Plugs & Sockets

There is no mention of being able to lock in the on or off position in any standards, obviously locking in the off position is no problem but being able to lock in the on position is an extra feature that is used for critical equipment.

As 63A and 125A units as less common they are only offered in the higher ingress protection.

RCD’s are only offered in 25A, 40A, 63A and 100A ratings so the rating above is often used. A 16A outlet would have 25A fitted and 32A would have 40A. An RCD does not offer any overload protection so the current rating is purely the maximum current it will handle without failing so the socket outlet must have a suitable rated MCB fitted upstream.

This is called a pilot pin which is used to give feedback that the connection has been made. This can turn on a contactor so the power is switched off prior and on when connected to avoid arcing, it is also used for earth monitoring purposes too, so if the earth is lost on the appliance the socket is disconnected with a contactor. All of Lewden/Palazzoli 63A and 125A plugs and sockets are come with the extra pin as standard which is not counted when specifying the number of pins.