Fisher 2502 Series Level-Trol User Manual

D200126X012
250 2 S erie s L evel-Trol

C ontroller
Contents
Introduction 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Scope of Manual 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Description 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Specifications 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controller Action 2. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Installation%2
249 Series Sensors 2. . . . . . . . . . . . . . . . . . . . . . . . . .
Uncrating 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Controller Orientation 4. . . . . . . . . . . . . . . . . . . . . . . . .
Mounting Caged Sensors 4. . . . . . . . . . . . . . . . . . . . .
Mounting Cageless Sensors 5. . . . . . . . . . . . . . . . . . .
Side-Mounted Sensor 7. . . . . . . . . . . . . . . . . . . . . . .
Top-Mounted Sensor 7. . . . . . . . . . . . . . . . . . . . . . . .
Special Constructions 7. . . . . . . . . . . . . . . . . . . . . . . .
Temperature-Compensated Displacer 7. . . . . . . . .
Piezometer Ring 8. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Regulator Supply Pressure 8. . . . . . . . . . . . . . . . . . . .
Prestartup Checks 9. . . . . . . . . . . . . . . . . . . . . . .
Adjustments 10 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Level Set Adjustment 10. . . . . . . . . . . . . . . . . . . . . .
Proportional Band Adjustment 10. . . . . . . . . . . . . .
Reset Adjustment 10. . . . . . . . . . . . . . . . . . . . . . . . .
Differential Relief Adjustment 10. . . . . . . . . . . . . . .
Calibration 11 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Precalibration Requirements 11. . . . . . . . . . . . . . . . .
Wet Calibration 11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Dry Calibration 11. . . . . . . . . . . . . . . . . . . . . . . . . . .
Controller and Torque Tube Arm Disassembly 11
Determining Suspended Weight for Calibration 12
Calibration Procedure 12. . . . . . . . . . . . . . . . . . . . . .
Startup 13 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Principle of Operation 13. . . . . . . . . . . . . . . . . .
Type 2502 Controller 15. . . . . . . . . . . . . . . . . . . . . . .
Type 2502F Controller with Reset Relief Valve 15.
Figure 1. Type 2502 Controller Mounted on
Type 249B Sensor
W3121-3/IL
TYPE 249B SENSOR
TYPE 2502 CONTROLLER
Maintenance 15. . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Troubleshooting 16 . . . . . . . . . . . . . . . . . . . . . . . . . . .
Removing Controller from Sensor 16. . . . . . . . . . . .
Changing Mounting Method 18. . . . . . . . . . . . . . . . .
Installing Controller on Sensor 19. . . . . . . . . . . . . . .
Changing Proportional, Reset, or
Differential Relief Valve 19. . . . . . . . . . . . . . . . . . . .
Testing Relay Dead Band 19. . . . . . . . . . . . . . . . . . .
Changing Relay 20. . . . . . . . . . . . . . . . . . . . . . . . . . . .
Replacing Bellows 20. . . . . . . . . . . . . . . . . . . . . . . . .
Reversing Action 20. . . . . . . . . . . . . . . . . . . . . . . . . . .
Disassembling Relay 20. . . . . . . . . . . . . . . . . . . . . . .
Parts Ordering 21. . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts Kits 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Parts List 21. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Instruction Manual
Form 1446
June 1994
2502 Series

Fisher 2502 Series Level-Trol Specifications

General

Manufacturer	Fisher
Series	2502
Category	Controller
Type	Level-Trol
Accuracy	±1% of span
Output Signal	3-15 psi
Supply Pressure	20 psi
Ambient Temperature Range	-20 to 180°F (-29 to 82°C)
Materials	Aluminum, Stainless Steel

Summary

Prestartup Checks and Adjustments

Level Set Adjustment

Proportional Band Adjustment

Reset Adjustment

Controller Calibration Procedures

Precalibration Requirements

Wet Calibration Method

Procedure for calibrating the controller using process liquid.

Dry Calibration Method

Procedure for calibrating using simulated weights.

Controller and Torque Tube Arm Disassembly

Determining Suspended Weight for Calibration

Method to calculate substitute weights for dry calibration.

Principle of Operation

Type 2502 Controller Operation

Type 2502F Controller with Reset Relief Valve

Maintenance and Troubleshooting

Troubleshooting Guide

Guide to identifying and resolving common controller faults and issues.

Removing Controller from Sensor

Step-by-step instructions for detaching the controller from its sensor.

Changing Mounting Method

Installing Controller on Sensor

Changing Control Valves

Instructions for replacing proportional, reset, or differential relief valves.

Testing Relay Dead Band

Method to check the controller's relay for dead band issues.

Changing Relay Assembly

Steps for removing and reinstalling the controller's pneumatic relay.

Replacing Bellows

How to replace the bellows assembly within the controller.

Reversing Controller Action

Disassembling Relay

Detailed steps for taking apart the controller's relay for inspection or repair.