ZIEHL MS 220 DA, Operating Instructions Manual

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1.4 Block Diagram
1.5 Detailed Description
A current monitors continuously the resistance of the sensors. In cold state, the resistance is < 250
Ω
per sensor (sensor circuit < 1.5 k
Ω
). The output
to X44/12 is high = 1. The resistance of the sensor rises rapidly at nominal response temperature TNF. At a resistance of 3…4 k
Ω
output to X44/12
changes to low = 0. The devices also switches off in the case of sensor or line short-circuit
1)
(< 20
Ω
) or sensor or line interruption. It switches on
automatically when the temperature has decreased approx. 5 °C.
Attention !
2) : trip status is not stored and not non-volatile.
Depending on the number of sensors the following tripping and release
temperatures will be achieved with respect of TNF (nominal response
temperature of the sensors):
Trip temperature Release temperature
3 sensors in series TNF + 5 K TNF – 5 K
6 sensors in series TNF TNF – 20 K
1 Application and short description Motor Protection MS 220 DA
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MG33V102 - VLT ® is a regisered Danfoss trademark
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