ABB helps the desert bloom

ABB is supplying MCBs, ACBs and softstarters to a project that is taking water from the Nile and pumping it to an irrigation system to provide water to small farmers, growing maize and other crops.

The electrical components form a vital part of 12 power stations produced for the project by Westac Power. During the planning stage, ABB supplied its own experts to Westac to help it define the technical aspects of the project, in particular the sizing and selection of the motor starters.

The eventual solution involved building a number of generator sets, each with a diesel engine, an alternator, a motor control centre and a motor. These drive pumps are submerged in the river. The new power stations involve a total of 34 generator sets ranging in size from 650 kVA to 1850kVA. Some of the power stations have up to four generator sets, allowing different combinations of pumping power to be operated, depending on demand, and allows some of the sets to be shut down for scheduled maintenance. ABB’s MCBs and ACBs were sized to suit these different possible combinations.

Managing Director of Westac, Tony Shirtliff, says: “The benefits of the ABB softstarters are that they prevent stress on the generators.

“When the motor stops, a column of water supported by the pump collapses, turning the pump in the reverse direction and hence the motor itself. This generates a back EMF, a voltage acting in the reverse direction that can produce currents which can damage the generator. This obviously leads to interruption of water supply. The slow starting and stopping allows us complete control over the motor and pump, rather than the pump taking control.”

This system of electrically-driven pumps has benefits over the previous method, which involved diesel engines driving mechanical pumps, mounted on barges in the river. As the demand for water grew as the project irrigated more land, more barges were needed and their operation became cumbersome and inconvenient. It was difficult to maintain electrical connections to the barges due to significant changes in the Nile’s water levels.

A significant part of Westac’s contract was training, an aspect that ABB played a full part in, providing a day’s training to six of the customer’s onsite electrical engineers. They were trained in how to set up the motor starters and how long they would take to start and stop the motors

Shirtliff says: “We have standardised on ABB products for four years. ABB has a worldwide reputation and by using them, we give the customer the confidence that he is getting what he needs. The customer wants to know that the equipment we use is first rate and that he will get the back up he needs. We get that with ABB.”