Phoenix Contact 1708 M12 POE, Руководство пользователя, Страница: 13 / 34

Mounting and installation
105648_en_01 PHOENIX CONTACT
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– The 24 V outputs of the power supply unit are grounding-free and subject to the voltage
limitations of the SELV circuit according to IEC/EN 60950-1.
– Insulation requirements according to IEEE 802.3af (at), i.e., dielectric strength of the
secondary 24 V outputs leading to the (grounded) housing must be at least 1500 V AC
at 50 to 60 Hz or 2250 V DC for one minute each.
– The power supply unit must be properly sized for the total occurring power (see “Tech-
nical data” on page 25).
Where the device is connected to a redundant power supply (two separate power supplies,
see Figure “Redundant operation with two power supplies (example)” on page 12), both
power supply units must comply with above requirements.
All devices operated on the external power supply unit must have a dielectric strength of at
least 1500 V AC at 50 to 60 Hz or 2250 V DC for one minute each between their 24 V supply
potentials on the one hand and between all conductive parts that can be touched on the
other hand.
The power supply unit and the FL SWITCH 1708 M12 POE together are a current source
with limited power (“limited power source” for the connected PDs according to
IEC 60950-1.
2.3.2 Signal contact/diagnostic socket
Signal contact The device has two floating signal contacts. An error is indicated when the contact is
opened.
Please note that load distribution does not take place. The device selects the supplying
power supply unit independently.
In the case of non-redundant power supply, the switch indicates the failure of a supply
voltage by opening the signal contact. You can prevent this by applying the voltage to both
supply voltage connections in parallel, as illustrated in Figure 2-3 on page 12.
Table 2-1 Pin assignment of the diagnostic socket
Illustration Pin number Function
1 Signal contact
2 Digital input (DI)
3 Ext. GND
4 Signal contact
5 n. c.