Building electric system
BEMS (Building Energy Management System).

Building Management Systems are computer-based control systems (software and hardware) installed in buildings that control and monitor – either locally or remotely – the building’s mechanical and electrical equipment such as ventilation, lighting, power systems, fire systems and security systems, by collecting data from a series of sensors installed. According to SearchDataCenter, a very basic BMS consists of: “software, a server with a database and smart sensors connected to an Internet-capable network. Smart sensors around the building gather data and send it to the BMS, where it is stored in a database. If a sensor reports data that falls outside pre-defined conditions, the BMS will trigger an alarm.” BMS are especially used for large infrastructures, such as tunnels, industrial facilities (factories, data centres) and real estate developments. With 24/7 surveillance and alarm triggering, they’re designed to optimise energy efficiency and the reliability of installations. They also help cut down on on-site maintenance visits thanks to remote maintenance capabilities. BMS systems typically include a number of sub-systems, such as CTM (Centralized Technical Management), which involves centrally managing and monitoring the technical parameters of equipment, such as heating and lighting, in order to optimise consumption and cost efficiency. There are typically specific CTM systems for each functional aspect of a building, (for example, lighting), often because each area is covered by specific standards and regulations. The concept of BAS – Building Automation System, is similar to that of BMS:

Building Electrical Products

Backup batteries in a Battery room

Busbars

Breaker and Fuse Panels

Circuit breaker

Common Electrical Codes

Disconnect Switch

Distribution boards

Distribution frames

Electrical Panels

Electrical Emergencies

Electrical wiring

Electrical Products

Electrician

Electrical room

Electrical System Basics

Electrical wiring

Electric switchboards

Electricity meter

Electrical Service Connection

Fire alarm control panels

Getting Started

General Design Procedure

Glossary of Electrical Terms

General Design Procedure

Installing Light Fixtures

Load Estimation

Outlets (Receptacles)

Power Distribution in Large Buildings

Power Distribution in Small Buildings

Power Control Rooms

Power Equipment Centers

Replacing Switches & Outlets

Repairing Lamps & Cords

Regulation of Electrical Installations

Running Cable

Regulation of Electrical Installations

Substation in Building Power Lines & Substations

Switches

Service Panel

State department of electricity

Safety Steps

Transformers

Wiring Methods

What’s the difference between a fuse and a circuit breaker? Where’s the “main panel?” Are the outlets grounded? What is a building automation system? How can a building automation system help me? How do I know that the Building Automation System is actually reducing my energy demand? What is my boiler number? Do I need a permit to install an elevator or boiler? What is my elevator device number? Do I need a permit to renovate, remodel or remove an elevator? What kind of electrical work requires a permit? What do I do if I need to perform emergency electrical work? How do I resolve an electrical violation? What type of work requires a licensed plumber? Who is authorized to do electrical wiring? When is an electrical permit required? Will the Electrical Inspector design my system for me? Is an inspection required before power can be connected? How do I get a wiring approval? Has my wiring approval been received? Why do I need a wiring approval? Can my electrician provide me with a wiring approval? Do I need an additional wiring approval when going from temporary to permanent service? Do I need to call back once my wiring approval is completed? How long will it take my service to be connected once my wiring approval has been received?

Building Electrical Products 12 Volt Accessories 12 Volt Breakers 12 Volt Switches & Plates Conduit Couplings / Locknuts / Bushings / Miscellaneous Fittings Fan Boxes Fluorescent Lighting Fuses / Terminals / Connectors Ground Lugs Light Bulbs / Lamps / WP Floods Panels & Breakers Plastic Boxes / Covers Plugs & Connectors Receptacles (Outlets ) Romex / SEU Wire SCD Devices Seals / Washers / Straps / Connectors Smoke Detectors/Extinguishers Staples / Wire Protectors Switches TV / Phone Accessories W/P & Steel Boxes / Covers Wallplates Wire Loom Wire Nuts / Sleeves / Ties / Clamps Circuit breaker What is Circuit Breaker? Definition of circuit breaker : - Electrical circuit breaker is a switching device which can be operated manually as well as automatically for controlling and protection of electrical power system respectively. As the modern power system deals with huge currents, the spacial attention should be given during designing of circuit breaker to safe interruption of arc produced during the operation of circuit breaker. This was the basic definition of circuit breaker. Types of Circuit Breaker According different criteria there are different types of circuit breaker. According to their arc quenching media the circuit breaker can be divided as- 1) Oil circuit breaker. 2) Air circuit breaker. 3) SF6 circuit breaker. 4) Vacuum circuit breaker. According to their services the circuit breaker can be divided as- 1) Outdoor circuit breaker 2) Indoor breaker. According to the operating mechanism of circuit breaker they can be divided as- 1) Spring operated circuit breaker. 2) Pneumatic circuit breaker. 3) Hydrolic circuit breaker. According to the voltage level of installation types of circuit breaker are referred as- 1) High voltage circuit breaker. 2) Medium voltage circuit breaker. 3) Low voltage circuit breaker. or Types of circuit breakers Single-pole breakers Single-pole breakers Ground fault circuit interrupter (GFCI) circuit breakers AFCI breakers Low-voltage circuit breakers Magnetic circuit breakers Thermal magnetic circuit breakers Common trip breakers Medium-voltage circuit breakers High-voltage circuit breakers Sulfur hexafluoride (SF6) high-voltage circuit breakers Disconnecting circuit breaker (DCB) Carbon dioxide (CO2) high-voltage circuit breakers Other breakers Inside of a circuit breaker The design includes the following components: 1.Actuator lever - used to manually trip and reset the circuit breaker. Also indicates the status of the circuit breaker (On or Off/tripped). Most breakers are designed so they can still trip even if the lever is held or locked in the "on" position. This is sometimes referred to as "free trip" or "positive trip" operation. 2.Actuator mechanism - forces the contacts together or apart. 3.Contacts - Allow current when touching and break the current when moved apart. 4.Terminals 5.Bimetallic strip. 6.Calibration screw - allows the manufacturer to precisely adjust the trip current of the device after assembly. 7.Solenoid 8.Arc divider/extinguisher Here are further guidelines. Electrical room Electrical rooms typically house the following equipment: Electric switchboards Distribution boards Circuit breakers and disconnects Electricity meter Transformers Busbars Backup batteries in a Battery room Fire alarm control panels Distribution frames Disconnect Switch A disconnect switch is mounted on the outside of your home close in proximity to the meter on the outside of your home or power pole. The advantage of having a disconnect switch is for safety. In the event of a fire or flash flood, you can shut the power off from the outside of your home verses having to enter a burning home or a flooded basement. The other instance is having a transfer switch in which you can switch between live power and a generator for backup power. Breaker and Fuse Panels A breaker panel consists of a main breaker that is sized according to your homes’ load needs. Typically, homes have a 100 amp or a 200 amp service. A main breaker of 100 amps will only allow 100 amps to flow through it without tripping. In a tripped state, no current will flow throughout the panel. It is the interrupt between the service and the branch circuits of the panel. This main breaker protects the main service wires from damages that would occur given an overload. In that case, the wires would heat up and eventually could cause a fire. Switches Switches are the devices that turn on and off lights and fans in your home. These switches come in many different styles and colors to suit your design needs. There are single-pole, three-way, four-way and dimmer switches. Their purpose is to alter the flow of current to your lights and fans in a home. Outlets Electrical outlets are used to plug portable devices into. Televisions, lights, computers, freezers, vacuums and toasters are all good examples of devices that can be plugged into an outlet. Outlets consist of a hot feed, a neutral and a ground. Power Distribution in Large Buildings Large buildings have a much higher electrical load than small buildings; therefore, the electrical equipment must be larger and more robust. (America 13.8kV) Transformer, which lowers the voltage to a more usable level (in the US, 480/277 volts). The electricity is then transmitted to switchgear. The role of the switchgear is to distribute electricity safely and efficiently to the various electrical closets throughout the building. The equipment has numerous safety features including circuit breakers, which allow power to be disrupted downstream - this may occur due to a fault or problem, but it can also be done intentionally to allow technicians to work on specific branches of the power system. It should be noted that very large buildings or buildings with complex electrical systems may have multiple transformers, which may feed multiple pieces of switchgear. The electricity will leave the switchgear and travel along a primary feeder or bus. The bus or feeder is a heavy gauge conductor that is capable of carrying high amperage current throughout a building safely and efficiently. The bus or feeder is tapped as needed and a conductor is run to an electric closet, which serves a zone or floor of a building. Each electrical closet will have another step-down transformer - in the US, this will drop the power from 480/277 volts to 120 volts for convenience outlets. That transformer will feed a branch panel, which controls a series of branch circuits that cover a portion of the building. Each branch circuit covers a subset of the electrical needs of the area - for instance: lighting, convenience outlets to a series of rooms, or electricity to a piece of equipment. Power Distribution in Small Buildings The transformer reduces the voltage from 13.8kV down to 120/240 or 120/208 volts and then passes the electricity to a meter, which is owned by the utility and keeps a record of power consumption. Wires transfer the electricity from the meter to a panel board, which is generally located in the basement or garage of a house. The panel board will have a main service breaker and a series of circuit breakers, which control the flow of power to various circuits in the building. Each branch circuit will serve a device (some appliances require heavy loads) or a number of devices like convenience outlets or lights. Safety Steps Before you do any electrical work on a circuit, make sure the power is off. Turn off the breaker (or pull/unscrew the correct fuse) to the circuit you'll be working on. Post a sign on the service panel so nobody tries to restore power while you're working on the circuits. Double-check the circuit with a circuit tester before you touch it to make sure the correct breaker has been tripped. Labeling or drawing a diagram before unhooking wires will take any guesswork out of how to reconnect them. Wear shoes with non-conductive soles, use tools with rubber grips and don't stand in water to avoid a potentially dangerous shock. Finally, never push yourself to finish a wiring job. That's when mistakes happen. If you run into a difficult stretch of work, take a break and think about what needs to be done. If you're still not sure, don't take chances -- contact a professional. What’s the difference between a fuse and a circuit breaker? Fuses and circuit breakers are both found in the electrical panel (or sub-panel) of a house. They both serve the purpose of cutting the flow of electricity when a circuit gets overloaded—a potentially dangerous situation. Circuit breakers will be found in most houses built after the 1960s or in older buildings that have had their electrical systems upgraded. Fuses have a thin strip of metal that literally blows when there’s too much electricity flowing through it. When this happens, the fuse needs to be taken out and replaced. Since the 1960s circuit breakers have been used instead of fuses. They are more convenient, as they just need to be flipped back on if they are tripped. Unlike a fuse, they don’t need to be replaced. Both circuit breakers and fuses are rated according to how much electricity can flow through them before they trip and shut down the circuit. A 15- or 20-amp fuse is typical for regular light fixtures and such. If the right fuse or circuit breaker isn’t used, it can cause a dangerous situation. Clearly, if a fuse or circuit breaker becomes problematic, an electrician should be called in to look at it. Where’s the “main panel?” This is where all the circuits in the house originate from and it’s usually near where the electric power enters the building. It will be filled with circuit breakers (or fuses in an older building). The main panel has a rating that determines the total amount of current that can flow out to the circuits at one time before the main circuit breaker shuts the entire system down. Most moderately sized older houses have 100 amp service, though a smaller house might only have 60 amp service. Larger new houses are often built with 200 amp service to accommodate all the electronics used these days. Are the outlets grounded? These days most electrical outlets that you see accept three prong plugs. This means, almost always, that the outlet is grounded. A grounding wire, which connects to the round third hole, protects against electric current escaping from the circuit and causing shocks. Older houses might only have two prong outlets, meaning there’s no grounding protection in the circuits. Upgrading an electrical system to include grounding wires involves opening the walls and can be a significant amount of work. How much work it is depends on the size, construction and layout of the house. GFI outlets (GFI stands for “ground fault interrupter”) are typically required by building codes when installing an outlet near a water source or a damp location. These are the three prong outlets that have two buttons on them reading “test” and “reset.” Since water and metal handles and spouts conduct electricity, it makes a ground fault particularly dangerous in wet locations such as a bathroom. A ground fault is where the electricity goes astray despite the grounding wire. If this happens the GFI quickly cuts the power. GFI outlets are also called GFCI, or ground fault circuit interrupter. Knowing how to talk the talk about a listing’s electrical system will help to put a little spark in your sales pitch. The important thing to remember is that for a price, electrical systems can be upgraded and expanded to meet the needs of the buyer as well as building code requirements. What is a building automation system? A BAS is a network of small, dedicated microcomputers designed to control various parts of a building, such as lighting, heating, air conditioning, elevators, blinds, boilers, chillers, fans, and other parts of the building infrastructure. A scalable and flexible building automation system is the foundation of any energy conservation program for a building. How can a building automation system help me? A well designed system effectively reduces energy consumption year after year. How do I know that the Building Automation System is actually reducing my energy demand? Measurement is a key component of any energy program in verifying that energy conservation measures are turning in the results that were predicted. The combination of metering and building automation system data logging takes measurements as frequently as necessary through the system network to produce energy use reports. These reports then permit before/after comparison of energy demand. By aligning this data with the time energy conservation measures that were put in place, the system verifies whether energy reduction actually occurred and why. What is my boiler number? A - Your boiler number is an identification provided by the Department that identifies a specific boiler in a building. Do I need a permit to install an elevator or boiler? Yes. What is my elevator device number? Do I need a permit to renovate, remodel or remove an elevator? A – Yes. Q - What kind of electrical work requires a permit? Q - What do I do if I need to perform emergency electrical work? Q - How do I resolve an electrical violation? What type of work requires a licensed plumber? A - Any plumbing work beyond the direct replacement of a same-type plumbing fixture, or a simple repair. Who is authorized to do electrical wiring? When is an electrical permit required? An electrical permit is required anytime electrical wiring is installed or modified. Will the Electrical Inspector design my system for me? The Electrical Inspectors are not permitted to design an electrical system for you, but they will be happy to answer any questions regarding _______ codes. If you have any questions on your plans or rough drafts, contact the Electrical Inspector in your area. Is an inspection required before power can be connected? Electrical wiring in North America follows regulations and standards for installation of building wiring. When must a project be classified as electrical or mechanical? A project must be classified as Electrical or Mechanical when the majority of the work falls under that classification. What is the definition of "bus bar"? A grounded metal bar in a breaker box to which all neutral and grounding wires are connected.