Power conditioning and protection

Manufacturers provide a wide array of answers to power quality questions. Some of these answers are whole new technologies, while others are reincarnations - in greatly improved form - of older technologies.An example of an improved older technology is synchronous power factor correction. This technology exists in at least three forms. One is a synchronous condenser, in which a synchronous motor acts

Manufacturers provide a wide array of answers to power quality questions. Some of these answers are whole new technologies, while others are reincarnations - in greatly improved form - of older technologies.

An example of an improved older technology is synchronous power factor correction. This technology exists in at least three forms. One is a synchronous condenser, in which a synchronous motor acts as a VAR generator. Another is a synchronous motor generator, in which a motor and generator act together as a power-conditioning rotary filter. A third form is the rotary UPS, which basically is a motor generator with a battery and the requisite switching. Improvements make these older technologies worth a serious look.

Surge protectors come in two varieties: Surge diverters, which are based on Metal Oxide Varistors (MOVs) and surge suppressors, which filter and modulate the surge. Diverters are most common. Surge diverters conduct overvoltages to ground while surge suppressors filter overvoltages. A key factor to look for in a suppressor is its inductor mass; a heavy enough inductor will experience absolutely no degradation and will have no delay in response.

Along with line protection, we have surge diverters for data lines (i.e., telephone/modem, ISDN, LAN, WAN, T1, 4-20 mA loops, RS232, RS422, RS423, RS485) incorporated into LIPS equipment or available separately. These devices come in a myriad of configurations and mounting options - plug-in-the-wall to DIN-mounting to a full-blown rack-mounted system.

Protection for desktop, workstation, and server units continues to progress. Now there are even portable surge protectors for portable computers (i.e., laptops and notebooks) - complete with modem/fax protection.

Uninterruptible power supplies used to have no instrumentation. The old way of monitoring batteries was finding out they were dead - after a power failure knocked your data center out. Part of the problem was you had to take the UPS out of service to do any maintenance at all. Today, you can swap batteries while the UPS is running. UPSs now warn of impending battery failure, so power failure is no longer the means of discovery.

Battery redundancy, expandability, and float charging are common features. The modularity offered in today's units means you can buy for today's needs without bearing the cost for tomorrow's needs until tomorrow. Modularity increases reliability by confining failure to one small section, which you can easily replace.

Today's UPSs can shut down running applications automatically in a predetermined orderly manner as the limit of battery charge approaches. They have remote-control, event-logging, data-logging, self-test, battery management, query-answering, power analysis, and graphical display features. UPS software has kept up with advances in computer operating systems. Recent feature improvements have been dramatic - they will be even more so as PC software developers shift to Windows NT 4.0 in 1997.

For extremely critical loads, consider the engine-coupled UPS. It combines a rotary LIPS with a diesel or natural gas engine to provide long-term backup in a single unit. This approach eliminates the buyer's integration worries, and it saves installation space and cost because it requires no separate UPS room. Also, no harmonics feed back to the engine-generator. Such a UPS is available in both series and parallel configurations, in sizes from 180kVA to 1300 kVA.

Category Fourteen


These items have appeared over the past year in EC&M's Product News section and received the highest reader response in their category.

Surge suppressor receptacle

As part of the SpecGuard line of transient voltage surge suppressors (TVSS), the receptacle-type provides point-of-use protection. These units are UL-listed and offer three modes of protection; line-to-neutral, line-to-ground, and neutral-to-ground. Current handling capacity is 6500A. Protection is provided by an 80 joule MOV rated at 150V rms that is placed across each mode. Product also provides RH and EMI noise filtration at an average 7 to 1 reduction from 500 kHz to 300 MHz.

Pass & Seymour/Legrand

Three-phase lightning arrester

The AG6503 provides 600V electrical service protection - the first line of defense against power surges or spikes caused by lightning, utility switching, electric motor cycling, insulation arcing, and any other large or sudden change in electrical power flow. It intercepts potentially dangerous spikes and reduces them to acceptable power levels. The 3-pole, 4-wire model uses parallel MOV (metal oxide varistor) technology, with each line protected to the grounded neutral. UL-listed as a secondary surge arrestor.


Lightning protection kit

The company's new, complete Lightning Protection Kit is designed for the homeowner, small commercial facility, or contractors interested in doing installation themselves. Each kit contains all necessary materials and equipment to fit almost every possible application.

Heary Bros. Lightning Protection

Automatic power factor correction

The modular construction of the new UL- and CSA-listed Accuvar Plus, an automatic power factor correction system, allows delivery of a completed system within two weeks of ordering. Features a controller that provides harmonic resonance, overvoltage, and overtemperature alarms. Built with industrial-grade capacitors to ensure system reliability and long capacitor life in harsh electrical environments.

Aerovox Group

Lightning protection kits

A series of coax grounding kits is available to divert lightning energy to earth before it can reach a facility's electrical system. Provides low inductance grounding system that is designed for shields and protectors. Built to straddle 16 in. on center wall studs. The typical installation time is under 2 hrs for a 10 entrance panel.


Surge suppressor

The SPR-32T Series is designed to protect measurement and control equipment, current loop instrumentation, data processing, telecommunication equipment, etc. Ideally suited for multi-line applications where a concentration of data lines is found. Subnano second response time stops failures due to lightning, spikes, and overvoltage surges while minimizing other electrical noise.

Surge Control

Category Fourteen


Three-phase UPS

The UPStation S3 uninterruptible power system uses true on-line design. Developed for loads in the 12kVA to 50kVA range, the unit has a low audible noise of 57 dBA. Features include a low harmonic distortion of 5 %, a 96 % power factor rating, and selectable voltages and battery configurations.


UPS systems

Available are new UPS configurations: the 2.1kVA SX21, rack-mounted versions of the SX21 and 31 (3.1kVA), and the SX31 and 60 (6.0kVA). The SX on-line design ensures reliable power even in harsh environments. By using the latest advancements in double-conversion technology, microprocessor-controlled circuitry continuously provides critical loads with well regulated sine wave power.

Square D

Surge protectors

The 7090 Series of Network Interface Devices, called NIDs, (the new 356H Hybrid Station Protector and the 1740 Series Coax Protector) provides surge protection for both regular phone lines and coaxial cables at the station. The 7090 Series can be configured as a 1-to-6 pair NID using 356H Hybrid Station Protectors, or a 1-to-4 pair NID with the capability of receiving up to two 1740 Series Coax Protectors or two 180 [degrees] COAX jumpers.

Joslyn Electronic Systems

Hybrid rotary UPS

This combined static and rotary UPS system is part of the RHS Series of systems that provide pure sine wave power to computers and other critical loads with total isolation from both utility and emergency power sources. The system completed performance testing and construction requirements under UL Subject 1701, which is specific to rotary systems.


Surge and noise monitor

The Surge Alert accurate plug-in powerline surge and noise monitor provides data for troubleshooting power quality at the point of the outlet connection. No computer interface is required. There are two separate monitoring functions: Level 1 is indicative of power line noise and Level 2 of transient voltage activity.

Zero Surge

Surge suppression devices

This line of surge suppression devices addresses the power quality needs of communications systems and equipment. Product safeguards LAN/WAN networks, coaxial/twin-axial communication lines, and concentrators. Includes the TSC Series for token ring, Ethernet, arcnet, and modem/fax protection; and the CCC Series for Ethernet, arcnet, twinax, IBM 3270, AS400, cable, and satellite TV applications.

Current Technology

Coaxial protectors

The 1740 Series of Coaxial Surge Protectors is designed for use on 75 ohm Premise Entry subscriber drops, such as those deployed in new powered or unpowered hybrid fiber-coax networks carrying CATV, telephony and/or interactive high-frequency information. Has UL listing number UL 587N.

Joslyn Electronic Systems

Single-phase UPS

This single-phase uninterruptible power system is available in 4.5 kVA and 6kVA ratings. Units are equipped with NEMA receptacles for plug-and-play operation and with connections for hardwired input and output. Double-conversion technology removes harmful electrical disturbances. Modules can be hot swapped, if necessary, without loss of power.

International Power Machines

Transient protection

The new Sentron Transient Protection System (TPS) is designed to protect electrical power systems from voltage spikes or surges caused by lightning strikes or switching transients. It's available as an option for new Sentron panelboard orders or can be retrofitted in the field to existing Sentron S1 or S2 panelboards. Provides 80 or 160kA peak current protection per phase.

Siemens Energy & Automation

Rack-mount UPS

The CFR-RM Series of rack-mount UPS systems employs the Alpha-developed controlled ferroresonant technology, which further enhances the ferroresonant transformer's already natural isolation, surge, and spike rejection characteristics. They correct for load-generated poor power factor and nonlinear current waveforms without costly add-on transformers or electronic correction packages common in PWM designs. The systems also feature superior isolation, noise attenuation, and backup times in excess of eight hrs.

Alpha Technologies

Suppression and filtering systems

The Titan line of high-performance suppression and filtering systems for medium- to high-exposure applications are available in all voltage configurations with single impulse surge current ratings from 150,000A to 480,000A per phase. All units can be equipped with monitoring and disconnect options. Redundant, volt-down, user-re-placeable protection modules are connected by way of a low-impedance busbar. All systems are UL 1449 and UL 1283 listed.

EFI Electronics

Power factor capacitors

This is a new line of dry metallized self-clearing capacitors. The AMD style 3-phase capacitor is available in voltage ratings of 240, 480, and 600V, with a frequency of 60 Hz. Product is designed, built, tested, and listed to UL standard 810, and CSA approval is pending. Designed for 180,000 hrs (or 20 years) of 24 hrs per day, heavy-duty use.

Aerovox Group

Harsh environment UPS

This single-phase UPS is designed for harsh environments. The unit is built in a tamper-resistant enclosure that can be placed in any location, even outdoors. The system has internal batteries and is available up to 10kVA. Aso approved for use in backing up emergency lighting.

On-Line Power

Surge protection devices

The Pulsar line of high performance surge protection devices is rated from 40kA to 400kA. All models feature field-proven, MOV-based technology that responds to voltage variations instantaneously, effectively intercepting potentially damaging spikes and surges. Located at service entrances, distribution panels, and branch panels to provide facility-wide protection from internally induced line transients or external high- energy surges.

Automatic Switch

High-voltage power capacitor

To help reduce losses due to extreme demands of industrial electrical systems, the EX-D high-volt-age power capacitor is designed for 125% continuous overvoltage capability. The product shrugs off 135% peak overvoltages and 100 kVA current transients. Can even handle 15 kVA through faults and still achieve fuse coordination without harmonic or rupture problems.

Cooper Power SyStems

Surge control devices

A new line of Everguard surge control devices is designed to protect equipment connected to AC power lines. The line includes a full range of products designed specifically to block the passage of harmful spikes of voltage to sensitive equipment. The devices feature patented circuitry to optimize performance at the lowest cost and optional incident counters to advise frequency of voltage spikes overcome.


Power monitor

There are two new features to the 7100 PQNode power monitor: power consumption measurement (kWh and kVAh) in power quality mode, and an ON/OFF switch, enabling easy capture of motor starts, transformer energizations, etc. The 7100 installs easily using plug-in connectors, and with all three monitoring modes installed, switches between monitoring power quality for all harmful power disturbances, power flow with demand calculated every cycle, and harmonics using 4-cycle FFTs to the 49th.

Basic Measuring Instruments

Transient voltage surge suppressor

This Transient Voltage Surge Suppressor (TVSS) is installed in the NQOD panelboard and protects sensitive electronic equipment from voltage and current spikes. The system combines superior clamping voltage performance and high levels of surge current capacity in a modular suppression unit. TVSS units are both UL component recognized and CSA-certified.

Square D

Flexible UPS

The Matix series of high-performance UPS units is available with ratings from 3 to 5 kVA. The series now includes power management software that helps with power and monitoring requirements.

American Power Conversion

Transient voltage suppressor

The HS-P-SP is a series wired, terminal strip connected active tracking network TVSS device with integral remote alarm and two pairs of telecommunication circuit protection. Product is a highly durable combination unit that protects an individual piece of equipment from damaging transient surges on both power and/or standard telecommunication lines.

Innovative Technology

Surge protector

The UL-listed Surge Master II is a main service panel protector with peak current handling ability (1 p = 480kA). Innovative front-panel LCD indicates the exact percentage of protection present. If damage occurs, the display will pinpoint the module that needs replacement. Transient Event Counter provides a data/time stamp on the occurrence of the most recent transient.

MCG Surge Protection

UPS system

The STABILINE UPS Model SL 3000B regulates voltage, protects equipment from noise, and provides battery backup in the event of utility power failure. The UL-listed unit is rated for user selectable 110, 120, or 127VAC, 60 Hz, single-phase operation with an output rating of 3000VA.

Warner Electric Linear and Electronics Div./Superior Electric

Surge protection

The Surgepak products protect motors, transformers, and rotating machines from surges, faults, and lightning strikes. Available from 2.4 through 13.8 kV. Each unit consists primarily of surge capacitors and lightning arresters, contained in a NEMA-rated indoor enclosure. Products will accommodate a wide variety of applications.

ASC Industries

UPS units

The CFR Series of on-line LIPS products, ranging in capacity from 600 VA to 15kVA, offers virtual noise-free operation, constant output voltage regulation (+1%) and unequaled reliability - with efficiency ratings of more than 90%. Design provides maximum isolation from EMI and FRI interference.

Alpha Technologies

Three-phase 150-500 kVA UPS

This on-line 3-phase Model EPS 6000 UPS features Insulated Gate Bipolar Transistors combined with Digital Power Quality Logic. Product is rated at 94% overall efficiency. The output voltage total harmonic distortion (THD) for the unit is less than 4% for 100% non-linear loads with a crest factor as high as 3.5% and 2% maximum THD for linear loads. Also features compact design, battery monitor, standard RS232 communication port, local networks, and remote monitoring.

Square D

PF controller

The EMR Power+Trol controller is a diagnostic self-programming power factor controller that measures simultaneously each 1/2 cycle the system content of amperes, voltage, and harmonics. Displays are PF, reactive, active, and apparent amperes; voltage and ampere harmonics; capacitor steps; and eight programmable alarms.

VAR + Controls

Single-phase UPS

The BalancedPower Advantage UPS has been expanded to a 3kVA rating. Consists of three matching modules. The electronic module contains rectifier, inverter, and user controls. The standard battery module provides 6.5 min of full load backup. The bypass distribution module contains user power connections, full time isolation transformer, and maintenance bypass switch.

International Power Machines

Hide comments


  • Allowed HTML tags: <em> <strong> <blockquote> <br> <p>

Plain text

  • No HTML tags allowed.
  • Web page addresses and e-mail addresses turn into links automatically.
  • Lines and paragraphs break automatically.