SPDs are typically installed at the main distribution board or consumer unit to protect the entire electrical installation from incoming surges. They can also be installed at specific equipment or machinery panels to protect sensitive electronics.

Three-phase electrical systems often power industrial machinery, HVAC systems, data centers, and other critical equipment that is susceptible to damage from voltage surges. SPDs help protect this equipment, ensuring reliability and reducing downtime.

While not mandatory in all cases, SPDs are recommended in many three-phase installations to comply with best practice guidelines and to protect sensitive electronic equipment. They may also be required by specific industry standards or regulations.

SPDs for three-phase systems come in various configurations:

• Type 1 SPDs: Provide protection at the main distribution board, suitable for locations with high exposure to direct lightning strikes.
• Type 2 SPDs: Provide protection against switching surges and indirect lightning strikes at the distribution board or equipment level.
• Type 3 SPDs: Provide additional protection at the point of use for sensitive equipment.

SPDs are typically installed at the main distribution board or at specific equipment panels. Proper installation involves connecting the SPD’s terminals to the phases, neutral, and protective earth (if applicable) according to manufacturer instructions and local regulations.