Motor name plate query

[DM7.ENG]

I have some calculations to do for aproject I’m working on and the more I look in to things the more confused imbecoming.
When I apply the formula I know relatingto motors I don’t get the parameters which are stated on the name plate forexample…..
I have a name plate with the following
Kw 4 4 4 4.4
VΔ 380 400 415 400
VΎ 660 690 690
AΔ (7.8) 7.63 7.65 8.29
AΎ 4.5 4.41 4.79
Cosф 0.88 0.85 0.81 0.86
So for example I want to know the current for delta
I = kw/V*PF
I = 4000/√3*380*0.88
I = 6.9A?? Nameplate states 7.8A
Am I missing something obvious?

 

[Darkwood]

The KW is wrong ..If this was a 4444.4 KW motor you would be the first person to ever see one never mind the thing would be bigger than you and at that voltage probably the size of a bus...

You have a Star/Delta motor there
Missing is motor efficiency but your post is misleading and doesn't make sense ...can you post a pic of the rating plate...rather than trying to interpret it.

 

[DM7.ENG]

Apologies its suposed to represent 4kW for each set of characteristics vertically and the last set up is 4.4kW

The KW is wrong ..If this was a 4444.4 KW motor you would be the first person to ever see one never mind the thing would be bigger than you and at that voltage probably the size of a bus...

You have a Star/Delta motor there
Missing is motor efficiency but your post is misleading and doesn't make sense ...can you post a pic of the rating plate...rather than trying to interpret it.

 

[telectrix]

as DW said. that difference between 6.9A and 7.8A suggests efficiency of 0.88

 

[Marvo]

I have some calculations to do for aproject I’m working on and the more I look in to things the more confused imbecoming.
When I apply the formula I know relatingto motors I don’t get the parameters which are stated on the name plate forexample…..
I have a name plate with the following
Kw 4 4 4 4.4

Refers to the mechanical output power of the motor which is how much actual work the motor can do. A motor rated at 4kW does not mean it's electrical consumption is 4 kW, as Darkwood stated this figure is electrically meaningless with taking efficiency into account which is the losses involved in converting Kilowatts of electrical power into Kilowatts of mechanical power.