Electric motors

Having a management policy for your three phase motor system could save up to 15% of your business’ electricity use.

It’s often more cost effective to replace old motors than to repair and return them to service. International studies estimate that by improving the way electric motors are commissioned and maintained, businesses can reduce their electricity use by up to 15%.

Develop a motor replacement policy

When faced with in-service motor failures and aging motors that risk failure, your business needs to decide whether to replace or repair its motors. Our motor replacement policy guide helps you to develop a policy that supports these decisions.

Electric motor replacement policy: a development guide [PDF 585KB]

Performance standards for electric motors

Three-phase electric motors must comply with minimum energy performance standards (MEPS) if they’re to be sold or hired in New Zealand.

Three-phase electric motors - EECA website

Electronic soft starters

Starting a motor without control of the current and torque is called direct on line (DOL) starting. A DOL start typically causes motor current more than 6 times the rated current. With larger motors, high starting currents can cause flickering lights and voltage drops.
Electronic soft starters, which work by reducing the voltage supplied to the motor, are a way of addressing these issues.

Managing the energy losses from electronic soft starter motor control systems [PDF 726KB]

Use quality-certified motor rewind workshops

Poor motor rewinding endangers motor efficiency and reliability. That’s why we support quality certification of rewind workshops. For example, a 55kW motor may lose 3% efficiency through a poor quality rewind. If that motor then runs fully loaded for 6,000 hours per year, the electricity loss will be around $1,200 per year (at 12 cents per kWh). Reduced reliability and increased maintenance can cost you more on top of this.

Motor rewinders can be quality certified in two ways: either to the ISO 9001 Quality Management System, or to the Telarc Motor Rewind Workshop Quality Code.

Quality-certified motor rewind workshops

There are certified workshops around New Zealand. Make sure you choose one which has been quality-certified to one of the standards above.