UL Class 1 vs UL Class 2
UL Class 2 drivers comply with standard UL1310, meaning output is considered safe to contact and no major safety protection is required at the LED/luminaire level. There is no risk of fire or electric shock. These drivers operate using less than 60 volts in dry applications, 30 volts in wet applications, less than 5 amps, and less than 100 watts. However, these limitations pose restrictions on the number of LEDs a Class 2 driver can operate.
UL Class 1 drivers have output ranges outside UL Class 2 designations. An LED Driver with a UL Class 1 rating has a high-voltage output and safety protection is required within the fixture. A Class 1 driver can accommodate more LEDs, making it more efficient than a Class 2 driver.
In addition, confusion often exists regarding the difference between Class 2 and Class II rated ac-dc power supplies. The differences are significant and important to understand. The NEC(National Electric Code) identification of Class 2 refers to the output voltage and power capabilities of ac-dc supplies, while the IEC (International Electrotechnical Commission) designator of protection, Class II, refers to a power supply’s internal construction and electrical insulation.
Class II and Class2 Product
IEC Class II and Class I Insulation Protection
The IEC protection classes govern the construction and insulation of power supplies to protect the user from electrical shock. In a Class II power supply, there are two layers of insulation (or a single layer of reinforced insulation) between the user and the internal current carrying conductors. In supplies designed with two layers of insulation, the first layer of insulation is typically referred to as “Basic Insulation.” The second layer of insulation is often an insulating case enclosing the product, such as the plastic case present on wall mount and desktop power supplies.
A common example of basic insulation is the insulation present on wires. IEC Class I input models have basic insulation and must incorporate a protective earth (ground) connection to mitigate the risk of electric shock.
Label showing the IEC protection Class II symbol
IEC protection Class II power supplies will have a two-wire power cord as opposed to a three-wire power cord (Class I) with Safety Earth connection. Products designed with Class II insulation often are labeled as “Class II” or “double insulated” or will have the concentric square symbol on the safety label. This symbol just like Chinese characters “回”
In brief, the table below shows the difference between Class I, Class II, Class1 and Class2.
|Classify||Class1||Class2||Class I||Class II|
|Insulation||Electrical limitation||Electrical limitation||basic insulation||Double Insulated|
|Characteristic||Power≤1000 Volt-Amps||Voltage≤60（Dry）||three-wire power cord||two-wire power cord|