Hi Basil,
here's a copy/paste of some IEC and NEMA wiring examples.
Three Phase Motors-Single Speed
Nema Nomenclature--6 Leads:
Single Voltage--External WYE Connection
L1 L2 L3 Join
1 2 3 4&5&6
Single Voltage--External Delta Connection
L1 L2 L3
1,6 2,4 3,5
Single Voltage WYE-Delta Connections
Operating mode Connection L1 L2 L3 Join
Start WYE 1 2 3 4&5&6
Run Delta 1,6 2,4 3,5 -------
Dual Voltage WYE-Delta Connections
Voltage Connection L1 L2 L3 Join
High WYE 1 2 3 4&5&6
Low Delta 1,6 2,4 3,5 -------
NEMA Nomenclature--9 Leads:
Dual Voltage WYE-Connected
Voltage L1 L2 L3 Join
High 1 2 3 4&7, 5&8, 6&9
Low 1,7 2,8 3,9 4&5&6
Dual Voltage Delta-Connected
Voltage L1 L2 L3 Join
High 1 2 3 4&7, 5&8,6&9
Low 1,6,7 2,4,8 3,5,9 ------------
NEMA Nomenclature--12 Leads:
Dual Voltage--External WYE Connection
Voltage L1 L2 L3 Join
High 1 2 3 4&7, 5&8, 6&9, 10&11&12
Low 1,7 2,8 3,9 4&5&6, 10&11&12
Dual Voltage
WYE-Connected Start
Delta-Connected Run
Voltage Conn. L1 L2 L3 Join
High WYE 1 2 3 4&7, 5&8, 6&9, 10&11&12
Delta 1,12 2,10 3,11 4&7, 5&8, 6&9
Low WYE 1,7 2,8 3,9 4&5&6, 10&11&12
Delta 1,6,7,12 2,4,8,10 3,5,9,11 ------------
IEC Nomenclature--6 & 12 Leads:
Single Voltage WYE-Delta Connections Single Voltage WYE-Delta Connections
oper-
mode Conn. L1 L2 L3 Join
Start WYE U1 V1 W1 U2&V2&W2
Run Delta U1,W2 V1,U2 W1,V2 --------------
Dual Voltage WYE-Delta Connections
Volt Conn. L1 L2 L3 Join
High WYE U 1 V1 W1 U2&V2&W2
Low Delta U1,W2 V1,U2 W1,V2 --------------
Dual Voltage WYE-Connected Start
Delta-Connected Run
Volt Conn. L1 L2 L3 Join
High WYE U 1 V1 W1 U2&U5,V2&V5, W2&W5,U6&V6&W6
Delta U1,W6 V1,U6 W1,V6 U2&U5,V2&V5,
W2&W6
LOW WYE U1,U5 V1,V5 W1,W5 U2&V2&W2,
U6&V6&W6
Delta U1,U5,
W2,W6 V1,V5
U2,U6 W1,W5
V2,V6 -----------------------------
NEMA Nomenclature--6 Leads:
Constant Torque Connection (Low-speed HP is half of high-speed HP)
Speed L1 L2 L3 Typical
Connection
High 6 4 5 1&2&3Join 2 WYE
Low 1 2 3 4-5-6 Open 1 Delta
Variable Torque Connection (Low-speed HP is 1/4 of high-speed HP)
Speed L1 L2 L3 Typical
Connection
High 6 4 5 1&2&3Join 2 WYE
Low 1 2 3 4-5-6 Open 1 WYE
Constant Horsepower Connection (HP is the same at both speeds)
Speed L1 L2 L3 Typical
Connection
High 6 4 5 1-2-3 Open 1 Delta
Low 1 2 3 4&5&6-Join 2 WYE
IEC Nomenclature--6 Leads:
Constant Torque Connection
Speed L1 L2 L3 Typical
Connection
High 2W 2U 2V 1U&1V&1W--JOIN 2 WYE
Low 1U 1V 1W 2U-2V-2W OPEN 1 Delta
Variable Torque Connection
Speed L1 L2 L3 Typical
Connection
High 2W 2U 2V 1U&1V&1W--JOIN 2 WYE
Low 1U 1V 1W 2U-2V-2W OPEN 1 WYE
.............................................................................
looks like we can swap the terminal names like this:
1=U1....2=V1....3=W1....4=U2....5=V2....6=W2
Hope that doesn't muddy the waters more than it helps,
cheers, dave