Grinder burnout

Angle Grinder Burnout Prevention Explained

Angle grinder burnout can be avoided with these simple steps.

Grinder burnout occurs because the motors are very powerful and they generate a lot of heat during normal use, but when overused they need cooling. To keep them cool they have a strong fan inside the angle grinder that sucks air in from the trigger switch area and blows it out the front of the grinder. This air passes across the brushes and the windings to prevent overheating and grinder burnout during normal concrete floor grinding.

Excessive grinding conditions

Nine inch angle grinders are mostly used for heavy duty concrete floor grinding and are often used beyond their normal limits when the work is slow and difficult.

If your angle grinder smells like it is too hot while working very hard, do not switch it off, immediately lift the grinder off the floor or move it to an area on the floor that you have already ground where it can spin freely at high speed again which will allow the fan to pass lots of cool air through the grinder and cool it down. This will only take about 5-10 seconds.

Angle grinders are usually fine to use to their capacity which naturally slows them down a bit, but try not to slow them too much for too long because slowing the grinder down dramatically increases heat – here is why:

When an angle grinder is used to remove sticky materials the friction from the diamond grinding wheel on the floor can cause the grinder to work so hard that it slows down to half its speed.

Stop grinder slowdown with Tearitoff wheels

The extra load pulls more current through the windings and causes them to heat up while at the same time it slows down the fan that is meant to keep them cool.

This causes a dramatic rise in heat through the windings and stopping the grinder at this time will remove all cooling and result in grinder overheating and burnout.

Grinders can take a lot of punishment

Experience indicates that grinders can get very hot many times without problems if they are cooled again quickly in the manner described above.

But why work on the edge of disaster?

Here are three things you can do to prevent it:

  1. If the grinder is slowing down strongly on sticky material just take smaller bites into the coating!
  2. Change to a Tearitoff wheel which will cut through glue and sticky coatings quickly and easily without causing a dramatic slowdown of the angle grinder.
  3. Change to a PCD scraper wheel. See coating removal