RCD safety switches come in a few different configurations, with standard RCDs protecting against electric shock by detecting current imbalance and switching off power, while RCBOs combine this protection with the overcurrent protection function of a standard circuit breaker in a single device. Understanding which type of device is installed in a specific workplace matters for how testing is approached, since the two device types, while related, aren't identical in function or in how they're checked. Newcastle Test and Tag identifie... read full review »