End-of-life indication of a SPD

From Electrical Installation Guide

End-of-life indicators are associated with the internal disconnector and the external SCPD of the SPD to inform the user that the equipment is no longer protected against overvoltages of atmospheric origin.

Local indication

This function is generally required by the installation codes. The end-of-life indication is given by an indicator (luminous or mechanical) to the internal disconnector and/or the external SCPD.

When the external SCPD is implemented by a fuse device, it is necessary to provide for a fuse with a striker and a base equipped with a tripping system to ensure this function.

Integrated disconnecting circuit breaker

The mechanical indicator and the position of the control handle allow natural end-of-life indication.

Local indication and remote reporting

iQuick PRD SPD of the Schneider Electric brand is of the "ready to wire" type with an integrated disconnecting circuit breaker.

Local indication

iQuick PRD SPD (see Fig. J53) is fitted with local mechanical status indicators:

  • the (red) mechanical indicator and the position of the disconnecting circuit breaker handle indicate shutdown of the SPD;
  • the (red) mechanical indicator on each cartridge indicates cartridge end of life.
Fig. J53 – iQuick PRD 3P +N SPD of the Schneider Electric brand

Remote reporting

(see Fig. J54)

iQuick PRD SPD is fitted with an indication contact which allows remote reporting of:

  • cartridge end of life;
  • a missing cartridge, and when it has been put back in place;
  • a fault on the network (short circuit, disconnection of neutral, phase/neutral reversal);
  • local manual switching.

As a result, remote monitoring of the operating condition of the installed SPDs makes it possible to ensure that these protective devices in standby state are always ready to operate.

Fig. J54 – Installation of indicator light with a iQuick PRD SPD
Fig. J55 – Remote indication of SPD status using Smartlink

Maintenance at end of life

When the end-of-life indicator indicates shutdown, the SPD (or the cartridge in question) must be replaced.

In the case of the iQuick PRD SPD, maintenance is facilitated:

  • The cartridge at end of life (to be replaced) is easily identifiable by the Maintenance Department.
  • The cartridge at end of life can be replaced in complete safety, because a safety device prohibits closing of the disconnecting circuit breaker if a cartridge is missing.