Booyco Electronics has entered the arena of centralised blasting systems (CBS), becoming one of the first South African manufacturers to be granted an Inspection Authority (IA) number shortly to be required by law for all CBS products. The IA number was awarded by a SANAS Accredited and Approved Test Laboratory (ATL) for Booyco Electronics’ C3 CBS, making it the only approved alternative to electronic detonator driven centralised blasting technology.
“The C3 is a simple ‘workhorse’ system that can be configured to fire any non-proprietary initiator or detonator with precision from a remote location,” Anton Lourens, Managing Director of Booyco Electronics, explains. “It is now the only approved open system on the South African market. The C3 is unique in that it allows for a single power point on surface and draws an extremely low current, while delivering a guaranteed output.
“The system has been developed specifically for the unique requirements of the South African mining industry. Even in the deepest mine, it does not need repeaters. It’s safe, cost effective, reliable and low maintenance and we’re able to offer a complete CBS solution from installation to commissioning, including operator training. The C3 can be upgraded, making for a low cost transition from electric to electronic detonation.”
Booyco Electronics’ C3 CBS was originally designed for the safe electric blasting of Shurstart® Instantaneous Electronic Detonators (IEDs), but as the electronic detonator market grew the system was increasingly used to fire electric detonators such as Shock Tube Starters (Handistarts) and Statsafe Carricks.
“The system was patented because its design philosophy of offering a guaranteed output was unheard of at the time,” Lourens says. “The ability to run extremely long cables, between 10 and 15 m in a single run, is also a unique feature of the system. We adopted an approach of allowing the user as much freedom as possible, while ensuring safety when following standard blasting practice. This means that the customer can expand the system by adding units without any fear of exceeding the system’s capabilities.”
The blast signal is provided from a single point on surface – the control unit. Lourens says this is the safest possible configuration, since the underground units don’t have their own power backup batteries with the inherent potential to initiate a blast. Each unit is galvanically isolated from the rest of the system preventing any blasting circuit from affecting the rest of the system. The C3 does not rely on software or codes, but rather on hard mechanical interlocks.
“Having a simple design that has operated without incident for 20 years has several advantages,” Lourens says. “These include allowing the user ease of use, especially under difficult mining conditions. ”
The system comprises three components – a centralised blasting control unit, a level isolator and a centralised basting booster. The control unit is typically situated on surface and monitors the status of the CBS network. It incorporates a cable fault detection system that provides an audible and visual warning of short circuit faults.
Level isolators are used for diagnostic purposes or to switch off a section of the network that, for instance, will not be blasted. The isolator joins the inter-level shaft supply cables, which are traditionally interconnected to the outgoing cable, supplying all the boosters in one level. It continuously indicates the state of the centralised blasting cable network.
Boosters perform the function of energy conversion and blasting, and these units remain inert until the key switch is turned on. All units are fitted in a lockable steel enclosure to prevent access or tampering. The boosters operate over a wide supply voltage range and do not fire at supply voltages below 70 V AC. Owing to extremely low supply current requirements, only light feed cables (1.5 mm2) are required at each level to interlink the boosters. Boosters can be individually isolated from the supply cable network.
Data sheets associated with the units indicate the full specification of each unit, as well as the number and type of detonator that can be used with the system, which includes most electric detonators on the market.
Lourens says his team is already at work designing the NECST generation CBS.