Following the successful commissioning of two MoviDrive B ventilation and air conditioning variable-speed drives (VSDs) at an underground mine in the North West, in South Africa, drive engineering specialist SEW-Eurodrive South Africa (SA) will commission an additional four of its MoviDrive B drives early next year, once the project planning phase has been completed.

The project, inclusive of planning, installation and commissioning, should take about four months to complete.

La Cock further states that the reason for installing a drive in any application is to enhance control.

He cites that the North West underground mining project, where the building system incorporates a programmable logic controller to feed data to the SEW VSDs, can use this data to determine whether to open or close the application to increase or decrease ventilation and flow of cool air.

As an additional offering to the industry, the company offers its LTP-B Eco heating, ventilation and air conditioning (HVAC) drive – which was launched at last year’s Electra Mining exhibition, in September. The drive is an example of how SEW-Eurodrive aims to respond to the growing demand for a product that meets specific customer requirements in the ventilation and cooling industry, including that of mining.

SEW-Eurodrive SA national sales manager Norman Maleka explains that fans ensure the flow of clean air underground, so that activities such as excavation may continue unabated.

“While we do have general-purpose units for fans, pumps and even conveyors, we have decided to focus on and expand into ventilation and cooling industry applications, owing to an increase in demand, as we have previously not had a presence in market,” he comments.

With the HVAC sector remaining a niche sector, Maleka says energy savings remain a key benefit for clients, especially mining.

“What distinguishes this purpose-built drive is that different parameters can be set, such as for fan or pump control. This enables our customers to realise the full energy efficiency benefits of different functions,” SEW-Eurodrive SA electronics application engineer Juandre La Cock explains.

In terms of commercial buildings, such as hospitals, traditional drives require fans to operate constantly at full speed.

However, La Cock explains that the improved functionality of the LTP-B Eco HVAC drive, available from 0.75 kW to 250 kW, enables mining and commercial facility managers to operate fans only according to demand.

This represents a major advantage in terms of energy saving, as allows for total flow control, with energy optimisation achieved through the design of the HVAC drive, he says.

LTP-B Eco HVACs are designed with film capacitors, replacing the traditional electrolytic capacitors used in the direct current (dc) link.

Film capacitors have lower losses and also remove the need for alternating current (ac), dc or swinging chokes, improving overall drive efficiency by about 4%, compared with a standard ac drive.

The LTP-B HVAC has many advantages, including easy start-up, a user-friendly system, and a text-based screen that guides the parameters, La Cock notes.

Other advantages of the system include the fire override mode and energy optimisation mode bypass control, as well as maximum motor control efficiency.

“The fire override mode ignores signals and alarms, keeping the LTP-B HVAC operating for as long as possible. This feature is crucial for ensuring smoke extraction from buildings in the event of a fire,” Maleka explains, adding that it is particularly useful for emergency stairwells in commercial buildings.

In mining applications, however, Maleka notes that this will help – in the case of dust or smoke underground – to suck the air out in the case of an emergency situation such as a fire.

Although the system requires minimal to no maintenance, La Cock highlights that the system also has a settable service interval parameter for routine drive or system maintenance alerts; a read-only, time-to-service parameter in the diagnostics menu displayed on the onboard, built-in keypad when a service is due; and a simple service reset procedure.

“With a life span of about 90 000 hours, the time-to-service parameter will indicate the maintenance interval by giving reminders when the next service of the machine is due, thereby avoiding costly downtime,” he explains.

The LTP-B Eco HVAC drive, he notes, will always spread the number of operating hours between drives evenly if more than one LTP-B HVAC drive is installed.

“Doing so enables all the HVAC drives to run for a certain number of hours, with one drive always available for operations.”

With energy saving often not at the top of a mining operation’s agenda, Maleka explains, SEW-Eurodrive discusses energy saving and efficiency with mining operations to showcase the benefits of using energy-saving products.

“We have plenty of products available in our portfolio and are able to discuss costs for projects that are especially capital-intensive, while attempting to get the best return on investment by amortising the total cost of ownership of the equipment over its operating life,” he adds.

Owing to a range of customer-orientated service modules, SEW-Eurodrive SA can offer customers added value and measurable benefits, Maleka concludes, noting that this is made possible by powerful drives, high-quality standards and customised solutions.

SEW-Eurodrive SA can service and support customers from any of its five branches, namely Johannesburg, Cape Town, Durban, Port Elizabeth and Nelspruit.