Three phase connections , VSD relevant

[delbs]

Hi All,

Just moved into the new house and unpacking the garage, i am going to get some electrical work done to get it up to scratch, getting 4 x 240v GPOs installed, 2 circuits 1x 20amp for the combo machine and the other a 30amp(i think) for DC and other tools.
Because of the layout of the switch box is on the outside of the garage but only the meter, the switches themselves are in the house so i will be making that a sub board and getting a new switch board installed at the garage.

When i open up the switch box it turns out i have 3 phase wiring running to the house (only one in use at the moment) and theres enough fuses in the street box, so to get 3 phase connected it costs $0 as far as actew AGL are concerned which is great. I will get the sparkie to installa 3 phase switch box and get all the work done blah blah, my question is do 3 phase motors still draw a lot at start up ie is it still worth having a vsd/vfd installed on 3 phase to 3 phase purely for its efficiency in startup and reducing upstart consumption? or are 3 phase motors pretty good and dont draw that much from the grid on startup?

[BobL]

. . .my question is do 3 phase motors still draw a lot at start up ie is it still worth having a vsd/vfd installed on 3 phase to 3 phase purely for its efficiency in startup and reducing upstart consumption? or are 3 phase motors pretty good and dont draw that much from the grid on startup?

Yes 3P motors still have a start up current but if you are worried about consumption on start up then thats no worth the worry.

The soft start capability in only one of the options that VSDs provide, As well as soft start they can be set up for things like rapid stopping and variable speed control including driving motors above 50Hz which can be useful especially because many machines are also capable of running at 60Hz or more. The one downside I can see of 3P to 3P VFDs is that for low powered they seem to cost cost more than 1P to 3P VFD.

[artme]

Now how did I know That Bobble would reply to this??