Fisher 3660 - Split-Range Operation

Instruction Manual
D101402X012
3660 and 3661 Positioners
September 2015
25
15. Readjust the travel (span) adjustment to achieve correct actuator travel.
Note
When a travel (span) adjustment is made, there will be a zero shift.
16. Repeat steps 11 through 15 as necessary to achieve correct actuator travel.
17. Install the cover (key 19T) on the feedback lever assembly (key 19) with cover screw (key 19U).
18. Install the positioner cover (key 21) and secure with the machine screws (key 24). Make sure the Fisher logo reads
correctly and the vent is pointing downward.
Split‐Range Operation
3660 and 3661 positioners can be used for split‐range operation with the instrument input signal from a single
controller or another instrument split between two or three control valves. Tables 7 and 8 show some typical split
ranges for the positioners. To change from a full range to a split range, change the range spring (key 30, figure 24 or
25) to the appropriate spring shown in the tables. Contact your Emerson Process Management sales office
for range
spring ordering information. Complete the Changing Range Spring portion of the Maintenance section. Refer to tables
7 and 8 for valve stem travel available with split range operation.
Table 7. Range Spring Selection for Fisher Actuators
TYPE 3660 3660 3661
VALVE STEM TRAVEL
WHEN USING
3660 AND 3661
RANGE SPRING
SELECTION
(KEY 30)
(1)
Split
0.2 to 1.0 bar
(3 to 15 psig)
Input Signal
0.4 to 2.0 bar
(6 to 30 psig)
Input Signal
4 to 30 mA DC
Input Signal
Bar Psig Bar Psig mm Inches
One Way 1:1 0.2 to 1.0 3 to 15 0.4 to 2.0 6 to 30 4 to 20 19 to 50 0.75 to 2.0 Standard
Two Way 2:1
0.2 to 0.6
0.6 to 1.0
3 t0 9
9 to 15
0.4 to 1.2
1.2 to 2.0
6 to 18
18 to 30
4 to 12
12 to 20
19 to 50 0.75 to 2.0 Split Range
Three Way 3:1
0.2 to 0.5
0.5 to 0.8
0.8 to 1.0
3 to 7
7 to 11
11 to 15
0.4 to 1.0
1.0 to 1.5
1.5 to 2.0
6 to 14
14 to 22
22 to 30
4 to 9.33
9.33 to 14.66
14.66 to 20
15 to 33.3 0.591 to 1.311 Split Range
1. Contact your Emerson Process Management sales office for range spring ordering information.