44 | Baker Hughes.
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Typical Control Systems using Intrinsic Safety methods must have a compliance voltage
greater than 17.64 V
.
Typical system setups are shown in Figure 25 on page 44, for General Purpose and
Explosion Proof (EEx d) Installation Schematic and Figure 26 on page 45, for Intrinsically
Safe Installation Schematic. The SVI3 digital valve positioner can be located in a
general-purpose or hazardous area protected by Explosion Proof (EEx d) methods. Wiring
diagrams are generalized, actual wiring must adhere to Electrical Installation section of
manual and local electrical codes. The use of a Handheld Communicator or a HART
®
modem is not permitted in the Hazardous Area protected by Explosion Proof (EEx d)
methods.
Since the process control system, the source of the input signal, is located in a
non-hazardous location, setup requires an intrinsic safety barrier be placed between the
process control system and the SVI3. If the SVI3 is located in a hazardous area with
Intrinsically Safe protection a barrier is not required for a flameproof installation
.
Alternatively the system can be installed as Explosion Proof ⁄ flameproof.
The SVI3 can communicate with a remote PC running ValVue software via a HART modem
connected to the PC's serial port. The PC, which is not intrinsically safe, must be
connected to the circuit on the safe area side of the intrinsic safety barrier if the valve is
located in a hazardous area.
The SVI3 is polarity sensitive so the positive lead must be connected to the positive (+)
terminal and the negative lead to the negative (-) terminal. Reversal of input will not cause
damage but the unit will not function
.
Figure 25 General Purpose and Explosion Proof Installation
REMOTE
PV
1-5Vdc
D/I
+ -
4-20mA OUT
+ -
1
SW #2
+ -
SW #1
+ -
2
3
+ -
4-
20
m
A
IN
+
-
REMOTE
PV
1-5Vdc
D/I
+ -
4-20mA OUT
+ -
1
SW #2
+ -
SW #1
+ -
2
3
+ -
4-
20
m
A
IN
+
-
HART
Modem
HART
Modem
HART Compliant
Control System
4-20mA Output
SVI3
Computer
HandHeld
HART
Communicator
Hazardous
Area
Non-Hazardous
Area
+
-