Inst ToolsInst ToolsInst Tools
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Erection & Commissioning
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
  • Request
Search
  • Books
  • Software
  • Projects
  • Process
  • Tools
  • Basics
  • Formula
  • Power Plant
  • Root Cause Analysis
  • Electrical Basics
  • Animation
  • Standards
  • 4-20 mA Course
  • Siemens PLC Course
Reading: Define Normal Status for each of the Process Switch
Share
Notification Show More
Font ResizerAa
Inst ToolsInst Tools
Font ResizerAa
  • Courses
  • Design
  • PLC
  • Interview
  • Control System
Search
  • Courses
  • Automation
    • PLC
    • Control System
    • Safety System
    • Communication
    • Fire & Gas System
  • Instrumentation
    • Design
    • Pressure
    • Temperature
    • Flow
    • Level
    • Vibration
    • Analyzer
    • Control Valve
    • Switch
    • Calibration
    • Erection & Commissioning
  • Interview
    • Instrumentation
    • Electrical
    • Electronics
    • Practical
  • Q&A
    • Instrumentation
    • Control System
    • Electrical
    • Electronics
    • Analog Electronics
    • Digital Electronics
    • Power Electronics
    • Microprocessor
  • Request
Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Inst Tools > Blog > Switches > Define Normal Status for each of the Process Switch

Define Normal Status for each of the Process Switch

Examine process switches normal status, such as pressure switch, level switch, temperature switch, and flow switch.

Last updated: September 27, 2020 11:20 am
Editorial Staff
Switches Practical Questions
No Comments
Share
2 Min Read
SHARE

Switches, whether they be hand-actuated or actuated by a physical process, come in two varieties: normally-open (NO) and normally-closed (NC).

You are probably accustomed to seeing both types of switch represented in the pushbutton form on schematic diagrams:

Normally-open pushbutton switches

Normally-open pushbutton switches close (pass current) when actuated (pressed). When un-actuated, they return to their “normal” (open) state.

Normally-closed pushbutton switches are just the opposite: they open (stop current) when actuated (pressed) and return to their “normal” (closed, passing current) state when un-actuated.

This is simple enough to comprehend: the “normal” status of a momentary-contact pushbutton switch is the state it is in when no one is touching it. When pressed, the pushbutton switch goes to the other (opposite) state.

Things get more confusing, though, when we examine process switches, such as pressure switches, level switches, temperature switches, and flow switches:

Process Switch

Process Switches Normal Status

Define “normal” for each of these process switches. In other words, explain what condition(s) each process switch must be in to ensure it is in the “normal” state; and conversely, what condition(s) need to be applied to each switch to force it into its other state.

Answer:

The “normal” condition for a process switch is the condition of the least stimulus.

For example:

  • A pressure switch will be in its “normal” state when there is minimum pressure applied.
  • A level switch will be in its “normal” state when there is no level detected by the switch.
  • A temperature switch will be in its “normal” state when it is cold.
  • A flow switch will be in its “normal” state when there is no flow detected by the switch.

Read Next:

  • Design of Switch Contact
  • Make/Break Sequence
  • Diode Switching Circuits
  • PLC Switch Example
  • Transistor Switch Principle

Credits: Tony R. Kuphaldt

Don't Miss Our Updates
Be the first to get exclusive content straight to your email.
We promise not to spam you. You can unsubscribe at any time.
Invalid email address
You've successfully subscribed !

Continue Reading

Differential Pressure Transmitter with 5 Way Manifold Valve
Calculate Process Temperature using a Thermocouple
Basics of Limit switches
Draw Wiring of a Pressure Switch to control two lamps
Find Thermocouple Ouput Voltage
Analytical Process Control Question
Share This Article
Facebook Whatsapp Whatsapp LinkedIn Copy Link
Share
Leave a Comment

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Stay Connected

128.3kFollowersLike
69.1kFollowersFollow
210kSubscribersSubscribe
38kFollowersFollow

Categories

Explore More

Practical Process Control System Questions & Answers – 4
Hydrostatic Level Measurement – Temperature related Density Change Effects
Question on Remote Seal with Capillary Tubing Transmitter
Hydrostatic Pressure Measurement Questions
Magnetic Proximity Detectors – Types, Principle, Advantages
Proximity switches Circuit Diagram Operation
Pull Up and Pull Down Switch Circuits
Solenoid-controlled Valve Problem

Keep Learning

Tank uses 3 Pressure Transmitters to Measure Level & Density

Tank uses 3 Pressure Transmitters to Measure Level & Density

Applications of Tilting Level Switch

How Tilt Level Switch Works ?

Calculate Hydraulic System Fluid Pressure

Calculate Hydraulic System Fluid Pressure

Steam flow to the heat exchanger

Analytical Control System of Heat Exchanger Questions

Allen-Bradley MicroLogix 1000 controller

PLC Switch Actuation Status

Mechanical Vibration Switch

Vibration Switch Working Principle

PLC Circuit with Switches

PLC Example with Switches

A Question on Density Gauge

Learn More

Pressure Measurement

How to Measure Pressure in Inches of Water Column

Magnetostrictive Transducers Objective Questions

Magnetostrictive Transducers Objective Questions

PLC Programming Example on Bottle Line Control

PLC Programming Example on Bottle Line Control

psv-principle-of-operation

Instrumentation Inspection Report

PLC Program for motor operation based on time cycle

PLC Motor Operation based on Time Cycle Sequence – Program

On Delay Timer using PLC

ON Delay Timer using PLC

How to Program Sequential Outputs in PLC

Timer-Based Sequential PLC Program with One Button

Moisture and Dew Point Analyzer Problems

Moisture and Dew Point Analyzer Problems and Troubleshooting Tips

Menu

  • About
  • Privacy Policy
  • Copyright

Quick Links

  • Learn PLC
  • Helping Hand
  • Part Time Job

YouTube Subscribe

Follow US
All rights reserved. Reproduction in whole or in part without written permission is prohibited.
Welcome Back!

Sign in to your account

Username or Email Address
Password

Lost your password?