always run the ignition cables separate from the unit and other cables while

observing the greatest possible distances!

• Before putting the flame safeguard into operation, check the wiring carefully!

The LAE10 / LFE10 are of plug-in design and consist of power section, flame signal amplifier, flame relay, an auxiliary relay for controlling the UV 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 compliance with the relevant regulations and - in connection with LEC1 burner controls - is tested in respect of proper functioning each time the burner is started up. 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 two types of plug-in bases available, designed for cable entry from the front, the side or below. Two 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!). The plug-in bases - like the housing - are made of impact-proof and heat-resistant plastic. For illustrations of the bases and other notes, refer to «Base versions» and «Dimensions».

– LAE10:

Automatic light simulation test by increasing the sensitivity of the amplifier during the burner off and purge times, as programmed by the LEC1 burner control

– LFE10:

Automatic testing of the UV detector by increasing the operating voltage of the UV tube during the burner off and purge times, as programmed by the LEC1 burner control

Warning notes

Engineering notes

Mounting notes

Installation notes

Mechanical design

Special features

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Landis & Staefa Division CC1N7781E June 01, 1999 3/8

– UV detector QRA... (refer to data sheet 7712) – Selenium photocell detectors RAR7 and RAR8 (refer to data sheet 7713) – Flame rectification 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 d.c. component of the flame signal (ionization current), a short-circuit across the detector electrodes cannot simulate a flame signal.

CE conformity Mains voltageAC 220 V -15 %...AC 240 V +10 % According to the directives of the European Union AC 100 V -15 %...AC 110 V +10 % Electromagnetic compatibility EMC 89 / 336 EEC incl. 92 / 31 EEC Mains frequency 50...60 Hz ±6 % Directive for gas appliances 90 / 396 EEC Low voltage directive 73 / 23 EEC Prefuse (external) max. 10 A (slow)

Environmental conditions Power consumption 4.5 VA Transport IEC 721-3-2 Climatic conditions class 2K2 Max. contact rating 2 A Temperature range -20...+60 °C Humidity < 95 % r.h. Degree of protection IP 40 Mechanical conditions class 2M2 provided cable entry is in Operation IEC 721-3-3 compliance with IP 40 Climatic conditions class 3K5 Temperature range -20...+60 °C Mounting orientation optional Humidity < 95 % r.h. Condensation, formation of ice and ingress of water are not permitted!

LAE10 LFE10

Weight without plug-in base 305 g 395 g

Weight with normal plug-in base 380 g 470 g

Weight with high plug-in base 415 g 505 g

Flame supervision Series 02

LFE10 LFE10 LAE10

Rectification probe UV detector Selenium cell

Required min. detector current in µA

- At AC 100 V and AC 220 V min. 8 150 8

- At AC 110 V and AC 240 V min. 9 200 8

Max. possible detector current in µA

- At AC 100...110 V and AC 220...240 V approx. 100 approx. 650 approx. 25

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

¹) In case of greater distances, use low-capacitance cable (total max. 2 nF), such as single-core RG62

²) Run detector cables separately, at least 5 cm away from other cables and, in case of greater distances, use selenium photocell detector RAR8

A C FE M QRA...

Illumination of flame Electrolytic capacitor 100 µF, DC 10 V Detector electrode Microammeter UV detector

Ignition may affect the ionization current!

Remedy: exchange the connections on the primary side of the ignition transformer

Flame detectors

Technical data

Measurement circuits

LFE10

810

QRA...

LFE10

109

910

LAE10

77 81a07 / 119 8

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4/8 CC1N7781E June 01, 1999 Landis & Staefa Division

Basic mode of operation of the flame safeguards in connection with the LEC1 burner control

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 purge 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 two auxiliary relays «HR1» and «HR2» of the LEC1 burner control.

The LEC1 also delivers the program for the flame simulation test in connection with the LAE10, and the UV detector test with the LFE10.

The tests are 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 pre-purge time

• end 3 seconds before the start of the safety time

Any flame signal detected during this test time, caused by – extraneous light – ageing UV detectors – other defects of the flame supervision equipment, leads to lockout with interlocking of the LEC1 burner control.

In the flame safeguard, the switching functions required are performed by auxiliary relay «HR3».

Since in the case of flame supervision with a flame rectification 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.

Instead, terminal 6 must be connected to the live wire. For 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 on the flame safeguard.

Function

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Landis & Staefa Division CC1N7781E June 01, 1999 5/8

Mode of operation of the flame safeguards when used for dual-supervision

Dual-supervision (detailed connection diagram, e.g. for oil burners)

N(Mp)P(R)

OV1 OV2

2 LAE107 5

3 4

1634

2 LAE10

7 5

RAR...

7781a01/1198

With this type of supervision, one flame is supervised by two

independently operating flame safeguards, aimed at reducing the

possibility of loss of flame during operation in case of a simultaneous

failure of both flame safeguards to an "improbable coincidence".

With dual-supervision, the control contacts of the flame relays of both

flame safeguards are connected in series so that loss of the flame

signal of either of the flame safeguards is sufficient to cause

lockout of the burner.

A faulty signal by only one of the two flame safeguards during burner

off times or purge times also leads to lockout.

An ignited UV tube is a source of UV radiation!

In case of flame supervision by means of UV detectors, both detectors

must be placed such that there is no direct visual contact between

them.

Supervision of two manually controlled burners

N(Mp)

A Z

P(R)

LFE10

N(Mp)

46 3

8 9

LFE10

P(R)

N(Mp)

QRA...

Brenner B

QRA...

Brenner A

77 81a02/ 11 98

Mode of operation of the flame safeguards when used for the

supervision of two manually operated burners

With this type of supervision, too, the burner can be started only if the

UV detector or flame simulation test has been successful.

This means that neither of the two 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 of both flame safeguards - relay «d» is now maintained in its

energized condition via circuit path 3 - 7 of the two flame relays.

When releasing button «I», ignition will be switched off, thus

completing the startup sequence.

If the event of loss of flame on one of the burners, the respective

flame relay is de-energized, 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 monitor in the phase wire connection.

In the case of flame supervision with flame rectification probes,

terminal 6 of the flame safeguards must be connected directly to the

phase wire since no detector test is required here.

For example: connection to terminal 1!

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6/8 CC1N7781E June 01, 1999 Landis & Staefa Division

Detailed connection diagram (e.g. for gas burners)

75621

P(R) N(Mp)

GV1 GV2

LFE10

7 5

QRA...

GV1 GV2

I0 L1

LFE10

7 5

163 4

GV1 GV2

3 4

LFE10

7 5

LEC1

QRA...

7781a03/1198

Mode of operation of flame safeguards with multi-flame

supervision

Like with dual-supervision, the control contacts of the flame relays of

all flame safeguards must be connected in series.

A burner causes all other burners to go to lockout if

– the flame is not established during the safety time, or – the flame is lost during operation

Correctly operating burners can be restarted only - after the burner

control has been reset - when the faulty burner has been shut down.

In that case, the operating switch must not only bridge the control

contacts of the respective flame safeguard, thus closing the control

chain again, but must also break the phase wire connection to the

ignition transformer and the fuel valves.

Likewise, after rectification of the fault, the burner can only be

restarted in connection with the other burners, that is, only after all

burners have previously been shut down.

Terminal 10 must be connected to earth also when using the UV

detector QRA...

BS Operating switch OFF / ON

→ Per burner

L1 Built-in signal lamp

→ Indication of flame

FE Detector electrode for flame rectification QRA... UV detector

FR Flame relay Z Ignition transformer

GV1/...2 Gas valves 1

and 2nd stage

Legend

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Landis & Staefa Division CC1N7781E June 01, 1999 7/8

Basic circuit diagrams

P(R)

6157

15 LEC1

hr3

N(Mp)

14 LEC1

HR3

RAR...

7781a04/1198

LAE10

With selenium photocell detector RAR...

P(R)

6157

15 LEC1

hr3

N(Mp)

14 LEC1

HR3

QRA...

7781a05/0199

LFE10

With UV detector QRA...

Terminal 10 must be connected to earth!

P(R)

hr3

N(Mp)

14 LEC1

615

HR3

7781a06/0199

LFE10

With flame rectification probe

FE Detector electrode for flame rectification L1 Built-in signal lamp

FR Flame relay → Indication of flame

H Main isolator QRA... UV detector

HR3 Auxiliary relay for UV detector or flame simulation

test

RAR... Selenium photocell detector

Legend

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8/8 CC1N7781E June 01, 1999 Landis & Staefa Division

Dimensions in mm

Dimensions

Base versions

16,2

4,6

90 4

12 345 678 910

12 345 678910

7781m02/1198

42,5

Low plug-in base, AGK 4 104 1345 0

Design features:

Ten-pole (screw terminals), with additional earth terminals.

Cable entry either through the bottom of the base

(two knock-out holes), the front, from the right or left side

(total of five cable entries).

High plug-in base, AGK 4 104 9025 0

with removable front

(shaded area in the drawing)

Design features:

Ten-pole (screw terminals):

and

- two auxiliary terminals with markings 11 and 12

- two neutral terminals, wired to terminal 2 (neutral input)

- two earth terminals, with earthing lug for the burner

For cable entry:

two cable entries in the bottom of the base and four threaded knock-

out holes for cable glands Pg11, one on the right, one on the left,

and in the removable front.

High plug-in base, AGK 4 104 9169 0

Features as above, but without the removable front (shaded area in

the drawing is open).

Front, AGK 4 104 9112 0

As a separate item, suited for use with plug-in base AGK 4 104 9169

0 (can also be used with AGK 4 104 9025 0, shaded area in the

drawing).

10 ,5

23,5

31,5

4,5

11 12

123456789 10

11 0 4

77 81m0 1/1198

 1998 Landis & Staefa Produktion GmbH