The application of alternative battery technology by safety warning system company Booyco Electronics has resulted in the development of an intrinsically safe (IS), uninterruptible power supply (UPS), which offers reliable performance under the harshest operating conditions.
Booyco Electronics MD Anton Lourens says it is crucial for mines and other organisations to have IS UPS systems in place in the underground environment, especially with the uncertainty of power supply in Southern Africa.
“The Booyco IS UPS is locally manufactured under stringent quality management systems and meets all statutory regulations pertaining to IS equipment,” he adds.
While there are many UPS systems available on the market, few of these are IS and suitable for underground use. Booyco Electronics identified the need for such a UPS and this is a natural extension of the company’s IS high-current power supply range of equipment.
“The company made use of alternative technologies, which were combined to provide, what we believe to be, a unique and affordable solution for underground applications,” says Lourens.
A conventional UPS makes use of alternating current (ac) voltage input that cannot be made IS because of the nature of ac voltage and the constraints of IS specification. Further, the types of battery used for backup when power supply to the unit fails, are normally lead-acid or lithium-ion. These batteries are not immune to operational incidents, such as short circuits of the battery’s pole, which results in the battery heating up and ultimately exploding.
Also, the chemical makeup of the battery includes dangerous chemicals such as acid that will damage any material it comes into contact with and can also release flammable and poisonous gases.
Owing to the dangers that normal batteries present, a solution had to be found to eliminate or reduce these dangers. “Usually, the only option is to install the batteries into an explosion-proof (EP) enclosure and fill it with sand. However, this causes significant difficulties as the panel becomes extremely heavy and expensive,” explains Lourens.
He adds that, when repairs or work on the panel need to take place, all the sand needs to be removed and replaced afterwards, being highly maintenance intensive.
Booyco noticed that this seemed too problematic to be a solution to creating an IS power supply unit (PSU) and UPS applications, so the company undertook research and found alternative solutions.
The company manufactured an IS PSU that provides a direct current output of 12 V or 24 V. The IS PSU is installed in an EP enclosure as specified under IS requirements, which state any device that is coupled to a non-IS input must be installed in an EP enclosure.
“Our UPS uses a unique battery unit that eliminates the dangers of conventional batteries. The unit is installed in its own enclosure with additional components and is separately approved to IS specifications,” says Lourens.
He adds that combining the IS battery with the IS PSU eliminates all the dangers of a conventional UPS. Because of this, the rule to install the components in an EP enclosure is not applicable and sand is not required, which means the unit does not have a heavy enclosure, and makes it fairly inexpensive.
“We specifically chose not to place our UPS in an EP enclosure or to use sand as an additional layer of protection. This application required its own solution and not simply a modification of a conventional UPS,” states Lourens.
The Booyco IS UPS is able to deliver 2 A at 12 V or 1Amp at 24 V, or a combination of both for extended periods of time, and, to cater for individual application requirements, the units can be supplied in multiple outputs.
The various models available deliver power up to 80 A/h and are suitable for a number of critical applications including maintaining communications systems and fire detection systems.
