Project Description
Our engineers were called to a site in Witham, Essex to replace a 110kW electric motor for a blower that kills bacteria by aerating the sewage water. Adding air to wastewater allows aerobic biodegradation of the organic materials. By adding air to circulate the water, small bubbles of air rise up through the water. Dissolved gasses are then able to leave the water and allowed to escape into the surrounding air.
After arriving at the plant room, our engineers began removing the panels to the unit to gain access to the motor. The unit had already been isolated before they arrived and once the motor was electrically disconnected, the motor could then be removed safely with an overhead crane.
While on-site, our engineers also checked the variable-speed drives and it was noted that the essential planned maintenance was due for the ACS800 VSD cooling fans. The parts were quickly ordered from ABB spares so that the work could be carried out and the drives be reset.
The old motor was replaced with a 110kW, IE4 super premium efficiency ABB electric motor. Using a laser aligning tool, the motor was positioned accurately and bolted down in line with the pulleys. Once everything was positioned correctly, the motor could then be reconnected and the panels from the unit were put back in place. Our engineers advised the on-site Anglian Water engineer to replace the motor pulley and belts as they were worn and missing balance weights. The belts could then be fitted to the pulleys and adjusted using the belt tensioner.
The Anglian Water engineer removed the electrical isolation from the control panel and once everything was complete and our engineers were happy, the motor was tested to make sure it was running in the correct direction.
Both blowers are now back online with the ABB inverter drives’ planned maintenance up to date to ensure maximum reliability. The old motor was taken from the site to be recycled.
