A surge-protective device (SPD) must be provided as an integral part of the elevator system or installed immediately adjacent to the disconnecting means. SPD) is required to be installed on dwelling unit services. A study commissioned by the Fire Protection Research Foundation found t sonnel against. Surge protection is a cost-effective solution to prevent downtime, improve system and data reliability and elimination of equipment damage due to transients and surges for both power and signal lines. It is suitable for any facility or load (1000 volts and below). They are very important for modern. Under NEC 2023 Article 230. For Surge Protection to be most effective, a cascading protection scheme should be used through an entire system.