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Building Technologies Basic documentation LMV37.4... CC1P7546en
HVAC Products 1 Safety notes 01.12.2009
The functions of the following available or required input status signals must be check-
ed:
• Air pressure
• Minimum gas pressure / maximum gas pressure or POC
• Gas pressure valve proving
• Minimum oil pressure and maximum oil pressure
• Safety loop (e.g. safety limiter)
Duties of the expert when making the approval tests
Action Check / response
a) Burner startup with flame detector
darkened
Lockout at the end of safety time 1 (TSA1)
b) Burner startup with flame detector exposed to ex-
traneous light, e.g. to incandescent light with detec-
tors for visible radiation, quartz-halogen bulb or
cigarette lighter flame with detectors for UV radia-
tion
Lockout at prepurge time (t1)
c) Simulation of loss of flame during operation. For
that, darken the flame detector in the operating po-
sition and maintain that state
Lockout or restart, depending on the basic unit’s con-
figuration
d) Check the plant’s response time with loss of flame
during operation. For that purpose, manually dis-
connect the fuel valves from power and check the
time from this moment the basic unit requires to turn
off power to the valve
Turning off power to the valves by the basic unit within
the period of time permitted for the respective type of
plant
e) Check the safe operation of the burner while giving
consideration to system tolerances
System tolerances are the result of a number of factors,
such as:
- Tolerances of actuators plus mechanical linkage to
the controlling elements
- Environmental conditions
(temperature, air conditions)
- Type of fuel (calorific value / pressure)
- Type of supply air path and flue ways
Example of procedure for checking the burner’s re-
sponse to actuator tolerances:
- Approach a output point in programming mode (e.g.
low-fire or high-fire)
- Change the actuator’s position against the optimum
fuel-air ratio setting as can be expected in the case
of tolerances
- Check the flue gas values with a flue gas analyzer
Recommendation:
Make this readjustment against the optimum fuel-air ra-
tio setting for one actuator at a time!
Further checks may be required, depending on the field of use and the relevant stan-
dards.
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