Controls And Status Indicators; Tab. 2: Meaning Of The Status Indicators Of The Moc3Za; Fig. 1: Controls And Status Indicators Of The Standstill Monitor Moc3Za - SICK MOC3ZA Notice D'instructions

Operating instructions
MOC3ZA
Fig. 1: Controls and status
indicators of the Standstill
Monitor MOC3ZA
Tab. 2: Meaning of the status
indicators of the MOC3ZA
8014608/1DS0/2022-02-16
Subject to change without notice
Product description
The MOC3ZA measures a voltage at the winding terminals of the motor as it coasts down;
the voltage is induced by residual magnetism. For this purpose two redundant
measurement channels (L2 against L1 and L3 against L1) are used. If the induced voltage
on both channels drops simultaneously below the voltage threshold set (U
signifies for the device that the motor is at standstill and the output relay is activated, i.e.,
the outputs are enabled.
To be able to adjust the device to a large number of different motors and applications, the
voltage threshold U is adjustable. Also adjustable is the length of time for which the
an
voltage must drop below U
an
enabled (standstill time t ).
s
The device detects wire breaks on the measurement channels (L1/L2/L3). If a wire break
is detected, then the output relay switches to the safe position (as for a running motor).
This state is saved and can be deleted by fitting a jumper to terminals S2/X1.
The input voltages on the measurement channels (L1/L2/L3) are continuously compared.
If the input voltages are different for longer than approx. 2.5 s, a simultaneity error is
triggered. This error is reset when all measurement channels simultaneously have input
voltages that are above the voltage threshold U
The terminals S1/X1 are the feedback circuit for monitoring externally connected
contactors (EDM or external device monitoring, N/C contact). If external device monitoring
is not required, a jumper must be fitted to the terminals S1/X1, as otherwise an error
message will be output.
3.2

Controls and status indicators

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so that standstill is finally detected and the output circuit is
set.
an
en
Chapter 3
), this situation
an
51