Solutions - Pumping

Soft starters provide significant benefits to pumping applications by adjusting the motor's operation to compensate for the behaviour of fluids. Some of the major benefits of soft start in pumping are:

• soft starting can smooth the acceleration profile, minimising pressure surges through the pipework
• soft stop slows the water more gradually, preventing water hammer and extending the life of pumps, pipes, valves and headworks.
• advanced soft starters can protect the pump from damage from reverse operation, jamming and blocked pipe

Soft starters also reduce installation costs by reducing the size of transformers and fuses needed on remote installations and providing direct interface of monitoring devices.

Pumping case studies

• Dewatering the Channel Tunnel
• Large-scale agricultural irrigation in New Zealand.
• Clean water and sewerage pumping in South Africa
• Municipal water supply in the Philippines

 

 

Case Studies - Pumping
Dewatering the Channel Tunnel

AuCom soft starters have been used since the 1990s to drain water from the Channel Tunnel linking Great Britain to Europe.

The Eurotunnel system consists of two rail tunnels, each 50 kilometres long, and a smaller service tunnel. Water is drained from the tunnels by large submersible pumps, and reliable operation is critical - there are more than 200 train movements in each direction every day.

Eurotunnel engineers sought a high-quality solution to control all pumping processes during excavation. Voltage disturbances, jammed pumps and fluid hammer could all bring this vital transport link to a standstill.

AuCom soft starters offer important features which keep the tunnel running smoothly:

• Soft start reduces voltage disturbance and reduces current levels during starting.
• Soft stop prevents water hammer, avoiding the possibility of serious damage to pipework.
• Start monitoring prevents damage to the pump if it stalls or jams. Instead of stepping through to full voltage and subjecting the pump and motor to damaging electrical and mechanical stresses, AuCom soft starters shut the equipment down safely.
• Extensive motor and system protection features (such as overcurrent, overtemperature and phase loss) make AuCom soft starters the obvious choice for such a critical application.

From the outset, the Eurotunnel engineers knew they needed to work with an experienced supplier who could guarantee maximum reliability. In an international tender process, they selected AuCom based on the company's product range, experience and excellent level of support.

 

TOP

 

Case Studies - Pumping

Agricultural Irrigation in New Zealand

As dairy conversions spread across the New Zealand countryside, the irrigation of pasture is increasing. Robindale Dairy Farm in Canterbury is one of many sites using AuCom soft starters to ensure optimal operation of their irrigation system.

Robindale operates two giant centre pivot irrigators, each covering a 1.8 kilometre circle of prime pasture and taking 32 hours to complete one circuit. The irrigation system is fed by two bores which draw water from 160 metres underground, using 230 kW submersible pumps.

When an irrigator is started, a soft starter activates the first 230 kW pump and water starts to fill the mainline and pivot. After 5 minutes the second pump, 1000 metres away, also starts, helping to fill the mainline and build system pressure. Both pumps are soft-started using AuCom's advanced Torque Control feature, which minimises pressure surges during starting. This ensures a smoother, more linear acceleration to full speed.

The system was designed and commissioned by Gary Roxburgh of Nairn Electrical. Gary has installed hundreds of soft starters into irrigation systems since 1991, and he prefers to use AuCom products because of the advanced features which ensure safe and trouble-free operation of the system.

• Torque control soft starting provides near-linear acceleration during starting, eliminating pressure surges and mechanical stress.
• Pump control soft stopping prevents water hammer, extending the life of pipework and reducing the need for maintenance.
• A low pressure switch wired to the starter's programmable input monitors pressure levels once the mainline has filled and allows the starter to stop the pump if it detects a loss of pressure during operation.
• Programmable relay outputs are used to activate variable speed drives, which operate booster pumps on the surface. The soft starter-drive combination keeps pressure constant throughout start and operation, even when the irrigators move across varying terrain.
• User-programmable electronic shearpin and undercurrent protection provide customisable defence against problems including broken pipes or faulty valves. This protection is built into the IMS2, eliminating the need for additional relays, indicators and wiring.
• The easy-to-read feedback display provides comprehensive status information on inputs, outputs and motor operation, without extra costly interface displays.
• The adjustable busbar configuration of larger IMS2 soft starters simplifies cabinet design, reducing installation costs.

Robindale is one of New Zealand's largest dairy farms, and demands the highest standards of reliability. "With pumps of this size it was important to get it right," says Gary. "We needed a tailored solution from a company with a commitment to back-up and service. The AuCom starters give us all the benefits of using motor controls from a specialist in the field."

 

TOP

 

 

Case Studies - Pumping
Mossel Bay Water Utility in South Africa

“They are so simple but they do so much for me!” exclaims Johnny Meerholz as he proudly displays the AuCom IMS2 soft starter he has just installed. Electrical Supervisor for Mossel Bay Municipality (MBM), Johnny has worked with CHI Control's Western Cape Branch Manager, Kevin Russell, to install over 100 IMS2 starters in 60 different clean water and sewerage pumping stations since 2002. CHI Control is the exclusive distributor of AuCom soft starters in South Africa, boasting an authorized AuCom Service Centre at their Head Office in Wadeville, Johannesburg.

With requirements ranging from 55 kW in a seaside station, to 400 kW in the Kleinbrak Filter Station, MBM uses IMS2 soft starters to meet a challenging range of environments and hydraulic demands. As well as their reliability, Johnny loves the simplicity of the IMS2 – “We have occasionally taken delivery of other soft starters in the past, but you have to have a university degree to program them. The IMS2 is so simple, I wouldn’t have anything else!”

CHI’s specialist product knowledge has helped Johnny maximize the benefits of the IMS2 to provide the residents of Mossel Bay with a reliable, cost effective pumping system.

• Torque control soft starting provides near-linear acceleration during starting, eliminating pressure surges and mechanical stress. Using torque control together with AuCom's accurate current ramp, Johnny has kept starting currents as low as 200% at many stations.
• Pump control soft stopping has eliminated the water hammer experienced prior to installation of the soft starters. The benefits are most noticeable on the 400 kW pumps that push water through 10 km of pipe from Kleinbrak over the Mossel Bay Hill.
• Programmable relay outputs and analogue motor current readout feed directly into the MBM Telemetry System, allowing Johnny to instantly identify problem stations from his office. Downtime and losses have fallen sharply and daily manual inspections are a thing of the past.
• User-programmable electronic shearpin and undercurrent protection provide customisable defence against problems including broken pipes or faulty valves. This protection is built into the IMS2, eliminating the need for additional relays, indicators and wiring.
• The easy-to-read feedback display provides comprehensive status information on inputs, outputs and motor operation, simplifying monitoring by MBM operators.
• Conformal coating of the printed circuit boards keeps the IMS2 reliable even in the harsh atmospheres of coastal stations.
• The adjustable busbar configuration of larger IMS2 soft starters simplified installation, allowing the soft starter to slot into existing cabling configurations.

Johnny laughs that he just installs the starters and forgets about them, but he knows that CHI Control can provide full specialist back-up and support if required. Knowing that the starters are manufactured by specialists at AuCom and have full local support from a well-established company like CHI Control has given Johnny great peace of mind as he has transformed the MBM pumping controls over the past three years.

 

TOP

 

 

Case Studies - Pumping
Municipal Water Supply in the Philippines

Water is one of the necessities of life, and water utilities must meet extremely demanding standards of reliability. They use only the highest quality, most reliable equipment – and in Mindanao, Philippines, the municipal water utilities use AuCom soft starters.

LRCA Engineering installs and maintains the municipal pumping systems throughout Mindanao, and works hard to ensure the pumps make use of the best control and protection solutions available. In many cases LRCA are upgrading existing facilities, so the starters need to be compact as well as flexible -
"The pumps may be small but they need protection as well as motor control, so CSXi is ideal. It's an all-in-one solution which fits easily into the available space. We can build the CSXi into a panel complete with a well water level control, or a floatless sensor for tanks."

Each application is different, so LRCA particularly appreciates the adjustable protection and choice of starting profiles. These allow the soft starter to meet the precise needs of each application.

Key benefits for the water authorities include:

• Reduced start current which reduces the peak demand electricity level. Philippines power suppliers levy a demand charge, so lower start current can significantly reduce power costs.
• Superior motor protection. Many of the facilities previously used older types of motor starter, with extremely limited motor protection.
• Low installation cost. The CSXi can be supplied in a panel, complete with additional metering equipment, and still cost much less than most alternative starting systems.
• Ease of use. With numerous operators at each water authority, the simple interface is easy to understand and minimises training time.
• Monitoring interface. The CSXi provides clear feedback on its operating state.

LRCA are so pleased with the performance of AuCom soft starters that they now make them a standard part of every pumping and motor installation. Engineer Art Davis is an enthusiastic advocate: "In terms of cost, size and functionality, the CSXi is absolutely ideal. The combination of protection and control makes it the perfect cost-effective solution for our customers."

 

TOP