Grounding - Panasonic WHS1 Series User Manual

The unit must always be grounded to earth with 1.5mmsq wire size minimum.
The power supply circuit may be floating or grounded. In the latter case, connect to ground the power
source common as shown in figure (see below) with a dashed line.
When using the floating power scheme, note that the HMI devices internally connects the power
common to ground with a 1MΩ resistor in parallel with a 4,7nF capacitor.
The power supply must have double or reinforced insulation.
The suggested wiring for the power supply is shown in figure.
All the electronic devices in the control system must be properly grounded.

2.3 Grounding

Use dedicated grounding:
・ Make the grounding point as close as possible to the GT and keep the distance of the grounding wire
short.
・ Sharing the ground with another device may have an adverse effect. Therefore, be sure that
grounding is dedicated.
(Notes)
・ Conversely, depending on your environment, grounding may cause a problem.
・ Since the power line of the HMI unit is connected to a functional earth via electronic
parts, the electronic parts may become damaged if there is an abnormal potential
between the power line and the physical ground.
PROGRAMMABLE DISPLAY WHS1 Standard Model
3