Plan protection for the actual installation
Surge protection and earthing must be designed for the cabinet, incoming supply, connected cables and site conditions. A generic rod length, resistance target or surge-current rating is not a complete design. Use the applicable local electrical requirements and the instructions for each selected device.
Information to collect
Record the supply voltage and earthing arrangement, cabinet drawings, cable routes, external communications and existing protective devices. Identify exposed field circuits and the equipment that each protective device is intended to protect.
Select and coordinate protective devices
Check device type, rated voltage, protective level, short-circuit suitability and required upstream protection against the installation design. Coordinate power and signal-line protection. Follow the manufacturer’s connection arrangement, conductor requirements and permitted lead lengths; do not copy dimensions from an unrelated product.
Inspection and maintenance records
Qualified personnel should inspect bonding, connections, device indicators and enclosure condition under an approved safe-work procedure. Select an earthing test method appropriate to the electrode network and site. Record the method, conditions, readings and acceptance criteria rather than treating one resistance number as universal.
Define the procurement scope
Request a cabinet drawing and a model-specific list of included protection components. Agree who supplies, installs, tests and maintains the earthing system. Do not assume that every controller includes the same surge protection or that on-site installation is part of the supply contract.