Seaward 372A955 PAT Testing Adapter, For Use With Europa Plus, Prime Test 250, Prime Test 350, Supernova Elite

The NTB-1 is designed to eliminate the risk of tripping the main RCD when carrying out RCD trip time tests with RCD test instruments. It isolates the electricity supply to the RCD under test, allowing the test operative to continue testing without the worry of causing disruption to the premises they're working on by tripping the main RCD.
In the past, isolation transformers have been used for this purpose, but these are bulky and typically weigh around 10kg in comparison to the Non Trip Box's (NTB) lightweight 0.6kg. The NTB-1 is portable and can be used with any test instrument which is used to carry out the RCD trip time test.

Test portable RCDs without tripping the installation RCD
Compact, lightweight and portable
Universally compatible with all RCDs and RCD test instruments
Can be used in all situations and locations where an RCD test is required
230Vac/ 50Hz

The IEE Code of Practice requires RCD protected devices to be tested to ensure correct performance