Watson-Marlow MM440 - Manual (Page 199)

Issue 10/06 3 Functions
MICROMASTER 440 Operating Instructions
6SE6400-5AW00-0BP0 199
WARNING
¾ It is not sufficient to select the status signal r0052 bit 12 "Motor holding brake
active" in P0731 – P0733. In order to activate the motor holding brake, in
addition, parameter P1215 must also be set to 1.
¾ If the frequency inverter controls the motor holding brake, then a commissioning
may not be carried-out for potentially hazardous loads (e.g. suspended loads for
crane applications) unless the load has been secured. Potentially hazardous
loads can be secured as follows before commissioning is started:
♦ Lower the load to the floor
♦ During the commissioning phase or after the frequency inverter has been
replaced, the frequency inverter must be inhibited from controlling the motor
holding brake (it is not permissible that the frequency inverter controls the
holding brake). Quick commissioning or a parameter download using
STARTER etc. may only be carried-out after this has been absolutely
ensured. The motor holding brake terminals can then be re-assigned (in this
case, it is not permissible that digital output P0748 is inverted for the motor
holding brake).
♦ In order to hold the motor against the mechanical brake at a specific
frequency, it is important that the min. frequency P1080 approximately
corresponds to the slip frequency. If the value is selected to be too high,
then the current drawn can be too high so that the frequency inverter shuts-
down (trips) due to an overcurrent. If the value selected is too low, then it is
possible that not enough torque is produced to hold the load.
¾ It is not permissible to use the motor holding brake as operating brake. The
reason for this is that generally it is only dimensioned/designed for a limited
number of emergency braking operations.
Motor with motor holding brake (example)
A motor with motor holding brake for a hanging (suspended) axis is connected to
the frequency inverter. This holding brake is to be controlled using the 1
st digital
output.
Which settings have to be made?
¾ Select the "motor holding brake active" function (52.12) at digital output P0731.
¾ Activate the brake sequence control in the frequency inverter (P1215 = 1).
¾ Set parameter P1216 to open the holding brake after an ON command.
The brake opening time P1216 must be set so that it is equal to or longer than
the time required to open the holding brake. The opening time of the brake
(refer to the Motor Catalog, e.g. M11) plus the relay opening time can be used
as nominal value for P1216.
¾ Set parameter P1217 to close the holding brake after an OFF1/3 command.
The brake delay time P1217 must be set so that it is equal to or longer than the
time required to close the holding brake. The closing time of the brake (refer to
Motor Catalog, e.g. M11) plus the relay closing time can be used as nominal
value for P1217.
¾ Set the load holding
The opening / closing times of mechanical brakes are subject to certain
fluctuations; this is the reason that a weight equalization function must be
parameterized in the frequency inverter for the time P1216 and P1217. The
following parameters must be defined so that the axis cannot sag (i.e. the axis
cannot drop/fall).