Circuit Breaker

 

Breaker is static device which make & break the power supply. It is used as protective device. 

Unlike fuses, which must be replaced when they open, a circuit breaker can be reset once the overcurrent condition has been corrected. Pushing the handle to the “OFF” position then back to the “ON” position restores the circuit. If a circuit reopens upon reset to the “ON” position, the circuit should be checked by a qualified electrician.

In the following illustration, an AC motor is connected through a circuit breaker to a voltage source. When the circuit breaker is closed, a complete path for current exists between the voltage source and the motor allowing the motor to run. Opening the circuit breaker breaks the path of current flow and the motor stops. The circuit breaker automatically opens when it senses a fault. After the fault has been cleared, the breaker can be closed, allowing the motor to operate.

Below CBs are low capacity Breakers:    (6 Amp to 400 Amp) 

1. Miniature Circuit Breaker (MCB)

MCB or Miniature Circuit Breaker is an automatically operated electromechanical device used for the protection of the circuit from overloading or short circuit. It breaks or opens the circuit when the current flowing through it exceeds its rated limit. MCB is used for the protection of low voltage circuit 240/415 v AC having a wide range of current ratings below 125V.

MCB doesn’t trip (switch off) instantly, instead there is a time delay between fault occurrence & the breaking of contacts. Generally, they are designed to have a time delay of less than 2.5 millisecond for short circuit & 2 sec to 2 min for overloading. It is to make sure the CB does not trip every time with a momentary surge or starting of inductive load due to high inrush current from such loads such as electrical motors.

MCB does not have adjustable trip characteristics. While the breaking mechanism could be either thermal or thermal-magnetic in operation. The thermal breaking mechanism is used in case of overloading while the magnetic breaking mechanism is used in case of short circuit.

MCB is enclosed in an insulating casing. The fixed & moving contacts made of copper or silver alloy connects with the two terminal for current supply. There is an arc chute consisting of multiple conducting plates called arc splitters that dissipate the arc energy. While the operating mechanism as discussed earlier is of two types i.e. thermal & magnetic.

The thermal tripping mechanism consists of a bimetallic strip (made from two different metals having different thermal expansion) usually made from steel & brass is used for breaking the circuit in case of overloading. When the current above-rated limit starts flowing through the metallic strip, it heats up & starts expanding due to which it bents & triggers the latch to separate the contacts.

The magnetic tripping mechanism consists of a coil or solenoid that produces a magnetic field when current flows through it. In case of a short circuit or very high current, the solenoid produces a strong magnetic field to pull the lever & separate the contacts.

2. Molded Case Circuit Breaker ( MCCB) 

Molded Case Circuit breaker is an electromechanical circuit breaker having very high current ratings up to 2500 Amps. It is used in applications where the current ratings exceed the range of MCB (Miniature Circuit Breaker). It offers a thermal-magnetic tripping mechanism where the thermal mechanism is used for overloading & magnetic is used for short circuit conditions. It can interrupt current around 10k – 200k amps.

The best & most prominent part of MCCB is that its trip characteristics are adjustable in any current rating. MCB does not have such a feature. MCCB is suitable for applications where normal current is above 100 amps. They are installed in industries.

MCCB can have fixed or interchangeable trip unit. The trip unit is responsible for breaking the contacts upon meeting the fault condition

3. Earth Leakage Circuit Breaker (ELCB)

ELCB is a type of circuit breaker that breaks its circuit upon sensing of leakage current. Leakage current occurs due to insulation failure of the wiring & it can flow through a person’s body & cause electrical shock. Thus they are used for protection against electrical shock. They do not offer protection against overloading or short circuit. Therefore, they must be used in series with an MCB.

There are two types of ELCB;

• Voltage ELCB
• Current ELCB (aka RCCB)

Both types of ELCB detect the leakage current but their sensitivity & the level of protection they offer are different. Voltage ELCB was invented before current ELCB. Voltage ELCB is inferior to current ELCB. Therefore, to avoid confusion, the voltage ELCB is renamed ELCB while the current ELCB is renamed as RCCB.

Voltage ELCB

Voltage ELCB operates on voltage level between earth & the body of the equipment. Such ELCB has an extra terminal for earth connection which is directly connected to the load or equipment’s body. If the load’s body comes in contact with the live wire, it may cause electrical shock upon touching it.

A relay is connected in series with the earthed wire. This relay senses voltage difference between the body & earth. It trips the circuit breaker off if there is a substantial amount of current flow through the earth wire due to the potential difference.

However, ELCB cannot sense the current leakage if a person comes in contact with a live wire. Therefore, ELCB cannot offer protection for other types of leakage current.

4. Residual Current Circuit Breaker ( RCCB) 

Current ELCB is generally known as RCD or RCCB. Residual Current Device (RCD) or Residual Current Circuit Breaker (RCCB) is a type of ELCB that breaks the circuit in case of leakage current. It helps in protection against electrical shock or downed line.

The current leakage occurs when the current flows in an unintended path. In normal conditions, the current flows into the load through a hot or live wire & flows out of the load through the neutral wire.  The current leaks if the current flows out through the ground wire or through a person’s body connected with the ground.

RCCB works on the principle of Kirchhoff’s current law, according to which the amount of current entering the circuit must be equal to the amount of current leaving the circuit. It continuously monitors the current in the hot wire & neutral wire. The difference between these two currents is called residual current. When there is an imbalance in the circuit, the residual current will trip the circuit breaker.

The live & neutral wire goes through a zero-sequence current transformer (it is used for sensing an imbalance of current between the two wires). The live & neutral wire is used for current going into & out of the circuit respectively. Since the amount of current is same in both wires, their flux cancels each other. when the imbalance occurs due to any ground fault, the resultant flux induces a voltage in the current transformer which is connected with a relay that breaks the circuit.

Below CBs are high capacity Breakers:    (800 Amp to 10000 Amp) 

1. Air Circuit Breaker (ACB)

2. Air Blast Circuit Breaker

3. Oil circuit Breaker

4. Sulphur Hexa Fluoride CB (SF6 CB) 

5. Vacuum Circuit Breaker (VCB) 

If you have any questions or query then mail us on abhijack143@gmail.com we will help you. 

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Facility Management?

What is Facility Management?

Facility management refers to the discipline and practice of coordinating and overseeing the physical assets, infrastructure, and services of an organization or facility. It involves the effective and efficient management of buildings, equipment, systems, and resources to support the organization's core operations and ensure a safe, functional, and productive environment for its occupants.

 

The role of facility management encompasses a wide range of activities and responsibilities, including:

 

1.Maintenance and Operations: Managing the day-to-day operations of the facility, including maintenance, repairs, cleaning, and security. This involves ensuring that all equipment and systems are functioning properly and that the facility is clean, safe, and comfortable for its occupants.

 

2.Space Planning and Utilization: Optimizing the use of available space within the facility to meet the organization's needs. This includes space allocation, layout design, furniture arrangement, and office move.

 

3.Health and Safety: Implementing and maintaining health and safety policies and procedures to minimize risks and ensure compliance with applicable regulations. This involves conducting regular inspections, addressing hazards, and providing training and awareness programs.

 

4.Environmental Sustainability: Promoting sustainable practices and initiatives within the facility to minimize environmental impact. This includes energy conservation, waste management, water efficiency, and the use of eco-friendly materials.

 

5.Asset Management: Managing the lifecycle of physical assets, such as equipment, machinery, and infrastructure. This involves planning for their acquisition, maintenance, replacement, and disposal to ensure optimal performance and cost-effectiveness.

 

6.Vendor and Contract Management: Engaging and overseeing external service providers and contractors to deliver various facility-related services, such as cleaning, security, landscaping, and maintenance. This includes vendor selection, contract negotiation, and performance monitoring.

 

7. Technology Integration: Utilizing technology solutions to enhance facility operations and management. This may include implementing computerized maintenance management systems (CMMS), building automation systems, and other software applications for efficient tracking, reporting, and analysis.

 

Effective facility management requires a multidisciplinary approach, involving knowledge and skills in areas such as engineering, architecture, project management, finance, and interpersonal communication. The goal is to optimize the facility's performance, reduce operating costs, enhance occupant satisfaction, and support the organization's overall objectives.

Facility Management is an organizational function which integrates people, place and process within the built environment with the purpose of improving the quality of life of people and the productivity of the core business.

This combination of job responsibilities supports the operations of each organization to create an environment where the systems work together seamlessly, from the parking lot to the executive suite. Facility managers are the people who make sure we have the safest and best experience possible, by coordinating the processes that make the built environment succeed.

How Facility Management work?

Facility management involves the coordination and management of various aspects of a building or facility to ensure its smooth operation, maintenance, and functionality. It encompasses a wide range of services and activities aimed at optimizing the physical environment and supporting the people and processes within the facility.

Here are some key elements and processes involved in facility management:

• Planning and Strategy: Facility management starts with establishing goals and objectives for the facility. This includes developing strategies, budgets, and long-term plans to achieve operational efficiency, cost-effectiveness, and sustainability.

 

• Maintenance and Repairs: Regular maintenance and repairs are crucial to keeping the facility in optimal condition. This involves scheduling and performing routine inspections, addressing maintenance issues, and coordinating repairs or replacements of equipment, systems, and infrastructure.

• Space Management: Facility managers are responsible for effective space utilization within the facility. This includes planning and allocating space for different functions, departments, and personnel. They may also oversee office layout, furniture arrangement, and optimizing space usage. 

• Health and Safety: Ensuring a safe and healthy environment for occupants is a key responsibility of facility management. This involves compliance with safety regulations, conducting risk assessments, implementing emergency response plans, and maintaining appropriate safety measures such as fire prevention systems, security protocols, and building access controls. 

• Energy and Sustainability: Facility managers are increasingly focused on energy efficiency and sustainability initiatives. They may analyze energy consumption, implement conservation measures, explore renewable energy options, and oversee waste management and recycling programs to minimize the facility's environmental impact. 

• Vendor and Supplier Management: Facility managers often engage and manage contracts with external vendors and service providers. This includes selecting and monitoring contractors for maintenance, repairs, cleaning, security, and other facility-related services. 

• Budgeting and Financial Management: Facility managers are responsible for budget planning, financial forecasting, and cost control. They need to track expenses, allocate funds for maintenance and repairs, and identify opportunities for cost savings without compromising the facility's performance. 

• Technology and Systems: Facility management increasingly relies on technology and integrated systems for efficient operations. This may include computerized maintenance management systems (CMMS), facility management software, energy management systems, building automation systems, and IoT (Internet of Things) devices for monitoring and controlling various facility parameters. 

These are just some of the core aspects of facility management. The specific tasks and responsibilities may vary depending on the type of facility (e.g., office building, hospital, educational institution) and the organization's objectives and priorities.

If you have any questions regarding Facility Management then mail us on abhijack143@gmail.com we will help you. 

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Technical Team

Technical Facility Management

The role of Technical team in Facility Management services is as per below:

• Ensuring all Electrical & Mechanical equipment/system is working under normal condition. 
• Attending breakdowns & complaints related to E&M system. 
• Vendor management. 
• Providing building maintenance general services,
• Managing and optimizing all costs related to technical building operation,
• Ensuring the performance of all mandatory actions related to the building operation.

Equipment/ Systems which are need to be handle by Technical Team:

• Electrical equipment ( LT panel, APFC panel, Breaker, UPS & other electrical equipment) 
• heating, ventilation, air conditioning equipment, ( All types of AC) 
• plumbing and Carpentry work,
• fire and Life Safety equipment ( FAS, CCTV, PA, FM200, WLD) 
• mechanical and industrial equipment. 

Role & Responsibilities of Technical services:

• To ensure overall maintenance and management of the site including infrastructure, common assets and services and equipment s like DG system, HVAC system, elevators and escalators, BMS, HT and LT panels, APFC panels, server rooms, data center, UPS and VFD (variable-frequency drive), pumping system, WTP,STP, fire alarms, hydrant systems, switch yard, digital application etc.
• To ensure the people management at site - selection, site induction, attendance, discipline, leave, registers.
• To ensure that AMC schedules, renewals are followed. All maintenance is carried out as per schedule and service reports are kept properly.
• To plan, forecast and execute, all the PPM / shutdown schedules in co-ordination with site team.
• To maintain documents on monthly, quarterly, half yearly, yearly basis for planned preventive maintenance of equipment s as per the audit standards.
• To identify, suggest and implement avenues for cost control, savings - maintenance, operational and energy.
• All material and equipment maintained as per 5S and Kaizen principles.
• To report all incidents within 24 hours of occurrence along with incident report to reporting manager / client.
• To ensure timely closure of any breakdowns and report to the concern.
• To ensure effective implementation of best safe work practices to maintain a high awareness of safety among all site staff.
• To lead a team of housekeeping / guest relations/ helpdesk and other site personnel and allocate shifts (wherever applicable).
• To ensure the cleaning, disinfection, sanitization as per the schedule to maintain highest hygiene standards at the premises.
• To take periodic rounds of the building for the inspection and modification of systems/procedures and note any shortcomings and plan to fix the same immediately.
• To ensure the adherence of the SOP s related to any emergency scenario (e.g. COVID19).
• To prepare and execute duty roster for all site staff.
• To prepare annual budget for the support services at site.
• To provide recommendations for the disposal, conversion or upgrade of the equipment.
• To ensure monthly bills are submitted to client as per SLA / agreement and timely collection of payment.
• To ensure all client complaints / queries are addressed within the TAT.
• To maintain periodic reports and documents as per site requirements.
• To ensure invoices being raised in coordination with the operations and commercial team within the stipulated time period. Vendor invoices need to be certified as expected by the client.
• To maintain professional relationship within vendor team and vendors deployed on site to obtain cooperation and synergy of delivery module.
• To carry out vendor performance evaluation on monthly basis and maintain score card for SLA tracking and necessary action for improvement.
• To monitor and control attrition / absenteeism of vendor staffs and make necessary arrangements to manage shortfall.
• To coordinate with vendors, checking and submitting invoices for timely pay-out.
• To coordinate for timely pay-out of vendor staff salaries.
• To organize and coordinate formal monthly meetings with the client and vendors.
• To maintain and submit attendance and overtime details as per SOP.
• To maintain statutory registers at site like muster roll, overtime register, register of fines and deductions etc.
• To liaison with statutory authorities and municipal departments for permission, licenses etc.
• To prepare and analyses various site reports like DSR, MMR, QBR etc and identify loopholes to avert crisis.
• To maintain and update database, feedback, MMR from vendors, statutory / technical compliances are met by vendors as per deliverables.
• To ensure site profitability.
• To maintain and keep records of Petty cash.
• To ensure adherence to company and client policies and SOPs.

To understand how below systems are work, click on it.

    1) Electrical System

    2) HVAC System

    3) Fire & Safety System

If you have any questions regarding technical facility then mail us on abhijack143@gmail.com we will help you. 

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Electrical System

 

Each organization is required electric supply 24X7 to run their company. In industry, it used for machinery & in IT companies, used for PC, server & other support systems. Due to that electrical energy is most important for any company or organization. 

Electric Power is the main source of our daily life activity and use of Electric Power is increasing every day in the world. Electricity is being generated through various sources i.e. thermal, hydro, nuclear, solar etc. but its transmission, distribution and utilization is almost everywhere in the world. 

There is a technical team in facility management to handle this electrical system. In this team Facility Manager, Assistant Facility Manger, Technical Executive, Supervisor & Electrician (MST) are working for continuous power supply. 

When you join any site in facility management then you need to understand the Single Line Diagram of the building.

Single-line diagrams use standard symbols for the different nodes of power systems. The power source is displayed at the top of the diagram so that the power path can easily be followed downstream from node to node and redundant power paths can be visualized side-by-side. 

• It is used to analyze a building's electrical system,

• Building maintenance staff and electricians rely on one-line diagrams to show them the way around the electrical system,

• Inaccuracy in this documentation and failure to update one-line diagrams on a regular basis as electrical systems invariably grow over time often results in increased down time when system failures occur,

• Facility supervisors may use the info found in single-line diagrams to greatly enhance the performance of service activities, 

• The single line diagram offers several benefits to the facility it outlines, especially identification of possible problem places, improved safety conformity, and enhanced staff safety.

 

The one-line diagram provides the following information:

 

• Manufacturers type designations, and ratings of devices.

• Ratios of current and power transformers, taps to be used in multi-ratio transformers, and connections of double-ratio transformers.

• Rating connections of wye and delta power transformer windings 

• Circuit breaker ratings in volts and amperes. 

• The interrupting rating, type, and number of trip coils on circuit breakers.

• Switch and fuse ratings in volts and amperes.

• Function of relays.

• The sizes, type, and number of incoming and outgoing cables.

• The voltage, phase, and frequency of incoming and outgoing circuits. The available short circuit and ground currents of the power company system, and type of ground used.

• Metered points and type of metering.

• The amount of the load on all feeders.

 

In above SLD there are lots of equipment's which is used to carry power from one end to another end.

 

1) Transformer

2) Breaker

3) Diesel Generator (DG)

4) APFC Panel

5) UPS

6) ATS

7) Mega Switch

8) Isolation Transformer

If you have any questions regarding electrical system then mail us on abhijack143@gmail.com we will help you. 

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Transformer

 What is a Transformer? 

A Transformer is a static electrical machine which transfers AC electrical power from one circuit to the other circuit at the constant frequency, but the voltage level can be altered that means voltage can be increased or decreased according to the requirement.

It works on the principle of Faraday’s Law of Electromagnetic Induction which states that “ the magnitude of voltage is directly proportional to the rate of change of flux.”

Here are some key reasons why electrical transformers are necessary:

Voltage Transformation: Transformers are primarily used for voltage transformation. They can step up or step down the voltage levels as required. High voltage is used for efficient transmission of electricity over long distances, while low voltage is suitable for safe distribution and utilization of power in homes, offices, and industries.

Power Distribution: Transformers facilitate the distribution of electrical power across various locations. They are used in substations to step down the high-voltage electricity transmitted through power lines to lower voltage levels suitable for local distribution networks.

Loss Reduction: Transformers help reduce power losses during transmission and distribution. High-voltage transmission lines are used to minimize the current and hence the I2R losses, as power loss is proportional to the square of the current. By stepping up the voltage at the generation end, the current is reduced, resulting in lower transmission losses.

Isolation and Safety: Transformers provide electrical isolation between input and output circuits. This isolation ensures the safety of individuals and equipment by preventing direct contact with high-voltage components. It also helps protect sensitive equipment from voltage fluctuations and electrical disturbances.

Impedance Matching: Transformers are used to match the impedance between different electrical systems. Impedance matching ensures efficient transfer of power between the source and load, maximizing power transfer and minimizing reflection losses.

Power Conversion: Transformers are integral to various power conversion processes. They are used in AC to DC conversion (rectifiers) and DC to AC conversion (inverters) to adapt electrical power to different types of equipment and applications. 

Overall, electrical transformers are essential components in modern power systems, enabling efficient transmission, distribution, and utilization of electrical energy while ensuring safety, minimizing losses, and enabling power conversion. 

Construction of Transformer:

Basically a transformer consists of two inductive windings and a laminated steel core. The coils are insulated from each other as well as from the steel core. A transformer may also consist of a container for winding and core assembly (called as tank), suitable bushings to take our the terminals, oil conservator to provide oil in the transformer tank for cooling purposes etc. The figure at left illustrates the basic construction of a transformer.

In all types of transformers, core is constructed by assembling (stacking) laminated sheets of steel, with minimum air-gap between them (to achieve continuous magnetic path). The steel used is having high silicon content and sometimes heat treated, to provide high permeability and low hysteresis loss. Laminated sheets of steel are used to reduce eddy current loss. The sheets are cut in the shape as E,I and L. To avoid high reluctance at joints, laminations are stacked by alternating the sides of the joint. That is, if joints of first sheet assembly are at front face, the joints of the following assembly are kept at the back face.

Working: 

The basic principle behind working of a transformer is the phenomenon of mutual induction between two windings linked by common magnetic flux. The figure at right shows the simplest form of a transformer.

Basically a transformer consists of two inductive coils; primary winding and secondary winding. The coils are electrically separated but magnetically linked to each other. When, primary winding is connected to a source of alternating voltage, alternating magnetic flux is produced around the winding. The core provides magnetic path for the flux, to get linked with the secondary winding. Most of the flux gets linked with the secondary winding which is called as 'useful flux' or main 'flux', and the flux which does not get linked with secondary winding is called as 'leakage flux'. As the flux produced is alternating (the direction of it is continuously changing), EMF gets induced in the secondary winding according to Faraday's law of electromagnetic induction. This emf is called 'mutually induced emf', and the frequency of mutually induced emf is same as that of supplied emf. If the secondary winding is closed circuit, then mutually induced current flows through it, and hence the electrical energy is transferred from one circuit (primary) to another circuit (secondary).

Parts of Transformer:

Laminated Core: 

The main function of a laminated core is to separate primary and secondary windings. The core is laminated in order to reduce the core losses in a transformer. The core is generally made up of Cold Rolled Grain Oriented (CRGO) steel material windings. 

Insulating materials:

The main function of insulating material is to provide insulation to windings so that it does not come in contact with the transformer core or other conducting material. The windings are wrapped in insulating paper or cloth.

Transformer oil:

The main function of the transformer oil is to provide insulation as well as act as a cooling agent due to its chemical properties and dielectric strength. It dissipates heat generated from the core and windings to the environment. Hence cooling the transformer.

Conservator tank:

The main function of a conservator tank is to provide extra space to accommodate the transformer oil during oil expansion inside the transformer when the ambient temperature rises. It is a cylindrical tank mounted on the top of the supporting structure of a transformer. It is generally half-filled with transformer oil.

Buchholz Relay:

The main function of the Buchholz relay is to protect the transformer from different internal faults such as inter-turn fault, short circuit fault, etc. It detects the occurrence of a fault and generates the alarm circuit. It is present between the main tank and the conservator tank.

Breather:

The main function of a breather is to prevent moisture to enter the transformer during the breathing cycle of a transformer. It contains the silica gel that absorbs the moisture from the air and hence prevents transformer oil to contaminate and thereby saves the internal parts.

Cooling tubes:

The main function of the cooling tubes is to transfer heat from the transformer core and coils to the environment. The heated transformer oil circulates through the cooling tubes where the heat radiates out by natural airflow and hence cooling the transformer oil.

Tap Changer:

The main function of the tap changer is to regulate the transformer output voltage by altering the number of turns in one winding and thereby changing the turn ratio of the transformer.

Protective Devices for Transformer:

1. Transformer-Electrical Protection Types:

• Over Current/Earth Fault:
• Under Impedance/Distance relay protection. 
• Differential Current Protection. 
• Restricted Earth fault Protection. 
• Three Phase Overload Protection. 
• Over Fluxing Protection. 
• Over Voltage /Under Voltage protection. 

2. Transformer-Mechanical Protection Types:

• Oil Temperature Indicator. 
• Winding Temperature Indicator. 
• Oil Pressure. 
• Gas Accumulation using Gas. Accumulation Relay (Buchholz Relay). 

Interview Questions. 

1. What is the transformer?            

Ans: Transformer is static device which transfer the power from one AC circuit to another AC circuit without change in frequency. 

   

2. What is the working principle of a transformer.? 

Ans: Transformer works on the principle of Faraday's law of mutual induction. When primary winding energized by supply voltage then due to mutual induction secondary winding is also energized. 

3. Can we use a transformer in DC system?

Ans:  No, we can't use DC supply for transformer because when DC supply apply on primary winding then it does not create mutual induction (emf) that's why secondary winding will not energized. AC supply have sine waves that's why it create mutual induction. 

4. How neutral is create in transformer? 

Ans: when windings second end is meet at one point then neutral is create. At that point voltage & current is zero. When secondary winding energized then it will reduced due to winding resistance & it becomes zero. 

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