Why WIMES? – setting the standard for water industry motors

Water treatment facilities, by their nature, are wet and dirty places, posing a tough challenge for any equipment used there. Electric motors are used in a wide range of pumping applications within the industry, so it makes sense to have motors specifically designed to resist the typically harsh conditions.

This is the role of the Water Industry Mechanical and Electrical Specification (WIMES), which specifies characteristics of equipment suitable for the water industry. The standard for low voltage
AC motors is WIMES 3.03 issue six and sets out minimum requirements for energy efficiency, build quality and environmental protection.

Defining the standard

In terms of energy efficiency, WIMES lays down minimum efficiencies for 2, 4 and 6 pole electric motors at full load in the range from 0.12 to 1,000kW. The minimum efficiencies required are equivalent to today’s IE3 efficiency level.

Under build quality and environmental protection, WIMES specifies that motors must be robust, with a good
level of protection against the harsh operating environment encountered in water utility applications. WIMES compliant motors needs a high IP rating and have seals in place to protect the bearings and other internal components against the ingress of contaminants. It must also be able to meet the continuous duty cycles common in the industry.

Better than minimum

So what features will a real motor that meets the WIMES standard actually have?

An example is the product range recently
launched by ABB. A specific industry focused development of the company’s low voltage motor range, it incorporates standard features that meet all the WIMES requirements and in some cases surpass them.

Windings are designed to meet or exceed IE3 or IE4 efficiency levels. This means the motor runs cooler with extended regreasing intervals and a longer life for both bearings and winding insulation.

To meet the required robustness, V-ring seals and labyrinth seals are used to protect the
bearings from ingress of water and solids. PTC thermistors in the motor windings protect against overheating, while larger motors are also fitted with PT100 temperature sensors, as specified by WIMES.

For environmental protection, the motor has heating elements and drain holes fitted to help protect against condensation. Frames are made of aluminium or robust cast iron with steel fan covers and stainless steel rating plates to withstand outdoor conditions. 

By meeting or even exceeding the WIMES specification, this motor ensures it will have a long life in water industry applications.