4
DM-S is always equipped by actuating mechanism BFL (BFN, BF) 24-T (further only "actuating
mechanism"). After being connected to power supply AC/DC 24V, the actuating mechanism
displaces the damper blade into operation position "OPEN" and at the same time it pre-stretches
its back spring. When the actuating mechanism is under voltage, the damper blade is in the
position "OPEN" and the back spring is pre-stretched. Time needed for full opening of the flap
blade from the position "CLOSED" to the position "OPEN" is maximum 140s. If the actuating
power supply is cut off (due to loss of supply voltage, activation of thermoelectrical actuating
mechanism or pushing the reset button on the thermoelectrical starting mechanism BAT), the
back spring displaces the damper blade into the breakdown position "CLOSED". The time of
displacing the blade from the position "OPEN" to the position "CLOSED" takes maximum 16 s. In
case that the power supply is restored again (the blade can be in any position), the actuating
mechanism starts to re-displace the damper blade into the position "OPEN". A thermoelectrical
starting mechanism BAT, which contains two thermal fuses Tf1 and Tf2, is a part of the actuating
mechanism. These fuses are activated when tempe72 °C has been exceeded (the fuse
Tf1 when the temperature around the damper and the fuses Tf2 when the temperature inside the
air-conditioning piping has been exceeded). After the thermal fuse Tf1 or Tf2 has been activated,
the power supply is permanently and irreversibly cut off and the actuating mechanism, by means
of the pre-stretched spring, displaces the damper blade into the breakdown position "CLOSED".
1
Damper body
3
Actuating mechanism
2
Damper blade
4
Inspection hole for camera
Dimensions
Summary of Contents for DM-S
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