An electric heater is a device that begins to heat up after being powered on. Electric heaters are not only widely used in water heaters, rice cookers, electric fryers, and water dispensers, but also in refrigerators and air conditioners for defrosting or auxiliary heating
1. Classification of Electric Heaters
According to power, electric heaters are divided into three types: high-power heaters, medium power heaters, and low-power heaters.
; According to structure, electric heaters are divided into three types: electric heating tubes, bare wire heaters, and PTC type heaters. Their physical appearance is shown in the following figure1. Electric heating tube
This type of electric heater is made by installing a resistance wire in a circular metal sleeve with crystalline magnesium oxide and adding insulation material, as shown in the following figure
This type of heater has advantages such as good insulation performance, high power, vibration resistance, and moisture resistance.
2. Bare wire heater
Bare wire heater is made by installing resistance wire, insulation layer, and porcelain insulator onto the bracket, as shown in the following figure. It has the advantages of fast heating and high efficiency, but also has the disadvantage of being prone to leakage. Some electric heating assisted and heat pump air conditioners use this type of heater
3. PTC type heater
As shown in the figure below, PTC type heater is a new type of heater. PTC type heaters use PTC thermistors as heating devices, which have advantages such as long service life, fast heating, high efficiency, automatic constant temperature, wide adaptability to power supply range, and good insulation performance. In addition, the heat sink of the heater is made of aluminum alloy in a corrugated shape, which is then glued and welded
2. Inspection of Electric Heaters
1. Inspection of On/Off
When inspecting electric heating pipes and PTC heaters, the first step is to check for rust and looseness in their joints. If so, repair or replace them; If it is normal, use the resistance range of a multimeter to measure the resistance between its terminals. If the resistance value is infinite, it indicates that it is open circuit. For bare wire heaters, some faults can be detected through visual inspection to find the breakpoint; If the visual inspection is normal, use a multimeter for testing
2. Insulation Performance Testing
Place the digital multimeter in the "200M" resistance range or place the pointer multimeter in the "R × At 10k "gear, one probe is connected to the lead pin of the electric heater, and the other probe is connected to the shell of the electric heater. Normally, the resistance value should be infinite, otherwise it indicates that it has leaked electricity
Function of testing report:
1. Project bidding: Issue authoritative third-party CMA/CNAS qualification report
2. Online e-commerce platform entry: Quality inspection report recognized by major e-commerce platforms 3. Used as a sales report: issuing legally effective testing reports to make consumers more confident 4. Papers and research: Provide professional personalized testing needs 5. Judicial services: providing scientific, fair, and accurate testing data 6. Industrial problem diagnosis: Verify the troubleshooting and correction of industrial production problemsBaijian and testing process:
1. Telephone communication and confirmation of requirements
2. Recommend solutions and confirm quotations 3. Mail samples and arrange testing 4. Progress tracking and result feedback 5. Provide reports and after-sales service 6. If urgent or priority processing is requiredTesting and testing characteristics:
1. The testing industry is fully covered, meeting different testing needs
2. Fully cover the laboratory and allocate localized testing nearby3. Engineers provide one-on-one services to make testing more accurate
4. Free initial testing, with no testing fees charged
5. Self service order delivery for free on-site sampling
6. Short cycle, low cost, and attentive service 7. Possess authoritative qualifications such as CMA, CNAS, CAL, etc 8. The testing report is authoritative and effective, and is generally used in China