Digital Megger meter

How to Use a Megohmmeter ?

Meggers generate voltage to determine the high resistance value of insulation. Typically, the smallest value that a megohmmeter can supply is 1,000 volts, while some hand-crank meggers can supply as much as 10,000 volts or more through a small generator inside the meter. To run a megger test, follow these steps 

Step 1. Cut power

Make sure you eliminate any voltage running through the wires you want to test. 

Step 2. Uninstall wires 

Disconnect the wires you want to test from both ends of the circuit and all feeding wires in motors.

Step 3. Connect the ground lead

Connect one of the megger’s leads to a ground connection such as the wire insulation, the electrical frame, or the ground.

Step 4. Connect to conductor

Connect the other megger lead to the conductor such as the exposed copper of the wire or motor terminal.

Step 5. Build voltage

Crank the generator handle to build voltage. This could take anywhere from two to five seconds.

Step 6. Read meter

Determining a safe reading depends on what you’re testing. Generally, a reading should equal one megohm for each 1,000 volts of operating voltage. For a motor that has a 1,500 operating voltage, a perfect reading would be 1.5 megohms. A minimum reading should never be less than one megohm.

If the insulation resistance value is high. if 440 volts motor has an IR value of more than 1 Mega-ohm and above, it means motor winding insulation is good.

Step 7. Complete testing

Complete testing of remaining wires or terminals.

After the megger test of the motor, We must connect the winding to the earth in order to discharge the build-up voltage of the winding.

Digital Clamp meter description

Digital Clamp meter, Panel description and functions of the clamp meter

Transformer trigger (A): To open the jaws.

Select button (B):To select measurement modes such as current, voltage and resistance.

Relative button (C): To nullify the current reading, and to use a zero-reference value for all subsequent measurements.

COM terminal (D): Common reference input (GROUND).

Transformer jaw (E): To pick up a current signal.

Function selection (F): To choose the parameter to be measured (like alternating current (AC), direct current (DC), AC and DC voltages, resistance and continuity).

Liquid crystal display (G): To show the results of measurement, function symbols and their units, low battery symbols, and max/min value of signals.

Data hold (H): To freeze the current reading on the LCD.

VΩ Input terminal (I): Input for voltage, resistance, continuity, or frequency measurements.

Digital Clamp meter

How to measure current with a clamp meter ?

Steps for measuring ac or dc current using a clamp meter's jaws:

Pre-measurement steps (to avoid electrical shock or personal injury):

• Disconnect test probes from the meter.
• Keep fingers behind tactile barrier on face of meter.

1. Turn the dial to the proper function, either A ac or A dc. You should see the jaws icon (  ) in the display, indicating that the measurement is coming from the jaw.
2. Note: When the measured current is < 0.5 A, the center dot in the display icon (  ) will flash on and off. When current is > 0.5 A, the center dot will be steady.
3. Before taking dc current measurements (if your meter is equipped to do so): Wait for the display to stabilize, then push the Zero button to ensure correct readings. Zeroing the meter removes dc offset from the reading. The Zero function works only when the dial is set in in the dc current measurement position.
4. Note: Before zeroing the meter, make sure the jaws are closed and no conductor is inside the jaw.
5. Press the jaw release level, open the jaws and insert the conductor to be measured inside the jaw.
6. Close the jaw; center the conductor using alignment marks on the jaw.
7. View the reading in the display.

Digital Multimeter Modes and Functions

HOW TO USE A DIGITAL MULTIMETER ?

MEASURING AC VOLTAGE

Connect the probes to their corresponding slots– the black probe to the “COM” or common slot, which is the ground, and the red probe to the “VΩ” slot.

Turn the knob to the AC Voltage sign, the letter V with this sign ~ above it.

Connect the black probe to the circuit.

Connect the red probe to the circuit.

Read the result on the screen.

MEASURING DC VOLTAGE

Connect the probes to their corresponding slots– the black probe to the “COM” or common slot, which is the ground, and the red probe to the “VΩ” slot.

This time, turn the knob to the DC Voltage sign, the letter V with a line above it.

Connect the red probe to the positive terminal.

Connect the black probe to the negative terminal.

Read the result on the screen.

MEASURING AC CURRENT

Connect the probes to their corresponding slots– the black probe to the “COM” or common slot, which is the ground, and the red probe to the “VΩ” slot.

Turn the knob to the AC Current sign, the letter A with the sign ~ above it.

Connect the probes to both ends of the circuit.

Read the result on the screen.

MEASURING DC CURRENT

Connect the probes to their corresponding slots– the black probe to the “COM” or common slot, which is the ground, and the red probe to the “VΩ” slot.

Turn the knob to the DC Current sign, the letter A with a line above it.

Connect the probes to both ends of the circuit.

Read the result on the screen.

MEASURING RESISTANCE

Connect the probes to their corresponding slots– the black probe to the “COM” or common slot, which is the ground, and the red probe to the “VΩ” slot.

Select the required range.

Touch the probes to the ends of the resistor.

Read the display on the screen.

MEASURING CAPACITANCE

Turn the knob to capacitance testing mode– with the icon or symbol of a capacitor.

Connect the probes to the capacitor ends.

If polarized, determine the positive and negative sides.

Read the result on the screen.

CONTINUITY

It is the presence of a complete path for the flow of current. If there is no continuity, it means that there is a break somewhere in the circuit. It will then produce no sound or tone in the digital multimeter. On the other hand, if two points are connected electrically, or are continuous, the digital multimeter will emit a sound or tone. This test ensures that there is a connection between two points.

Continuity is one of the most useful tests for electronics repair. Continuity tests are of utmost importance in avoiding fires, shocks, or damages to electrical devices.

Now, how to check continuity?

Turn off the system, unplug it, or remove the batteries.

Connect the probes to their corresponding slots– the black probe to the “COM” or common slot, which is the ground, and the red probe to the “VΩ” slot.

Turn the knob to continuity mode with the icon or symbol like that of sound waves.

To check if the continuity calibration of the multimeter works, touch the metal end of the probes together. If the number on the screen displays less than 1 or 0, then the multimeter is functioning properly. This will then indicate continuity, and the digital multimeter must emit a sound or a tone.

Place the probes at each end of the circuit or component you want to test. If the result is the same to step 4 then there is continuity in the circuit or the component.

TESTING TRANSISTORS AND DIODES

TRANSISTORS

Connect the probes to their corresponding slots– the black probe to the “COM” or common slot, which is the ground, and the red probe to the slot or terminal with the diode sign.

Turn the knob to the diode tester.

Connect alligator clamps to both metal end of the two probes.

Determine which of the transistor leads is the collector, base, and emitter.

Clamp the probes to the transistor leads– the black probe to the base of the transistor and the red probe to the emitter.

Read the display on the multimeter and take note of the resistance.

Remove the red probe from the emitter and move it to the collector side.

The display on the multimeter should be the same as when the red probe was on the emitter side.

Remove the black probe from the base side.

Clamp the red probe to the base side.

Clamp the black probe to the emitter side. Take note of the displayed value.

Clamp the black probe to the collector side. Take note of the displayed value.

If both previous readings (when the black probe is at the base) are higher than the current readings (when the red probe is at the base), the transistor is good.

If both previous readings are lower than the current readings, the transistor is good.

If it is neither steps 13 and 14, then the transistor is bad.

DIODES

Connect the probes to their corresponding slots – the black probe to the “COM” or common slot, which is the ground, and the red probe to the slot or terminal with the diode sign.

Turn off the power source.

Turn the knob to the diode tester.

Determine the cathode and the anode of the diode. Touch the anode using the red probe and the cathode using the black probe.

Read the display on the multimeter. If the reading is between 0.5 to 0.8V, then the diode is good. Otherwise, it’s not.

Switch the black probe and the read probe.

Read the display on the multimeter. If the reading is zero, then the diode is good. Otherwise, it’s not.

Weight variation or degree not change issue in Abro balancing SS100 machine

Remedy: This type of problem comes due to it's gone faulty EP825 or EP510 cards,So try replacing this card.

EP825 and EP510 cards show in Picture above 

EP825 card show in Picture above 

Why Does Hydraulics Use Oil And Not Water?

The necessity for lubrication inside hydraulic systems is the primary cause for this. A hydraulic system contains several moving pieces that brush against one another. This would result in corrosion and premature wear if not lubricated. Oil forms a layer on the surface of moving parts that functions as a lubricant while they are in motion. The industrial filters help to remove the dirt and keep the oil clean continuously.

The temperature inside a hydraulic system can reach dangerously high levels, and water has a low boiling point. The water boils very compressible, causing the entire system to work inefficiently.

Hydraulic oils have a more excellent boiling point and a lower freezing point. This indicates that the system can operate across a wide temperature range. In the presence of air, water causes the system’s interior components to rust and corrode. This causes the system to degrade prematurely.

Electric Circuit

What is an Electric Circuit?

An electrical circuit is a network of components used for energy storage, transmission, and conversion.

                     A path for transferring electric current is known as an electric circuit.

Types of Electric Circuits

There are many types of electric circuits including:

Series Circuit

Parallel Circuit

Series-Parallel Circuit

Star-Delta Circuit

Resistive Circuit

Inductive Circuit

Capacitive Circuit

Resistive, Inductive (RL Circuit)

Resistive, Capacitive (RC Circuit)

Capacitive, Inductive (LC Circuits)

Resistive, Inductive, Capacitive (RLC Circuit)

Linear Circuit

Non-Linear Circuit

Unilateral Circuits

Bi-lateral Circuits

Active Circuit

Passive Circuit

Open Circuit

Short Circuit

Closed Circuit

Pneumatic Cylinder

 

What is a Pneumatic Cylinder?

The pneumatic or compressed air control mechanical device’s final element is the pneumatic cylinder, sometimes known as an air cylinder. Pneumatic cylinders are machines that convert compressed air into mechanical energy.

The basic parts of a pneumatic cylinder are presented in the figure below:

These main parts are:

1.Cap-end port (A)

2.Tie rod (B)

3.Rod-end port (C)

4.Piston (D)

5.Barrel (E)

6.The piston rod (F)

Principle of a Pneumatic Cylinder

The pressure energy of a compressed air medium is converted into mechanical energy in the form of a linear or rotary motion by the pneumatic cylinder. Pneumatic cylinders can handle pressures ranging from 5 to 20 bar.

What Are the Types of Pneumatic Cylinders?

There are three common types of pneumatic cylinders

1.Single-Acting Pneumatic Cylinders

2.Double-Acting Pneumatic Cylinders

3.Telescoping Pneumatic Cylinders

Hydaulic Brake System

 

Hydaulic Brake System show in Picture above 

Engine Starting System

 

Engine Starting System show in Picture above 

Cross check alarm

Remedy:- PMC signal/communication will fail from system,Check signal/communication of PMC and system by LAN cabe otherwise restart the machine for again instablized signal/communication. 

Wrench and Types of Wrenches

Wrenches are made in various shapes and sizes and are used for gripping, fastening, turning, tightening and loosening things like pipes, pipe fittings, nuts and bolts. There are basically two major kinds of wrenches:

• Pipe wrenches used in plumbing for gripping round (cylindrical) things.
• General use wrenches used on nuts and bolts that have flat, parallel surfaces; e.g., square or hexagonal (hex).

Wrenches may be adjustable to fit different sized pipes, nuts and bolts or may be a fixed size.

 

What are the hazards of using wrenches?

Hazards may vary depending on the work and can include:

1.The wrench slips off of the work,

2.The work piece may suddenly break free causing you to lose balance,

3.The wrench or work piece may break, or

4.Turning the handle quickly or with pressure may create stress and strains on the hand or arm

What should I avoid doing when using wrenches?

1.Do not use push on a wrench - losing your balance is more likely if the wrench slips.

2.Do not use a wrench that is bent handle or damaged.

3.Do not use worn adjustable wrenches. Inspect the knurl, jaw, and pin for wear.

4.Do not pull on an adjustable wrench that is loosely adjusted.

5.Do not use pipe wrenches on nuts or bolts.

6.Do not use pipe wrenches for lifting or bending pipes.

7.Do not use a wrench on moving machinery.

8.Do not use the wrong tools for the job. Never use pliers instead of a wrench or a wrench as a hammer.

9.Do not use a make-shift wrench.

10.Do not insert a shim in a wrench for a better fit.

11.Do not strike a wrench (except a "strike face" wrench) with a hammer, or similar object, to gain more force.

Flange and Type of Flanges

What is Flange ?

A flange is a device that can be used to connect two pipes mechanically, it can also do the connection of a pipe to a tee, valve, choke, or any other equipment to form a piping system. The flanges are elements of a pipeline that would allow the assembly of parts, it is an element that can be supplied as a separate part or as a part that is attached from the factory to an element such as a valve, pump, or another part.  Basically, a flange is a kind of coupling that can join two lines together with the help of bolts and a gasket in between them. So the flange won’t individually make the joint. The flanged joints can be described as a combination of two flanges or it can be considered as bolting of two flanges and there would be a gasket in between these flanges

 

Safety Helmet and Type of safety Helmets

What is Safety helmet ?

Safety helmets (also known as hard hats) can prevent or minimise injuries to the head and brain, protecting against falling objects or debris, impact with other objects, electric shock and rain

 

Construction of an Industrial Safety Helmet :

1.Shell,

2.Harness

3.Harness fixing

4.Headband

5.Sweatband

6.Peak

7.Chinstrap

Saw and Types of saws

What is saw ?

Saw is hand or power tool or a machine used to cut hard material (such as wood, metal, or bone) and equipped usually with a toothed blade or disk

 

Ceiling fan connection diagram

Ceiling fan electrical connection show in Picture above 

Coupling and Types of Couplings

What is Coupling ?

A coupling is a mechanical element part that connects two shafts together to accurately transmit the power from the drive side to the driven side

 

The Purpose of Couplings

A shaft coupling can perform multiple functions in a machine these are :

1.Power transmission

2.Shock and vibration absorption

3.Misalignment accommodation

4.Heat flow interruption

5.Overload protection