Manual_S5_Airplus_2015_04_20
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Wodtke GmbH - Tübingen. All Rights and Changes Reserved.Printed 04/2015
Part No. 950 976
9.4
wodtke Air Volume Sensor
An air volume sensor sits in the central air intake
which measures the current flow velocity of the
combustion air in the intake, compares it to the tar-
get value specifications and, in case of deviations,
automatically corrects the speed of the exhaust
fan up or down. This allows the unit to automati-
cally adjust itself within the possible adjustment
range to changes to the chimney draft, changes to
the internal resistances (e.g. due to contamination
of the hot gas flues or the burner pot) and differing
resistance in the air intake. The unit is thus always
supplied with the optimal air volume.
Note:
In the case of differing draft ratios in the chimney
and differing air temperatures, the wodtke air vol-
ume sensor can also cause differences in the
flame pattern because the fan speed necessarily
changes. This is completely normal, however, and
does not represent a defect. Instead, this provides
for optimal combustion.
The air volume sensor also responds if the door of
the unit is opened, and interrupts the pellet feed.
This, together with the additional contact switch of
the combustion chamber door, prevents operation
with the door open and the units are classified as
type 1 (self-closing door).
The temperature of the air volume sensor (TL) in
the intake is also measured via the air volume sen-
sor. If this temperature is above the target value,
the unit is switched to fault. The same occurs if the
temperature rises too quickly (gradient).
9.5
Pellet chute temperature sen-
sor (TP)
A temperature sensor sits directly in the pellet
chute and monitors the temperature to the pellet
container. If the target temperature stored in the
programme is exceeded, a safety shut-down of
the unit occurs. The unit can only be reactivated
following sufficient cooling.
If the sensor should be defective and require re-
placing, the adjusting stop ring (A) of the defective
sensor must be installed on the new sensor. Push
the adjusting stop ring of the old sensor over the
new sensor and position precisely (22 mm from
the sensor tip), as measurement errors can other-
wise occur. Never install sensor without the adjust-
ing stop ring! Tighten all adjusting screws by hand
only (not with force / screwdriver) as the sensor
can otherwise be damaged.
Fig. 54: TP sensor
9.6
Flue Gas Temperature Sen-
sor (TR)
A temperature sensor sits directly in the flue gas
(above the deflection plate of the combustion
chamber) and monitors the temperature for igni-
tion and continuous operation. After starting, it is
monitored here whether the ignition was success-
ful. If no more pellets are supplied (e.g. container
empty), this is also detected via this TR sensor
and the unit shuts down. When operating with pel-
lets having a heat value / bulk density that is too
high, the output released from the unit can be
above the rated heating output. This is also de-
tected and balanced by the TR. The unit modu-
lates to low-load until the specified values are up-
held again.
A
