Heras HMD Basic, User Manual

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EN – Translation of the original user manual - 2.0 | 2019 36
Damaged cable glands must be replaced immediately by undamaged glands.
6.2 POWER SUPPLY FROM THE ELECTRICITY GRID
The power electronics of the HMD24 DC are designed for an input voltage of
around 24 V
DC
at the 24 V DC In terminal. This is used to produce the regulated
5 V
DC
, 7 V
DC
and 24 V
DC
required for the external connection elements and the
motor current.
The 24 V input current for the control system can be produced from a single-
phase power network (230 V
AC
/ 50 Hz) with the aid of a suitable transformer.
The alternating voltage present at the output of this transformer must be
converted into a pulsing direct voltage by a suitable rectifier. The output of the
rectifier is then wired to the two input terminals (24 V DC In) of the power
electronics.
Care should be taken to ensure that the + and - terminals are correctly
connected to the input of the electronics.
Likewise, great care should be taken to ensure that the grid power supply
to the transformer, and the
protective ground , are connected correctly.
Connection of the motor 6.2.1
The output voltage for the 24 V DC motor of the gate drive is produced by the
control system from the supply voltage of the power electronics with pulse-width
modulation.
To this end, the motor is connected to the
Motor A | B terminal. The electrical
output to the motor is protected by the left-hand blade-type fuse (10 A safety
fuse).
The current drawn from the DC power electronics of the control system by the
motor is continuously measured and monitored. To ensure that the entire system
(power supply, electronics and motor) is protected against excessive loading, the
maximum permissible current can be limited from within the software.
6.3 CONNECTING THE INPUTS AND OUTPUTS
There are two adjacent terminal blocks on the control system for the connection of
external devices. The left-hand block is intended for relay outputs, whereas the