User Instructions - Logix® 520MD+ Series Digital Positioner
FCD LGENIM0105-00
© Flowserve Corporation 34 Field Trial Version – Printed October 28, 2011
13 LIMIT SWITCHES
13.1 Limit Switch Principles of Operation
The Logix 520MD+ digital positioner can be equipped with
a limit switch unit. The unit has two main parts, the
electrical switch board and the vane. The switch board is
connected to the Inner cover. The vane connects to the
feedback shaft which extends through the positioner and
moves with the valve. The vane can hold a cam or
ferromagnetic device. As the shaft rotates, the pick-up
switch LS1 or LS2 is activated. The switching point can be
adjusted.
Four types of Limit Switches can be used with the Logix
520MD+.
13.2 Limit Switch Types
Mechanical switches are triggered by the use of a
mechanical cam and followers.
Reed switches are triggered by a magnetic force. No
physical contact occurs.
Inductive Slot switches are triggered when the sensor
detects a ferromagnetic vane inserted between the coils.
No physical contact occurs.
Inductive switches are triggered when the sensor detects a
ferromagnetic vane approaching the coils in the switch. No
physical contact occurs.
Table 18: Limit Switch Cross-References
Information IOM Section
Electronic
Connections
3.10 Limit Switch
Specifications
Electronic
Specifications
7.10 Limit Switches
Install or Adjust the
Limit Switch
16.2 Installing a Limit Switch
Figure 20: Limit Switches
Limit
Switches
To Next Page
Loading...
Need help?
General
