Instruction Manual

Installation
September 2013
2-31
Installation in a Safety Instrumented
System
A DVC6000 SIS instrument may be used in a Safety
Instrumented System (SIS) to control operation of a
safety block valve or vent valve. The actuator may be
either single-acting or double-acting with spring return.
DVC6000 SIS instruments will have the label shown in
figure 2-26 on the terminal box cover.
The digital valve controller may be installed with a
solenoid valve in either a 4-wire system, (figure 2-28),
in a 2-wire system (figure 2-29), or a 2-wire system
without a solenoid valve (figure 2-30). The digital valve
controller ships from the factory with the DIP switch on
the printed wiring board set to the correct position per
the ordered option.
When operating with a 4-20 mA current signal, the
digital valve controller must be setup for point-to-point
operation. When operating with a voltage signal, the
digital valve controller must be setup for multi-drop
operation. The operational mode is determined by a
DIP switch on the printed wiring board. As shown in
figure 2-27, the nameplate indicates the operational
mode set on the printed wiring board at the factory.
For information on verifying or changing the switch
position, refer to Replacing the PWB Assembly and
Setting the DIP Switch and table 7-2 in the
Maintenance section.
Installation in a 4-Wire System
Figure 2-28 is an example of the digital valve controller
installed in a 4-wire system. In this installation, two
separate signals are used: a 4-20 mA DC signal (from
the Logic Solver or DCS) for the digital valve controller
and a 24 VDC signal (from the Logic Solver) for the
solenoid valve.
Note
When a solenoid valve operated by an
independent power supply is used
pneumatically in series with a
DVC6000 SIS, the power source could
be 24/48 VDC, 110/220 VAC, etc. Power
supply is dependent on customer
specifications.
The digital valve controller control mode is set to
“analog”. When a shutdown condition exists, the logic
solver (or DCS) activates the solenoid valve and also
cuts the current to the digital valve controller to 0 or
4 mA, thus causing the valve to move to its zero travel
Figure 2-26. Terminal Box Cover Label on FIELDVUE
DVC6000 SIS Digital Valve Controllers
INFORMATION IN THIS AREA INDICATES THE
OPERATIONAL MODE SET AT THE FACTORY.
PT-PT INDICATES POINT-TO-POINT LOOP,
MULTI INDICATES MULTI-DROP LOOP
E0768
Figure 2-27. Typical Digital Valve Controller Nameplate
position. In this installation, the switch on the digital
valve controller printed wiring board must be set for
point-to-point operation. To set the digital valve
controller control mode in an SIS 4-wire system, from
the Online menu select Configure, Guided Setup, and
Setup Wizard.
The Setup Wizard will automatically setup the
instrument for a 4-wire installation based upon the
printed wiring board DIP switch setting.
Note
Using the digital valve controller in a
4-wire system with an ASCOt
low-power solenoid valve EF8316G303,
EF8316G304, EFX8553G305 103594 or
EFX8551G305 103594 (or an equivalent
low-power solenoid valve) requires a
separate external air supply for pilot.
Ensure that the solenoid valve’s
“selection gasket” is in the “External
Position”.
The use of external piloting when
using an EF8316G303 or EF8316G304
requires the pilot pressure to be at
least 15 psig higher than the main line
pressure.
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