Replaced by JB/T 7836.2-2005, JB/T 7836.3-2005 JB/T 7836.2-1995 Electric heater for motors Ordinary finned tube electric heater JB/T7836.2-1995 Standard download decompression password: www.bzxz.net

Mechanical Industry Standard of the People's Republic of China
Electric Heater for Motor
Subject Content and Scope of Application
Ordinary Finned Tube Electric Heater
JB/T 7836.2—1995
This standard specifies the classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage and technical guarantee requirements of ordinary finned tube electric heaters for motors (hereinafter referred to as electric heaters) and electric heating elements (hereinafter referred to as electric heating elements) for motors. This standard applies to electric heaters (or electric heating elements) inside motors or in pits working in general environments. 2 Reference standards
Basic test methods for low-voltage electrical appliances
GB 998-82
GB 2423. 493
GB 12665-90
JI3/T2379
JB4159--85
Basic environmental test procedures for electric and electronic products Test Db: Alternating damp heat test method Damp heat test requirements for motors used under general environmental conditions Metal tubular heating elements
General technical requirements for tropical electrical products
JB/T 7836.195
3 Product classification
Electric heaters for motors
General technical conditions
3.1 Heating elements are divided into the following two categories according to their structure: Single-ended lead-out:
b. Double-ended lead-out.
3.2 Electric heater type code and its meaning
4 Technical requirements
XXX/XXX
-Rated power W/rated voltage V
Structural code, indicating that the electric heating element is finned tubular "Ordinary electric heater for motor" code 4.1 In addition to meeting the following technical requirements, the electric heater (or electric heating element) shall also meet the technical requirements of Chapter 5 of JB/T7836.1. 4.2 Design requirements
The structure of the electric heating element (Figure 1) shall meet the following requirements. Approved by the Ministry of Machinery Industry on November 24, 1995
Implemented on June 1, 1996
Wiring part
JB/T7836.2--1995
Non-heating part
Heating part with resistance wire
1-Wiring device: 2-Insulator; 3-Sealing material: 4-Fastening device: 5-Metal tube: 6-Electrical insulating medium; 7-Resistance wire; 8-Metal sheet 4.2.1 The distance between the internal conductor of the electric heating element and the metal tube wall should not be less than 2mm. 4.2.2 When the shell of the electric heating element is made of ordinary steel or other alloy materials with better performance than ordinary steel, its wall thickness should not be less than 1mm. When the shell is made of copper or copper alloy, it must have corresponding mechanical strength to adapt to harsh working environment. 4.2.3 The bending radius of the wound-type electric heating element should not be less than 2.5 times the diameter of the fin tube. 4.2.4 The bending shape of the electric heating element must ensure that the inner end of the lead rod is on the straight part of the tube, and the distance from the starting point of the bend should not be less than 10mm
4.3 Performance requirements
4.3.1. Working temperature
On the premise of meeting the rated power, the working temperature of the electric heating element shall not exceed 200C, and the highest point working temperature shall not exceed 300C. If the user has special requirements, it can be determined by negotiation between the supply and demand parties. 4.3.2. Insulation resistance
4.3.2.1 The cold insulation resistance shall not be less than 50MQ during factory inspection. 4.3.2.2 The hot insulation resistance at the working temperature shall not be lower than the value calculated by the following formula, but the minimum shall not be lower than 1MαR=10-0. 0157×103
Where: R
Hot insulation resistance, Ma;
Heating length, mm;
Working temperature, C.
4.3.3 Insulation withstand voltage strength
Electric heaters (or electric heating elements) should be able to withstand a basic sine wave 50Hz, 1min withstand voltage test without breakdown, flashover and spark phenomenon in cold or hot state. The test voltage value is as follows: Rated voltage
4.3.4 Moisture and heat resistance
Test voltage
JB/T7836.2—1995
After the prescribed moisture and heat test, the appearance of the electroplated parts of the electric heating element shall not be lower than the second level requirement in "Appearance quality grading method of electroplated parts and chemically treated parts" in Article 2.4.1 of JB4159. The leakage current shall meet the requirements of Article 5.3.2 of JB/T7836.1, and its insulation resistance shall not be lower than 5M Q.
5 Test method
5.1 Working temperature measurement
Under full heating conditions, use a surface thermometer or thermocouple to measure the temperature at the specified temperature measuring points on the outer shell of the heating element, and take the average temperature measured at each temperature measuring point as the working temperature. At least three temperature measuring points shall be taken, which are located at the highest temperature point, the lowest temperature point and the middle temperature point on the surface of the heating element. 5.2. Insulation withstand voltage test
The insulation withstand voltage test of electric heaters (or heating elements) shall be carried out in accordance with the relevant provisions of Article 6.3 of GB998. The hot insulation withstand voltage test shall be started within 1 minute of cutting off the power supply. 5.3 Damp heat test
The heating element shall be subjected to the 40C alternating damp heat test method, and each cycle shall be The conditions are as specified in GB2423.4, 40°C alternating damp heat method as shown in Figure 2, and the test is carried out for a total of 6 cycles. End of heating
Start cooling
li15min
Figure 2 Test Db: Test cycle
Note: () The relative humidity should be as less than 100% as possible during the heating and cooling and low overflow stages. (2) For products with no obvious breathing effect, the relative humidity during the cooling stage may not be lower than the dotted line (85%). 5.4 The test methods for other technical requirements shall be carried out in accordance with the relevant provisions of JB/T7836.1. 6 Inspection rules
The product shall be inspected in accordance with the provisions of Chapter 7 of JB/T7836.1. 676
Marking, packaging, transportation and storage
JB /T7836.2-1995
The product should be able to comply with the provisions of Chapter 8 of JB/T7836.1. 8bZxz.net
Technical guarantee
Under the condition that the user complies with the storage, installation and use rules of the product, the manufacturer should ensure that the electric heater (or electric heating element) product can operate well within one year of use, but no more than two years from the date of manufacture. If the product is damaged or cannot work normally due to poor manufacturing quality within this specified time, the manufacturer should be responsible for repairing or replacing it for the user free of charge. Additional notes:
This standard was proposed and coordinated by Harbin Electric Motor Research Institute. This standard was drafted by Beijing Heavy Electric Motor Factory, Beijing Ruian De Technology Development Company, and Jiangyin Dianbo Electric Motor Instrument Factory. The main drafters of this standard are Xu Xiangmei, Chen Yinsheng, and Han Linsheng. 677
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