UL 1449 4th Edition—Free Download
The Necessary Safety Standard for Surge Protection Devices
The newly issued UL 1449 Standard for Surge Protective Devices for safety and is the preferred standard for all AC surge protection devices (SPDs).
Requirements that cover surge protective devices (SPDs) designed for the repeated limiting of transient voltage surges as specified in the standard on 50 or 60 Hz power circuits not exceeding 1000 V.
How the Standard Impacts Surge Protection Devices
- UL 1449 standard specifies various tests that OEMs must pass to claim compliance
- Standard SPDs must have UL 1449 certification to meet safety standards for specific markets
What SPD Types are Covered
Testing is Key
Critical to UL listing is standardized testing. This table details the testing regulations for Type 4 and Type 5 SPD component assemblies.
After Obtained UL certification, manufacturer take responsibility to meet standards seriously. All of SPDs include clear and permanent required markings to ensure the solutions you choose meet UL 1449.
- Manufacturer name
- Catalog number
- SPD Type
- Electrical ratings
- Nominal discharge current (In) rating
- Maximum continuous operating voltage rating (MCOV)
- Voltage protection rating (VPR)
- Measured limiting voltage (MLV)
- Date or period of manufacture
- Short circuit current rating (SSCR)
Type 4 component assemblies and Type 5 SPDs require MLV, MCOV, operating voltage, and In ratings. For Type 5 SPDs these ratings may be provided in data sheets.
Glossary of Key Terms
- Fault current – Current from power system that flows in a short circuit
- Maximum continuous operating voltage (MCOV) – Maximum amount of voltage that can be applied continuously to SPD
- Measured limiting voltage – Maximum magnitude of voltage measured when In is applied
- Nominal discharge current (In) – Peak value of current (8 x 20 wave shape) driven through the SPD 15 times (SPD must remain operational)
- Nominal operating voltage – Normal AC power voltage of the system
- Nominal voltage (Vn) – DC voltage measured across the SPD when 1mA flows
- Short circuit current rating (SCCR) – Suitability of an SPD to withstand a declared short circuit from the power source
- Voltage protection rating (VPR) – Voltage rating selected from a list of preferred values when a combination wave of 6kV 3kA is applied