Instruments in Zone 0, 1: Live Maintenance on Spurs Ex ia, High-Power Trunk

1. Trunk: protected installation according to IEC 60079-14
2. Spurs: one device per output FISCO or Entity: Ex ia IIC; intrinsically safe according to IEC 60079-11
3. Instruments: rated Ex ia for Zone 0 / 1 or Ex ib for Zone 1 according to Entity and FISCO
    

This is a typical installation for devices in Zone 1 or Zone 0. Trunk connections are equipped with Ex e-rated terminals (increased safety). The spur installation follows rules for intrinsic safety (Ex ia) enabling live work on the instrument.