Common rated power deviation of electric tubular heating element
In the production process, the length of the alloy wire will affect the resistance of the alloy wire during the production process, which will affect the power of the electric heating tube. The power error of the electric heating tube exists, but the power of the electric heating tube is based on "JB / T 2379-93 Industrial "Electric Heating Tube Standard", the deviation range of rated power is as follows:
Under sufficient heating conditions, the deviation of the rated power of the electric heating tube should not exceed the range specified below:
1. For the electric heating tube whose rated power is less than or equal to 100W: ± 10%;
2. For the electric heating tube whose rated power is greater than 100W: + 5% ~ -10% or 10W, whichever is greater.
According to the relevant national standards of the institute, the electric heating tube has the following requirements:
1 Heating time: under test voltage, the time for the component to rise from the ambient temperature to the test temperature should not exceed 15min
2 Rated power deviation: Under the condition of sufficient heat, the deviation of the rated power of the component should not exceed the following specified range; for components with a rated power less than or equal to 100W: ± 10%. For components with a rated power greater than 100W, + 5% to -10% or 10W, whichever is greater.
3 Leakage current: cold state leakage current and leakage current after water pressure and sealing test should not exceed 0.5mA, hot state leakage current at operating temperature should not exceed the calculated value in the formula, but the maximum does not exceed 5mA I = 1/6 (tT × 0.00001) I—thermal leakage current mA t—heating length mm T-operating temperature ℃ When multiple components are connected in series to the power supply, the leakage current test should be conducted with this group of components as a whole.
4 Insulation resistance: The cold insulation resistance should not be less than 50MΩ during the factory inspection. After long-term storage or use, the insulation resistance should not be less than the MΩ thermal insulation resistance at the working temperature should not be lower than the calculated value in the formula, but The minimum should not be less than 1MΩ
