What is it?

Injection braking is a method used to rapidly stop induction motors when the stop button is pressed. This is especially important in heavy machinery where the rotating parts have a large amount of inertia which results in the machinery slowing down gradually. In the event of an accident this hardware will ensure that the machine will come to a stop as quickly as possible.

Why do I need to know about it?

For wood working machinery this has become important due to the introduction of the PUWER 1998 regulations. The regulations state that "work equipment must be provided with controls which bring the quipment to a safe condition in a safe manner". This has been interpreted by the Health and Safety Executive (HSE) in an Approved Code of Practice (ACOP) to mean bringing the machine to a complete stop in less than ten seconds, as long as this is not likely to be harmful to the machine or dangerous to the operator or others close by.

ESR's Solution

Many woodworking machines are not fitted with controls that fulfil these regulations. We produce an electronic direct current injection brake which can be retrofitted to virtually any machine with an induction motor. This is a proprietary component that can be fitted in two to three hours. It can replace the machine's original on and off switch(s) with a set on the front of the supplied box. Retrofitting such a braking device is not as costly or as complicated as replacing the motor with a newer version that incorporates braking electronics, and far more effective than trying to brake the machine mechanically.

Our injection brake is able to stop 3-phase or single phase motors of any horsepower rating within the prescribed regulation time. When the machine has stopped, it can then be electrically isolated from the mains so no short circuit can cause the machine to start unexpectedly.

What other advantages are there?

For applications where the moving parts need adjustments between cuts, the running down time can lead to a significant loss in productivity. If the machine can be stopped in just a few seconds, the adjustment made and work recommenced, time is saved. This also removes the temptation to try and adjust the head and restart work whilst the tool is still moving.

On older machines the stop and start buttons may not be labelled with the standardised markings or the buttons may have become jammed due to a build up of dirt over the years. Our component has CE standard marked stop and start buttons which are membrane protected to IP54 standard against dust or moisture.

For more details, including pricing contact us.

Further Information

For further information on the requirements and regulations of Injection Braking for wood-working machines, please use the following links:

Health and Safety Executive (HSE) home page

The Provision and Use of Work Equipment Regulations 1998

Newsletter of the Woodworking National Interest Group