Emerson Fisher L2 User Manual

www.Fisher.com
Fisherr L2 Liquid Level Controller
Contents
Introduction 1.................................
Scope of Manual 1.............................
Description 3.................................
Specifications 3...............................
Education Services 3...........................
Installation 4..................................
Attaching Vertical Displacer 4...................
Attaching Horizontal Displacer 4.................
Attaching the Sensor to the Vessel 5.............
Pressure Connections 5........................
Vent 6.......................................
Changing Controller Action or Mode 6.............
Throttling and On/Off Controllers 6..............
Snap‐Acting Controller 6.......................
Span Adjustment 8.............................
Preliminary Checks 8...........................
Direct‐Acting Throttling Controllers 9............
Reverse‐Acting Throttling Controllers 9...........
Direct‐Acting On/Off and
Snap‐Acting Controllers 9....................
Reverse‐Acting On/Off and
Snap‐Acting Controllers 9....................
Principle of Operation 10........................
Maintenance 11................................
Removing the Controller From the Sensor 11........
Replacing the Sensor O‐Rings 11.................
Disassembly 11............................
Assembly 13..............................
Replacing the Controller Relay 13................
Replacing the Controller Supply Filter 13..........
Figure 1. Fisher L2 Liquid Level Controller
W8418‐1
Related Documents 14..........................
Parts Ordering 14...............................
Parts Kits 14...................................
Parts List 14...................................
Controller 14.................................
Sensor 16....................................
Introduction
Scope of Manual
This instruction manual includes installation, adjustment, maintenance, and parts ordering information for the Fisher
L2 liquid level controller.
Do not install, operate or maintain an L2 Liquid Level Controller without being fully trained and qualified in valve,
actuator, and accessory installation, operation, and maintenance. To avoid personal injury or property damage, it is
important to carefully read, understand, and follow all contents of this manual, including all safety cautions and
warnings. If you have any questions about these instructions, contact your Emerson Process Management sales office
before proceeding.
Instruction Manual
D103032X012
L2 Controller
July 2015

Emerson Fisher L2 Specifications

General

Category	Controller
Body Material	Aluminum
Type	Level Controller
Ambient Temperature Range	-40 to 180 °F
Connections	1/4-in. NPT

Summary

Specifications

Displacer Material and Maximum Sensor Working Pressure

Installation

Attaching a Vertical Displacer

Attaching a Horizontal Displacer

Attaching the Sensor to the Vessel

Pressure Connections

Changing Controller Action or Mode

Throttling and On/Off Controller

Procedure for changing control action and mode for throttling and on/off controllers.

Snap-Acting Controller

Procedure for changing control action for snap-acting controllers.

Span Adjustment

Preliminary Checks

Essential checks to perform before adjusting the span.

Direct-Acting Throttling Controllers

Reverse-Acting Throttling Controllers

Direct-Acting On/Off and Snap-Acting Controllers

Reverse-Acting On/Off and Snap-Acting Controllers

Principle of Operation

Maintenance

Removing the Controller From the Sensor

Step-by-step instructions for safely removing the controller from the sensor.

Sensor O-Ring Replacement

Procedure for replacing sensor O-rings, including disassembly steps.

Assembly