My Meter occasionally displays >50V and inhibits the test cycle, this is a safety feature
You may well have come across a situation where your tester inhibited your test button, indicating that the contact voltage is >50V. This is a safety feature that was made mandatory when 17th edition was introduced. The RCD tester will sense if there is excessive voltage between Neutral and PE, and by injecting, for example, injecting 150mA leakage in to a 30mA RCD ( 5 x current) this could create a dangerous voltage on the earth above the safe limit of 50v.
