VX121P/151P/171P(-QM57)
User’s manual rev.0.0 (Preliminary)
28 of 68
MU-C656.xxxxxxxxxx r.0.0-EN
5.3 Connecting 24Vdc power supply (option)
The Panel PC can be provided (as an order option) with an isolated DC/DC
converter with 24Vdc input. The DC/DC converter has a forced-air cooling by fan.
The user must supply the 24Vdc by connecting 2 conductors to the connector of
the DC power supply.
The cross-section of the conductors shall be adequate for the supplied current
(see “Internal Power supply 24Vdc”) and must be sufficiently oversized so that in
case of a short circuit on the Panel PC no damage can be caused by the cable.
Warning
The insulation towards the main voltage depends on the external
power supply to the Panel PC. The Panel PC must be supplied by a
limited power source according to EN60950. Use a switching power
supply protected against overcurrent which complies with the
requirements of safety extra low voltage (SELV) which conforms to
the safety standard EN60950 or equivalent.
It’s recommended using a power supply reserved for the Panel PC.
None of the wiring terminals is designed to be connected to parts at
hazardous voltage.
The wiring from the external power supply to the Panel PC must
comply with the requirements of safety extra low voltage (SELV).
Caution
The terminal on the 24Vdc input power supply is not suitable to switch
the Panel PC ON and OFF. Use a power switch on the external
power supply to switch ON-OFF the Panel PC.
Notice
The external power supply must provide the inrush current required
by the internal DC/DC converter at power-up without enter self
protecting mode otherwise the system start up is not guaranteed (see
“Internal Power supply 24Vdc” paragraph).
The internal DC\DC converter is protected against overcurrent by a fuse.
Warning
Do not try to disassemble the power supply unit to replace the fuse or
other parts. If a failure occurs on the power supply, the whole power
supply unit must be replaced with an equal or equivalent approved
spare part.
