Intern Ship Report Protection Mepco

TrainingRe

Govt. College of Technology Burewala Project Training Report Of P&I Division MEPCO Multan. B-Tech (Pass) Electrical Industrial Training Program Session 2007-2009 Affiliated With

Incharge B-Tech (Pass) Electrical Sig. Mr. Amir Gafoor Sb. Head of Department B-Tech (Pass) Electrical G.C.T. Burewala.

Industrial Training Officer Trainee Student Sig. Sig.

Mr. Ghulam Abbas Sb Muhammad Shoaib Saleem B-Tech (Pass) Electrical B-Tech (Pass) Electrical

G.C.T. Burewala. University Roll# 31

Of

Prepared by: Eng. Muhammad Shoaib Saleem B-Tech (Pass) Electrical University Roll #: 31

Introduction: Protection of Electrical System: Equipment applied to electric power systems to detect abnormal and intolerable conditions and to initiate appropriate corrective actions. These devices include lightning arresters, surge protectors, fuses, and relays with associated circuit breakers, reclosers, and so forth. From time to time, disturbances in the normal operation of a power system occur. These may be caused by natural phenomena, such as lightning, wind, or snow; by falling objects such as trees; by animal contacts or chewing; by accidental means traceable to reckless drivers, inadvertent acts by plant maintenance personnel, or other acts of humans; or by conditions produced in the system itself, such as switching surges, load swings, or equipment failures. Protective devices must therefore be installed on power systems to ensure continuity of electrical service, to limit injury to people, and to limit damage to equipment when problem situations develop. Protective devices are applied commensurately with the degree of protection desired or felt necessary for the particular system.

Electrical Protection & Grounding Electrical Protection: A Definition: Electrical protection, also widely known as “grounding” or “earthing,” is arguably one of the least understood, most under-rated, yet paradoxically most important elements of modern electrical systems and lightning protection designs. Without proper electrical protection, personnel are at higher risk of shock; equipment operation can be negatively impacted by ambient electrical noise; and electronic and electrical equipment is at risk of damage from voltage and current surges. It is a basic axiom that power system ground faults will find a path to

ground. Therefore, it is essential to deploy functional electrical protection systems that will safely channel and dissipate this errant electrical energy to prevent personnel injury and equipment damage. At its most basic, electrical protection is systems are the connection of bonded metallic systems through engineered, low impedance paths to earth. Alas, much easier said than done…

Overvoltage Protection Definition: Overvoltage Protector (OVP) refers to a circuit that protects downstream circuitry from damage due to excessive voltage. An OVP monitors the DC voltage coming from an external power source, such as an off-line power supply or a battery, and protects the rest of the connected circuitry using one of two methods: a crowbar clamp circuit or a series-connected switch. The crowbar short-circuits or clamps the supply line to limit the voltage, possibly triggering other forms of protection such as a fuse. See Crowbar. The series-connected switch uses a MOSFET or transistor connected as a switch in series with the supply line. During an overvoltage condition, the OVP circuit rapidly shuts off the MOSFET and disconnects the downstream circuit.

Protective relays: These are compact analog or digital networks, connected to various points of an electrical system, to detect abnormal conditions occurring within their assigned areas. They initiate disconnection of the trouble area by circuit breakers. These relays range from the simple overload unit on house circuit breakers to complex systems used to protect extrahigh-voltage power transmission lines. They operate on voltage, current, current direction, power factor, power, impedance, temperature. In all cases there must be a measurable difference between the normal or tolerable operation and the intolerable or unwanted condition. System faults for which the relays respond are generally short circuits between the phase conductors, or between the phases and grounds. Some relays operate on unbalances between the phases, such as an open or reversed phase. A fault in one part of the system affects all other parts. Therefore relays and fuses throughout the power system must be coordinated to ensure the best quality of service to the loads and to avoid operation in the nonfaulted areas unless the trouble is not adequately cleared in a specified time.

Zone protection: For the purpose of applying protection, the electric power system is divided into five major protection zones: generators; transformers; buses; transmission and distribution lines; and motors (see illustration). Each block represents a set of protective relays and associated equipment selected to initiate correction or isolation of that area for all anticipated intolerable conditions or trouble. The detection is done by protective relays with a circuit breaker used to physically disconnect the equipment. For other areas of protection See Grounding, Uninterruptible power system

Zones of protection on simple power system

Simple Zone:

Fault detection: Fault detection is accomplished by a number of techniques, including the detection of changes in electric current or voltage levels, power direction, ratio of voltage to current, temperature, and comparison of the electrical quantities flowing into a protected area with the quantities flowing out, also known as differential protection.

Differential protection: This is the most fundamental and widely used protection technique. The system compares currents to detect faults in a protection zone. Current transformers on either side of the protection zone reduce the primary currents to small secondary values, which are the inputs to the relay. For load through the equipment or for faults outside of the protection zone, the secondary currents from the two transformers are essentially the same, and they are directed so that the current through the relay sums to essentially zero. However, for internal trouble, the secondary currents add up to flow through the relay.

Overcurrent protection: This must be provided on all systems to prevent abnormally high currents from overheating and causing mechanical stress on equipment. Overcurrent in a power system usually indicates that current is being diverted from its normal path by a short circuit. In low-voltage, distribution-type circuits, such as those found in homes, adequate overcurrent protection can be provided by fuses that melt when current exceeds a predetermined value. Small thermal-type circuit breakers also provide overcurrent protection for this class of circuit. As the size of circuits and systems increases, the problems associated with interruption of large fault currents dictate the use of power circuit breakers. Normally these breakers are not equipped with elements to sense fault conditions, and therefore overcurrent relays are applied to measure the current continuously. When the current has reached a predetermined value, the relay contacts close. This actuates the trip circuit of a particular breaker, causing it to open and thus isolate the fault. See Circuit breaker

Distance protection: Distance-type relays operate on the combination of reduced voltage and increased current occasioned by faults. They are widely applied for the protection of higher voltage lines. A major advantage is that the operating zone is determined by the line impedance and is almost completely independent of current magnitudes.

Overvoltage protection: Lightning in the area near the power lines can cause very short-time overvoltages in the system and possible

breakdown of the insulation. Protection for these surges consists of lightning arresters connected between the lines and ground. Normally the insulation through these arresters prevents current flow, but they momentarily pass current during the high-voltage transient to limit overvoltage. Overvoltage protection is seldom applied elsewhere except at the generators, where it is part of the voltage regulator and control system. In the distribution system, overvoltage relays are used to control taps of tap-changing transformers or to switch shunt capacitors on and off the circuits. See Lightning and surge protection

Undervoltage protection: This must be provided on circuits supplying power to motor loads. Low-voltage conditions cause motors to draw excessive currents, which can damage the motors. If a lowvoltage condition develops while the motor is running, the relay senses this condition and removes the motor from service.

Underfrequency protection: A loss or deficiency in the generation supply, the transmission lines, or other components of the system, resulting primarily from faults, can leave the system with an excess of load. Solid-state and digital-type underfrequency relays are connected at various points in the system to detect this resulting decline in the normal system frequency. They operate to disconnect loads or to separate the system into areas so that the available generation equals the load until a balance is reestablished.

Reverse-current protection: This is provided when a change in the normal direction of current indicates an abnormal condition in the system. In an ac circuit, reverse current implies a phase shift of the current of nearly 180° from normal. This is actually a change in direction of power flow and can be directed by ac directional relays.

Phase unbalance protection: This protection is used on feeders supplying motors where there is a possibility of one phase opening as a result of a fuse failure or a connector failure. One type of relay compares the current in one phase against the currents in the other phases. When the unbalance becomes too great, the relay operates.

Another type monitors the three-phase bus voltages for unbalance. Reverse phases will operate this relay.

Reverse-phase-rotation protection: Where direction of rotation is important, electric motors must be protected against phase reversal. A reverse-phase-rotation relay is applied to sense the phase rotation. This relay is a miniature three-phase motor with the same desired direction of rotation as the motor it is protecting. If the direction of rotation is correct, the relay will let the motor start. If incorrect, the sensing relay will prevent the motor starter from operating.

Thermal protection: Motors and generators are particularly subject to overheating due to overloading and mechanical friction. Excessive temperatures lead to deterioration of insulation and increased losses within the machine. Temperature-sensitive elements, located inside the machine, form part of a bridge circuit used to supply current to a relay. When a predetermined temperature is reached, the relay operates, initiating opening of a circuit breaker or sounding of an alarm.

Purpose of Protection System: . . . .

Minimize damage. Leave unaffected equipment in-service. Maintain equipment operating limits. Maintain electrical system stability.

Requirements of a Protection System: . Speed . Reliability . Security . Sensitivity

Double Protection:

Duplicate Protection Schemes:

Bus Protection: . . . .

Over-current Differential Back-up Under voltage

Over-current Relay:

Differential Protection:

Fault Conditions:

Bus Protection Scheme:

Back-up relay:

Bus Under Voltage Protection:

Transformer Protection: . . . . .

Instantaneous Differential Gas Thermal Overload Ground

Transformer Characteristics: . . . . .

High magnetizing inrush currents Ratio mismatch with CTs aggravated by tap-changers Phase shifts Transformers are affected by over-fluxing Affected by over-temperature

Transformer Zone:

Differential:

Gas Relay:

Winding Temperature:

Ground Fault Protection:

Circuit breaker :-

A circuit breaker is an equipment, which can open or close a ckt under normal as well as fault condition. It is so designed that it can be operated manually ( or by remote control) under normal conditions and automatically under fault condition. For the latter operation a relay wt. is used with a C.B. generally bulk oil C.B. are used for voltage upto 66 KV while for high voltage low oil & SF6 C.B. are used. For still higher voltage, air blast vacuum or SF6 cut breaker are used.

The process of fault clearing has the following sequence: 1- Fault Occurs. As the fault occurs, the fault impedance being low, the currents increase and the relay gets actuated. The moving part of the relay move because of the increase in the operating torque. The relay takes some time to close its contacts. 2 - Relay contacts close the trip circuit of the Circuit Breaker closes and trip coil is energized. 3 - The operating mechanism starts operating for the opening operation. The Circuit Breaker contacts separate. 4 - Arc is drawn between the breaker contacts. The arc is extinguished in the Circuit Breaker by suitable techniques. The current reaches final zero as the arc is extinguished and does not restrict again. The Trip-Circuit Fig (1) below illustrates the basic connections of the Circuit Breaker control for the opening operation

The type of the Circuit Breaker The type of the Circuit Breaker is usually identified according to the medium of arc extinction. The classification of the Circuit Breakers based on the medium of arc extinction is as follows: (1) Air break' Circuit Breaker. (Miniature Circuit Breaker). (2) Oil Circuit Breaker (tank type of bulk oil) (3) Minimum oil Circuit Breaker. (4) Air blast Circuit Breaker. (5) Vacuum Circuit Breaker. (6) Sulphur hexafluoride Circuit Breaker. (Single pressure or Double Pressure). Type 1 – Air break Circuit Breaker 2 – Miniature CB.

Medium Air at atmospheric pressure Air at atmospheric pressure 3 – Tank Type oil CB. Dielectric oil

Voltage, Breaking Capacity (430 – 600) V– (5-15)MVA (3.6-12) KV - 500 MVA (430-600 ) V

4 – Minimum Oil CB. Dielectric oil 5 – Air Blast CB. Compressed Air (20 – 40 ) bar 6 – SF6 CB. SF6 Gas

(3.6 - 145 )KV 245 KV, 35000 MVA up to 1100 KV, 50000 MVA 12 KV, 1000 MVA 36 KV , 2000 MVA

(3.6 – 12) KV

7 – Vacuum CB. 8 – H.V.DC CB.

Vacuum Vacuum , SF6 Gas

145 KV, 7500 MVA 245 KV , 10000 MVA 36 KV, 750 MVA 500 KV DC

Breaker Design: Basic The simplest circuit protection device is the fuse. A fuse is just a thin wire, enclosed in a casing, that plugs into the circuit. When a circuit is closed, all charge flows through the fuse wire -- the fuse experiences the same current as any other point along the circuit. The fuse is designed to disintegrate when it heats up above a certain level -- if the current climbs too high, it burns up the wire. Destroying the fuse opens the circuit before the excess current can damage the building wiring. The problem with fuses is they only work once. Every time you blow a fuse, you have to replace it with a new one. A circuit breaker does the same thing as a fuse -- it opens a circuit as soon as current climbs to unsafe levels -- but you can use it over and over again. The basic circuit breaker consists of a simple switch, connected to either a bimetallic strip or an electromagnet. The diagram below shows a typical electromagnet design.

The hot wire in the circuit connects to the two ends of the switch. When the switch is flipped to the on position, electricity can flow from

the bottom terminal, through the electromagnet, up to the moving contact, across to the stationary contact and out to the upper terminal. The electricity magnetizes the electromagnet (See How Electromagnets Work to find out why). Increasing current boosts the electromagnet's magnetic force, and decreasing current lowers the magnetism. When the current jumps to unsafe levels, the electromagnet is strong enough to pull down a metal lever connected to the switch linkage. The entire linkage shifts, tilting the moving contact away from the stationary contact to break the circuit. The electricity shuts off. A bimetallic strip design works on the same principle, except that instead of energizing an electromagnet, the high current bends a thin strip to move the linkage. Some circuit breakers use an explosive charge to throw the switch. When current rises above a certain level, it ignites explosive material, which drives a piston to open the switch

Breaker Design: Advanced More advanced circuit breakers use electronic components (semiconductor devices) to monitor current levels rather than simple electrical devices. These elements are a lot more precise, and they shut down the circuit more quickly, but they are also a lot more expensive. For this reason, most houses still use conventional electric circuit breakers. One of the newer circuit breaker devices is the ground fault circuit interrupter, or GFCI. These sophisticated breakers are designed to protect people from electrical shock, rather than prevent damage to a building's wiring. The GFCI constantly monitors the current in a circuit's neutral wire and hot wire. When everything is working correctly, the current in both wires should be exactly the same. As soon as the hot wire connects directly to ground (if somebody accidentally touches the

hot wire, for example), the current level surges in the hot wire, but not in the neutral wire. The GFCI breaks the circuit as soon as this happens, preventing electrocution. Since it doesn't have to wait for current to climb to unsafe levels, the GFCI reacts much more quickly than a conventional breaker. All the wiring in a house runs through a central circuit breaker panel (or fuse box panel), usually in the basement or a closet. A typical central panel includes about a dozen circuit breaker switches leading to various circuits in the house. One circuit might include all of the outlets in the living room, and another might include all of the downstairs lighting. Larger appliances, such as a central air conditioning system or a refrigerator, are typically on their own circuit.

Testing Trailer Wiring: So you've hooked up your trailer to your tow vehicle, you've got the tow vehicle's engine running and the lights on the trailer refuse to come on. What do you do next? The Reese Towpower 74633 4-Way Tester is one of the simpler trailer wiring testers on the market The key to detecting a wiring issue is to eliminate possibilities until you can determine the source of the problem. First, you may want to check the lights on your trailer -- the problem may be as simple as a burned-out bulb. If that's not the problem, you'll need to disconnect your trailer's wiring system from your tow vehicle. Next, you'll need to check to make sure your vehicle's lights are in good working order. Test your vehicle's turn signals, brake lights and backup lights to make sure the problem isn't the tow vehicle itself.

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The key to detecting a wiring issue is to eliminate possibilities until you can determine the source of the problem. First, you may want to check the lights on your trailer -- the problem may be as simple as a burnedout bulb. If that's not the problem, you'll need to disconnect your trailer's wiring system from your tow vehicle. Next, you'll need to check to make sure your vehicle's lights are in good working order. Test your vehicle's turn signals, brake lights and backup lights to make sure the problem isn't the tow vehicle itself. If your vehicle's lighting system is working, the next step is to use a trailer wiring tester to check the socket on your tow vehicle. You'll need to make sure your tester fits your tow vehicle's socket. Some testing kits come with multiple attachments, letting you use the same kit to test more than one kind of wiring system. Plug the tester into your tow vehicle's socket. The tester should have one or more indicators that will alert you if it detects an electric current. Most testers have an indicator for each function. Test each system in turn and check your results. If the tester responded to each system, then the trailer's wiring system is the likely source of the problem. But if one or more of the tests results in no response from the tester, your tow vehicle may be at fault. If the tester lights up when it shouldn't -- for example, if the left-turn signal indicator lights up even when you haven't engaged the turn signal -- it could indicate that you have a short in your tow vehicle's wiring. You'll need to check the wiring in your tow vehicle to see if there is a point where two or more wires make contact. It's also

possible that two or more wires are connected to the wrong connection points. Some wiring problems are easy to fix. If two wires are connecting to the wrong connection points, it's usually just a matter of using some wire cutters, a wire stripper and a crimper to swap them. Others might require a visit to a mechanic. The important thing to remember is that if the wiring isn't working properly, you can't travel on the road safely. Other drivers could misinterpret your actions if the wrong lights activate on your trailer as you drive.

Installing Breakaway Kits:

Mounting a breakaway kit is a simple task with the right tools, but if you're not used to working with electrical wiring, you might want to opt for professional installation. After choosing the right type of breakaway kit, the next step is to install the kit onto your vehicle. There are basically two steps to this: mounting the breakaway kit and switch and connecting the electrical system. Mounting a breakaway kit is the simplest step, and if you have the right tools you should be able to do it on your own. Most breakaway kits come with either a mounting bracket or they have mounting holes built into the plastic battery box itself, so all you have to do is bolt the kit onto the trailer. Where you choose to mount the battery is up to you -- it can go almost anywhere on the trailer -- even on the inside. Most people choose to place the kit on the trailer frame for easy access.

Mounting the breakaway switch is just as easy. Again, you can mount it nearly anywhere on the trailer, but it's best to keep it away from any space that might be damaged by dragging or debris. Be sure that the switch wiring will reach the trailer hitch, as the disconnection of the trailer hitch is what triggers the breakaway switch. The next step, properly wiring the breakaway system, may be best handled by a professional. The process involves cutting and splicing several wires together, so unless you're experienced with electrical wiring you might want to leave this step to someone trained in breakaway kit installation. The wires from the battery connect to the breakaway switch, providing the necessary power. Then the wires from the breakaway switch are spliced to the trailer's brake wires. The breakaway switch, also known as a plunger, is connected to the hitch -- when the trailer separates from the tow vehicle, the switch immediately sends a signal to the trailer's brakes to slow down and safely stop the vehicle.

The Distribution Grid: For power to be useful in a home or business, it comes off the transmission grid and is stepped-down to the distribution grid. This may happen in several phases. The place where the conversion from "transmission" to "distribution" occurs is in a power substation. A power substation typically does two or three things: It has transformers that step transmission voltages (in the tens or hundreds of thousands of volts range) down to distribution voltages (typically less than 10,000 volts). It has a "bus" that can split the distribution power off in multiple directions. It often has circuit breakers and switches so that the substation can be disconnected from the transmission grid or separate distribution lines can be disconnected from the substation when necessary.

A typical small substation

The box in the foreground is a large transformer. To its left (and out of the frame but shown in the next shot) are the incoming power from the transmission grid and a set of switches for the incoming power. Toward the right is a distribution bus plus three voltage regulators.

The transmission lines entering the substation and passing through the switch tower

The switch tower and the main transformer

Now the distribution bus comes into the picture.

Distribution Bus: The power goes from the transformer to the distribution bus:

In this case, the bus distributes power to two separate sets of distribution lines at two different voltages. The smaller transformers attached to the bus are stepping the power down to standard line voltage (usually 7,200 volts) for one set of lines, while power leaves in the other direction at the higher voltage of the main transformer. The

power leaves this substation in two sets of three wires, each headed down the road in a different direction:

The wires between these two poles are "guy wires" for support. They carry no current.

The next time you are driving down the road, you can look at the power lines in a completely different light. In the typical scene pictured on the right, the three wires at the top of the poles are the three wires for the 3-phase power. The fourth wire lower on the poles is the ground wire. In some cases there will be additional wires, typically phone or cable TV lines riding on the same poles. As mentioned above, this particular substation produces two different voltages. The wires at the higher voltage need to be stepped down again, which will often happen at another substation or in small transformers somewhere down the line. For example, you will often see a large green box (perhaps 6 feet/1.8 meters on a side) near the entrance to a subdivision. It is performing the step-down function for the subdivision.

Regulator Bank: You will also find regulator banks located along the line, either underground or in the air. They regulate the voltage on the line to prevent undervoltage and overvoltage conditions.

A typical regulator bank

Up toward the top are three switches that allow this regulator bank to be disconnected for maintenance when necessary:

At this point, we have typical line voltage at something like 7,200 volts running through the neighborhood on three wires (with a fourth ground wire lower on the pole):

Taps: A house needs only one of the three phases, so typically you will see three wires running down a main road, and taps for one or two of the phases running off on side streets. Pictured below is a 3-phase to 2phase tap, with the two phases running off to the right:

Here is a 2-phase to 1-phase tap, with the single phase running out to the right:

At the House: And finally we are down to the wire that brings power to your house! Past a typical house runs a set of poles with one phase of power (at 7,200 volts) and a ground wire (although sometimes there will be two or three phases on the pole, depending on where the house is located in the distribution grid). At each house, there is a transformer drum attached to the pole, like this:

In many suburban neighborhoods, the distribution lines are underground and there are green transformer boxes at every house or two. Here is some detail on what is going on at the pole:

The transformer's job is to reduce the 7,200 volts down to the 240 volts that makes up normal household electrical service. Let's look at this pole one more time, from the bottom, to see what is going on:

There are two things to notice in this picture: • There is a bare wire running down the pole. This is a grounding wire. Every utility pole on the planet has one. If you ever watch the power company install a new pole, you will see that the end of that bare wire is stapled in a coil to the base of the pole and therefore is in direct contact with the earth, running 6 to 10 feet (1.8 to 3 m) underground. It is a good, solid ground connection. If you examine a pole carefully, you will see that the ground wire running between poles (and often the guy wires) are attached to this direct connection to ground. • There are two wires running out of the transformer and three wires running to the house. The two from the transformer are insulated, and the third one is bare. The bare wire is the ground wire. The two insulated wires each carry 120 volts, but they are 180 degrees out of phase so the difference between them is 240 volts. This arrangement allows a homeowner to use both 120-volt and 240-volt appliances. The transformer is wired in this sort of configuration: •

The 240 volts enters your house through a typical watt-hour meter like this one:

The meter lets the power company charge you for putting up all of these wires.

48-pulse, GTO-STATCOM-compensated power system This model implements a 48-pulse, GTO STATCOM connected to a 3-bus, 3-plant, and 2-load power system. The model demonstrates the advantages of using Opal-RT Time-Stamped Bridges and ARTEMIS to...

Electrical Ground:

© iStockphoto.com/ Effinity Stock Photography Power-distribution systems connect into the ground many times. Note the wire trailing down the side of the utility pole in this photo. When the subject of electricity comes up, you will often hear about electrical grounding, or just ground. For example, an electrical generator will say, "Be sure to attach to an earth ground before using," or an appliance might warn, "Do not use without an appropriate ground." It turns out that the power company uses the Earth as one of the wires in the power system. The planet is a good conductor, and it's huge, so it makes a handy return path for electrons. "Ground" in the powerdistribution grid is literally the ground that's all around you when you are walking outside. It is the dirt, rocks, groundwater and so on. If you look at a utility pole, you'll probably be able to spot a bare wire coming down the side of the pole. This connects the aerial ground wire directly to ground. Every utility pole on the planet has a bare wire like this. If you ever watch the power company install a new pole, you will see that the end of that bare wire is stapled in a coil to the base of the pole. That coil is in direct contact with the earth once the pole is installed, and is buried 6 to 10 feet (2 to 3 meters) underground. If you examine a pole carefully, you will see that the ground wire running between poles are attached to this direct connection to ground. Similarly, near the power meter in your house or apartment there is a 6-foot (2-meter) long copper rod driven into the ground. The ground plugs and all the neutral plugs of every outlet in your house connect to this rod. Our article How Power Grids Work also talks about this.

Explore the links on the next page to learn even more about electricity and its role in technology and the natural world. Electrical power is a little bit like the air you breathe: You don't really think about it until it is missing. Power is just "there," meeting your every need, constantly. It is only during a power failure, when you walk into a dark room and instinctively hit the useless light switch, that you realize how important power is in your daily life. You use it for heating, cooling, cooking, refrigeration, light, sound, computation, entertainment... Without it, life can get somewhat cumbersome.

11KV Panel:

Electrical Faults: . . . .

Phase Phase Phase Phase

to to to to

phase ground phase to phase phase to phase to ground

Breaker Failure: . Minimizes the amount of equipment removed from service in event of a failure . Failure Determination

. Not started opening in a certain time . Not open in a certain time . Current not broken in a certain time

Other Protections: . . . .

Phase Unbalance Loss of field Under frequency Out of Step

Reverse Power:

Visited the following Grid Stations with P & I Staff to rectify the defects & also to attend over hauling of different Transformers & C.Brs Etc.:

Sr #

Name of Grid Date

Station

Work Done Bahawalpur Testing of distance relay LZ31

02.06.

132KV Grid

09

Bahawalpur

01

circuit breakerBWP-2 and Calibration of KWH meter 11KV University Feeder

24.06. 02

132KV M/Rasheed

To attend the fault of Power Transformer TR-1

09 07.07.

132KV Basti

09 09.07.

Malook 132KV Vehari

Attend the shut down on VHR-1 & attend the

09 12.07.

Road

fault of differential relay of TR-1

132KV Sadiqabad

Commissioning of new 20/26 MVA P/Tr

03

To attend the shut down on BTM-2 & BTM-3

04 05 09 16.07. 06

Annual testing of 132KV breakers BSR-1 & 132KV Bosan Road

09 26.07. 07

BSR-2 Attend the fault of fan control cable of 132KV Lodhran

09 07.09. 08

P/Transformaer 132KV Mesco

To attend the 6 monthly routine testing of P/Tr

132KV M/Rasheed

To attend the fault on CT of 11KV O/G feeder

09 08.09. 09 09

Sr

Date

#

Name of Grid

Work Done

Station 10.09.

10 09 16.09.

132KV Bosan Road

To attend the shut down of TR-3

132KV Basti

To change the CT ratio of 11KV O/G Noori Lal

Malook

feeder

132KV Lodhran

For installation of new 11KV O/G Panel

132KV Vehari

To attend the 6 monthly routine testing of PTr-

Road

1

132KV Kabir Wala

To attend the fault of cooling fan circuit

132KV Ind: Estate

To attend the fault of Fan circuit of TR-1

11 09 19.09. 12 09 26.09. 13 09 29.09. 14 09 30.09. 15 09