5 Installation at Site
50 of 98
UPA / UPA S
3400.86/17-EN
Three-phase (3~) motors with two power cables for star-delta starting
The six current-carrying conductors of the two power cables are designated U1, V1,
W1 and U2, V2, W2; the earth conductor is marked PE.
The motors are wired for both star and delta operation, as shown on the name plate.
L1
L2
L3
U1 V1 W1
PE
PE
3~
U1
V1
W1
W2
U2
V2
W2
U2
V2
1
2
3
4
5
Fig. 23:
Circuit diagram: motors with two power cables for star-delta starting
1
Motor
2
Motor power cables
3
Core marking
4
Control unit
5
Line conductor
PE
Earth conductor; core marking:
green/yellow
Set the overcurrent relay for the applicable starting method:
▪
For DOL starting to the operating current or, at most, to nominal current I
N
▪
For star-delta starting to the operating current or, at most, to the nominal
current x 0.58.
NOTE
Fitting an ammeter is recommended.