VX121P/151P/171P(-QM57)
User’s manual rev.0.0 (Preliminary)
MU-C656.xxxxxxxxxx r.0.0-EN
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Inside the Panel PC there is an insulated AC\DC converter (power supply) which
converts the input voltage into the ATX standard low voltages needed for the
Panel PC to operate (see “Internal Power supply 115/230Vac” paragraph).
The 0V (GND) of the internal supply ATX is connected to the metal frame and
then to the Equipotential Bonding screw for earthing.
When the Panel PC is connected, through any not insulated I/O port, (e.g. serial,
or other port) to another equipment also with GND connected to earth both of
them must be connected to the same earth point to avoid circulation of current
because of the difference of potential between earth points.
5.2 Uninterruptible AC power supply (UPS)
The paragraph indications are referred to a use of the Panel PC connected to an
uninterruptible AC power supply (AC UPS).
Due to legal regulations finalized to reduce the reactive power in the electrical
networks, the Panel PC power supply has a built-in active PCF (Power Factor
Correction). The active PFC needs a sinusoidal wave input voltage.
Caution
The uninterruptible AC power supply (UPS) with non sinusoidal wave
can damage the power supply with active PFC.
Be careful the UPS, if connected to VX121P/151P/171P(-QM57) with
active PFC, supplies a sinusoidal wave output voltage during normal
and back-up mode.
