Special Designs; Control Head For Double-Acting Actuators; Anomalies; Fluid Diagram - Burkert 8681 Operating Instructions Manual

Control Head Type 8681
Specialdesigns
15.

SPECIAL DESIGNS

15.1.

Control head for double-acting actuators

This design is configured for double-acting actuators. Of the two internal solenoid valves, one is designed for NC
mode of operation and the other for NO mode of operation.

15.1.1. Anomalies

This design can be configured for all electrical designs.
This control head differs from control head Type 8681 (standard) in the following points:
• Solenoid valve 1: NC / Normally Closed;
Solenoid valve 2: NO / Normally Open (as a result safety position)
• The flow rate from P to A2 may be restricted to 50 l/min only, otherwise a reliable
switchover (from A2 to R) cannot be guaranteed!
• only Autotune function 1 and 2 possible

15.1.2. Fluid diagram

See "Fig. 3: Fluid diagram (design for double-acting actuators: 2 solenoid valves, NC* + NO** )" on page 16.

15.1.3. Activation of a double-acting actuator

To open or close the process valve, both solenoid valves (V1 and V2) must be activated simultaneously:
Process valve
Solenoid valve (V)
Open Y1 = ON
Close Y1 = OFF
For further information on the electrical installation and programming, see the relevant chapters for the individual
standard designs:
24 V - design: "10. 24 V DC - Design" on page 36,
AS-i - design: "11. AS Interface - Design" on page 43,
DVN - design: "12. DeviceNet - Design" on page 52,
120 V - design: "13. 120 V AC - Design" on page 65.
24 V / 120 V
V1 V2
Y2 = ON
Y2 = OFF
AS interface
V1 V2
D0 = 1 D1 = 1
D0 = 0 D1 = 0
English
DeviceNet
V1 V2
Bit0 = 1 Bit1 = 1
Bit0 = 0 Bit1 = 0
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