7 VG9H 70 en
15
3.6
Electrical connections
The VG9000H is powered by a 4–20 mA current loop from
the safety system that also functions as a carrier to the
HART communication.
The input signal cable is led through a M20 x 1.5 or 1/2" NPT
cable gland. Additional conduit entries are available with
extension housing or junction box. See type coding for details.
Connect the conductors to the terminal strip as shown in
Fig. 12. It is recommended that the earthing of the input cable
shield be carried out from the DCS end only.
Cable shall be one or more single-twisted pair shielded or
multiple-twisted pair with overall shield. Single and multi-
ple pair may be combined in a given network provided all
current input devices associated with multiple pairs of the
same cable shall be located nominally at one end of the
multi-pair cable. Unshielded cable may be used if it is
demonstrated that ambient noise or crosstalk does not
affect communication or functions of the safety valve con-
troller.
The (optional) position transmitter / status output is con-
nected to 2-pole terminal PT as shown in Fig. 12. The posi-
tion transmitter / status output needs an external power
supply. The VG9000H and the position transmitter / status
output circuits are galvanically isolated and withstand a 30
V DC voltage.
For SIL certified position transmitter, please see Sections 8,
11.1 and 11.6.
NOTE:
The VG9000H equals a load of 485 Ω in the current loop.
Fig. 12
Prewired terminals in the circuit board
Fig. 13
Wiring terminals when the extension housing is
used
Additional HART
connection
Position transmitter/
status output connection
Limit switch
connection
mA signal and
PT connection
Fig. 14
VG9000H electrical connections with and without RCI9H2.
See Section 11.6. for other installations.
VG9000H
Safety
system
AO
(4 - 20 mA
HART)
Safe area
Hazardous area
RCI9H2*
Safety
system
DO
(0/24 VDC)
24 VDC
power
supply
2
3
19
+
-
20
+
-
7
8/9
HART
(MUX or AI)
-/+
+/-
HART
POW ER
SUPPLY
OUTPUT
SAFETY
SIGNAL
VG9000H
+
-
mA input
+ HART
16
17
* Only part of the RCI9H2 wiring is shown here.
Detailed wiring can be found in the RCI manual (7RCI9H270EN)
