Feature Power & Design Supplement
Other significant features include alarm signals for AC OK and battery low, as well as short circuit, overload and overvoltage protection. Both PQP and PQE Series meet all relevant safety and EMI/EMS standards.
Going in with battery back-up
Peter Clark at Powersolve explores the demand increases for battery- backed industrial power supplies and the current innovations available
ower supplies that guarantee power in the event of mains loss have long been popular in the office environment where the need to protect data is seen as key. Recently, however, we have begun to see an increase in the demand for AC to DC power sources that can be bat- tery-backed to provide constant power in industrial applications as well as in medical and security systems. As a result, Powersolve has introduced a number of power supplies designed specifically for battery-backed power applications.
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First up is a range of industrial DIN- Rail power supplies that work from a wide AC input range and provide up to 600W. Designed for system applications in machine tools and process automa- tion, the TracoPower TIS Series pro- vides adjustable output voltages of 12, 24, 48 or 72VDC and come with several additional function modules to widen the range of possible applications. These include a battery controller module, battery packs and a clever buffer module that will maintain the output voltage of a 24VDC power supply during ‘typical’ mains faults, short time blackouts or voltage dips. Within this ‘buffer’ period, the module guarantees no deterioration of the output voltage.
The battery controller module provides the basis for a professional battery management system to charge and monitor an external battery. In the event of a power failure the battery is switched without any interruption to the DC output. Once mains power is restored, the battery is switched off. Back up time is limited only by the
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battery capacity and load current. Charger voltage/current can be adjusted to suit the battery type. The battery pack contains maintenance- free lead-acid 3.2Ah batteries. The units feature power fail and low battery alarm signals and, during normal operation, battery status is checked periodically while the exter- nal battery is fully protected under any operating conditions. They will oper-
ate at temperatures between -25⁰C to 70⁰C and meet all relevant safety and EMI/EMC standards.
Enclosed and open frame types Options including, PQP/PQE power sources are designed to be integrated into products and systems that need constant power. Together, the two ranges provide 16 models in an open frame (PQP) or enclosed (PQE) format – all models work from a universal AC input and provide 1 or 2 DC outputs with battery charger.
Output voltages are 12V or 24VDC plus charger output and models are also available with an auxiliary +5V 3A output. For 12V or 24V the appro- priate voltage battery needs to be used. Both open frame and enclosed versions are free-air convection cooled so require no fan and incorporate a number of features designed to ensure that constant power is available in the event of mains failure. These include ‘auto switch’ when power off, battery low protection, battery polarity protection, brown-out (AC input low) protection and an inte- gral constant current limiting circuit.
Operating temperature range is -25⁰C to 70⁰C.
The PKR Series from Powersolve are ideal for when a constant and reliable power is required for short periods in the event of mains supply failure
The enclosed PQE Series measures 129.5 by 97.5 by 37.5mm, the open frame PQP Series 123 by 95 by 31, with connection by screw terminals. Although designed primarily for IT
and Telecoms applications, the PKR Series is also finding widespread use in more industrial-type situations. These power supplies accept a wide input voltage range with models able to work with either 115VAC or 230VAC at 50/60Hz. Input power factor is high at >0.98. Output voltage is either 110/120VAC or 220/230VAC ±2 percent and battery hold-up times depend on the model selected. These units are available to provide between 1kVA and 10kVA. Battery recharge time is very quick – 90 percent charge in less than three hours for the smaller units and less than four hours for the 6 and 10kVA models. An automatic bypass is incorporated into the units, which switch over to the incoming mains in the event of an inverter failure. The company use Yuasa high capacity NPW45-12 5 year life batteries as standard with 10 year life versions available as an option. This series of UPS units use an online double conversion design normally found in more expensive units. The main advantage of an online UPS is the unit’s ability to provide an electrical ‘firewall’ between the mains and the equipment it protects. In effect, it provides full protection against all manner of power quality issues as well as mains failure, with zero transfer time when switching to battery backup.
Although most users will specify the PKR supplies for 19in rack mount, they can also be used as stand-alone tower units. An LED display indicates the unit’s status while an LCD display shows volts, frequency etc.
Alarms are fitted to alert users of UPS failure, low battery voltage and the presence of an abnormal mains supply, while these units are protected against overload, over temperature and short circuit. Operating temperature range is 0 to 40ºC.
Peter Clark is Managing Director at Powersolve
An intelligent RS232 communica- tions port allows for remote manage- ment via UPS power management software or UPSilon 2000 and users also have the option of control using an external SNMP, USB or dry contact connection. Output is via IEC sockets or screw terminals depending on power rating. Powersolve
www.powersolve.co.uk Enter 204
SEPTEMBER 2013 Electronics
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