Connecting Inputs And Outputs - gefran 850 Installation And Instruction Manual

Attention! Make sure the ground connection is
efficient. Absent or inefficient grounding can make
the device unstable due to excessive noise.
Specifically, check that:
• voltage between mass and ground is < 1 V;
• resistance is < 6 Ω
2.2.5.

Connecting inputs and outputs

The controller's input and output lines must be separated
from the power line.
To prevent noise, the controller's input and output cables
must be kept away from the power cables (high voltages or
high currents).
The input and output cables and the power cables must not
be placed parallel to one another.
Use shielded cables or separate cable trays.
To connect the output to an inductive load (relay, contactor,
electrovalve, motor, fan, solenoid, etc.) that works in AC,
mount a snubber, i.e., an RC group (resistor and condens-
er in series) placed parallel to the load. Installing this filter
lengthens the life of the relays.
NOTE: All condensers must conform to VDE (class X2)
standards and support voltage ≥ 220 VAC.
The power of the resistor must be ≥ 2 W.
Out
~
Figure 11 - Snubber connection diagram (AC)
For inductive loads that work in DC, mount a 1N4007 diode
parallel to the coil.
Out
+ -
Figure 12 - Snubber connection diagram (DC)
The filters must be connected as close as possible to the
controller.
C
L
R
D L
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Attention! If the controller is connected to devices
that are NOT electrically isolated (such as ther-
mocouples), ground with a specific conductor to
prevent grounding directly through the machine
structure.