Article 480 provides the electrical installation requirements for all stationary installations of electrical storage batteries (Photo). If you have batteries for photovoltaic (PV) systems, the additional requirements of Art. 690, Part VIII apply. But covering a battery system from square one to end of life requires far more knowledge than what is in Art. 480 (see SIDEBAR: Beyond Article 480).
Temperature is also a huge issue with batteries. The discussion often focuses on how temperature affects the charging rate, while overlooking the effects on conductor ampacity. The NEC now addresses these effects.
Nec Article 480 Storage Batteries Pdf 19
In most applications, batteries are critical equipment. Why does every large data center have battery installations that exceed NEC requirements? Because no executive wants to be the one who forced mediocre engineering decisions that resulted in a $2 million shutdown.
Battery maintenance is outside the scope of the NEC, but fail to do it properly and you have defeated the purpose of installing the batteries in the first place. The IEEE has several standards pertaining to battery maintenance, depending upon the type of battery involved.
The Informational Note under 480.1 lists seven standards that anyone with responsibility for a stationary battery system should take the time to become familiar with. If your job includes responsibility for keeping the battery system reliable, take advantage of the seminars and other training provided by manufacturers of batteries and battery test equipment.
The size of the wind turbine you need depends on your application. Small turbines range in size from 20 Watts to 100 kilowatts (kW). The smaller or "micro" (20- to 500-Watt) turbines are used in applications such as charging batteries for recreational vehicles and sailboats.
Home wind energy systems generally comprise a rotor, a generator or alternator mounted on a frame, a tail (usually), a tower, wiring, and the "balance of system" components: controllers, inverters, and/or batteries. Through the spinning blades, the rotor captures the kinetic energy of the wind and converts it into rotary motion to drive the generator, which produces either AC or wild AC (variable frequency, variable voltage), which is typically converted to grid-compatible AC electricity.
Costs in addition to the turbine and the tower are the balance of system, including parts and labor, which will depend on your application. Most manufacturers can provide you with a system package that includes all the parts you need for your application. For example, the parts required for a water-pumping system will be different from the parts required for a residential, grid-connected application. The balance of system equipment required will also depend on whether the system is grid-connected, stand-alone, or part of a hybrid system. For a residential grid-connected application, the balance of system parts may include a controller, storage batteries, a power conditioning unit (inverter), wiring, foundation, and installation. Many wind turbine controllers, inverters, or other electrical devices may be stamped by a recognized testing agency, such as Underwriters Laboratories or Intertek.
Stand-alone systems (systems not connected to the utility grid) require batteries to store excess power generated for use when the wind is calm. They also need a charge controller to keep the batteries from overcharging. Deep-cycle batteries, such as those used for golf carts, can discharge and recharge 80% of their capacity hundreds of times, which makes them a good option for remote renewable energy systems. Automotive batteries are shallow-cycle batteries and should not be used in renewable energy systems because of their short life in deep-cycling operations.[16]
Small wind turbines generate direct current (DC) electricity. In very small systems, DC appliances operate directly off the batteries. If you want to use standard appliances that use conventional household alternating current (AC), you must install an inverter to convert DC electricity from the batteries to AC. Although the inverter slightly lowers the overall efficiency of the system, it allows the home to be wired for AC, a definite plus with lenders, electrical code officials, and future homebuyers.
For safety, batteries should be isolated from living areas and electronics because they contain corrosive and explosive substances. Lead-acid batteries also require protection from temperature extremes.
In most cases, it is quite advantageous to interconnect a small turbine with the customer's utility service, thereby using the utility for backup power to cover the variability of the turbine's energy production as well as storage of excess energy. Such interconnection typically requires utility permission, which is usually in the form of an interconnection agreement. This agreement will address metering and billing arrangements with the utility and may include requirements for additional safety equipment or procedures, protection devices, and inspections.[38]
For the times when neither the wind turbine nor the PV modules are producing, most hybrid systems provide power through batteries and/or an engine-generator powered by conventional fuels such as diesel. If the batteries run low, the engine-generator can provide power and recharge the batteries. Adding an engine-generator makes the system more complex, but modern electronic controllers can operate these systems automatically. An engine-generator can also reduce the size of the other components needed for the system. Keep in mind that the storage capacity must be large enough to supply electrical needs during non-charging periods. Battery banks are typically sized to supply the electric load for 1 to 3 days.[39] 2ff7e9595c
Comments