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Overview
Flame monitor
Flame Detectors QRA…
Flame detectors for Siemens auto-
matic furnace controllers for the
monitoring of gas and oil flames
Application
The flame monitors are used for monito-
ring gas flames, yellow and blue
burning oil flames as well as for ignition
spark inspections.
QRA2 intermittent operation
QRA53continuous operation
WARNINGS:
When observing the following
warnings, unsafe conditions hazar-
dous to life, property and environ-
ment can be avoided!
- Never do any work in the power sup-
ply area without first disconnecting all
external power supplies.
- Provide for appropriate protection
against direct contact on the power
supplies.
- Check the wiring and all safety
functions.
- Halogen lamps, welding apparatus,
special lamps as well as the ignition
spark may have a sufficient high UV
portion so that the cell will ignite. X-ray
and gamma radiation may generate a
wrong flame signal as well.
Mounting
- Observe the applicable local safety
regulations.
Installation
- Allow only qualified personnel to per-
form the installation.
- Take care to observe the permissible
length of the detector cable, see
“Technical Data”.
- Always run the ignition cables separa-
tely keeping a large distance to the
QRA… and to other cables if possible.
Electrical connection of detector
Ensure a trouble-free and loss-free
signal transmission if possible:
- Never run the detector cable together
with other cables.
Cable capacitance reduces the
size of the flame signal.
Use a separate cable.
Commissioning
- Allow only qualified personnel to per-
form commissioning and maintenance
work.
- A trouble-free burner operation can be
ensured only if the intensity of the UV
radiation on the location of the detec-
tor is still so large that it is ignited
safely during each half-wave.The
intensity of the UV radiation on the
location of the detector is checked by
measuring the detector current.
Measuring circuit for
QRA2 ..., QRA10...
and QRA5 series D
Legend
Measuring circuit for
QRA5 up to series C
1… Circuit of micro-ammeter between adapter QGQ1.../AGQ2...and flame
detector
A – Incidence of radiation
M – Micro-ammeter direct current internal resistance 5000
Ω
C – Electrolytic capacitor 100...470...µF,DC 10...25 V
Design
Flame detector QRA2…
Plastic-encapsulated design, metalli-
zed to prevent a static charge in the air
flow of the blower, directly mounted on
burner. Shipment optional with/without
flange and shackle, see “Type Over-
view”.
Flame Detector QRA 5
The UV cell is located behind a swivel-
mounted shutter on the front end of the
detector pipe flanged onto the housing.
A quartz window protects the cell and
the shutter from contamination. The
detector housing contains a step motor
as shutter drive as well as the electronic
components for the shutter control.
Connector AGM19
Connector AGM19 with cable for the
electrical connection of the flame detec-
tors QRA53… and QRA55…
Required minimum detector current
values:
See the respective data sheets of the
automatic furnace controllers or the
operator’s manual of the KF8832.
Disposal
The detector contains electrical and
electronic components and must not be
disposed of as household waste. It is
essential to observe the local and appli-
cable legal conditions and regulations.
