Samson 3430, 430 Series, 3431, 3434-1, 3434-2 Operating Instructions Manual

Series 430

Pneumatic Indicating Controllers
Type 3430

Type 3432 Controller Station

– with Type 3435 Transmitter Module for Pressure
– with Type 3436 Transmitter Module for Temperature
– with Type 3438 Transmitter Module for Temperature (Pt 100)
– for standardized signals

Version shown with lockable door and integrated
Type 3436 Transmitter Module for Temperature

Fig. 1 · Controller stations

Mounting and
Operating Instructions

EB 7030 EN

Edition October 2010

Type 3431 Controller Station

– for standardized signals

Contents

Contents Page

1 Application. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2 Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.1 Settings at the controller modules . . . . . . . . . . . . . . . . . . . . 4

2.1.1 Operating action . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.1.2 Air supply . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

2.1.3 Proportional-action coefficient Kp . . . . . . . . . . . . . . . . . . . . 6

2.1.4 Reset time Tn . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.1.5 Rate time Tv. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.1.6 Operating point. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

2.2 Setting the limit switches. . . . . . . . . . . . . . . . . . . . . . . . . 7

3 Commissioning . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.1 Tuning the controller . . . . . . . . . . . . . . . . . . . . . . . . . . 8

3.1.1 Setting the operating point in P and PD controllers . . . . . . . . . . . . 9

3.2 Smooth automatic/manual mode changeover . . . . . . . . . . . . . 10

3.3 Smooth changeover between the internal and external reference variable 10

3.4 Readjusting the controller’s zero point . . . . . . . . . . . . . . . . . 10

4 Construction. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5 Principle of operation . . . . . . . . . . . . . . . . . . . . . . . . . 11

5.1 Transmitter modules . . . . . . . . . . . . . . . . . . . . . . . . . . 11

5.2 Controller station . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

5.3 Controller modules. . . . . . . . . . . . . . . . . . . . . . . . . . . 14

5.3.1 Type 3433 Controller Modules . . . . . . . . . . . . . . . . . . . . . 14

5.3.2 Type 3434 Controller Modules . . . . . . . . . . . . . . . . . . . . . 17

5.4 Additional modules . . . . . . . . . . . . . . . . . . . . . . . . . . 18

5.4.1 Type 6112 i/p Converter . . . . . . . . . . . . . . . . . . . . . . . 18

5.4.2 w

selector switch . . . . . . . . . . . . . . . . . . . . . . . . 18

int/wext

5.4.3 Supply pressure regulators . . . . . . . . . . . . . . . . . . . . . . . 18

5.4.4 Inductive limit switches . . . . . . . . . . . . . . . . . . . . . . . . . 19

6 Installation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.1 Mounting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

6.1.1 Changing scales. . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

6.2 Installing the temperature sensor . . . . . . . . . . . . . . . . . . . . 22

7 Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7.1 Pneumatic connections . . . . . . . . . . . . . . . . . . . . . . . . . 24

7.1.1 Typical applications . . . . . . . . . . . . . . . . . . . . . . . . . . 24

7.1.2 Adjusting the supply air for version with supply pressure regulator. . . . 25

7.2 Electrical connection . . . . . . . . . . . . . . . . . . . . . . . . . . 26

2 EB 7030 EN

Contents

8 Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

8.1 Checking the air supply . . . . . . . . . . . . . . . . . . . . . . . . 27

9 Conversion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28

9.1 Changing the controller function . . . . . . . . . . . . . . . . . . . . 28

9.2 Exchanging the transmitter module . . . . . . . . . . . . . . . . . . . 30

9.3 Checking the controller function . . . . . . . . . . . . . . . . . . . . 30

10 Use in hazardous areas . . . . . . . . . . . . . . . . . . . . . . . . 31

10.1 Servicing explosion-protected devices . . . . . . . . . . . . . . . . . 31

11 Technical data . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Certificates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35

General safety instructions

The device may only be assembled, started up or operated by trained and

4

experienced personnel familiar with the product.
According to these mounting and operating instructions, trained personnel is
referred to as individuals who are able to judge the work they are assigned
to and recognize possible dangers due to their specialized training, their
knowledge and experience as well as their knowledge of the relevant
standards.
Explosion-protected versions may only be operated by personnel who have

4

undergone special training or instructions or who are authorized to work on
explosion-protected devices in hazardous areas.
Any hazards that could be caused by the signal pressure are to be

4

prevented by means of the appropriate measures.
Proper shipping and appropriate storage of the device are assumed.

4

EB 7030 EN 3

Application

1 Application

The Series 430 Pneumatic Indicating Con
trollers are used for applications in process
automation and industrial plants.
The controllers directly measure the con
trolled variables (pressure, temperature,
electric or pneumatic standardized signal)
and display the value. They compare the
measured variable with the set point and is
sue a corresponding pneumatic control sig
nal from 0.2 to 1 bar (3 to 15 psi).

A supply pressure of 1.4 bar±0.1 bar
(20 psi±1.5 psi) is required or an operat
ing pressure of 2 to 12 bar (30 to 180 psi)
when a supply pressure regulator is in­stalled.

-

2 Operation

-

2.1 Settings at the controller
modules

The controller module in the station can be
accessed after the lock (Fig. 2) has been re
leased and the indicating unit (5) has been
opened out.

-

The settings for operating action (turnboard

-

A) and air supply (turnboard B) must be
performed prior to commissioning.

Unscrew the mounting screw (6) on the

4

-

controller module. Pull it off its self-seal
ing hose fittings and lift out of the con­troller station.

2.1.1 Operating action

The operating action for the control loop is
set at the turnboard A (Fig. 2), where the
position of its arrow symbol according to the
arrow symbol on the controller module de­termines the operation action of the control­ler.

34 Arrow tips facing opposite

directions:
Operating direction:
Increasing/decreasing =
As the controlled variable x increases,
the output signal pressure y
decreases.

44 Arrow tips facing the same direction:

Operating direction:
Increasing/increasing
As the controlled variable x increases,
the output signal pressure y
increases.

-

-

4 EB 7030 EN

Operation

Setting or modifying the operating direction:

Unfasten the screw in turnboard A (Fig. 2)
and lift it off together with the turnboard. If
necessary, lever the board at the side.
Do not lose the rubber seal.

Turn the board by 90° so that the re

4

quired arrow is aligned with the arrow
on the base plate.
Insert board and tighten screw.

4

Reassemble the controller module in the

4

controller station.

1 Controller station (Type 3432)

1

1.1 Scale

1.3

1.3 Actual value pointer (red)

1.1

1.4 Set point adjuster

4

2 Transmitter module

1.4

3 Controller module

5

3.1 Comparator

3.2 Connecting plate

3.3 Hex screws

2

Air supply

B

Oper. action

A 3.2 3.4 8 9 3.1

3.4 Screws (inside)

2.1.2 Air supply

(only with Type 3433 Controller Module)
The position of the turnboard B (Fig. 2) with
its arrow symbol determines the air supply
to the feedback bellows. It can be accessed

-

after the comparator (3.1) has been re
moved.

4yA Normal air supply, approx. 1 m

4R Large air supply, approx. 3 m

or connecting base

-

³/h

n

per % of the system deviation

³/h

n

per % of the system deviation
(not with P or PD controller modules)

4 Lock
5 Indicating unit
6 Mounting screw
7 Restriction
8 Zero adjuster
9 Kp adjuster
10 Tn adjuster
11 Tv adjuster (only in

PD or PID controller)

12 Operating point adjuster

(only in P or PD controller)

63109

Type 3432 Contr. Module

Side view without comparator

Fig. 2 · Turnboards and adjusters

3.3
3
6

7

Type 3433-2 (PI) Controller Module

10
12

11

Type 3434-2 (PI) Controller Module

Oper. action

A

8

EB 7030 EN 5

Operation

Unfasten screws (3.3) and pull off the

4

connecting plate (3.2) together with nuts
and bolts from the controller module.
Unscrew the hexagonal socket-head

4

screws (3.4) at the side and lift the com
parator (3.1) out of the controller mod
ule.

Setting or modifying the air supply:

Unfasten screw in turnboard B and lift it

4

off together with the turnboard. If neces
sary, lever the board at the side.
Do not lose the rubber seal.
Turn the board so that the arrow is

4

aligned with the mark yA or R on the
controller module. Insert board and
tighten screw.
Reassemble the controller module in the

4

controller station.

2.1.3 Proportional-action
coefficient Kp

2.1.5 Rate time Tv

For Type 3433 Controller versions with de
rivative-action component, the rate time Tv
needs to be set at the restriction (11). The

­setting depends on the controlled system that

­is being tuned (section 3.1).

2.1.6 Operating point

­Controller modules without integral-action

component such as P or PD controllers have
an operating point. In Type 3433 Controller
Module, it can be adjusted between 0 and
100 % which corresponds to 0.2 to 1 bar by
an operating point adjuster (12). The setting
depends on the manipulated variable y (sec­tion 3.1.1).
In Type 3434 P Controller Module, the oper­ating point is fixed at 0.6 bar.

-

The setting of the KP(adjuster 9) determines
the controller gain and is related to the con­trolled system that is being tuned (section

3.1).

2.1.4 Reset time Tn

Controller versions with integral-action com
ponent require the reset time to be set at the
restriction (10). The setting depends on the
controlled system that is being tuned
(section 3.1).

6 EB 7030 EN

-

2.2 Setting the limit switches

Only applies to controller stations with the
limit switch option:
To set the limit switches, first release the lock
(4, Fig. 2) and open out the indicating unit
(5). The contacts can be accessed at the
back.

Adjust proximity switches by placing a
screwdriver in the clamps between 0 and
100 % of the reference scale and move until
a contact is made over the connected switch
ing amplifier.

Clamps with proximity switch

Operation

-

Fig. 3 · Limit switches

EB 7030 EN 7

Commissioning

3 Commissioning

Prior to commissioning the control loop,
check all devices to make sure they are con
nected correctly, do not leak and function
properly.
Release lock (4) and open out the indicating
unit (5) to enable easy access to the operat
ing controls at the controller.
Check the turnboard to make sure the cor

­rect operating action is set at the controller
(see section 2.1.1).

3.1 Tuning the controller

The controller needs to be tuned to the char­acteristics of the controlled system using the

and Tnand/or Tvadjusters at the control-

K

P

ler module to ensure that the controller can
keep any system deviations for all set points
caused by the disturbance variables to zero
or at least to minimize them.

In case of controller stations which have a
manual/ automatic switch (1.6), the plant
must be started up manually.

We recommend to determine the settings by
using a tuning test (following the Ziegler and
Nichols method) which produces sufficient
results in most cases:

1. Apply supply air (1.4 ±0.1 bar).

2. Set the proportional-action coefficient K

to a low value at the comparator.

3. Set T

restrictor to its maximum value

n

and T

to its lowest value (applies only to

v

PI and PID controllers).

1.8

1.6

-

1.5

1.7

-

1.3 Actual value pointer (red)

1.4 Set point adjuster with green pointer

1.5 Signal pressure display

1.6 Manual/automatic switch

1.7 Adjuster for signal pressure (manual)

1.8 Differential pressure indicator
4 Lock
5 Indicating unit

Fig. 4 · Front view

Setting in manual mode:

4. Set manual/automatic switch to Manual.

5. Operate manual adjuster (1.7) for the
control signal so that the controlled vari­able (actual value pointer 1.3) slowly
settles on the adjusted set point (set point
pointer 1.4).
Should the differential pressure indicator
(1.8) move to zero, set the manual/auto
matic switch (1.6) to Automatic.

P

Proceed as described in points 6 and 7.

Setting in automatic mode:

4. Set the set point to the required value at
the rotary knob (1.4) on the indicating
unit.

5. Set the T

restriction briefly to its lowest

n

value (completely open) to move the red

1.3

1.4
4
5

-

8 EB 7030 EN

Commissioning

–

actual value pointer to the green set
point pointer. Close the T

restriction

n

again.

6. Starting from a low value, increase the
proportional-action coefficient K

P

until
the actual value pointer displays an har
monic oscillation pattern (uniform oscil
lation amplitudes as shown in Fig. 5) of
the controlled variable.
If oscillations do not arise with a large
K

setting, turn the rotary knob to

P

change the set point slightly and then re
turn it to its former setting. It may be
necessary to increase the gain (K

)

P

slightly until an harmonic oscillation pat­tern arises.

7. Write down the adjusted value of the K
scale you have just adjusted as the criti­cal proportional-action coefficient K

Pkrit

Use a stopwatch to time the oscillation
time for one entire oscillation as T

krit

(PI

and PID controller only).

Controlled variable
(actual value)

Tkrit

+

Tkrit

Cntr. K

P 0.50 · K

PI 0.45 · K

PID 0.59 · K

Fig. 5 · Harmonic oscillation, settings

P

P,krit

P,krit

P,krit

T

n

0.85 · T

0.50 · T

T

v

krit

0.12 · T

krit

Multiply both values with the values in
the table (Fig. 5) and set as the favor
able settings for K

, Tn, and Tvat the

P

controller.
Should oscillations still occur despite these
settings, slightly reduce K

­Repeat these steps, if necessary, until the

­control loop shows a satisfactory perfor

and increase Tn.

P

mance. Leave enough time in between set
ting to allow the controller to stabilize.

3.1.1 Setting the operating point in

-

P and PD controllers

(Type 3433 Controller Module only)
After setting the proportion-action coefficient

as described previously, set the operating

K

P

P

point for P and PD controllers instead of the

.

reset time T

Read off the controlled variable yA of the

4

.

n

controller at the display (1.5) when the
plant is in a steady-state condition and
set this value directly at the operating
point adjuster (12, Fig. 2). (Setting 0.2 to
1 bar = 0 to 100 %).
Recorrect slightly until the system devia

4

tion is zero. In case the signal pressure
display deviates, average the value.

Note!

On changing set point or reference variable,
the operating point must be set again as de
scribed above.
If the reference variable is changed more of
ten, set the operating point to 0.6 bar =
50 % (average value).

krit

-

-

-

-

-

-

EB 7030 EN 9

Commissioning

Note!

restriction must be completely opened

The T

n

with a P/PI controller is switched over to P
action to allow the operating point adjuster
to work without delay.

Version with w-dependent operating point

This version does not need to be adjusted
since the operating point automatically fol
lows the set point w.

-

3.2 Smooth automatic/manual
mode changeover

(only for controller station with manual/au­tomatic changeover, Fig. 4)

The smooth switchover ensures that no pres­sure surges can reach the valve when the
manual/automatic switch is activated as fol­lows:

Changeover from automatic to manual

Use the manual adjuster (1.7) to adjust
signal pressure manual yH until the differen
tial pressure indicator (1.8) is zero. Switch
over to manual at the switch.

Differential pressure indicator

With Without deviation

adjuster (1.4).
The switch (1.6) can only be set to automatic
after the differential pressure indicator (1.8)
is at zero.

Set the set point again to the required value.

3.3 Smooth changeover between
the internal and external re
ference variable

When combining the fixed set point control
and follower control, the Type 3432 Con
troller Station is equipped with a w
switch, a pressure adjuster and a differential
pressure indicator (Fig. 10).
The differential pressure indicator must first
be brought to zero by activating the pres­sure adjuster in order to switch between the
reference variables.

3.4 Readjusting the controller’s
zero point

Should deviations arise between the actual
value and set point during operation, the
zero point adjustment can be readjusted by

­turning the zero screw at the back of the dis

play unit (5) until the actual value and set
point on the front display are the same
again.

Deviations between the actual value and set
point can also be corrected at the zero point
adjuster (8, Fig. 2) of the controller module.

-

-

int/wext

-

Changeover from manual to automatic

If the plant is to be controlled manually to
the required value, the automatic signal
pressure yA must be matched to the manual
signal pressure yH by adjusting the set point

10 EB 7030 EN

Construction

4 Construction

The controllers designed according to the
modular principle form an entire automation
unit consisting of a controller station, a con
troller module tuned to the local conditions,
and, where applicable, a transmitter as well
as other additional modules.

Controllers with Type 3432 Controller Sta
tion are mainly designed for installation of a
Type 3435 Transmitter Module for Pressure
or a Type 3436 Transmitter Module for
Temperature with direct process fluid con
nection.
The Type 3431 Controller Station receives
the controlled variable as a standardized
signal from 0.2 to 1 bar or 3 to 15 psi. The
controlled variable can also be supplied as
a current signal from 4 or 0 to 20 mA or
1 to 5 mA over an integrated i/p converter.

The controller station can be equipped with
the Type 3433 or Type 3434 Controller
Module.
For special control applications, the Type
3433 Controller Module can be combined
with Type 3437 Additional Modules for
pressure limitation, control mode switchover
or smooth manual/automatic transfer.
The controller station can also be upgraded,
if required, with a manual/automatic trans
fer, consisting of a selector switch, adjuster
for manual mode, and differential pressure
indicator.
The controller station must be equipped with
an additional module for w

int/wext

over when used for applications as a com
bined fixed set point controller and follower
controller. An additional pneumatic or elec
tric output for the external reference variable

(e.g. 0.2 to 1 bar or 4 (0) to 20 mA)

w

ext

change

-

-

-

-

is likewise required when used as a follower
controller. Additionally, inductive limit
switches, that are adjustable at a scale, can
be mounted on the indicating units 1 or 2.

-

Note! Refer to the corresponding Data
Sheets for details about the controller sta
tions and their controller modules.

T 7030 EN · Pneumatic Indicating
Controllers - Information Sheet with product
overview.

T 7032 EN · Pneumatic Indicating
Controllers for Pressure

T 7034 EN · Pneumatic Indicating
Controllers for Temperature with Capillary
Sensor

T 7036 EN · Pneumatic Indicating
Controllers for Temperature with Pt 100
Resistance Thermometer

T 7038 EN · Pneumatic Indicating
Controllers for Standardized Signals

T 7040 EN · Type 3433 Pneumatic
Controller Modules and Type
3437Additional Modules

T 7041 EN · Type 3434 Pneumatic
Controller Modules

T 7045 EN · Type 6112 i/p Converter

-

Module

5 Principle of operation

5.1 Transmitter modules

Type 3435 for Pressure

The process fluid pressure p is transmitted to

-

the transmitter module (2) where it causes a
deflection at the Bourdon tube measuring

-

EB 7030 EN 11

Principle of operation

system (2.1). The deflection is converted by
the pneumatic servo system (2.2) into a
pneumatic signal (controlled variable x)
which is proportional to the pressure p. The
signal is transferred to the bellows measur
ing system of the actual value display (1.3)
as well as to the controller module (3).

Type 3436 for Temperature with capillary
sensor

The temperature of the medium produces a
pressure in the gas-filled sensor (2.3) of the
transmitter module which is proportional to
the temperature. This pressure is offset by a
force on the beam (2.4) and converted into
the output pressure p

at the feedback bel-

A

lows (2.6).
The supply air flows over the restriction (2.9)
and nozzle (2.8) and hits the flapper (2.7).
As the temperature rises, the flapper moves
closer to the nozzle. This results in an in­crease in output air pressure p

supplied to

A

the bellows (2.6) until a new state of equilib­rium is reached, i.e. until the output signal is
proportional to the temperature measured.
This signal is transmitted as the actual value
signal (controlled variable x) to the bellows
measuring system of the actual value display
(1.3) and the controller module (3).

Type 3438 for Temperature with Pt 100 re
sistance thermometer

The Type 3438 Transmitter Module consists
of an electric transmitter and a downstream
i/p converter to connect a Pt 100 sensor.
The resistance value of the Pt 100 sensor is
converted into a 4 to 20 mA current signal
in the electric transmitter. Its output signal (4
to 20 mA) is converted into a pneumatic sig
nal between 0.2 and 1 bar by the i/p con
verter. The output pressure, which is propor
tional to the temperature, is supplied to the

bellows measuring system of the controlled
variable display and the controller module
as a pneumatic controlled variable signal
(controlled variable x).

-

5.2 Controller station

The actual value signal x causes a deflection
at the bellows measuring system of the ac
tual value display (1.3) which is transmitted
to the pointer over a gear mechanism.
The set point (reference variable w) can be
adjusted at the scale (1.2) on the front. The
position of the set point adjuster (1.4) is
transmitted to the set point transmitter over a
gear mechanism. This pneumatic servo sys­tem (1.41) converts the adjusted set point
into a pneumatic set point signal (w) which
is transmitted to the controller module.
The controller module compares the actual
value signal (x) with the set point signal (w)
and controls using the control signal yA de­pending on the system deviation and the ad­justed control parameters. The control signal
is connected to the signal pressure display
(1.5) and the output port y.
The controller station with manual/auto
matic switchover (Figs. 2 and 4) additionally
features a manual/automatic switch (1.6),

-

an adjuster for manual mode (1.7), and a
differential pressure indicator (1.8).
Signal pressure display (1.5) and output
port y are connected to the automatic output
signal y
matic” and to the manual output signal y
set at the adjuster (1.7) with a switch posi
tion at “Manual”.

-

A smooth switchover from manual to auto

-

matic mode is possible when the differential

-

pressure indicator (1.8) shows that y
y

H

with a switch position at “Auto

A

are identical.

-

-

-

H

-

-

and

A

12 EB 7030 EN

Principle of operation

1.5 31.2

1

y

w

1.4 1.31.41 1.5 31.2 1.4 1.31.41

R
w

PI

z

P

A

y

PPI

/

PID

S
x

2.1

2

y

Z

2.2

Type 3432 with Type 3435 Transmitter for Pressure

1.5

1

y

w

1.2 1.4 1.3

3

R
w

PI

z

P

A

y

PPI

/

S

PID

x

Zx

Type 3431 and 3432 for pneumatic standardized signals

1 Controller station

1.2 Scale

1.3 Actual value display with pointer,
gear mechanism and bellows
measuring system

1.4 Set point adjuster with pointer,
gear mechanism and set point (1.41),
set point display only for follower
controllers

1.5 Signal pressure display

1.8 Differential pressure indicator
for smooth manual/automatic
switchover

1.9 Supply pressure regulator

2 Transmitter module

2.1 Bourdon tube meas. system

2.2 Pneumatic servo system

2.3 Temperature sensor

2.4 Beam

2.6 Feedback bellows

Fig. 6 · Principle of operation of controllers

1

2.4

2.6

2.3

wxwx

w

R
w

PI

z

P

y

A

PPI

/

PID

S
x

2.7

Z

y

2.9 2.8

Type 3432 with Type 3436 Transmitter for Temperature

y

A

w

1.21.41 1.4 1.3 3
w

xwx

R
w

PI

z

P

A

y

PPI

S

PID

x

x

/

1.6

1.5

1.7

1.8

y

H

S

y

H

4

Z

1

1.9
P

B

y

x

Type 3432 with manual/automatic switch (1.6),

supply pressure regulator (1.9) and i/p converter

2.7 Flapper

2.8 Nozzle

2.9 Restriction
3 Controller module
4 Type 6112 i/p Converter

 Z = Supply pressure 1.4 bar

= Output pressure

P

A

= Compressed air network

P

B

EB 7030 EN 13

Principle of operation

5.3 Controller modules

The controller modules are designed as
plug-in units. They are inserted into the
self-sealing hose fittings of the controller sta
tion and fastened in place by mounting
screw.

5.3.1 Type 3433 Controller
Modules

The controller modules consist of the com
parator equipped with four metal bellows
arranged in a square and the base plate
with plug-in connections. The base plate
contains the components necessary for the
corresponding function such as relays and
restrictors. The components can be ex­changed or retrofitted to upgrade a device
(refer to section 9.1 for more details).

Type 3433-2 PI Controller (Fig. 7, top)
The controlled variable x (actual value) and

the reference variable w (set point) are
transmitted as pneumatic signals between

0.2 and 1 bar to metal bellows w und x

over the turnboard A. When x is greater
than w, the actual value bellows tilts the
swashplate at its pivot towards the set point
bellows. This causes the pressure to rise
downstream of the nozzle which is con
nected to the swashplate over a pin and, as
a result, the comparator increases the output
pressure y

. The output pressure is fed back

A

over turnboard B to the bellows R2 on the
swashplate.
The pressure and the position of the
swashplate continue changing until the dis
tance between the nozzle and flapper
achieve the initial value and the output pres

-

-

-

sure y

reaches the value related to the con

A

trolled variable x and the proportional-ac
tion coefficient K

Outside of the controller module, y

­nected to R, meaning that the output pres

sure y

is also fed back to bellows R1 over

A

port R and the adjustable T

set at the screw.

p

restriction. As a

n

result, the effect caused by the pressures in
bellows R1 and R2 is balanced and system
deviation is eliminated.

Should a switching pressure exist at port S
after switching the controller station to man
ual mode, the T

start-up relay.

the T

n

restriction is bypassed by

n

Turnboard A determines the operating
action of the controller which can be
changed by turning the board. Refer to sec­tion 2.1.1.

Turnboard B determines the air supply to
the feedback bellows.
In delivered state, it is set to y

, i.e., the

A

output pressure is directly fed back to bel­lows R2, whereas, it is fed to bellows R1
over the manual control unit to port R. This
arrangement provides the controller with a
normal air supply and a damping of the out
put pressure.
Setting it to R results in the output pressure

being fed back to bellows R1 and R2

y

A

over port R which provides a higher air sup
ply.
This type of turnboard setting is suitable for
applications where the distance to the final
control element is long and the connected
volume is large as well as where controlled
systems react quickly. Refer to section 2.1.2
to set or change the air supply by turning
the turnboard B.

-

is con

A

-

-

-

-

-

-

-

14 EB 7030 EN

0.2

Kp

20

0.2

Kp

20

Principle of operation

Type 3433-2 PI Controller Module

The following versions of the controller mod
ules are similar in most aspects to the
Type 3433-2 PI Controller Module, how

­ever, they are fitted with, for example, an
operating point adjuster, derivative element,
or a selector switch, depending on the
application.

Type 3433-1 P Controller Module

corresponds to Type 3433-2.
An operating point adjuster is used in place
of the integral element.

-

R Feedback
R1/R2 Feedback bellows
 Z = Supply air 1.4 bar

Output pressure

Y

A

S Switching pressure

Fig. 7 · Type 3433 Controller Modules

A Operating action
B Air supply

Turnboards

0.2

Kp

20

Type 3433-3 PID Controller Module

corresponds to Type 3433-2.
Additionally, it contains a derivative element
which produces the rate action with approx
imately ten times the gain in the input
branch of the controlled variable x. The rate
time can be adjusted at the T

restriction.

V

EB 7030 EN 15

-

Principle of operation

Type 3433-4 PD Controller Module

corresponds to Type 3433-1.
Additionally, it contains a derivative element
which produces the rate action with approx
imately ten times the gain in the input
branch of the controlled variable x. The rate
time can be adjusted at the T

restriction.

V

Type 3433-5 P/PI Controller Module

with P/PI selector switch can optionally be
used as a P controller with operating point
adjustment or as a PI controller.
The structure is the same as that of the PI
and P controller module.
Type 3433-6 PD/PID Controller Module
with PD/PID selector switch can optionally
be used as a PD or PID controller.

0.2

-

Kp

20

0.2

Kp

20

Type 3433-9 P Controller Module

with set point-dependent operating point
corresponds to Type 3433-1 P Controller
Module, except that the operating point
shifts proportional to the set point w.

16 EB 7030 EN

0.2

Kp

20

Fig. 8 · Type 3433 Controller Modules