# star delta motor calcs

Discussion in 'General Electronics Chat' started by slama01902, Nov 12, 2007.

1. ### slama01902 Thread Starter New Member

Nov 12, 2007
2
0
whats the formula for working out the full load current of a star delta motor
i think its P/V X 0.58

2. ### thingmaker3 Retired Moderator

May 16, 2005
5,072
6
Star, or Delta?

For Star (also called "Wye"):
Eline = $\sqrt{3}$Ephase
and
Iline = Iphase

But for Delta:
Eline = Ephase
and
Iline = $\sqrt{3}$Iphase

3. ### slama01902 Thread Starter New Member

Nov 12, 2007
2
0
i need the calculation for the amps for a star delta started motor, terminal box has 6 terminals so you are using 6 wires U1 V1 W1 / U2 V2 W2
eg if you have a 550 kw 400 volts wired in star delta what amps is that???

4. ### recca02 Senior Member

Apr 2, 2007
1,211
0
in star
current is
power(input)/(sqrt(3)*line voltage)--line voltage is voltage across two phases.

for delta:
there are two currents
current in each phase and current thru the supply lines,
power/(sqrt(3)*line voltage)
gives line current,
line current=sqrt(3)*phase current