What is motor code?

For motors less than ½ horsepower, the code letter on the nameplate represents the locked-rotor kVA. On larger motors, it identifies the locked-rotor kVA per horsepower. … Generally, the farther a code letter is from A, the higher the inrush current per horsepower.

How do I find my motor code?

The starting kVA required by a motor starting at full voltage is determined from the nameplate on the motor or from the manufacturer.

NEMA locked rotor indicating code letters for electrical motors.

NEMA Code Letter kVA/HP with locked rotor Approximate Mid-Range Value
C 3.55 – 3.99 3.8
D 4.0 – 4.49 4.3

What is KVA motor code?

Induction motors at starting draw larger current than normal operation current. This starting current is represented as kilo volt ampere power. Each motor has its own starting power and is set on the motor nameplate as KVA code.

What is the start code letter of this motor?

Indicating locked rotor code letters for electrical motors

NEMA Code Letter KVA/HP with locked rotor Approximate Mid-Range Value
A 0-3.14 1.6
B 3.15-3.55 3.3
C 3.55-3.99 3.8
D 4.0-4.49 4.3

What is KVA code letter?

NEMA code letters designate the classification of electrical motors by the ratio of locked rotor kVA per horsepower.

Locked Rotor Design Code Letters.

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NEMA Code Letter kVA/HP with Locked Rotor Approximate Mid-Range Value
A 0- 3.14 1.6
B 3.15 – 3.55 3.3
C 3.55 – 3.99 3.8
D 4.0 – 4.49 4.3

What are 4 common types of motor enclosures?

The Most Common Types Of Electric Motor Enclosures

  • The most common types of enclosures are:
  • Open Drip Proof (ODP)
  • Weather Protected (WP1 / WP2)
  • Totally Enclosed Fan Cooled (TEFC)
  • Totally Enclosed Non-Ventilated (TENV)
  • Totally Enclosed Air Over (TEAO)
  • Totally Enclosed Forced Ventilated (TEFV)
  • XP (Explosion Proof)

How do I know if my rotor is locked?

Out in the field, the rule of thumb for locked-rotor current is six times the full-load amperes marked on the motor’s nameplate. The result of multiplying the full-load amperes of a motor by six might be close to the actual locked-rotor current or the result might not be anywhere near the actual locked-rotor current.

What information is learned in A locked rotor test?

A blocked rotor test is normally performed on an induction motor to find out the leakage impedance. Apart from it, other parameters such as torque, motor, short-circuit current at normal voltage, and many more could be found from this test. Blocked rotor test is analogous to the short circuit test of transformer.

What is motor insulation class F?

The F refers to the insulation class for the windings, while the B refers to an 80°C rise (the maximum temperature rise for Class B is 80°C). This type of notation is becoming more widespread because many motors use Class F insulation, and there is a reason for that.

How is kVA code calculated?

Here is the tabulation of those code letters and kVA per horsepower values.

Locked rotor KVA per Horsepower.

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Letter designation (KVA/HP) Minimum (KVA/HP) Maximum
E 4.5 4.99
F 5 2.59
G 2.6 6.29
H 6.3 7.09

How many motor designs does a NEMA designate?

NEMA has established the four different designs A, B, C and D for electrical induction motors. Different motors with the same nominal horsepower may have different start current, torque curves, speeds and other variables.