# How do you size a Wye-Delta contactor?

## How do you size a Wye-Delta contactor?

Size of Main Contactor (Starting-Transition-Running) = 58%X Full Load Current (Line). Size of Main Contactor =58%x13 = 8 Amp. Size of Delta Contactor (Running Condition) = 58%X Full Load Current (Line). Size of Delta Contactor =58%x13 = 8 Amp.

### Which is faster Wye or Delta?

Therefore, a scaled wye windings is better for high speed than a delta winding. For a wye wound motor as compared to a delta wound motor, presuming each phase resistance is the same, between any two phases, a delta wound motor has 1/3 the resistance as compared to the wye.

#### Should I wire motor as a Wye or Delta?

If leads are numbered 1-6, the winding can usually be connected wye or delta. On machines rated for two voltages, the wye connection is for the high voltage; the delta connection is for the low voltage. For a single voltage rating, most 6-lead machines are capable of wye-delta starting (and will run in delta).

How many contactors are needed for a wye-delta starter?

three separate
The most widely used configuration of the electromechanical wye-delta starter is referred to as open transition. The typical circuit includes three separate contactors, an overload relay, a timer, and an interlock.

How is contactor size calculated?

Size of Main Contactor = 100%X Full Load Current (Line). Size of Main Contactor =100%x6 = 6 Amp. Making/Breaking Capacity of Contactor= Value above Chart x Full Load Current (Line). Making/Breaking Capacity of Contactor=8×6= 52 Amp.

## What is the most critical part of connecting a wye delta starter?

Note that the 2M load contacts are used to make the delta connection. A diagram showing the connection of all load contacts is shown in FIG. 12. The most critical part of connecting a wye-delta starter is making the actual load connections to the motor.

### How do you determine Wye or Delta?

Delta systems have four wires total: three hot wires and one ground wire. Wye systems utilize a star configuration, with all three hot wires connected at a single neutral point. One neutral wire and one ground wire make for a total of five wires in 3-phase Wye systems. When comparing Delta vs.

#### Is 480 volts Delta or Wye?

Classification of Electrical Services

Wye Line-to-Neutral Voltage Wye or Delta Line-to-Line Voltage
230 400
240 415
277 480
347 600

Is Wye safer than Delta?

The Wye connection joins together one end of each of the coils and applies the individual phases to the open ends. These two connections produce very different results when power is applied. An advantage of the Delta connection is higher reliability.

Does a motor run faster in Star or Delta?

The speeds of Star connected motors are slow as they receive 1/√3 voltage. The speeds of Delta connected motors are high because each phase gets the total of line voltage.

## What is the most critical part of connecting a Wye-Delta starter?

### How do you select a contactor for a load?

You should select the suitable contactor according to the number of phases of the load. For example, if you want to control a 3 phase motor, you should use 3 pole contactor. If you want to disconnect the neutral, your choice should be 4 pole version.

#### How do you determine overload size?

The overloads are determined using 125% of the FLA, 7A x 1.25 = 8.75A. The maximum allowable size for the overloads is 9.8A. The overloads can be sized at 140% of the FLA if the overloads trip at rated load or will not allow the motor to start, 7A x 1.4 = 9.8A.

What are the two requirements that must be met before Wye Delta starting can be used?

There are two requirements that must be met before wye-delta starting can be used. 1. The motor must be designed for the stator windings to be connected in delta during the run period. Motors can be designed to operate with their stator windings connected in either wye or delta.

Is 120 240 Wye or Delta?

Classification of Electrical Services

Wye Line-to-Neutral Voltage Wye or Delta Line-to-Line Voltage
120 208
1201 240
230 400
240 415

## Is 480 Delta or Wye more common?

Anyway, 277/480 Wye is a very common service (secondary) voltage. More common than 480 delta which could also be 480/240 if it has a stinger leg.

### Is 480 a Wye or Delta?

The “480 Y” indicates the transformer is wye-connected and has 480 volts between any two phases. The “277 V” indicates there are 277 Volts between any phase and neutral (N). The phase-to-phase voltage is 1.732 times phase-to-neutral voltage (277 x 1.732 = 480).

#### What happens if a Delta motor is connected in star?

when you connect the delta connection motor into a star connection mode, the effective per phase voltage is reduced to (1/1.732) times hence to maintain the torque/speed it will draw 1.732 times higher current.

Why there is no neutral in delta connection?

Neutral is used to close a circuit but delta circuit is already closed so the neutral connection not used in delta circuit.

Can you oversize a contactor?

A contactor is a glorified switch and the ratings are for its own function. You want to avoid under-sizing a contactor, but you can oversize.