In order for an electrical installation to be considered as having been taken out of service, it must be separated from the electricity supply network reliably and in such a manner that voltage cannot be connected to it by regular means of operation. It is recommended that the electrical installation or any part of it to be taken out of service be entirely disassembled. You must remember to notify the network operator of the taking out of service, and in case of larger installations (filed with Tukes' register), Tukes as well.
However, if operations in the building end, e.g. production being discontinued, electrical installations are often not entirely separated from the electrical supply network. Electricity might still be needed, e.g. for heating and lighting. If the electrical installation has required a certified operation supervisor, the obligation shall not end unless the electrical installation is entirely separated from the electricity supply network.