Basic Tools and Test Equipment to Get the Job Done

At one time, it was common in many production facilities for the typical maintenance electrician to walk the floor with just a screwdriver and adjustable pliers in his back pocket. That transitioned to walking around with a tool pouch that had several screwdrivers and two sizes of adjustable pliers.

Things have advanced from there, including the carrying of an industrial DMM. But in your facility, have things advanced in the right direction? Or far enough?

You can get a head start by ensuring your tool pouch has the items you are most likely to need. Here’s an example for a maintenance electrician in a “typical” production plant:

• Basic hand tools (multipurpose screwdriver, commonly used standard wrenches, adjustable wrench, commonly used Allen screw wrenches).
• Various pliers (e.g., needle nose pliers, lineman’s pliers, pump pliers).
• Wire strippers.
• Spare test leads for your DMM.
• Roll of 600V tape.
• Roll of motor lead tape.
• Flashlight.
• Two locks and tags.
• The two smallish items that you most often have to walk back to the shop to get.

And what about the maintenance cart? If you’re doing preventive/predictive maintenance in the tool pouch and DMM mode, you’re no doubt making many unnecessary trips to and from the shop. It’s even worse if you are responding to downtime calls. Equip a cart so it covers the basic needs of both.

Here are suggestions for what a maintenance cart should have on board:

• Additional hand tools, such as a ratchet set.
• Shop rags.
• Portable light (larger than flashlight).
• Tachometer.
• Rotation tester.
• Infrared spot temperature gun.
• Four lockout hasps.
• Box of lockout tags.
• Calibration stickers.
• Plain label stickers.
• Box of ink pens (seriously, you don’t want to make a round trip to the shop for a pen!) and/or felt marker pens.
• Permanent marker.
• Insulating blanket.
• Box of nitrile gloves (do not use as electrical insulating gloves).
• Tube of gasket material.
• Boxes of solderless connectors (one box for each of the commonly used sizes).

The above lists may not work for your exact situation. They can serve as good starting points. Take the time to customize them so you aren’t making wasted trips. One way to determine if you’re carrying the right tools and supplies is by tracking how many trips you make back to the shop and which tools and supplies you had to get on each one.

If you pay attention to these basics, you will be more efficient and feel less pressured as you perform your various tasks. You also will end your day having walked fewer miles on concrete floors. Use that extra energy to do something you enjoy, but are often too tired to do, such as playing ball with the kids.

Universal motors(AC series Motor)

These motors are commonly employed in high starting torque and high starting speed applications,These are generally used in rough applications in steel industries

The universal motor is so named because it is a type of electric motor that can operate on AC or DC power. It is a commutated series-wound motor where the stator's field coils are connected in series with the rotor windings through Carbon brushes.

Working Of Universal Motor

A universal motor works on either DC or single phase AC supply. When the universal motor is fed with a DC supply, it works as a DC series motor. . When current flows in the field winding, it produces an electromagnetic field. The same current also flows from the armature conductors. When a current carrying conductor is placed in an electromagnetic field, it experiences a mechanical force. Due to this mechanical force, or torque, the rotor starts to rotate. The direction of this force is given by Fleming's left hand rule.

When fed with AC supply, it still produces unidirectional torque. Because, armature winding and field winding are connected in series, they are in same phase. Hence, as polarity of AC changes periodically, the direction of current in armature and field winding reverses at the same time.Thus, direction of magnetic field and the direction of armature current reverses in such a way that the direction of force experienced by armature conductors remains same. Thus, regardless of AC or DC supply, universal motor works on the same principle that DC series motor works.

Speed/Load Characteristics

Speed/load characteristics of a universal motor is similar to that of DC series motor. The speed of a universal motor is low at full load and very high at no load. Usually, gears trains are used to get the required speed on required load. The speed/load characteristics are (for both AC as well as DC supply) are shown in the figure.

Applications Of Universal Motor

• Vacuum cleaners
• Utility Appliances
• Angle grinders
• Feeder motors

Rotor of Angle Grinder

BATTERY LEVEL INDICATOR

WORKING

The LM3914 uses ten comparators, which are internally assembled in the voltage divider network based on the current-division rule. So it divides the battery level into ten parts.The circuit derives the power supply for its operation from the battery of the device itself. It uses ten LEDs wired in a 10-dot mode. The use of different coloured LEDs makes it easier to recognise the voltage level on the basis of the calibration made. Red LEDs (LED1 through LED3) indicate battery capacity of less than 40 per cent. Orange LEDs (LED4 through LED6) indicate battery capacity of 40 to less than 70 per cent and green LEDs (LED7 through LED10) indicate battery capacity of 70 to under 100 per cent. The brightness of the LEDs can be adjusted by varying the value of preset VR2 between pins 6 and 7. Diode D1 prevents the circuit from reverse-polarity battery connection. The tenth LED glows only when the battery capacity is full, i.e., the battery is fully charged. When the battery is fully charged, relay-driver transistor T1 conducts to energise relay RL1. This stops the charging through normally-open (N/O) contacts of relay RL1. For calibration, connect 15V variable, regulated power supply and initially set it at 3V. Slowly adjust VR1 until LED1 glows. Now, increase the input voltage to 15V in steps of 1.2V until the corresponding LED (LED2 through LED10) lights up.Now the circuit is ready to show any voltage value with respect to the maximum voltage. As the number of LEDs is ten, we can easily consider one LED for 10 per cent of the maximum voltage.

PARTS

IC=LM3914

LED

Resistor=As per in circuit

 RESISTOR:

The behavior of an ideal resistor is dictated by the relationship specified by Ohm's law:

Ohm's law states that the voltage (V) across a resistor is proportional to the current (I), where the constant of proportionality is the resistance (R).

Equivalently, Ohm's law can be stated:

This formulation states that the current (I) is proportional to the voltage (V) and inversely proportional to the resistance (R). This is directly used in practical computations.

Colour coding of resistors:

Carbon-composition and carbon film resistors are too small to have the resistance value printed on their housings. Therefore, bands of color are used to represent the resistance value.

The first and second band represents the numerical value of the resistor, and the color of the third band specifies the power-of-ten multiplier. The color bands are always read from left to right starting with the side that has a band closer to the edge.

For carbon-composition and carbon film resistors, the common tolerances are 5%, 10%, and 20%, indicating that the actual value of the resistor can vary from the nominal value by ±5%, ±10% and ±20%. If the band is gold, it specifies a 5% tolerance; silver specifies a 10% tolerance; if no band is present, the tolerance is 20%.

Note that the color-code system for capacitors is very similar to that of resistors except there is a fifth band representing the temperature coefficient. This band is the first one closest to one end of the capacitor. The other four fall into the same order as mentioned for resistors. In this case, the second, third, and fourth bands are used to determine the capacitance. The fifth band represents the tolerance of the capacitor. Color First-band Digit Second-band Digit Third-band Multiplier Fourth-band Tolerance Black 0 0 100 = 1 Brown 1 1 101 = 10 1% Red 2 2 102 = 100 2% Orange 3 3 103 = 1000 3% Yellow 4 4 104 = 10000 4% Green 5 5 105 = 100000 Blue 6 6 106 = 1000000 Violet 7 7 107 = 10000000 Gray 8 8 108 = 100000000 White 9 9 109 = 1000000000 Gold 5% Silver 10% None 20%

TPM(Total productive Maintenance)

TPM focused on achieving:

 • Zero Accidents

 • Zero Breakdowns

 • Zero Defects

The ultimate aim of TPM is to  eliminate  all types of production losses.

TPM emphasizes proactive and preventative maintenance to maximize the operational efficiency of equipment. It blurs the distinction between the roles of production and maintenance by placing a strong emphasis on empowering operators to help maintain their equipment.

The implementation of a TPM program creates a shared responsibility for equipment that encourages greater involvement by plant floor workers. In the right environment this can be very effective in improving productivity (increasing up time, reducing cycle times, and eliminating defects).

The 5S Foundation

The goal of 5S is to create a work environment that is clean and well-organized. It consists of five elements:

1. Sort (eliminate anything that is not truly needed in the work area)
2. Set in Order (organize the remaining items)
3. Shine (clean and inspect the work area)
4. Standardize (create standards for performing the above three activities)
5. Sustain (ensure the standards are regularly applied)

It should be reasonably intuitive how 5S creates a foundation for well-running equipment. For example, in a clean and well-organized work environment, tools and parts are much easier to find, and it is much easier to spot emerging issues such as fluid leaks, material spills, metal shavings from unexpected wear, hairline cracks in mechanisms, etc.

The Eight Pillars

The eight pillars of TPM are mostly focused on proactive and preventative techniques for improving equipment reliability.

Autonomous Maintenance(JH pillar)

• Gives operators greater “ownership” of their equipment.
• Increases operators’ knowledge of their equipment.
• Ensures equipment is well-cleaned and lubricated.
• Identifies emergent issues before they become failures.
• Frees maintenance personnel for higher-level tasks.

Focused Improvement(KK pillar)

• Recurring problems are identified and resolved by cross-functional teams.
• Combines the collective talents of a company to create an engine for continuous improvement.

Planned Maintenance(KH pillar)

• Significantly reduces instances of unplanned stop time.
• Enables most maintenance to be planned for times when equipment is not scheduled for production.
• Reduces inventory through better control of wear-prone and failure-prone parts.

Quality Maintenance

• Specifically targets quality issues with improvement projects focused on removing root sources of defects.
• Reduces number of defects.
• Reduces cost by catching defects early (it is expensive and unreliable to find defects through inspection).

Equipment Management

• New equipment reaches planned performance levels much faster due to fewer startup issues.
• Maintenance is simpler and more robust due to practical review and employee involvement prior to installation.

Training and Education

• Operators develop skills to routinely maintain equipment and identify emerging problems.
• Maintenance personnel learn techniques for proactive and preventative maintenance.
• Managers are trained on TPM principles as well as on employee coaching and development.

Safety, Health, Environment

• Eliminates potential health and safety risks, resulting in a safer workplace.
• Specifically targets the goal of an accident-free workplace.

TPM in Administration

• Extends TPM benefits beyond the plant floor by addressing waste in administrative functions.
• Supports production through improved administrative operations (e.g. order processing, procurement, and scheduling).

Introduction to OEE

OEE (Overall Equipment Effectiveness) is a metric that identifies the percentage of planned production time that is truly productive. It was developed to support TPM initiatives by accurately tracking progress towards achieving “perfect production”.

For Availability

Mean Time Between Failures & Mean Time To Repair

Mean Time Between Failures = (Total up time) / (number of breakdowns)

Mean Time To Repair = (Total down time) / (number of breakdowns)

The "availability" of a device is, mathematically, MTBF / (MTBF + MTTR) for scheduled working time.

Why 3 phase system requires

We assume that we will only connect single phase load (Light points, fans, TV, AC etc.) in this three phase electrical wiring installation. In other words, we will not power up 3 phase motors because in our homes, we haven’t that kind of (three phase) loads. If three phase load exists in your home, then you can so. As we can see that the total load is exceeded the limit of single phase electrical wiring installation, that’s why we have to wire our distribution in three phase system.

In a Three Phase Wiring Distribution System;

Line to Line Voltage = 440V

Line to NeutralVoltage = 230V

I.e.            

L₁ to L₂= 440V

L₂ to L₃= 440V

L₃ to L₁= 440 V

And

L₁ to N = 230V

L₂ to N = 230V

L₃ to N = 230 V

Electrical controls: Wiring of commercial Distribution Board(single ph...

Electrical controls: Wiring of commercial Distribution Board(single ph...: Required components for housing electrical service connection are 1 inch service pipe 7/20 GI wire 3/20 Service wire PVC Reels Arial ...

Wiring of commercial Distribution Board(single phase)

Required components for housing electrical service connection are

1. 1 inch service pipe
2. 7/20 GI wire
3. 3/20 Service wire
4. PVC Reels
5. Arial Board
6. 16 Amps Porcelain Fuse unit
7. Meter board
8. 16 Amps main Switch
9. 16 Amps Earth link(brass)
10. 16 Amps Neutral link(brass)
11.  Earth wire
12. 1 1/4 inch GI pipe
13. Earth plate
14. 63A 2 pole MCB with RCD
15. 20A 1 pole MCB-5 Nos

The above components are mandatory to get a electrical service from electricity board.The below diagram illustrates the wiring procedure,from meter to house hold appliances

Main Distribution Board or Fuse Boards

Main Distribution Board or Fuse Boards ( Consumer Unit) usually contains three things. They are:

DP = Double Pole MCB  (The main switch)

RCD (Also DP) Residual Current Devices.

SP = Single Pole MCB ( Circuit Breakers and Fuses)

1)
DP = Double Pole MCB  (The main switch)
This allows you to turn off and on the electric supply to your home because this is the main operating switch to control electric supply. remember that immediately switch off the main switch in emergency i.e. in electric shock, fire or  while working on main board. You can use also multiple mains switch if you has more supply unit i.e storage heater etc. so then use a separate Fuse board. 
2)

RCD (Also DP) Residual Current Devices.
A (RCD) residual-current device, or (RCCB) residual-current circuit breaker , is an electrical wiring device or switch that disconnects or trip a circuit whenever it detects that the electric current is not balanced between the energized conductor and the return neutral conductor. And then instantly disconnect the electricity (in dangerous conditions). 
3) 
Circuit Breakers  
Circuit breaker is a device which switch off and on electric supply at normal ( and abnormal) condition). These are automatic protection devices in the Main switch board or fuse-box that switch off a circuit if they detect a fault. the size of the fuse and Circuit Breaker are similar, but it give more and more protection. You can reset it again if the trip ever.
Wiring of the distribution board , Single phase, from Energy meter to the main distribution board (Without RCD = Residual Current Devices). 

it is used to control and distribute electric supply (safely to electrical appliances) around your home  

Connection circuit for household electronic choke Tube light

This is applicable for 230VAc 50Hz mains,and it is a simple connection procedure to execute,the below diagram explains you all.

Components Required are

1. Tube light 40Watts,230VAC
2. Tube light frame
3. Electronic choke 0.15A,40Watts,0.9 pf
4. 230 volt AC Mains

Electronic choke consists of 2 incoming wires(Red and black) for input,connect it with AC mains,and it consists of 4 out wires(2 in one colour and another 2 in other colour) connect one pair wire in one side and another pair on other side.Handle things safely and switch on mains.Good luck.

Connection circuit for household electronic choke Tube light

This is applicable for 230VAc 50Hz mains,and it is a simple connection procedure to execute,the below diagram explains you all.

Components Required are

1. Tube light 40Watts,230VAC
2. Tube light frame
3. Electronic choke 0.15A,40Watts,0.9 pf
4. 230 volt AC Mains

Electronic choke consists of 2 incoming wires(Red and black) for input,connect it with AC mains,and it consists of 4 out wires(2 in one colour and another 2 in other colour) connect one pair wire in one side and another pair on other side.Handle things safely and switch on mains.Good luck.

Simple forward reverse control circuit of 3 phase induction motor

Simple forward reverse control circuit of 3 phase induction motor

In order to forward reverse 3 phase induction motor up to 10 Hp via DOL starter , the required control circuit is given below

Required components are

• 1 off push button
• 2 on push buttons
• 2 Main Contactors 4 pole(110V coil voltage or 230 V coil voltage)
• 3 Indication lamps (110v/230vAC)

Depending upon your control circuit voltage choose coil voltage of contactor preferably 110v,230V.

Indication lamp voltage should also be the same

Diagram Description

• MC1 - Main contactor 1
• MC2 - Main contactor 2
• NO   - Normally open
• NC   - Normally closed

1. Parallel NO connection to On buttons will give holding for the respective contactors
2. Series NC connections to On buttons will be employed for interlocking.

DOL(Direct on line) starters for Three phase motors

Direct on line starting is a starting technique of three phase induction motors.During starting period induction motors will draw more starting current,which is six times greater then normal rated current of that motor.so it is important to reduce the starting current,for these purpose starters are widely used.There are different types of starters they are

1. Direct online starters
2. Star delta Starters
3. Auto transformer starters

Wiring of DOL Starter

1. Main Contact

• Contactor is connecting among Supply Voltage, Relay Coil and Thermal Overload Relay.
• L1 of Contactor Connect (NO) to R Phase through MCCB
• L2 of Contactor Connect (NO) to Y Phase through MCCB
• L3 of Contactor Connect (NO) to B Phase through MCCB.

NO Contact (-||-):

• (13-14 or 53-54) is a normally Open NO contact (closes when the relay energizes)
• Contactor Point 53 is connecting to Start Button Point (94) and 54 Point of Contactor is connected to Common wire of Start/Stop Button.

NC Contact (-|/|-):

• (95-96) is a normally closed NC contact (opens when the thermal overloads trip if associated with the overload block)

2. Relay Coil Connection

• A1 of Relay Coil is connecting to any one Supply Phase and A2 is connecting to Thermal over Load Relay’s NC Connection (95).

3. Thermal Overload Relay Connection:

• T1,T2,T3 are connect to Thermal Overload Relay
• Overload Relay is Connecting between Main Contactor and Motor
• NC Connection (95-96) of Thermal Overload Relay is connecting to Stop Button and Common Connection of Start/Stop Button.

Working principle of DOL Starter

The main heart of DOL starter is Relay Coil. Normally it gets one phase constant from incoming supply Voltage (A1).when Coil gets second Phase relay coil energizes and Magnet of Contactor produce electromagnetic field and due to this Plunger of Contactor will move and Main Contactor of starter will closed and Auxiliary will change its position NO become NC and NC become (shown Red Line in Diagram)  .

Pushing Start Button

When We Push the start Button Relay Coil will get second phase from Supply Phase-Main contactor(5)-Auxiliary Contact(53)-Start button-Stop button-96-95-To Relay Coil (A2).Now Coil energizes and Magnetic field produce by Magnet and Plunger of Contactor move. Main Contactor closes and Motor gets supply at the same time Auxiliary contact become (53-54) from NO to NC .

Release Start Button

Relay coil gets supply even though we release Start button. When We release Start Push Button Relay Coil gets Supply phase from Main contactor (5)-Auxiliary contactor (53) – Auxiliary contactor (54)-Stop Button-96-95-Relay coil (shown Red / Blue Lines in Diagram).

In Overload Condition of Motor will be stopped by intermission of Control circuit at Point 96-95.

Pushing Stop Button

When we push Stop Button Control circuit of Starter will be break at stop button and Supply of Relay coil is broken, Plunger moves and close contact of Main Contactor becomes Open, Supply of Motor is disconnected.