What does code mean on electric motor?
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What does code mean on electric motor?
Generally, the farther the code letter from A, the higher the inrush current per hp. A replacement motor with a “higher” code may require different upstream electrical equipment, such as motor starters.
What does the letter for locked rotor code have to do with anything?
Locked Rotor Design Code Letters – Electrical Motors NEMA code letters designate the classification of electrical motors by the ratio of locked rotor kVA per horsepower. Generally, smaller motors require a higher starting kVA than larger motors.
What is A design B motor?
NEMA B-design motors are considered to be normal-torque motors. They are used for low-starting-torque loads, such as with centrifugal pumps and fans. NEMA C and NEMA D motors are used for applications that require high starting torque (e.g., positive-displacement pumps and compressors).
What is A kVA code?
The kVA code letters in the National Electrical Code (NEC) represent a range of kilovolt-amps per horsepower during locked rotor (starting) of induction motors. KVA code G means this motor can consume KVA power ranged between 5.6 to 6.29 kVA/hp at its starting.
How do you read a motor label?
The RPM listed on the nameplate is the shaft speed for the motor. The speed of the motor is directly related to the frequency of the line voltage and the number of poles in the motor. At 60 Hz, a 4 pole motor will rotate at approximately 1800 RPM (7200/4 poles).
What is the locked rotor current?
Inrush current, also referred to as “locked rotor current,” is the excessive current flow experienced within a motor and its conductors during the first few moments following the energizing (switching on) of the motor.
What is A NEMA Class B motor?
NEMA Design Classes These characteristics make them well suited for a wide vareity of applications and they are often found powering fans and pumps. NEMA Class B motors also have a maximum 5% slip and a normal breakdown torque but include a low starting current, and a high locked rotor torque.
What is design on motor nameplate?
Design letter covers the characteristics of torque and current of the motor. Design letter (A, B, C or D) defines the different categories. Most motors are design A or B motors. A design A motor torque characteristic is similar to the characteristic of a design B motor; but there is no limit in starting inrush current.
What is NEMA Design L?
NEMA Design L: A Design L motor is a single-phase medium motor designed to withstand full-voltage starting and to develop a breakdown torque with a locked-rotor current.
What is kVA per HP?
Equivalent Horsepower and kVA Ratings
| HP | kVA |
|---|---|
| 1 HP | 0.933 kVA |
| 2 HP | 1.87 kVA |
| 3 HP | 2.8 kVA |
| 4 HP | 3.73 kVA |
What information is on a motor nameplate?
The nameplate-defined parameters for the motor – such as power factor, efficiency, torque and current – are at rated voltage and frequency. When the motor is used at other voltages than the voltage indicated on the nameplate, its performance will be affected.
Is 208V single phase or 3-phase?
120/208V single phase is derived from 208V three phase power. If viewed on an oscilloscope, the three voltage waveforms on the three “hot” conductors all peak at different times: each one is 120 degrees behind the next.
How do you convert LRA to amps?
The answer is simply divide 1500 by your mains voltage. If you live in a 220v area, the answer is 1500/220. 7 amps is near enough. If your voltage is 110, the answer is 1500/110.
How do you convert HP to LRA?
LRA (lock rotor amps) can be converted to HP using this formula: (LRA Watts x Volts)/ 746 Watts = Horsepower. You can also use the BTUh. For example, 18,000 BTUh equals 2 HP or 24,000 2.5 HP.
