Abacus Automation, a specialist in fitting new control systems to old plants, has racked up yet another successful electrical renovation project, this time in Abu Dhabi, according to the company.

The UK-based company recently renovated the 25 year-old Marini Asphalt plant in the UAE, plant wiring of which had been heavily modified over the years. With no circuit diagrams or manuals available for the plant, Abacus says that maintenance had proven highly complex.

The client, Hilal Bil Badi & Partners Contracting Company (Hilalco), commissioned Abacus to modify the plant at minimum cost and with minimal downtime. The brief was simple - existing wiring and equipment was to be retained where possible. After a detailed survey, Abacus produced a new electrical plant design. The control cabin was stripped and refitted with a new motor starter panel (built by associate firm Rum Engineering of the UAE) and control desks (built by Abacus in the UK) and a simple-to-operate and maintain Abacus computer system - based on a Mitsubishi FX2n PLC, designed for contractors and said to be ideal for plant renovations - was fitted.

Meanwhile, the existing single loadcell and levers system was replaced with a full four cell loadcell direct suspension system on all three scales. Damaged wiring cables were stripped out and replaced and existing cables were, where possible, reused. Most of the original terminal boxes were retained, though the terminals inside them were replaced with new ones arranged for the new electrical design, says Abacus.

Plant rewiring was performed by Hilalco staff in an eight-week summer shutdown when daytime temperatures often reached 45 deg C. Some mechanical work was also carried out during the electrical refit, including a rebuild of the screen and work on the dryer.

The asphalt plant is now operating reliably and is, according to Abacus, expected to give many more years of efficient service.