VSD Current settings

Hi,
Not directly PLC related but I think the forum has a wealth of knowledge.

I have a single phase to three phase VSD (LG - SV20SV008iC5)

Now the motor it's connected to is a 1HP (.75kw).
What do I set the VSD current too?
Name plate says:

Amps: 3.6/1.8.
Voltage: 190/380.

I take that 3.6 is Star connected and 1.8 is Delta.

I can't open the motor terminal block up to have a look. (not on site right now)

Is there any rules of thumb when Putting VSD's onto motors. Like do they always have to be in Delta or star?

And when they are connected you still input the current related to the connection type?

Sorry if sounds like a basic question but I just want to be 100% sure.

Thanks

Usually the motor will be wired for the higher voltage. At least that is true of all the places I have worked. Knowing how the motor is wired is going to be important when setting up the drive output parameters, so you might have to wait until you are on site, or ask someone that is on site.

Will

Shark93 said:

Hi,

Now the motor it's connected to is a 1HP (.75kw).
What do I set the VSD current too?
Name plate says:

Amps: 3.6/1.8.
Voltage: 190/380.

I take that 3.6 is Star connected and 1.8 is Delta.


Thanks

Click to expand...

There is something strange about the nameplate values.
With a 380 volt 3phase motor, the lower rating should be 220 volts, which is the Square root of 3 of the higher value,
which follow an old European standard voltage.
Your lower voltage reading is actually half the higher voltage.
Your current readings also follow that pattern it should be 3.12 amps not 3.6.

If you are on Australian single phase supply you will have 230 or 240 volt single phase
and would connect that motor in Delta and set the
Nameplate rating inside the VSD to the lower voltage and highest current


NOTE
This statement disagrees with yours

Each winding in that motor is designed to withstand the lower voltage
so you connect the motor in delta when the supply voltage is the same as the lower voltage
and because star puts 2 windings across the supply voltage it can withstand the higher voltage

Now from the info you supplied I am unsure what voltage the motor is currently connected to
so can't advise as to wheather the current connection is right or wrong,
you need to inspect the connections in the terminal box.

What you have is a motor originally designed for the US market as a 460/230V 60Hz motor where the windings are in series for the higher voltage and in parallel for the lower. Then when used in a country with 50Hz, the V/Hz ratio makes it useable at 380V, but if connectect for low voltage would maket it 190V, which is not a real voltage anywhere in the world, so it was kind of pointless to add that. Maybe they did it just to point out that in a 50Hz country, it is NOT really a dual voltage motor.

So just forget the lower voltage connection pattern, it means nothing to you. Use the high voltage pattern and you will be fine. I didn't however check your VFD part number against the current rating, that's up to you.

As with jraef on the motor . I didn't find the part no. you gave for the drive , however normally a 1 phase to 3 phase inverter only puts out the same voltage as the input . So for you , I think you will get 230 v 3 phase from the inverter . I would check with supplier that the inverter parameter for max output voltage will adjust down to 190 VAC .
Paul