Star Delta Starter required?

[flyingsparks]

I have this motor, 5.5KW as a replacement for an existing one on a large fan. This new one was connected DOL in Delta, and was pulling 80A ish on start up and taking out the overload.

It has now been connected in star to get it running, but according to the plate I believe it should be in Delta, and so a Star-Delta starter is required?

Motor

• flyingsparks
• 10 Jul 2017

is required?

 

[Simon35]

A soft starter may be an option, you could maybe fit it in the existing panel in place of the existing contactor.

Similarly priced.

 

[stillp]

A VSD would probably save energy, as fans are often over-powered.

 

[333rocky333]

Been a while since i done motors, but isnt that plate saying use
Star/Delta or Delta only

 

[flyingsparks]

Been a while since i done motors, but isnt that plate saying use
Star/Delta or Delta only

This was my thinking too. I got it running on star and the FLC was around what the plate said so I didn't worry too much, but going back tomorrow to fit a star-delta starter and hopefully all will be ok then! Just looking for some clarification!

 

[flyingsparks]

A VSD would probably save energy, as fans are often over-powered.

This one isn't over powerd - it blows air through under ground ducts and up through mesh in a grain store to dry grain. The client needs as much air as possible to dry the grain quicker.

 

[ericmark]

With a mines and quarries 660 volt supply no problem running star. But with 400 volt must be delta, there are a number of methods to reduce the start current.
1) Star/delta.
2) Auto transformer.
3) Resistor start.
4) Electronic this could be a soft start or inverter.
The star/delta has just two stages, using a auto transformer or resistor you can have many stages, for pumps because you can't really start no load auto transformer was normal method, for things like crushing plants where you can start no load the resistor start was more normal. But if you can get away with it star/delta is the cheapest. Today soft starts and inverters have taken over from the resistor and auto transformer starters as the latter needed so many contactors.

Even the soft start tends to still have a contactor take over once at speed. Since you have been able to start in star it would seem star/delta is best option, however running a motor under voltage for any time will likely cause damage, in star it is a 660 volt motor and should not be powered from 400 volt for any length of time. As well as voltage reduction often we also use fluid couplings to reduce the start load and torque, much depends on rotating mass, using the other options to star/delta also reduces the start torque and with some systems the resistor start is more to protect the drive shafts than reduce the start current.

 

[flyingsparks]

Thanks Eric for confirming. Fitted star delta starter today and all good.