Transformers, engine-generators, power supplies, and batteries are important components of power distribution systems, and their improved performance and reliability are key to facility operation.
New technology has revolutionized generator sets. For example, you now can monitor and control all gen-set functions from a single interface. It provides selectable analog meters and digital readouts for such quantities as kW, kWhrs, PF, AC volts, frequency, % amps, %kW, % regulation, battery hours, and a 3-phase view. It also provides alarm indicators and detailed event messages. The system runs a battery load test and monitors battery voltage at each start, and continuously monitors the battery charging system, alarming as necessary. Smart starting integrates fuel ramping, field excitation, and temperature dynamics to minimize frequency and voltage overshoot. This means more accurate combustion and less black smoke. Using a Windows-based interface and RS232 communications, the system can monitor and adjust switchgear as well as communicate with the outside world.
Need to control parallel generator sets? Use the gen-set mentioned in the previous example, but add software and a small module. No separate box is required, no extra floor space is used, no voltage regulators are required, and there are no protective relays to contend with. This means less to specify, less to buy, and less to coordinate in the design, installation, and maintenance of the system. The easy-to-use software is so powerful it allows you to control multiple gen-sets, even review event records and receive remote alarms, from anywhere. If you are away from the PC, it will call your pager and send you the alarm messages!
Gas turbine improvements have significantly reduced the emission of nitrogen and carbon monoxide. Lean premixed combustion allows a much higher air-to-fuel ratio than possible before. Duel fuel turbines allow you to switch to cheaper fuel without having to duplicate turbines.
Expect small diesel turbines to be powered by the winners of the struggle for King of the Alpha range (7 to 55 hp) in diesel engines. Engines squeeze more energy from every drop of fuel than ever, with lower emissions and increased reliability thanks to advances in cylinder head and camshaft design.
Microprocessors have given transfer switches such features as digital control; highly advanced display and alarming functions; easy programming; password protection; RS-485, 422, and 232 communication; monitoring of both main and emergency sources (phase, voltage, current, etc.); and various time delay functions for transfer, engine cool down, and retransfer. Manufacturers recently introduced feature-packed switches that make upgrading an existing installation an attractive option. For new installations, the latest offerings are perfect.
Just as running athletes demand specialized shoes, watercraft athletes demand specialized batteries - and they are not alone. Electric vehicles, portable computers, and wireless communications are driving battery technology to produce new sizes and longer battery lives. Manufacturers now tune battery design, even in the separator materials and patterns, toward specific applications. Even though batteries are the weak link in UPS systems, they are undergoing continual design improvements to increase their performance and longevity.
These items have appeared over the past year in EC&M's Product News section and received the highest reader response in their category.
Two megawatt gen-set
The new 2000R OZD engine-generator set has the ability to accept its fully rated load within 10 sec. The brushless, rotating-field generator has broadrange reconnectability and is permanent magnet pilot excited for superior short-circuit capability. An electronic isochronous governor provides precise frequency regulation. The diesel turbocharged two-cycle engine, with 2980 cu in. of displacement, provides quick, one-step, full-load response. The engine has a 20V cylinder head arrangement and is rated at 1800 rpm at 60 Hz and 1500 rpm at 50 Hz. The alternator provides sustained short-circuit current up to 300% of rated current for up to 10 sec., and this short-circuit capability enables downstream circuit breakers to trip without collapsing the generator field. Voltage regulator has [+ or -] 0.25 % no load to full load regulation. Electronic engine control comes standard on this unit, with a computerized controller monitoring the amount of fuel going into the system and load requirements.
This maintenance-free, lead acid, high-capacity battery provides reliability and long life for applications ranging from UPS, security, and telecommunications to panels and emergency lights. Designated the NP18-12B, the battery's capacity is rated at 17.2 Ah for a 20-hr rate of 0.9A to 10.5V. The battery has a nominal voltage of 12V, and performs reliably over an operating temperature range of 5 [degrees] F to 122 [degrees] F(- 15 [degrees] C to 50 [degrees] C).
A series of diesel-powered generator sets is available with ratings from 320kW to 17,025kW. Efficiency ranges from 41.7% to 45.5%. The engines are designed to burn heavy fuel. A new combustion process optimizes fuel consumption and output while minimizing emission levels. The design and construction of the sets are focused on providing reliable operation and performance. Lean-burn gas-fueled engine generator sets are also available.
Generator power control
The enpower Generator Power Control parallels gen-sets together and/or with the utility grid. Features include synchronizing, load sharing, soft loading/unloading, VAR/power factor control, import-export control, and protective relays. Also provides power monitoring (kW, kvar, power factor, voltages, currents, harmonic distortion, etc.) with built-in network communications.
The line of SR4B Brushless Generators efficiently delivers optimal power quality and long trouble-free life while providing ease of installation and serviceability in standby, continuous, and harsh-environment package generator applications. Available in a variety of sizes - in voltages ranging from 380V to 5000V at 60 and 50 Hz. Permanent magnet excitation is standard on prime and continuous. Three-phase sensing and a digital voltage regulator are available as an option.
This new family of gen-set products is smaller, lighter, more fuel-efficient and provides utility-grade or better power to the electrical market. The Precise Power Products (P3) technology has led to some unique products including the Uninterruptible Energy System (UES), a combined UPS and SPS for continuous uninterrupted backup power.
Digital paralleling system
The Digital Paralleling System is based on microprocessor control technology, which includes integrated distributed logic design, Amp Sentry for paralleling, and digital synchronizing controls. Guards electrical integrity from the effects of overcurrent, over/under voltage, over/under frequency, and overload without risk of nuisance tripping.
The mid-size Phoenix series of sealed, valve-regulated batteries for UPS back-up power applications includes four models, ranging from 12V, 300W/cell to 6V, 575W/cell. Design improvements include redundant, recessed pressure relief valves for safety and .160 in. thick plastic walls. The series can be used in computer rooms, office environments, and other areas with sensitive electronics, without the need for a separate battery room.
This new line of automatic line voltage regulators, the SBL Series, provides improved performance through the use of CTR linear variable transformers and roller type contacts, which replace sliding brushes. Standard features include single board computer control, individual phase regulation, input circuit breaker, output contactor, no break bypass, and digital meters.
The operating range of this generator line now extends up to 13MW. Designed for use in prime power and cogeneration applications, these large generators offer end users durability and dependability even in the harshest conditions and operating environments. Units are available from 625kW to 13,000kW; 480V to 13,800V; 600 rpm to 1800 rpm; 50 or 60 Hz and are fully compatible with all prime movers. Approved by most world agencies, including NEMA, IEEE, CSA, Lloyds, API, UL, and IEC.
Batteries for telecommunications
The Gold UXL MVP System, a premium valve regulated lead acid modular battery system, provides high performance and long life for telecommunication and other applications. For use with cellular telecom, PBX, microwave, and photovoltaic applications. The battery life is optimized by the patented air-cooled design feature located between the cells for thermal management. Operating temperature range is - 10 [degrees] F to 125 [degrees] F.
The new medium power transformer uses barrel-type winding construction to make it more reliable, smaller, and less expensive. Barrel windings use a thermally upgraded epoxy-coated insulation that produces a good bonding of the components of the coil and increases the short-circuit strength. Reliability is increased because the conductor is not subjected to frequent bending stresses. Ratings extend up to 7.5MVA and up to 69kV.
Composed of a lithiated manganese dioxide cathode, a carbon anode, and a unique solid polymer electrolyte, the Solid State System (SSS) rechargeable batteries are thin, flexible, and provide high energy per unit weight and volume. Each has a rated capacity of approximately 75 mA-hrs. Can withstand a fast charge/discharge cycle at the demanding "C rate" - a quick-charge to full capacity in one hour followed by a complete (100%) discharge in one hour.
The Spectron ILS System provides a central battery-operated source of continuously conditioned sine wave AC output to connected equipment: lighting (including those products using electronic ballasts), egress systems, fire protection, communication, security, building management and support functions.
Power distribution cabinets
Self-contained, the DPS 2500 power distribution cabinets include a double-shielded, delta/wye, k-factor transformer, a circuit monitor, and up to four distribution panel-boards with circuit breakers. Ratings range from 15 to 225kVA. Input requirements are 208, 480, or 600V, 3-phase, 3-wire+ground. Output is 208/120V wye, 3-phase+ground. There is convection cooling. Easy to install and relocate.
Square D/Groupe Schneider
75kVA encapsulated transformers
The top rating of this line of encapsulated transformers now goes from 45 to 75kVA. The line encompasses ratings from 3 through 75kVA, 480 to 208Y/120V. These units are extraordinarily compact, with a cubic volume up to 40% less than other dry-type designs of equal kVA ratings. Operation is quiet. A large terminal compartment with flexible leads accelerates and lowers the cost of installation.
Challenger Electrical Equipment
Cast coil transformers
Dynapower offers Ultracast Cast Coil Transformers to 5000kVA and 200kV BIL. The Ultracast System, provides the ultimate in reliability, efficiency, and flexibility and features copper high- and low-voltage windings, 220 [degrees] C electrical insulation cast in 185 [degrees] C epoxy resin; and a precision core for quiet, low loss operation. The glass-reinforced epoxy resin castings are impervious to most common industrial contaminants, and the epoxy system is nonflammable.
Generator voltage regulator
This programmable microprocessor-based digital voltage regulator (DVR) allows users to easily modify voltage regulator characteristics for superior voltage regulation, on-site power quality, and system performance. The DVR provides voltage regulations of [+ or -]0.25% at no load to full load with a temperature drift of less than 0.5% for any 40 [degrees] C change over the operating temperature range. Operation in either kvar or power factor (PF) modes is possible with an optional kvar/PF controller.
The underground commercial transformers (UCTs), designed to withstand the corrosive environment of underground utility vaults, meet or exceed ANSI C57.12.24-1982 for corrosion resistance in underground 3-phase units. Available in ratings of 75 through 1000kVA, with a primary voltage range through 34500Y/19920 and a secondary voltage range through 480V.
ABB Power T&D
UL approval of transformer fluid
A new UL classification granted exclusively to R-Temp fluid provides multiple overcurrent protection options in meeting the requirements of the 1996 NEC, Sec. 45023. The classification permits, only with R-Temp fluid, the use of immersed internal expulsion fuses (i.e. Bay-O-Net) used in conjunction with back-up current limiting fuses. Full range current-limiting fusing is also an option. For installations where CL fusing is not desired, this classification permits the use of any alternate over-current protection that does not include internal fuses that vent during operation.
Cooper Power Systems
The NP26-12 battery is one of the highest capacity batteries within the industry standard case size. The lead-acid NP series, which offers high quality and maximum reliability, has been used widely in UPS systems and other applications. The 12V product has a capacity of 26 Ah at the 20-hr rate.
600V class transformers
These general-purpose distribution transformers operate on single-phase power with 50/60-Hz load frequency. Features UL-3R enclosures for indoor or outdoor service, UL Class 180 [degrees] C insulation system, and 115 [degrees] C temperature rise under full load. Can be banked for 3-phase service, and are efficient, easily installed, and electrostatically shielded for quality power on sizes 1 kVA and larger (to 25kVA).
Paralleling load transfer equipment
PowerCommand PLTE paralleling load transfer equipment offers the features of Power-Command Digital Paralleling, including active digital synchronizing and ramping controls that eliminate any significant disturbances when transferring between live sources. The new design includes a touchscreen operator interface with an animated power system one-line, comprehensive true rms metering, report generation and many other features.
The Sprint model gives users 1.25-kVA power conversion for changing from 50 to 400 Hz to fixed frequencies of 50, 60,400, or 420 Hz. Provides single phase in and single phase out.
High performance transformer
An air-cooled transformer was recently operated under water to prove its moisture resistance integrity. The Uniclad unit offers high electrical and mechanical performance, low cost, and good design. Ratings from 1 to 10,000kVA.
Two primary switching power supplies, in 5A and 2.5A ratings, have built-in electronic overload and short circuit protection with autoreset. Included is autoranging input from 90 to 264VAC or 110 to 370VDC as well as an adjustable output range of 22.5 to 28.5VDC. Operate in ambient temperatures of -20 [degrees] C to 60 [degrees] C with no derating.