Page 265 - Bürkert

Digital electropneumatic positioner

8791 Basic version

• Compact metal body
• Easy to start using tune function
• Dynamic positioning system
with high air performance
• Extensive additional software functions
via communication software configurable
• Mounting according to IEC 534-6/VDI
VDE 3845

The robust and compact positioner is designed to a standardisation Dimensions [mm] (see datasheet for more details)
acc. to IEC 534-6 or VDI/VDE 3845 for assembly with linear and rotary
actuators. In addition, the remote version with the displacement position
sensor can be combined with Bürkert process control valves.
A
The setpoint setting for the electro-pneumatic digital Positioner SideCon-
trol BASIC occurs using a standard signal 4-20 mA or with AS-Interface
as an option. In addition there is a binary input and an optional analogue
feedback available.
The valve opening is signalled by a mechanical indicator element and the C
device status is shown on three coloured LEDs. All the operational ele-
ments are found in the housing .
The start-up happens automatically, and directly at the device the follow- B
ing functions by a DIP switches are activated:
- Close tight function A B C
- Inversion of the operating direction of the setpoint signal 171.1 77 144.6
- Characteristic curves selection
- Switching - manual and automatic operation
Additional possibilities on configuration and parameter setting, for exam-
ple, linearisation of the operation characteristics by using communications
software which allows customised programming.
The pilot valve system can be used equally for single and double-acting
drives. It is characterised by a defined safety feature in case of failure of Technical data (continued)
the electrical or pneumatic power supply and possesses an enormous air Threaded ports G 1/4”
capacity range with pressure supply up to 7 bar. Pilot air ports
Supply pressure 1.4 to 7 bar 1)
Air supply filter Exchangeable (mesh aperture ~0.1 mm)
Technical data Actuator system Single and double-acting up to 150 lN/min.
2
Air capacity 95 lN/min (with 1.4 bar ) for aeration and ventilation
Material 150 lN/min (with 6 bar ) for aeration and ventilation
2
Body Aluminium plastic-coated (QNn = 100 lN/min (acc. to the definition with de-
Seal EPDM, NBR, FKM crease in pressure from 7 to 6 bar absolute)
Operating voltages 24 VDC +/-10%
Position detection Potentiometer max. angle 180°
Residual ripple Max. 10% module
Setpoint setting 4-20 mA Stroke range valve Min. 30º on the rotary shaft, depending on lever
(0-20 mA adjustable using configurations software) spindle
Input resistance 0/4-20 mA: 180 Ω Installation As required, display above or sideways
Analogue feedback 4-20 mA (0-20 mA adjustable using configurations Type of protection IP 65/67 acc. to EN 60529 (NEMA 4x in prepara-
software, max. Burden 560 Ω) tion)
Binary input 0-5 V = log “0”, 10-30 V = log “1” Power consumption < 3.5 W
Control medium Neutral gases, air DIN ISO 8573-1 Electrical connection
Dust concentration Class 5 (<40 µm particle size) Multipole connection M12, 8-pin
Particle density Class 5 (<10 mg/m ) 3 Cable gland 2xM20x1.5 (cable Ø 10 mm) on screw terminals
Pressure condensation Class 3 (<-20 °C) (0.14-1.5 mm )
2
point Remote Version 1xM12x1.5 (cable Ø 3 to 6.5 mm)
Oil concentration Class 5 (<25 mg/m ) 3
1) The supply pressure has to be 0.5-1 bar above the minimum required pilot pressure for the
Ambient temperature 0 °C to +60 °C
valve actuator
2) Pressure values [bar]: Overpressure with respect to atmospheric pressure
264