Burkert Type 8643 - Handbuch (Seite 9)

32
supply connection 2-wire 8.4.3.
device
The 2 conductor device is supplied via the bus.
Supply connection 2-wire device Bild 3:
Bus terminal
Connection for the bus supply in accordance with IEC
1158-2.
Bus supply in ignition protection type Ex e II
(max. connected loads see EC Type Examination Certi-
ficate in Appendix of the Operating Instructions)
english 33
supply connection 4-wire 8.4.4.
device
Supply connection 4-wire device Bild 4:
Terminal 24 V DC
Connection for the power supply in the ignition protection
type Ex e II. Max. connected loads see EC Type Exami-
nation Certificate in Appendix of the Operating Instructions.
Bus terminal
Connection for the bus supply in accordance with IEC
1158-2.
There are two options available depending on the device
model.
Bus supply with increased safety •
Ignition protection type: Ex e II
Intrinsically safe bus supply
•
Ignition protection type Ex ia IIC or ignition protection
type Ex ia IIB
english
34
Danger!
Danger of explosion due to unauthorized combi-
nation of the ignition protection types!
Unauthorized combination of the ignition protection types
may cause hazardous situations!
If the bus supply of the 4-wire version of the device •
was operated once in ignition protection type of
increased safety (e), the bus supply may no longer be
intrinsically safe in the ignition protection type (i).
connection of the shield 8.4.5.
terminal
Connection for the cable shield of the bus line.
There are two options available for connection of the cable
shield.
Direct earthing to the housing (PA) 1.
Connection of the cable shield:
Connect cable shield to the right terminal.
→
Capacitive earthing to the housing (PA) 2.
To discharge EMC interference to the earth potential, a capa-
citor with a capacity <10 nF is installed in the device.
english 35
If several devices are connected in parallel with capacitive
shield earthing, the energy stored in the capacitors in the
event of a fault must not exceed the authorized limit values
(see IEC/EN 60079-11) of the valid gas group. To determine
the stored energy, the maximum authorized bus voltage must
be taken into consideration.
Connection of the cable shield:
Connect cable shield to the left 2 terminals.
→
Connect the shield in a continuous manner.
→
Earth the shield at a point in the bus line.
→
The terminals for the bus and power supply have a
cover to protect against unintentional contact.
Housing terminals
Connection for the potential equalisation (PA).
electromagnetic compatibility
To ensure an adequate discharge of EMC interference,
connect the earth terminal to the potential equalisation (PA)
via a shortest possible line. If this is not possible, use suitable
measures to prevent electromagnetic interference from unduly
influencing the Power I/O Box Type 8643.
english
Type 8643