Tough motor targets process industries

A new motor designed for high reliability, targeted at the process industry, has been launched by ABB.

The M3000 'Motor for Process Industries' features improved cooling to double the operational life of bearings and windings, thus addressing the causes of 90% of motor failures. A large terminal box and a new terminal board enable easy installation.

Qualifying for the highest European efficiency class, eff1, and rated from 4-710kW, the new motor is intended for applications with high costs for unplanned stoppages, such as pulp & paper, metals, building materials, chemical, water and cement industries.

'This is a motor designed specifically for applications with long continuous running hours, high energy costs and even higher downtime costs,' says Steve Ruddell, general manager, electrical machines, for ABB in the UK. 'In recent years, motor manufacturers have tended to economise on materials to save costs. This motor bucks that trend and is aimed at discerning users who have realised that better quality motors demand a higher purchase price but cost significantly less in the long run.'

The M3000 Motor for Process Industries, with its new bearing end-shield and housing, features 20-30% greater cooling surface than the previous motor generation, reducing the internal temperature significantly.

This gives longer component life and protects the motor from overheating, even when covered with dust. Particular attention has been paid to the design of the bearing housing. 70% of motor failures in industry are due to bearing failure; with improved cooling, lubrication intervals are 50% longer as lower temperature increases the life of the bearing grease. The motors are fitted with SPM nipples for bearing monitoring as standard, and have dedicated areas to fit sensors for continuous vibration monitoring.

The high efficiency of the motor means lower heat losses. This results in lower winding temperature, reducing the incidence of winding failure, the cause of 20% of motor failures.

The new motor is fitted with re-greasable bearings as standard, as appropriate re-greasing under a planned maintenance scheme will achieve the longest service life. The rating plate now gives information about recommended service intervals and appropriate grease quality. ABB has re-introduced the valve disc to the whole range, a feature of many motor designs of the past but little used in recent years. This extracts excess grease from the bearing, protecting against over-greasing, which can cause bearing failure, by pushing expended and excess grease out through the grease outlet.

The motor housing has been generally strengthened. For example, a new foundry method has been developed following analysis of the resonance frequencies of the casing, minimising vibrations. The larger terminal box enables easy servicing. Using a cable flange, the terminal box features a large recess where the cable is placed, rather than the standard arrangement with insertion through a drilled hole in the side. A spacious interior accommodates the bends of heavy gauge cables. A new terminal board also makes the connection easier and faster.

'Five minutes of downtime costs as much as a new motor. Our target is no unplanned downtime,' says Ulf Ringström, responsible for preventative maintenance at paper mill SCA Ortviken in Sundsvall, northern Sweden, and part of an industry reference group during development of the new motor.

'This is a motor that can handle the tough environment in a process plant,' Ringström says. 'It is solidly built and easy to service. Its high efficiency reduces energy consumption, which saves money and reduces the environmental impact, helping us reach our ISO14001 targets. We have about 3,500 motors, some of them in operation for decades. When these are replaced, we need a motor that is built to last.'

The M3000 'Motor for Process Industries' will be available in IEC frame sizes 112-400, 4-710kW. Cast iron enclosure is standard from frame size 160 and above, while aluminium is used in frame sizes 112-132.

All ABB motors are suitable for use with a variable speed drive as standard. Special attention has been paid to ease of installation for encoders and forced ventilation. As with all of the M3000 range, numerous factory supported design modifications are available.