Slow Start for Three Phase Motor

Sounds to me like your motor/gearbox is too light for your heavy gate. If this is not a homebrew setup then return it for a properly sized unit.

You should also make sure that the gate rollers are well greased, that everything is properly aligned, level, and that there is no binding anywhere. Ideally you should be able to disconnect your actuator and move the gate through its entire range of motion with very little effort, otherwise your actuator will be overloaded and shake or stall when the gate binds.

thanks

there is no problem with the gate it self the thing is how can i slow the start of the motor for first few seconds.

If the sliding gate has high inertia then VFD will be a better option. My apprehension is that the soft starter may not be able to develop adequate starting torque to overcome the static inertia. But the cost factor needs to be taken into consideration.

Sorry to steal your spot here oneking....

...but I've been on the prowl for a softstarter for a 2kW motor (pump) this week too...not looking too hard yet as the client has to still revert with some more information, but yeh, a quick look on the interweb didn't reveal anything that small and the price was definitely not inexpensive. Ranging in price from $600 to $1300...

Can you suggest a (small) model for me to sniff out please JRaef? How about a small VFD?

Most automatic gates use sheaves and belts. One to reduce speed and the other a safety factor. A adjustable clutch is used also. The slip of this type set up takes some of the jar out at start up. The clutch is adjusted to slip if someone or something gets caught in the gate.

If it is a sliding gate, maybe there is crud in the parts that slide on each other.

Clean and lubricate all moving parts, and try again.

I'd do it with just three cheap power resistors. It's a zero duty cycle gate for heaven's sake. S.M.

thanks

can you explain that more i am in Afghanistan we dont have much possilbilities to buy a standard device that made by Europian companies the door works good there is one problem when its starts it shakes the whole door i want to reduce the first start of the motor slower for few seconds then the normal speed i am looking for a very simple and cheap solution .

regards

Viscous coupling would do it.