WA ASIC

Over the last fifteen years WA has developed a range of custom ICs for use in RCDs and RCMs (residual current monitors). The ASIC presently used on most of our RCD products is the WA030. This RCD IC is unique in that it responds to the RMS value of the earth fault current rather than to the peak value which many standard RCD ICs do.

The ASIC also has a programmable response time which is independent of the magnitude of the fault current. These characteristics enable the WA030 to detect pulsating DC fault currents (Type A response) in accordance with IEC61008 and ensure optimum immunity to nuisance tripping problems associated with some standard RCD ICs.

The company has a policy of improving its residual current device technology and the WA030 ASIC may be superseded by an even better performance ASIC in due course.

WA Generic RCD Module.

The generic RCD module is a fully assembled and tested PCB complete with electronics, a circuit breaker (tripping mechanism) and test button. The module is intended for use in PRCDs (portable residual current devices) and SRCDs (socket residual current devices).

There are two basic versions available:

1. Latching type, with the contacts remaining closed (latched) on loss of supply
2. Delatching type, with the contacts opening automatically (delatching) on loss of supply.

The latching version is rated at 230/20A and the delatching version is rated at 230V/16A. These modules have been designed for compliance with BS7071 and BS7088, and also for compliance with IEC61540 (PRCDs) and IEC61541 (SRCDs).

The WA RCD module is unique in that it uses a single button to perform three functions:

• Test
• Reset
• Manual delatch (latching version only)

Two-button versions (Reset and Test) are also available.

The RCD module is ready for placing into a housing and merely requires connection of supply and load terminals. These fully assembled and tested modules can provide customers with the ability to develop PRCDs and SRCDs with minimal need for development time and costs associated with the RCD elements. This can reduce the product development lead time by several months in most cases, and substantially reduce the costs associated with PRCD or SRCD product design, testing, certification, etc.