Heras HMD Basic, User Manual

Page: 39 / 88

EN – Translation of the original user manual - 2.0 | 2019 39
Limit switches 6.4.1
The HMD24 DC control system is preconfigured for operation on doors and gates
with limit switches. It is possible to use limit switches of various types (proximity
switches, mechanical switches, etc.) but these must all be designed as normally
closed contacts. Section “6.5.6 Overview installation plan of the inputs” of this
documentation shows the electrical connection of both limit switches for the
positions “Gate open” and “Gate closed”. The gate limit switches are connected
and checked as follows during set-up:
 Switch off the power supply to the motor drive.
 Mechanically fit the two limit switches into the correct limit positions of the
gate.
 Connect the signal line from the CLOSE limit switch to terminal IN1.
 Connect the signal line from the OPEN limit switch to terminal IN2.
 Connect the power supply of the limit switch to 24V.
 If a ground connection is required for the limit switch, connect this to 0 V.
 Switch on power supply and check that the limit switch is connected
correctly.
Operating keys for hold-to-run operation 6.4.2
Before a gate can be put into operation, at least one OPEN and one CLOSE
pushbutton must be connected for operation without self-locking (hold-to-run
operation). These keys are necessary for setting up the limit positions. To install
these keys, perform the following steps in the order shown:
 Switch off the power supply to the motor drive.
 Connect the power supply for the pushbuttons to 24V.
 Connect the OPEN pushbutton [hold-to-run key] to the input terminal In8
(normally open contact).
 Connect the CLOSE pushbutton [hold-to-run key] to input terminal In7
(normally open contact).
 Switch on the power supply to the control system and check the function of
the keys in hold-to-run operation.
In automatic mode these pushbuttons are similar to the command devices for
operation with self-locking. Even a brief impulse triggers gate movement, which
does not stop when the motor pushbutton is released. Of course, this requires
that the gate fuse is intact.