Scope
This part:
- specifies the test method for determining the sound power level of rotating electrical machines
- For rotating motors that comply with GB755, are classified according to the cooling method specified in GB/T 1993-1993, and have the following characteristics according to the
protection classification specified in GB/T 4942.1-2006, the maximum A-weighted sound power level under the factory acceptance test method for grid power supply is specified:
Regardless of whether AC or DC motors are standard designs; Excluding designs specifically designed to reduce sound power levels from electrical, mechanical, or acoustic aspects The rated output ranges from 1 kW (kVA) to 5500 kW (kVA) The speed should not exceed 3 750 r/min
- Provides guidelines for determining the noise level of cage induction motors powered by frequency converters The purpose of this section is to specify the maximum sound power level LwA of air noise emitted by standard designed motors characterized by power, speed, and load, in dB (A); And it specifies the testing methods and conditions for determining the sound power level of the motor, and provides assessment criteria for whether the motor noise reaches the specified maximum sound power level. This section does not provide any modifications to the pure tone characteristics In practical situations such as hearing protection, a sound pressure level at a certain distance from the motor may be required. This data is obtained according to the standard test environment in Article 7 Note 1: This section suggests that considering economic factors, standard noise level motors can be used in non critical situations or where additional measures are needed to reduce motor noise. Note 2. When the sound power level requirements below Table 1 and Table 2 are required, the manufacturer and buyer must reach an agreement - due to special electrical, mechanical, or acoustic characteristics
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