2-4-13

Rotation meter conductor leads are normally engraved ?

1,2,&3

A three phase waveform ? If the sequence is changed from. 1-2-3 to 2-1-3

Not change

It is essential to take rotation readings, when ?

Paralleling, three phase transformer banks

Only the ? Changes when there is a change in the rotation in a three phase line

Phase sequence

The order in which voltage waveforms reach their peak is referred to as ?

Phase sequence

Voltage and current magnitude remain unchanged when ?

Rotation is reversed

If a phase rotation reading is taken at the customer service entrance before an outage the next reading should be taken at the ? When service is restored

Same point

Meters instruments and relays on three phase circuits, depend on proper rotation to operate correctly

True

Normally, in new construction, the customer's electrician takes care of proper rotation to the customer's motors.

True

When using a three phase induction rotation, meter, it is important to get into the habit of placing the leads in the same order every time (normally left to right) and to make a notation of phase rotation

True

A transformer bank has been replaced ? To check the phase sequence to be sure the customers three phase motor will turn in the same direction as before.

Use rotation meter

A good way to check if the rotation meter is working properly is to swap two rotation meter leads the rotation meter should

reverse rotation

When replacing a pole that has a three phase takeoff, it is always better to make the corners so the phasing will be A, B, & C with A phase on the roadside

False

A 120/240 V service is connected from a delta banked secondary to reverse the rotation only the ? Phases can be swapped.

120V

For a three phase generator there is/are only ? Possible directions it can turn.

2

The rotation of a three phase motor can be changed by changing any two of the service leads on a delta service, such as one providing three phase ? Or ?

240/480

Rotation leads are normally placed 1, 2, & 3, ? When taking a rotation reading on the top of a meter base

Left to right

If equipment is protected by phase sequence relays, the equipment will not work and it may ? If it's rotation has been reversed.

Lock itself out

The order in which the voltage waveforms of a polyphase AC generator reach their respective peaks is called the phase __?__.

Sequence

One advantage, a three phase motor has over a single phase motor is that ? For the same horsepower capacity

The physical size is smaller

It is necessary to check rotation on circuits that serve motors ?

When the circuits are to be tied together