Wiring Notes

Wiring of 110 V circuits: European vs USA.

Ground
Hot
Neutral
Europe
Green/White or Green/Yellow
Brown
Blue
USA
Green wire
Black

White

USA-plug
round prong
Small flat prong

Large flat prong

 

Wiring 230 V single phase: European vs USA

Ground
Hot 1
Hot 2
Europe
Green/White or Green/Yellow
It makes no difference how the other two wires are matched.
USA
Green wire
Wiring of 3-phase motors from Europe vs USA
Ground
L1
L2
L3
Europe
Green/White or Green/Yellow
Brown
Black
Blue
USA
Green
Black
Red
Blue
Phase Rotation Tester This meter indicates which lines are L1, L2, and L3. Sometimes you cannot easily see the wire colors and it is always good to know that the wires were not mixed up when installed.

DELTA (230 V) vs WYE (208 V) . There are two common types of 3-phase power. This subject is a little complicated but the important thing to remember is that 208 V means Wye, and 230 V means Delta. Europe is Wye nearly exclusively, while North America is Delta and Wye.

Wye has three legs with 208 V between any two legs. There is 120 V from any of the legs to Neutral.
Delta has three legs with 230 V between any two legs. There is 115 V between Ground and 2 of the hot legs. The voltage between Ground and the other hot is ~160 V (this is not used).

The advantage of Wye is that you get three 120 V services for each three phase service, where as you only get two with Delta. This advantage is useful for large industrial sites.
The advantage of Delta is the higher voltage (230 vs 208).

We have been speaking of Delta vs Wye sources. But Delta vs Wye can also refer to the wiring of a 3-phase motor. In Wye, the outlet of the three windings are wired together. In Delta, the outlet of a winding is tied to the inlet of another. It does not make a significant difference in many applications, but Delta will provide more starting torque for most of the motors that we offer.

208 vs 230 Volts. All modern motors run well with voltage variations in this range. Same is true for 120 V vs 115 V. There can however be differences particulalry in starting high torque conditions. Higher voltage 230 V will be better.

50 vs 60 Hz. Europe uses 50 Hz power while USA utilizes 60 Hz. All the machines that we sell are supplied with 60 Hz motors. 50 Hz motors run at 60 Hz (i.e., European motors run in the USA) will run too fast. (and draw a little more current). This is not a big problem for motors run under low load conditions but is serious for medium to high load machines (which is most winery equipment).

Single Phase from a 3-phase outlet. If you have a 3-phase outlet and want only single phase power, simply use the ground and two of the hot wires. It doesn't matter which of the hot wires you use.

4-Wire Single Phase 230 V. This is essentially what is provided to every home in America. This is 1-phase 230 V power with a 115 V power in the same line. It is a ground wire, two hot 230 Volt wires, and a Neutral wire. The voltage across the 230 volt wires will be 230 volts, and the voltage across the neutral and the either of the 230 Volt wires will be 115 volts. You may see this type of wiring also on electric driers, travel trailers, etc in which both 230 V and 115 volt service are used in the same unit.

5-Wire 3-Phase 208 V. This is Wye. This is the simply 3-phase power (3 hot wires and a ground) with a neutral wire to provide 120 V.

Wire Gauge. 3-phase power draws less current than single phase (given same horsepower). More current dictates larger wire (heavier gauge). Thus, extension cords and wiring for single phase motors should be larger gauge and shorter in length than for 3-phase motors. As a rule of thumb, use minimum 12 gauge extension cords.

kW vs HP (kilowatt vs horsepower). European motors are often labelled with kilowatts. 0.75 kW = 1 HP.

3-Phase Power and Direction of Rotation. To change the direction of rotation of a 3-phase motor, simply switch any two of the hot wires.