Product Overview: IEC Process Screw Terminal Blocks
The 2005 National Electrical Code (NEC) and UL 508A (effective April 25, 2006) now require many electrical panels to have short-circuit current ratings (SCCRs). Rockwell Automation is an industry leader in supplying a wide range of SCCR-rated products, including, but not limited to: terminal blocks, power units, circuit breakers, contactors, disconnect switches, and actuators.
Rockwell Automation has tested Bulletin 1492 screw and spring-type terminal blocks for SCCR ratings. These ratings allow the terminal blocks to be used with fuses, motor protection circuit breakers, and motor circuit protection devices in power circuits. By combining components with SCCR ratings, the process of obtaining SCCR ratings for UL 508A electrical panels can be simplified.
When the new UL 508A standard was adopted, all terminal blocks were assigned a default SCCR of 10 kA for use in power circuits. The SCCR of an electrical panel is based on the component with the lowest SCCR in the circuit, creating a 10 kA limitation for power circuits using terminal blocks. Many users of UL 508A-compliant terminal blocks strive to achieve a total system current rating of 25 kA to 100 kA.
To meet UL requirements, Rockwell Automation offers several Bulletin 1492 screw and spring terminal blocks with high-reliability SCCRs.
Features and Benefits
- Provides 45% space savings per signal loop compared to solutions using traditional feed-through, fuse, and ground terminals.
- Offers integrated shielding connection, reducing the number of terminal blocks per signal loop by 33%.
- Provide a multi-functional design that includes fuse blocks with disconnect capability and isolating terminal blocks with fuse capability.
- Offer fuse blocks with blown fuse indication and low leakage current rating.