A major switch for La Marche: company develops new switchmode battery chargers/rectifiers, converter systems and testers

Diesel Progress North American Edition, May, 2004 by Mike Brezonick

In what may be the most extensive launch of new products in its nearly 60 year history, La Marche Manufacturing Co. has developed new battery charger/rectifiers, along with a new dc to dc converter system and a live circuit battery tester. All of the new products except the battery tester are targeted toward utility and other power generation applications and have been phased into full production over the last several months. The battery tester, known as the Battery Informer, can be used anywhere batteries are installed.

The new products reflect changes that have taken place in market demand and La Marche's experience in the telecommunications segment, according to Stan Burg, director of sales and marketing at the Des Plaines, Ill., company.

"Our magnetic amplifier and ferroresonant technology chargers are built like tanks and are basically bullet-proof," said Burg. "We've got Mag-Amp chargers out there that are 30 years old and they just don't break. But it's a matter of fact that in today's environment, people are thinking a little more short-term than they used to. They're not looking for products that will last forever, but will be reliable. And of course, price is always an issue so we have to be competitive."

"Our new products are based on 130 Vdc switchmode technology, which has really been embraced in the telecommunications market over the last 15 years. The tradeoff is that they don't last quite long as, say, a ferroresonant or a magnetic amplifier charger. But they have a lot of features that make them very attractive to the market."

The newest switchmode products are the A96 and A97 utility rectifiers/battery chargers. Both units are designed to provide reliable, easy to replace 130 Vdc power with full load sharing capability in a compact system. Along with being a rectifier/battery charger, both also function as a power supply/battery eliminator. The A96 offers complete front panel accessibility in a plug-and-go, hot swappable design to ensure quick and convenient installation, while the A97 is available in wall, floor or rack mounted configurations.

"The telecommunications market has embraced switchmode technology because of its inherent features such as lighter weight, hot swappability for ease of replacement and high power density, in watts per cubic inch," said Burg. "It's also in recognition that in this day and age, a lot of utilities and telecommunications companies are sending out one person to do maintenance work and if you compare a 7 lb. or a 14 lb. item versus something that weighs 200 or 300 lb., there is a size-able difference in their ease of handling for maintenance purposes."

According to Tom Steinke, La Marches president, "we thought it was about time that the utilities took a serious look at switchmode technology and, in the process, we came up with a modular switchmode rectifier that is 20 amps at 130 Vdc and we packaged it in two different configurations.

"One configuration (the A96) is in a power shelf, similar to what we do for telecommunications, where you can place up to four modules per power shelf to achieve 80 amps at 130 Vdc (additional power shelves can be paralleled). The other configuration (A97) is a floor, wall or rack mounted system that you can purchase at either 20 amps or 40 amps. The A97W enclosure can be mounted on a wall or on a shelf. The A97R can be mounted in either 19 or 23 in. wide relay racks. It's prepackaged with all the controls, meters, breakers and everything so that it's really ready to go as one assembly."

Adverse power conditions do not affect either unit, the company said, as the ac input line regulation operates over a range of 185 to 264 Vac with a frequency range of 45 to 66 Hz. This allows the two systems to be used with any 50/60 Hz, 208 to 240 Vac service line, which eliminates the need and expense of stocking different rectifiers for each input voltage, La Marche said. Steady state output voltage remains within [+ or -] 1/2% of the setting from no load to full load to handle charging a wide range of battery technologies.

Both units also include fan cooling, LED status indicators, high voltage shutdown and have a range of options, including remote communications capability that is SCADA compatible.

The new A63 series dc-dc converters are designed to allow utilities to utilize 48 Vdc or 24 Vdc or 12 Vdc equipment at a site--where 130 V batteries are installed, saving battery; charger and installation costs as well as reducing maintenance time and optimizing space, the company said.

"This device is designed with the concept of having one 130 V battery plant in a situation where you may have some telecom requirements or other switchgear that works on 48 Vdc or 24 Vdc or 12 V," said Burg. "You can save the cost of an additional battery plant by simply using the 130 Vdc and converting it to those other voltages. This is also switchmode technology, lighter weight and hot swappable."

The A63 converter is a compact self-contained unit that can accommodate a dc input range of 105 to 150 V with adjustable outputs of 12 to 14.5 Vdc (12 Vdc models) 24 to 29 Vdc (24 Vdc models) and 48 to 58 Vdc (48 Vdc units). Output ranges from 15 amp 48 Vdc and 30 amp 24 Vdc for models rated at 750 W, or 30 amp 12 Vdc modules rated at 375 W.