Fisher 4194B Series User manual

D200154X012
EFisher Controls International, Inc. 1983, 1995; All Rights Reserved
Fisher, Fisher-Rosemount, and Managing The Process Better are marks owned by Fisher
Controls International, Inc. or Fisher-Rosemount Systems, Inc.
All other marks are the property of their respective owners.
4194A, B, and C Series Differential Pressure
Controllers
Contents
1. Introduction
Scope of Manual 1–3. . . . . . . . . . . . . . . . . . . . . . . . . .
Description 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 1–3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
2. Installation
Controller Mounting Orientation 2–1. . . . . . . . . . . . .
Pipestand Mounting 2–1. . . . . . . . . . . . . . . . . . . . . . .
Panel Mounting 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . .
Wall Mounting 2–1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Actuator Mounting 2–1. . . . . . . . . . . . . . . . . . . . . . . .
Pressure Connections 2–1. . . . . . . . . . . . . . . . . . . . .
Process Pressure Connections 2–1. . . . . . . . . . . .
Supply Pressure Connection 2–3. . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Pressure Connection 2–3. . . . . . . . . . . . . . . . . . .
Vent 2–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
3. 4194A Series Proportional-Only Con-
trollers
Adjustments for 4194A Series Controllers 3–1. . . .
Manual Set Point Adjustment 3–1. . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Adjustment 3–1. . . . . . . . . . . . . . . . . . . . . . . . . . .
Proportional Band Adjustment (PB ADJ) 3–1. . . .
Changing Controller Action 3–2. . . . . . . . . . . . . . . .
Switching the Auto/Manual Station
(suffix letter E) 3–2. . . . . . . . . . . . . . . . . . . . . . . .
Prestartup Checks for 4194A Series
Controllers 3–2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Startup for 4194A Series Controllers 3–3. . . . . . . . .
Calibration of 4194A Series Controllers 3–3. . . . . .
General Calibration Instructions 3–3. . . . . . . . . . . .
Process Indicator Zero and Span
Calibration 3–3. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Zero and Span Calibration 3–4. . . . . . . . . . . . . .
Flapper Alignment 3–6. . . . . . . . . . . . . . . . . . . . . . .
Principle of Operation for 4194A Series
Controller 3–6. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overall Operation 3–6. . . . . . . . . . . . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Operation 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto/Manual Station (suffix letter E)
Operation 3–7. . . . . . . . . . . . . . . . . . . . . . . . . . . .
4. 4194B Series Proportional-Plus-Reset
Controllers and 4194C Series Propor-
tional-Plus-Reset-Plus-Rate Controllers
Adjustments for 4194B and C Series
Controllers 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Manual Set Point Adjustment 4–1. . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Adjustment 4–1. . . . . . . . . . . . . . . . . . . . . . . . . . .
Proportional Band Adjustment (PB ADJ) 4–2. . . .
Changing Controller Action 4–2. . . . . . . . . . . . . . . .
Reset Adjustment 4–2. . . . . . . . . . . . . . . . . . . . . . . .
Rate Adjustment 4–2. . . . . . . . . . . . . . . . . . . . . . . . .
Anti-Reset Windup (suffix letter F)
Adjustment 4–2. . . . . . . . . . . . . . . . . . . . . . . . . . .
Switching The Auto/Manual Station
(suffix letter E) 4–2. . . . . . . . . . . . . . . . . . . . . . . .
Prestartup Checks for 4194B and C Series
Controllers 4–3. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Startup for 4194B and C Series Controllers 4–3. . .
Calibration of 4194B and C Series Controllers 4–4
General Calibration Instructions 4–4. . . . . . . . . . . .
Process Indicator Zero and Span
Calibration 4–4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Zero and Span Calibration 4–6. . . . . . . . . . . . . .
Flapper Alignment 4–6. . . . . . . . . . . . . . . . . . . . . . .
Anti-Reset Windup Differential Relief Valve
(suffix letter F) Calibration 4–8. . . . . . . . . . . . . .
Principle of Operation for 4194B and C Series
Controllers 4–9. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Overall Operation 4–9. . . . . . . . . . . . . . . . . . . . . . . .
Anti-Reset Windup (suffix letter F)
Operation 4–10. . . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Operation 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Auto/Manual Station (suffix letter E)
Operation 4–11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Instruction Manual
Form 5196
November 19954194A, B, and C Series

4194A, B, and C Series
1–2
5. Maintenance
Inspection and Maintenance 5–1. . . . . . . . . . . . . . . .
Troubleshooting 5–1. . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing Common Controller Parts 5–1. . . . . . . . .
Replacing the Process Pressure Scale 5–1. . . . . .
Replacing the Relay 5–5. . . . . . . . . . . . . . . . . . . . . .
Replacing the Case and Cover 5–5. . . . . . . . . . . .
Replacing the Gauges 5–6. . . . . . . . . . . . . . . . . . . .
Replacing the Pressure Control Block 5–6. . . . . .
Replacing the Supply Gauge, Proportional,
Reset, and Reset Valve Tubing
Assemblies 5–6. . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the Proportional Band Adjustment
Knob, Nozzle Assembly, and Set Point
Beam Assembly 5–6. . . . . . . . . . . . . . . . . . . . . . .
Replacing the Flapper Assembly and
Flapper Flexure Pivot Assembly 5–10. . . . . . . .
Replacing the Proportional or Reset
Bellows 5–13. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the Reset Restriction Valve
(4194B Series) 5–15. . . . . . . . . . . . . . . . . . . . . . .
Replacing the Rate/Reset Valve Assembly
(4194C Series) 5–15. . . . . . . . . . . . . . . . . . . . . . .
Replacing the Anti-Reset Windup
(suffix letter F) Differential Relief Valve 5–16. .
Replacing the Anti-Reset Windup
(suffix letter F) Relief Valve Tubing
Assembly 5–16. . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the Links 5–17. . . . . . . . . . . . . . . . . . . . .
Replacing Link 1 5–17. . . . . . . . . . . . . . . . . . . . . . .
Replacing Link 2 5–17. . . . . . . . . . . . . . . . . . . . . . .
Replacing Link 3 5–18. . . . . . . . . . . . . . . . . . . . . . .
Replacing Link 4 5–18. . . . . . . . . . . . . . . . . . . . . . .
Replacing Link 5 5–19. . . . . . . . . . . . . . . . . . . . . . .
Replacing the Capsular Element
Assembly 5–20. . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the Long Pivot Assembly 5–20. . . . . . .
Replacing the Short Pivot Assembly 5–21. . . . . . .
Replacing the Process Drive Flexure 5–21. . . . . .
Replacing the Process Tubing 5–22. . . . . . . . . . . .
Capsular Element Maintenance Calibration 5–22. .
Precalibration Procedures 5–22. . . . . . . . . . . . . . . .
Aligning the Drive Bracket Assembly 5–22. . . . . .
Setting the Travel Stops 5–22. . . . . . . . . . . . . . . . .
Aligning the Linkage 5–22. . . . . . . . . . . . . . . . . . . . .
Zero and Span Adjustment 5–23. . . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Maintenance 5–25. . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the Remote Set Point
Assembly 5–25. . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing Remote Set Point
Assembly Parts 5–26. . . . . . . . . . . . . . . . . . . . . .
Replacing Pivot Assembly A (key 114) 5–26. . . .
Replacing Pivot Assembly B (key 115) 5–27. . . .
Replacing the Drive Flexure 5–27. . . . . . . . . . . . .
Replacing the Remote Set Point Tubing 5–28. .
Replacing Link A 5–28. . . . . . . . . . . . . . . . . . . . . .
Replacing Link B 5–28. . . . . . . . . . . . . . . . . . . . . .
Remote Set Point (suffix letter M)
Maintenance Calibration 5–28. . . . . . . . . . . . . . . .
Precalibration Procedures 5–28. . . . . . . . . . . . . . . .
Aligning the Flexures 5–28. . . . . . . . . . . . . . . . . . . .
Setting the Travel Stops 5–29. . . . . . . . . . . . . . . . .
Aligning the Linkage 5–29. . . . . . . . . . . . . . . . . . . . .
Remote Set Point Zero and Span
Adjustment 5–29. . . . . . . . . . . . . . . . . . . . . . . . . .
Remote Set Point Linearity Adjustment 5–30. . . .
Auto/Manual Station (suffix letter E)
Maintenance 5–30. . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing the Auto/Manual Station 5–30. . . . . . . .
Replacing the Switch Body Assembly,
Lever O-ring, Switch Body O-ring
and Tubing Assembly 5–31. . . . . . . . . . . . . . . . .
Replacing the Loader Range Spring,
Diaphragm Assembly, Ball Seat,
Tubing, and Ball 5–32. . . . . . . . . . . . . . . . . . . . . .
Replacing the Loader Valve Plug and
Valve Plug Spring 5–32. . . . . . . . . . . . . . . . . . . .
6. Parts
Parts Ordering 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Kits 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List 6–1. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Abbreviations Used in the Parts List 6–1. . . . . . . .
Controller Common Parts 6–1. . . . . . . . . . . . . . . . .
Process and Set Point Indicator
Assembly 6–4. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Capsular Element Assembly 6–4. . . . . . . . . . . . . .
Indicator Assembly 6–4. . . . . . . . . . . . . . . . . . . . . . .
Type 83U Relay 6–4. . . . . . . . . . . . . . . . . . . . . . . . .
Remote Set Point Assembly
(suffix letter M) 6–5. . . . . . . . . . . . . . . . . . . . . . . .
Auto/Manual Station (suffix letter E) 6–5. . . . . . . .
Internal and External Set Point
Assembly (Option) 6–5. . . . . . . . . . . . . . . . . . . . .
Controller Mounting Parts 6–6. . . . . . . . . . . . . . . . .
Pipestand Mounting 6–6. . . . . . . . . . . . . . . . . . . . .
Pipestand Mounting with Regulator 6–6. . . . . . .
Panel Mounting 6–6. . . . . . . . . . . . . . . . . . . . . . . .
Wall Mounting 6–6. . . . . . . . . . . . . . . . . . . . . . . . . .
Controller Mounting Parts for Actuator
With Casing-Mounted Controller 6–6. . . . . . . .
Controller Mounting Parts for Actuator
With Yoke-Mounted Controller 6–6. . . . . . . . .
Regulator Mounting Parts 6–7. . . . . . . . . . . . . . . . .
Regulator Mounting Parts for
Casing-Mounted Regulator 6–7. . . . . . . . . . . .
Regulator Mounting Parts for
Yoke-Mounted Regulator (Mounting
Bracket Not Required) 6–7. . . . . . . . . . . . . . . .
Regulator Mounting Parts for
Yoke-Mounted Regulator
(With Mounting Bracket) 6–7. . . . . . . . . . . . . . .
Fittings 6–7. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .

4194A, B, and C Series
1–3
Section 1
Introduction
Scope of Manual
This instruction manual provides installation, operat-
ing, calibration, maintenance, and parts ordering in-
formation for the 4194A, 4194B and 4194C Series dif-
ferential pressure indicating controllers.
Portions of this manual apply only to specific configu-
rations in the 4194 Series controller configurations.
These configurations are indicated by letter suffixes in
the type number that correspond to the mode and op-
tion designated in table 1-2.
The specific controller type number (with letter suf-
fixes) is located on the nameplate shown in figure 1-1.
Refer to table 1-2 for the definition of each 4194 Se-
ries type number.
Only personnel qualified through training or experience
should install, operate, and maintain this controller. If
there are any questions concerning these instructions
contact your Fisher Controls sales representative or
sales office before proceeding.
Description
The controllers described in this manual provide differ-
ential pressure control with options as shown in table
1-2.
D4194A Series: Proportional-only control
D4194B Series: Proportional-plus-reset control
D4194C Series: Proportional-plus-reset-plus-rate
control
These controllers show process differential pressure
and set point on an easy-to-read process scale. The
controller output is a pneumatic signal that operates a
final control element.
Specifications
Specifications for the 4194A, B, and C Series control-
lers are listed in table 1-1.
Figure1-1. 4194 Series Differential Pressure Controllers
W3358 / IL W6390 / IL

4194A, B, and C Series
1–4
Table1-1. Specifications
Available Configurations
See table 1-2
Input Signal(Differential Pressure Sensing Ele-
ment Range)(1)
Lower and Upper Range Limits: As shown in
table 1-3
Maximum Allowable Pressure: As shown in table
1-3
Output Signal
Proportional-Only, Proportional-Plus-Reset, or
Proportional-Plus-Reset-Plus-Rate Range: 3 to
15 psig (0.2 to 1.0 bar) or 6 to 30 psig (0.4 to 2.0
bar)
Action: Field-reversible between direct (increasing
differential pressure increases output pressure) or
reverse (increasing differential pressure decreases
output pressure)
Process Scale
Standard scale is matched to the range of the differ-
ential pressure sensing element. Linear, square
root, and optional(2) scales available
Process Connections
Standard: 1/4 inch NPT female stainless steel (all
input ranges); also available, steel or stainless steel
reducing adapters that permit 1/2 inch male or fe-
male connections
Optional: 1/2 inch NPT male stainless steel
Supply and Output Connections
1/4 inch NPT female
Supply Pressure Requirements
See table 1-4
Remote Set Point Pressures
3 to 15 psig (0.2 to 1.0 bar) or 6 to 30 psig (0.4 to
2.0 bar)
Controller Adjustments
Proportional Band(1):5 to 500% of process scale
range
Reset(1):Adjustable from 0.01 to more than 74 min
per repeat (from 100 to less than 0.0135 repeats
per min)
Rate(1):Adjustable from 0 to 20 minutes
Set Point: Adjustable from 0 to 100% of the scale
range
Controller Performance
Repeatability(1):0.4% of output span
Dead Band(1):Less than 0.5% of process scale
span
Typical Frequency Response(1):1.5 Hz and 90
deg phase shift with 10 ft (3.05 m) of 1/4 inch (6.4
mm) tubing and 100 cubic inch (1639 cm3) volume
Steady-State Air Consumption(1,3)
Without Auto/Manual Station
3 to 15 Psig (0.2 to 1.0 Bar) Output: 3.5 scfh (0.1
m3/hr)
6 to 30 Psig (0.4 to 2.0 Bar) Output: 2.0 scfh (0.14
m3/hr)
With Auto/Manual Station (suffix letter E)
3 to 15 Psig (0.2 to 1.0 Bar) Output: 10.0 scfh (0.28
m3/hr)
6 to 30 Psig (0.4 to 2.0 Bar) Output: 10.0 scfh (0.28
m3/hr)
Delivery Capacity(3)
3 to 15 Psig (0.2 to 1.0 Bar) Output: 240 scfh (5.6
m3/hr)
6 to 30 Psig (0.4 to 2.0 Bar) Output: 350 scfh (9.9
m3/hr)
Exhaust Capacity(3)
3 to 15 Psig (0.2 to 1.0 Bar) Output: 186 scfh (4.6
m3/hr)
6 to 30 Psig (0.4 to 2.0 Bar) Output: 295 scfh (7.0
m3/hr)
Operative Ambient Temperature Limits(1)
–40 to 160_F (–40 to 70_C)
Housing
Designed to NEMA 3 (Weatherproof) and IEC 529
IP54 specifications
Mounting
Controller can be mounted on actuator, panel,
wall, or pipestand
Approximate Weight
10 lb (4.5 kg)
1. These terms are defined in ISA Standard S51.1-1979
2. Consult your Fisher Controls sales office or sales representative for additional
information
3. Scfh—Standard cubic feet per hour (60_F and 14.7 psia). Normal m3/hr—Normal cubic
meters per hour (0_C and 1.01325 bar, absolute).

4194A, B, and C Series
1–5
Table1-2. AvailableConfigurations for 4194A,4194B,and 4194C Series Controllers
MODES OPTIONS
SERIES TYPE
NUMBER(1)
Proportional-
Only
(One-Mode
Controllers)
Proportional-
Plus-Reset
(Two-Mode
Controllers)
Proportional-
Plus-Reset-
Plus-Rate
(Three-Mode
Controllers)
Internal
Auto/Manual
Station
(suffix letter E)
Anti-ResetWindup
(suffix letter F)
Remote
Set point
(suffix letter M)
4194A
4194A
4194AE
4194AM
4194AME
X
X
X
X
–––
–––
–––
–––
–––
–––
–––
–––
–––
X
–––
X
–––
–––
–––
–––
–––
–––
X
X
4194B
4194B
4194BE
4194BF
4194BFE
4194BM
4194BME
4194BFM
4194BFME
–––
–––
–––
–––
–––
–––
–––
–––
X
X
X
X
X
X
X
X
–––
–––
–––
–––
–––
–––
–––
–––
–––
X
–––
X
–––
X
–––
X
–––
–––
X
X
–––
–––
X
X
–––
–––
–––
–––
X
X
X
X
4194C
4194C
4194CE
4194CF
4194CFE
4194CM
4194CME
4194CFM
4194CFME
–––
–––
–––
–––
–––
–––
–––
–––
–––
–––
–––
–––
–––
–––
–––
–––
X
X
X
X
X
X
X
X
–––
X
–––
X
–––
X
–––
X
–––
–––
X
X
–––
–––
X
X
–––
–––
–––
–––
X
X
X
X
1. Reverse-acting constructions are designated by the suffix letter R added to the type number.
Table1-3 Process Sensor (Capsular Element) Pressure Ratings and Material
CAPSULAR DIFFERENTIAL
SPAN STATIC PRESSURE OPERATING RANGE(3)
OPERATING
STANDARD
UNITS
CAPSULAR
ELEMENT
RANGES Minimum(1) Maximum(2) Minimum
Inches of
Mercury Maximum
OPERATING
LIMITS(4) STANDARD MATERIAL
U. S.
Units
0 to 5 psid
0 to 10 psid
0 to 20 psid
0 to 30 psid
2.5 psid
5.0 psid
10.0 psid
15.0 psid
5 psid
10 psid
20 psid
30 psid
–10
–20
–30
–30
6.5 psig
13.5 psig
27.0 psig
40.5 psig
7.5 psig
15.0 psig
30.0 psig
45.0 psig
Ni S
p
an C
Metric
Units
0 to 350 mbar
0 to 0.7 bar
0 to 1.4 bar
0 to 2.0 bar
175 mbar
0.4 bar
0.7 bar
1.0 bar
350 mbar
0.7 bar
1.4 bar
2.0 bar
–350mbar
–0.7 bar
–1.0 bar
–1.0 bar
455 mbar
0.9 bar
1.8 bar
2.7 bar
500 mbar
1.0 bar
2.1 bar
3.1 bar
Ni-Span-C
1. Span is adjustable between minimum shown and maximum of the capsular element operating range and can be positioned any where within this range. For example, if a 0 to 30
psid (0 to 2.0 bar) capsular element is used with a minimum span of 15 psid (1.0 bar), 15 to 30 psid (1.0 to 2.0 bar), or any value between the minimum and maximum values of the
operating range is possible.
2. Maximum difference between the two input supply pressures.
3. Capsular element may be pressured to this value without permanent zero shift or structural damage to controller components.
4. With travel stops set, capsular element may be pressured to this value without permanent zero shift or structural damage to controller components.
Table1-4. Supply Pressure Data
Output Signal Range Normal Operating
Supply Pressure(1)
Maximum Pressure
To Prevent Internal
Part Damage(2)
U. S.
Units 3 to 15 psig 6 to 30 psig 20 psig 35 psig 40 psig 40 psig
Metric
Units 0.2 to 1.0 bar 0.4 to 2.0 bar 1.4 bar 2.4 bar 2.8 bar 2.8 bar
1. If the pressure is exceeded, control stability may be impaired.
2. If the pressure is exceeded, damage to the controller may result.

4194A, B, and C Series
1–6

4194A, B, and C Series
2–1
Section 2
Installation
Controller Mounting Orientation
Mount the controller with the housing vertical, as
shown in figure 2-1, so that the vent points down.
Pipestand Mounting
Refer to figure 2-2. Pipestand mounting parts are pro-
vided to mount the controller to a 2-inch (nominal)
pipe. Attach a bracket (key 68) to the controller with
cap screws (key 66) and lock washers (key 67). Attach
two clamps (key 69) to the bracket, and fasten the
controller to the pipe.
Panel Mounting
Using the dimensions shown in figure 2-3, cut a hole in
the panel surface. Slide the controller into the hole and
attach the bracket (key 68) to the rear of the controller
using three cap screws (key 66) and lock washers
(key 67). Tighten the screws (key 70) to seat the case
snugly and evenly against the panel surface.
Wall Mounting
Using the dimensions in figure 2-4, drill holes in the
wall to align with the four holes in the bracket (key 68).
If the tubing is to run through the wall, drill a hole in
the wall large enough to accept the tubing.
Mount the controller to the bracket using three cap
screws (key 66) and lock washers (key 67). Attach the
bracket to the wall, using suitable screws or bolts.
Actuator Mounting
Refer to figure 2-1. A controller specified for mounting
on a control valve actuator is mounted at the factory. If
the controller is ordered separately for installation on a
control valve actuator, mount the unit as described in
this section. Mounting parts vary for different actuator
types.
Attach the mounting bracket to the actuator yoke with
cap screws, lock washers, and spacer spools. Attach
the controller to the bracket with cap screws, lock
washers, and spacer spools. On some designs, the
mounting bracket is attached to the actuator casing
rather than to the yoke.
Figure2-1. TypicalActuatorMounting
MOUNTING
PLATE
TYPE 657
ACTUATOR
TYPE 4194
CONTROLLER
TYPE 67FR
FILTER
REGULATOR
W5661 / IL
Pressure Connections
WARNING
To avoid personal injury or property
damage resulting from the sudden re-
lease of pressure, do not install any sys-
tem component where service condi-
tions could exceed the limits given in
this manual. Use pressure-relieving de-
vices as required by government or ac-
cepted industry codes and good engi-
neering practices.
Refer to figure 2-5 for piping connection locations.
Supply, output, remote set point, and vent connections
are 1/4-inch NPT, female. Process pressure connec-
tions are 1/4- or 1/2-inch NPT (optional).
Process Pressure Connections
Process pressures are piped to the connections
marked A and B on the bottom of the case, shown in
figure 2-5. Pipe the high pressure line to connection B
and the low pressure line to connection A.
When installing process piping, follow accepted prac-
tices to ensure accurate transmission of the process
pressure to the controller. Install a three-valve bypass,
shutoff valves, vents, drains, or seal systems as need-
ed in the process pressure lines. If necessary, install a

4194A, B, and C Series
2–2
Figure2-2.Pipestand Mounting
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49A3196-A
A6732 / IL %
Figure2-3. Panel Mounting
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36A9760-A
A6733 / IL
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  
needle valve in a process pressure sensing line to
dampen pulsations.
If the instrument is located such that the adjacent pro-
cess pressure lines are approximately horizontal, the
Figure2-4. WallMounting
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36A9761-B
A6734 / IL

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lines should slope downward to the instrument for liq-
uid-filled lines and upward toward the instrument for
gas-filled lines. This reduces the possibility of air be-
coming trapped in the sensor with liquid-filled lines or
of condensation becoming trapped in gas-filled lines.

4194A, B, and C Series
2–3
The recommended slope is 1 inch per foot (83 millime-
ters per meter).
Supply Pressure Connection
WARNING
Personal injury or property damage may
occur from an uncontrolled process if
the supply medium is not clean, dry, oil-
free, or non-corrosive gas. Industry
instrument air quality standards de-
scribe acceptable dirt, oil, and moisture
content. Due to the variability in nature
of the problems these influences can
have on pneumatic equipment, Fisher
Controls has no technical basis to rec-
ommend the level of filtration equipment
required to prevent performance degra-
dation of pneumatic equipment. A filter
or filter regulator capable of removing
particles 40 microns in diameter should
suffice for most applications. Use of
suitable filtration equipment and the es-
tablishment of a maintenance cycle to
monitor its operation is recommended.
Supply pressure must be clean, dry air or noncorrosive
gas that meets the requirements of ISA Standard
S7.3-1975 (R1981). Use a suitable supply pressure
regulator to reduce the supply pressure source to the
normal operating supply pressure shown in table 1-4.
Connect supply pressure to the SUPPLY connection
on the bottom of the case, shown in figure 2-5.
Remote Set Point (suffix letter M)
Pressure Connection
If the controller has remote set point (suffix letter M),
connect the remote set point pressure to the top of the
controller case at the location shown in figure 2-5. Use
clean dry air or noncorrosive gas. Use a 3 to 15 psig
(0.2 to 1.0 bar) remote set point pressure range for a 3
to 15 psig (0.2 to 1.0 bar) controller output signal
range or a 6 to 30 psig (0.4 to 2.0 bar) remote set
point pressure range for a 6 to 30 psig (0.4 to 2.0 bar)
controller output signal range. If pressure is supplied
to the remote set point connection with a regulator, a
small bleed orifice should be placed between the regu-
lator and remote set point connection to prevent pres-
sure variations due to regulator lock-up.
Figure2-5. Location of Connections
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46A9765-A
A3001 / IL
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Vent
WARNING
If a flammable, toxic, or reactive gas is
to be used as the supply pressure me-
dium, personal injury or property dam-
age could result from fire or explosion
of accumulated gas or from contact with
toxic, or reactive gas. The controller
case and cover assembly do not form a
gas-tight seal, and when the assembly
is enclosed, a remote vent line, ade-
quate ventilation, and necessary safety
measures should be used. However, a
remote vent pipe alone cannot be relied
upon to remove all hazardous gas. Vent
line piping should comply with local
and regional codes and should be as
short as possible with adequate inside
diameter and few bends to reduce case
pressure buildup.
CAUTION
When installing a remote vent pipe, take
care not to over-tighten the pipe in the
vent connection. Excessive torque will
damage the threads in the connection.
If a remote vent is required, the vent line must be as
short as possible with a minimum number of bends
and elbows. Vent line piping should have a minimum
inside diameter of 3/4 inches (19 mm) for runs up to
20 feet (6.1 meters) and a minimum inside diameter of
1 inch (25 mm) for runs from 20 to 100 feet (6.1 to
30.5 meters).

4194A, B, and C Series
2–4
The vent must be protected against the entrance of
any foreign material that could plug it; or, if a remote
vent is not required, the vent opening in the case,
must be protected against the entrance of any foreign
material that could plug it. Check the vent periodically
to be certain it is not plugged.

4194A, B, and C Series
3–1
Figure3-1. 4194A Series Controller Adjustment Locations
SET POINT
INDICATOR
PROCESS POINTER
PROPORTIONAL BAND
ADJUSTMENT
PROPORTIONAL BAND
INDICATOR COVER
OUTPUT PRESSURE
GAUGE
W6391 / IL
METAL BALL
SWITCHING ZONE
INDICATOR
LOADER KNOB
AUTO/MANUAL
SWITCH
W3679 / IL


Section 3
4194A Series
Proportional-OnlyControllers
Adjustments for 4194A Series
Controllers
This section includes descriptions of adjustments and
procedures for prestartup, startup, and calibration. Ad-
justment locations are shown in figures 3-1 and 3-3. To
better understand the adjustments and overall control-
ler operation, refer to the principle of operation section
and to the schematic diagrams in figures 3-4 and 3-5.
Unless otherwise noted, key numbers given in this
section are found in figure 5-21.
Manual Set Point Adjustment
Adjust the set point by moving the set point indicator
until the line on the set point indicator is over the de-
sired value on the process differential pressure scale.
Move the indicator to the right to increase the set
point, and to the left to decrease it. Adjusting the set
point does not affect the proportional band setting.
If the controller is equipped with the optional internal or
external set point adjustment, turn the adjustment
knob clockwise to increase the process set point and
counterclockwise to decrease the process set point.
Remote Set Point (suffix letter M)
Adjustment
CAUTION
Do not manually move the set point in-
dicator on controllers with remote set
point. Manually moving the set point in-
dicator could damage the controller.
If the controller is equipped with remote set point (suf-
fix letter M), vary the remote set point pressure to
change the set point. Increase the pressure to in-
crease the set point, and decrease the pressure to
decrease the set point.
Proportional Band Adjustment (PB ADJ)
The proportional band determines the output sensitiv-
ity of the controller. The proportional band adjustment
is marked in percentages of process differential pres-
sure required to drive the controller from zero output to
full output.

4194A, B, and C Series
3–2
Figure3-2. Changing Controller Action
(4194ASeries Controllers)
W3439 / IL
To adjust the proportional band, open the controller
cover and locate the proportional band adjustment (PB
ADJ) knob. Rotate the knob until the desired value is
opposite the line on the proportional band indicator
cover.
Changing Controller Action
To change the controller action from direct to reverse
or vice versa, loosen the screws on the proportional
band indicator cover. Lift the cover out as shown in
figure 3-2 and rotate the proportional band adjustment
to the desired action. Setting the proportional band to
the values in the white portion of the adjustment pro-
vides direct controller action; setting proportional band
in the black portion provides reverse controller action.
For direct control action:
An increasing sensed differential pressure increases
output pressure.
For reverse control action:
An increasing sensed differential pressure decreases
output pressure.
After changing the action, tighten the two screws on
the proportional band indicator cover.
Switching the Auto/Manual Station (suffix
letter E)
CAUTION
Switching the controller between auto-
matic and manual mode without balanc-
ing can disturb the process and cause
controller cycling.
Refer to figure 3-1 if the controller has the auto/manu-
al station (suffix letter E). To switch from automatic to
manual mode, or from manual to automatic, you must
first balance the manual output with the controller out-
put. Two balance methods are available to equalize
the manual output with the controller output.
To switch from automatic to manual mode, carefully
adjust the loader knob until the metal ball inside the
plastic tube moves into the switching zone. Then
move the automatic/manual switch to MANUAL. Turn
the loader knob clockwise to increase the controller
output or counterclockwise to decrease it.
To switch from manual to automatic mode, adjust the
set point to move the ball into the switching zone. Turn
the switch to AUTO and adjust the set point to control
the output.
When the auto/manual switch is in AUTO, adjusting
the loader knob has no effect on the controller output.
When the auto/manual switch is in MANUAL, changing
the set point has no effect on the controller output.
Prestartup Checks for 4194A Series
Controllers
Refer to figure 3-1 for adjustment locations and refer
to figure 5-21 for key number locations.
When performing the checks, open loop conditions
must exist. An open loop exists when the controller
output does not affect the input pressure or other con-
trol signal to the controller.
Note
If the controller has the auto/manual sta-
tion (suffix letter E), be sure the control-
ler is in the automatic mode before per-
forming prestartup checks.
1. Provide a means of measuring the controller output
pressure by connecting the controller output to a pres-
sure gauge. Connect supply pressure to the supply
pressure regulator and be sure it is delivering the
proper supply pressure to the controller. Do not ex-
ceed the normal operating pressure in table 1-4.
2. For a controller with remote set point (suffix letter
M), connect regulated pressure of 3 to 15 psig (0.2 to
1.0 bar) or 6 to 30 psig (0.4 to 2.1 bar) to the remote
set point connection at the top of the controller case.
3. Remove the two machine screws (key 6) and lift off
the proportional band indicator cover (key 36).
4. Adjust the set point a minimum of 20 percent of
input span above the process pointer.
5. Adjust the proportional band for 5 percent DIRECT.
6. If necessary, connect a pressure source to the pro-
cess connection and adjust the process pointer to the

4194A, B, and C Series
3–3
last mark on the left side of the scale. If the last scale
mark is 0 psig, a pressure source is not required.
7. The controller output pressure should be 0 psig.
8. Rotate the proportional band to 5 percent RE-
VERSE.
9. The controller output should be within 2 psig (0.14
bar) of the supply pressure.
10. If the controller output is within tolerance, adjust
the proportional band to 400 percent in the desired
action, secure the proportional band indicator cover
(key 36) with the machine screws (key 6), and go to
the startup procedure. If the controller output pressure
is not within tolerance, go to the 4194A Series calibra-
tion procedure for recalibration.
Startup for 4194A Series Controllers
Perform the prestartup checks and, if necessary, cali-
brate the controller prior to this procedure.
Note
When performing the startup proce-
dures, keep in mind that the initial set-
tings are guidelines. They will vary de-
pending on the actual process being
controlled.
1. Be sure the supply pressure regulator is delivering
the proper supply pressure to the controller.
2. For controllers with:
Manual set point:
Move the set point indicator to the desired set point.
Remote set point:
a. See figure 2-5 for the location of the remote set
point connection. Connect an adjustable pressure
source to the remote set point connection.
b. Adjust the pressure source until the set point
indicator reaches the desired set point. Remember:
Increasing the remote set point pressure increases
the set point.
3. Set the proportional band adjustment to 100 per-
cent for fast processes. For slow processes, calculate
the proportional band percentage from the equation
below:
Proportional
Band
Adjustment +200 Allowable Overshoot
Pressure Span
For example: 200 2Psig
30 Psig ^13%
4. Create a load upset by momentarily changing the
set point. Check for system cycling. If the system does
not cycle, lower the proportional band setting (thus
raising the gain) and disturb the system again by
changing the set point. Continue this procedure until
the system cycles. At this point, double the proportion-
al band setting (proportional band setting 2).
5. Check the stability of the recommended proportion-
al band setting by introducing a disturbance and moni-
toring the process.
Calibration of 4194A Series Controllers
General Calibration Instructions
Note
If the controller has the auto/manual sta-
tion (suffix letter E), be sure the control-
ler is in the automatic mode before per-
forming calibration.
If the prestartup checks, or startup, reveal faulty con-
troller operation, perform the calibration described in
this section. These instructions are valid for either
shop or field calibration, provided that open process
loop conditions exist. Unless otherwise noted, key
numbers are found in figure 5-21.
Do not use the gauges supplied with the controller dur-
ing calibration. Monitor process pressure, supply pres-
sure, controller output pressure, and, if applicable, re-
mote set point pressure with external gauges.
Process Indicator Zero and Span
Calibration
Before starting this procedure:
DProvide a regulated process differential pressure
to the controller and a means of measurement exter-
nal to the controller.
DProvide a means of measuring the controller out-
put pressure by connecting the controller output to a
pressure gauge (open-loop conditions must exist).
Provide a regulated supply pressure to the controller.
Do not exceed the normal operating pressure in table
1-4.
Note
Any change to the process pointer span
adjustment will require readjustment of
the process pointer zero adjustment.

4194A, B, and C Series
3–4
Refer to figures 3-1 and 3-3 for adjustment locations.
1. Remove the two screws (key 6) and lift off the pro-
portional band indicator cover (key 36).
2. Set the proportional band between DIRECT and
REVERSE.
3. Apply process differential pressure equal to the
process scale span lower limit.
4. The process pointer should indicate the process
scale lower limit. If not, adjust the process pointer to
the process scale lower limit by loosening the zero
adjustment locking screw and turning the zero adjust-
ment screw. Tighten the zero adjustment locking
screw.
5. Apply process differential pressure equal to the
process scale span upper limit.
6. The process pointer should indicate the process
scale upper limit. If not, adjust the span screw to cor-
rect one-half the error as follows: clockwise to in-
crease span for a low indication (below the upper lim-
it); counterclockwise to decrease span for a high
indication (above the upper limit).
7. Repeat steps 3 through 6 until the error is elimi-
nated.
8. Apply process differential pressure equal to the
mid-scale value of the process scale span. The pro-
cess pointer should indicate the mid-scale mark, ±2
percent of span. If the error is greater than ±2 percent,
refer to the Maintenance section and perform the zero
and span adjustment procedure.
9. Adjust the process pointer to within ±1 percent of
the mid-scale mark by loosening the locking screw and
turning the zero adjustment screw. This distributes the
error over the entire scale span and brings all points
within ±1 percent of the process scale span.
10. Apply process differential pressure equal to the
process scale span lower limit.
11. The process pointer should indicate the process
scale lower limit ±1 percent of the scale span.
12. Apply process pressure equal to the process
scale span upper limit.
13. The process pointer should indicate the process
scale upper limit ±1 percent of the process scale span.
14. If the error is greater than ±1 percent, repeat
steps 3 through 13.
Remote Set Point (suffix letter M) Zero
and Span Calibration
Refer to figures 3-1 and 3-3 for adjustment locations.
Refer to figures 5-21 and 5-26 for key number loca-
tions.
Note
Any adjustment of the remote set point
span adjustment screw requires read-
justment of the remote set point zero
adjustment screw.
1. Remove the two screws (key 6) and lift off the pro-
portional band indicator cover (key 36).
2. Set the proportional band between DIRECT and
REVERSE.
3. Apply remote set point pressure equal to the lower
range limit.
4. The set point indicator should indicate the process
scale lower limit. If not, loosen the remote set point
zero adjustment locking screw and adjust the remote
set point zero adjustment screw until the set point indi-
cator aligns with the process scale lower limit. Tighten
the zero adjustment locking screw.
5. Apply remote set point pressure equal to the upper
range limit.
6. The set point indicator should indicate the process
scale upper limit. If not, adjust the remote set point
span adjustment screw to correct one-half the error as
follows: clockwise to increase span for a low indica-
tion; counterclockwise to decrease span for a high in-
dication.
7. Repeat steps 3 through 6 until the error is elimi-
nated.
8. Apply remote set point pressure equal to the mid-
range value.
9. Make sure the set point indicator is within ±1 per-
cent of the mid-scale mark and if so, proceed to step
12. If the set point indicator is not within 1 percent, but
is within ±2 percent of the mid-scale mark, then pro-
ceed with step 10. If the set point indicator is not within
±2 percent, proceed to the remote set point calibration
procedure in the Maintenance section.
10. Loosen the remote set point zero adjustment lock-
ing screw and adjust the remote set point zero adjust-
ment screw to correct for half the error at mid-scale.
Tighten the zero adjustment locking screw.
11. Apply remote set point pressure equal to the lower
and upper range limits and make sure the set point
indicator is within ±1 percent.

4194A, B, and C Series
3–5
Figure3-3. 4194A Series Controller Calibration Adjustment Locations
PROCESS
POINTER
SPAN
ADJUSTMENT
REMOTE SET
POINT
SPAN ADJUSTĆ
MENT
(SUFFIX LETTER
M)
SCREW 1
SCREW 2
SCREW 3
SIDE VIEW OF SET POINT/
PROCESS INDICATOR ASSEMBLY
SIDE VIEW OF CONTROLLER
SHOWING FLAPPER LEVELING SCREWS
56A9752-SSHT 1
39A1126-B
A6730 / IL
POINTER ZERO
ADJUSTMENT
POINTER ZERO
ADJUSTMENT
LOCKING SCREW
REMOTE SET POINT
ZERO ADJUSTMENT
(SUFFIX LETTER M)
W6391 / IL
REMOTE SET POINT
ZERO ADJUSTMENT
LOCKING SCREW
(SUFFIX LETTER M)
PROCESS POINTER
SPAN ADJUSTMENT
FRONT VIEW

4194A, B, and C Series
3–6
12. If necessary, perform the process indicator zero
and span calibration procedure in this section. Other-
wise, perform the flapper alignment procedure in this
section.
Flapper Alignment
Note
Perform the process indicator zero and
span calibration procedure and, for con-
trollers with remote set point (suffix let-
ter M), the remote set point zero and
span calibration procedure before the
flapper alignment.
Flapper leveling screw numbers and adjustments are
shown in figure 3-3. Key number locations are shown
in figure 5-21.
Provide a means of measuring the controller output
pressure by connecting the controller output to a pres-
sure gauge (open-loop conditions must exist). Provide
a regulated supply pressure to the controller. Do not
exceed the normal operating pressure in table 1-4.
After performing the flapper alignment procedure, go
to the startup procedure.
1. For a controller with manual set point, move the set
point indicator to the mid-scale mark on the process
scale. For a controller with remote set point (suffix let-
ter M), adjust the remote set point pressure until the
set point indicator is at the mid-scale on the process
scale.
2. Apply process differential pressure equal to the
mid-scale value of the process scale span. If pressure
is not available to pressure the input element to the
mid-scale value, an alternate method is to disconnect
link number 1 at the input element and tape the pro-
cess pointer at the mid-scale mark of the process
scale. Note the hole from which link number 1 was
removed for proper replacement. This method should
only be used if pressure is not available to pressure
the input element to the mid-scale value.
3. Remove the two machine screws (key 6) and lift off
the proportional band indicator cover (key 36).
4. Set the proportional band between DIRECT and
REVERSE.
5. The controller output should be 9 ±0.10 psig (0.62
±0.007 bar) for a 3 to 15 psig (0.2 to 1.0 bar) output or
18 ±0.2 psig (1.2 ±0.01 bar) for a 6 to 30 psig (0.4 to
2.0 bar) output. If not, adjust flapper leveling screw 2
(the screw nearest the nozzle) until the output is within
tolerance.
6. Set the proportional band to 30 percent DIRECT.
7. The controller output should be 9 ±0.25 psig (0.62
±0.02 bar) or 18 ±0.5 psig (1.2 ±0.04 bar). If not, ad-
just flapper leveling screw 3 (the screw nearest the
nozzle).
8. Set the proportional band to 30 percent REVERSE.
9. The controller output should be 9 ±0.25 psig (0.62
±0.02 bar) or 18 ±0.5 psig (1.2 ±0.04 bar). If not, ad-
just flapper leveling screw 1 (the screw nearest the
nozzle).
10. Repeat steps 4 through 9 until the controller out-
put remains in tolerance without further leveling screw
adjustment.
11. If link 1 was disconnected, remove the tape and
reconnect link 1 to the input element.
12. Set the proportional band to 400 percent in the
desired controller action and replace the proportional
band indicator cover.
Principle of Operation for 4194A Series
Controllers
Overall Operation
Refer to the schematic diagram in figure 3-4.
The input element is connected to the process pointer
and to the flapper by connecting links. As the process
differential pressure increases (in a direct-acting con-
troller), the flapper moves toward the nozzle, restrict-
ing flow through the nozzle and increasing nozzle
pressure. When this occurs, relay action increases the
output pressure (delivery) of the controller. Output
pressure is fed back to the proportional bellows. The
action of the proportional bellows counteracts the flap-
per movement that resulted from the process differen-
tial pressure change and backs the flapper away from
the nozzle until equilibrium is reached.
Moving the set point indicator changes the distance
between the nozzle and flapper as does a change in
process pressure, except that when the set point is
changed, the nozzle moves with respect to the flapper.
The proportional band adjustment positions the nozzle
on the flapper. Increasing (widening) the proportional
band moves the nozzle to a position on the flapper
where less input and more feedback motion occurs,
which decreases the gain of the controller. Decreasing
(narrowing) the proportional band moves the nozzle
toward a position where more input and less feedback
motion occurs, which increases the gain. The control-
ler action is changed from direct to reverse by turning
the proportional band adjustment to position the
nozzle on the flapper quadrant to a point where the
direction of the flapper motion versus input motion is
reversed as shown in the flapper detail of figure 3-4.
With the controller in the reverse-acting mode, an in-
crease in process differential pressure causes a de-
crease in output pressure.

4194A, B, and C Series
3–7
Figure3-4. 4194A Series Controller Schematic
SET POINT INDICATOR RESET BELLOWS (VENTED) REVERSE ACTION
QUADRANT
PROPORTIONAL
BELLOWS PROPORTIONAL
BAND ADJUSTMENT
FLAPPER PIVOT
DIRECT ACTION
QUADRANT
FLAPPER
NOZZLE
BEAM
CONNECTING
LINK
PROCESS POINTER
REMOTE SET POINT
CONNECTED HERE
INPUT ELEMENT
CONNECTED HERE
SUPPLY
PRESSURE
RELAY
OUTPUT PRESSURE
TO FINAL CONTROL
ELEMENT
SUPPLY PRESSURE
OUTPUT PRESSURE
PROPORTIONAL PRESSURE
NOZZLE PRESSURE
FEEDBACK
LINK
FEEDBACK
MOTION
INPUT
MOTION

46A9764-A
B1489-2 / IL
Remote Set Point (suffix letter M)
Operation
The capability to adjust the controller set point from a
remote location is available with all 4194A Series con-
trollers. This option is designated by the suffix letter M
in the type number.
A control pressure is applied to the capsular element
within the remote set point assembly. The expansion
and contraction of the capsule moves the set point
indicator via a connecting linkage. Increasing the con-
trol pressure to the capsule increases the set point
setting and decreasing the control pressure reduces
the set point setting.
Auto/Manual Station (suffix letter E)
Operation
A controller with the auto/manual station (designated
by the suffix letter E in the type number) has piping on
the output side of the relay as shown in figure 3-5.
Supply pressure to the relay is also applied to the
manual loader. The manual loader, functioning as a
regulator, applies pressure to one side of the plastic
tube and to the auto/manual switch. Output pressure
from the relay registers on the other side of the plastic
tube as well as in the auto/manual switch.
When the auto/manual switch is in the MANUAL posi-
tion, the manual loader output is channeled through
the auto/manual switch and becomes the controller
output. When the auto/manual switch is in the AUTO
position, the relay output is channeled through the
switch to become the controller output.
Before the auto/manual switch is operated, the relay
output must equal the manual loader output to avoid
bumping the process. Adjusting the set point varies
the pressure on the left-hand side of the plastic tube.
Adjusting the manual loader knob varies the pressure
on the right-hand side. When the pressures are equal,
the metal ball is centered in the tube and is held in
place by a small magnet. A pressure imbalance forces
the ball to one end of the tube where it forms a seal,
blocking air flow through the tube.

4194A, B, and C Series
3–8
Figure3-5.Auto/Manual Station Schematic
AUTOMATIC
POSITION
OUTPUT PRESSURE
TO FINAL CONTROL
ELEMENT
SUPPLY
PRESSURE
RELAY
AUTO/MANUAL
SWITCH
MANUAL LOADER
MANUAL
LOADER
KNOB
MANUAL
POSITION
AUTO/MANUAL
SWITCH
OUTPUT PRESSURE
TO FINAL CONTROL
ELEMENT
PLASTIC TUBE
METAL BALL
RELAY OUTPUT PRESSURE
SUPPLY PRESSURE
MANUAL LOADER OUTPUT PRESSURE
48A5230-A
A2999-1 / IL

4194A, B, and C Series
4–1
Figure4-1. 4194B and C Series Controller Adjustment Locations
METAL BALL
SWITCHING ZONE
INDICATOR
LOADER KNOB
AUTO/MANUAL
SWITCH
W3679 / IL


RATE
ADJUSTMENT RESET
ADJUSTMENT
W3599–1 / IL





W6392 / IL

















Section 4
4194B Series Proportional-
Plus-Reset Controllers And 4194C
SeriesProportional-
Plus-Reset-Plus-RateControllers
Adjustments for 4194B and C Series
Controllers
This section includes descriptions of adjustments and
procedures for prestartup, startup and calibration. Ad-
justment locations are shown in figures 4-1 and 4-3. To
better understand the adjustments and overall control-
ler operation, refer to the principle of operation section
and to the schematic diagrams in figures 4-5 through
4-8. Unless otherwise noted, key numbers given in this
section are found in figure 5-21.
Manual Set Point Adjustment
Adjust the set point by moving the set point indicator
until the line on the set point indicator is over the de-
sired value on the process differential pressure scale.
Move the indicator to the right to increase the set
point, and to the left to decrease it. Adjusting the set
point does not affect the proportional band setting.
If the controller is equipped with the optional internal or
external set point adjustment, turn the adjustment
knob clockwise to increase the process set point and
counterclockwise to decrease the process set point.
Remote Set Point (suffix letter M)
Adjustment
CAUTION
Do not manually move the set point in-
dicator on controllers with remote set
point. Manually moving the set point in-
dicator could damage the controller.
If the controller is equipped with remote set point (suf-
fix letter M), vary the remote set point pressure to
change the set point. Increase the pressure to in-
crease the set point, and decrease the pressure to
decrease the set point.
Proportional Band Adjustment (PB ADJ)
The proportional band determines the output sensitiv-
ity of the controller. The proportional band adjustment

4194A, B, and C Series
4–2
Figure4-2. Changing Controller Action
(4194B and C Series Controllers)
W3439 / IL
is marked in percentages of process differential pres-
sure required to drive the controller from zero output to
full output.
To adjust the proportional band, open the controller
cover and locate the proportional band adjustment (PB
ADJ) knob. Rotate the knob until the desired value is
opposite the line on the proportional band indicator
cover.
Changing Controller Action
To change the controller action from direct to reverse
or vice versa, loosen the screws on the proportional
band indicator cover. Lift the cover out as shown in
figure 4-2 and rotate the proportional band adjustment
to the desired action. Setting the proportional band to
the values in the white portion of the adjustment pro-
vides direct controller action; setting proportional band
in the black portion provides reverse controller action.
For direct control action:
An increasing sensed differential pressure increases
output pressure.
For reverse control action:
An increasing sensed differential pressure decreases
output pressure.
After changing the action, tighten the two screws on
the proportional band indicator cover.
Reset Adjustment
To adjust reset, open the controller cover and locate
the RESET adjustment. Rotate the adjustment clock-
wise to decrease the minutes per repeat or counter-
clockwise to increase the minutes per repeat. Increas-
ing the minutes per repeat provides a slower reset
action.
Rate Adjustment
To adjust rate, open the controller cover and locate the
RATE adjustment. Rotate the adjustment clockwise to
decrease the minutes (less rate action) or counter-
clockwise to increase the minutes (more rate action).
Anti-Reset Windup (suffix letter F)
Adjustment
If the arrow on the differential relief valve points toward
the bottom of the controller case, as shown in figure
4-1, the relief valve opens with increasing controller
output pressure. If the arrow points in the opposite
direction, the relief valve opens with decreasing con-
troller output pressure. Differential relief pressure is
factory set at 5 psig (0.3 bar). Maximum relief pres-
sure is 7 psig (0.5 bar); minimum is 2 psig (0.1 bar).
Turn the adjusting screw counterclockwise to increase
differential relief pressure, clockwise to decrease it.
Switching The Auto/Manual Station (suffix
letter E)
CAUTION
Switching the controller between auto-
matic and manual mode without balanc-
ing can disturb the process and cause
controller cycling.
Refer to figure 4-1 if the controller has the auto/manu-
al station (suffix letter E). To switch from automatic to
manual mode, or from manual to automatic, you must
first balance the manual output with the controller out-
put. Two balance methods are available to equalize
the manual output with the controller output.
To switch from automatic to manual mode, carefully
adjust the loader knob until the metal ball inside the
plastic tube moves into the switching zone. Then
move the automatic/manual switch to MANUAL. Turn
the loader knob clockwise to increase the controller
output or counterclockwise to decrease it.
To switch from manual to automatic mode, adjust the
set point to move the ball into the switching zone. Turn
the switch to AUTO and adjust the set point to control
the output.
When the automatic/manual switch is in AUTO, adjust-
ing the loader knob has no effect on the controller out-
put. When the automatic/manual switch is in MANU-
AL, changing the set point has no effect on the
controller output.