Input Signal Ranges; Valve Positioner Split-Range Operation - Emerson Fisher 3582 Instruction Manual

3582, 582i, and 3583
INSTRUMENT INPUT
SIGNAL RANGE
0.2−1.0 bar (3−15 psig)
(2)
4−20 mA
0.4−2.0 bar (6−30 psig)
1. Minimum and maximum allowable input signals ensure functional operation.
2. For 3582i only.
bypassing the valve positioner sends
the input signal directly to the
actuator. Such a change will affect the
desired operation and possibly upset
the system. Use bypass only when the
input signal range is the same as the
valve positioner output range required
for normal actuator operation.
Labels on the bypass block (key 34A) and a pointer
on the bypass handle (key 34D) indicate if the input
signal from the instrument goes to the positioner or
directly to the control valve actuator. Push the
bypass handle toward the back of the positioner to
move the pointer over the word POSITIONER. With
the bypass handle in this position, the input signal
goes to the valve positioner bellows and the output
pressure of the valve positioner goes to the actuator.
Pull the bypass handle forward to move the pointer
over the word BYPASS. In this position, the input
signal goes directly to the actuator.
A difference between the input signal
pressure and the valve positioner
output pressure could cause a
transient bump in the controlled
system when the bypass handle is
moved to BYPASS.
With a reverse-acting or split-range valve positioner,
the bypass handle may be locked in the
POSITIONER position so that bypass cannot be
used. To lock the bypass handle in the
POSITIONER position, first shut off the instrument
and supply pressure to the valve positioner. Then,
remove the hex head shoulder screw from the center
of the handle. Remove the handle and rotate it 180
degrees and re-install it with the handle between the
two lugs cast on the bypass block. Replace the
shoulder screw.
22
Table 11. Standard Instrument Input Signals and Range Springs
ALLOWABLE INPUT SIGNAL
STANDARD SPAN
Minimum
0.8 bar (12 psig) 0.07 bar (1 psig)
16 mA
1.6 bar (24 psig) 0.07 bar (1 psig)
Note
(1)
Maximum
1.4 bar (21 psig)
2 mA 22 mA
2.4 bar (35 psig)

Input Signal Ranges

Standard input signal ranges for valve positioners
and valve stem position transmitters are shown in
table 11. Changing from one standard range to
another requires changing the range spring. To
change the range spring, refer to the instructions for
changing the range spring in the maintenance
section of this manual. Split-range operation of 3582
valve positioners or the 3582i valve positioner
normally does not require changing the spring. Refer
to the section below for split-range information.

Valve Positioner Split-Range Operation

3582 valve positioners and the 3582i valve
positioner are suitable for split-range operations. In
split-range operation, the input signal, either
pneumatic or DC current, from a single control
device is split between two or more control valves.
No additional parts are required to use an existing
valve positioner for split-range operation.
Table 12 shows some typical split-ranges for the
valve positioners.
To change to split-range operation, perform the
beam alignment procedures then perform the
calibration procedure using the desired split range
inputs that result in full valve travel. For example, for
a 3582 positioner with a 0.2 to 1.0 bar (3 to 15 psig)
input signal range in a two-way split, a 0.6 bar (9
psig) input signal should completely stroke the valve
for a 0.2 to 0.6 bar (3 to 9 psig) signal range.
Instruction Manual
RANGE SPRING RANGE SPRING PART
COLOR NUMBER
Silver 1V621727012
Red 1V621927012
June 2010