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Chrism3
24th January 2013, 05:52 PM
I was asked today whether my Triton TRB001 router has a 'soft start'. I had never considered this question before. By 'soft start' the questioner meant did it work up to speed gradually, to reduce load on the bearings. My answer was no, with my router there is approximately a 1 second delay after turning on the router, but after that delay the router seems to reach full speed straight away. (I am not sure of the purpose of the 1 second delay).
What are the experiences of others?

snowyskiesau
24th January 2013, 06:22 PM
Mine definitely has what I would consider a soft start. There's no 'kick' when you turn it on, unlike the Hitachi TR-12 I have.

Chrism3
24th January 2013, 06:37 PM
Is there a delay before anything happens?

chambezio
24th January 2013, 07:23 PM
The "Soft Start" is a safety device to not let the starting tool be ripped from your grip due to the thrust of the very powerfull motor. The early 230mm angle grinder were a real beast and a big hand full if you had not been told about them.
It has nothing to do with bearings it is to do with safety and a good thing it is too.

Chief Tiff
25th January 2013, 09:14 AM
I have two Triton routers; the original big 2.4kw and the baby 1.1kw. Both feature the soft start.

Yes, there is a slight delay after you switch on; it would appear that yours is working correctly. Perhaps it is a deliberate pause so the machine can gird its loins... or maybe it gives you that extra time to ensure your hands are firmly on the handles after switching on.....

The point of a soft start has nothing to do with looking after bearings, it's to reduce the kick you get. A direct start machine immediately throws all it's volts into the motor, a soft start gradually builds up to full voltage. Well, when I say "gradually" it only takes about a second or so, but this is sufficient.

Get hold of an old Makita 3612 or 3600B and use their starting charactoristics as a basis for comparison!

The Bleeder
25th January 2013, 09:26 AM
I've got the 3612....hold on then power on...no delay

Chrism3
25th January 2013, 09:05 PM
Thanks for the replies. In the light of your answers my guess is that the delay is caused by the circuitry taking up the initial power surge and then releasing it slowly.

malb
25th January 2013, 09:29 PM
Normally what happens is that the soft start is part of the speed control, and slowly (abt 1-2 sec) accelerates the motor to the required speed by slowly increasing the voltage supplied to the motor. The current drawn is a function of the difference between the supplied voltage from the controller and the motor back emf. (Back emf is a voltage generated by the motor when rotating, which opposes the supplied voltage, the faster the motor runs, the greater the back emf.)

For a non soft start, at start the applied voltage is 240V, back emf is zero because the motor is not rotating, surge current and torque kick is extreme.

With soft start, at start applied voltage is around 40V (limited by controller), back emf is still zero because motor is not rotating, surge current and torque kick are much lower. Applied voltage increases steadily as back emf is increasing (due to motor spinning up), until tacho sensed speed selected at controller is reached.

The start up current surge is limited by the soft start system, rather than stored and released as the original poster suggest.