ABB Electro-Pneumatic Positioner TZIDC

Description

The TZiDCis anelectronicallyconfigurable positioner with

communication capabilities designed for mounting to pneumatic

linear or rotary actuators. lt features a small and compact design, a

modular construction, and an excellent cost-performance ratio.

Fully automatic determination of the control parameters and

adaptation to the final control element yield considerable time savings

and an optimal conirol behavior.

1.1

Pneumatics

An |/P module with subsequent pneumatic amplifier is used to control

the pneumatic actuator. The well-proven IP module proportionally

converts the permanent electrical positioning signal from the CPl

into a pneumatic sianal used to adjust a 3/3-way valve.

The air flow for pressurizing or depressurizing the acuator is

continuously adiusted,As a result, excellent control is achieved

When reaching the set point, the 3/3-way valve is closed in centei

position to minimize the air consumption.

Four different pneumatics versions are available: for single-acting or

double-acting actuators, each with "fail-safe" or "fail-freeze" function.

1.1.2

*Fail-freeze* function

lf the electrical power supply should fail, the positioner output i (and

2,if applicable)is closed and the pneumatic actuator stops

"freezes")the valve in the current position. lf compressed air supply

should fail.the positioner depressurizes the actuator.

1.2

Operation

The positioner has a built-in operating panel providing a 2-ine LCD

and 4 pushbuttons for optimal local configuration, commissioning ano

operational monitorng.

Alternatively, the appropriate configuration program and the available

communication option can be used.

1.3

Communication

The standard TZlDC model has a local communication interface (LKS

connector).Additionally,aHART communication"option fo

communication via the20mAsignal is available. Both

communications are based on the HART Protocol.

“Fail-safe* function

If the electrical power supply fails,the positioner output 1 is

depressurized, and the pneumatic actuator's return spring moves the

valve to the defined safe position. in case of a double-acting actuatoi

the second output 2 is additionally pressurized

1.4

Inputs and outputs

In addition to its input for the analog position set point the TZlDC

positioner is equipped with a digital input which can be used to

activate various protective functions in the device via the process

control system. A diqital output allows you to output collective alarms

or fault messages.

1.5

Modular design

The TZlDC basic model can be enhanced at any time by retrofitting

optional equipment. Option modules for analog or digital position

feedback or a shutdown-module can be installed. Additionally, a

mechanical positionindicator,proximity switches or24 v

microswitches are available for indicating the position independently

of the mother board function.