3. Intrinsic Safety Explosion Protection Instrumentation
3-10
TI 32S01J30-01E
Apr. 25, 2022-00
Wiring of Intrinsic Safety Explosion Protection
An intrinsic safety circuit must be isolated from non-intrinsic safety circuit.
Wiring should be prepared in accordance with IEC 60079-14, NEC (National Electrical Code
: NFPA-70), or the standard of the country and the area in which it is set. The wiring in cabinet
should keep the distance to non-intrinsic safety circuit.
After setting, check the wiring according to the checklist described in IEC 60079-17.
An intrinsic safety circuit of barrier is indicated by the following ratings.
Maximum voltage of intrinsic safety circuit
Uo
Maximum current of intrinsic safety circuit
Io
Maximum electricity of intrinsic safety circuit
Po
Permissible inductance of intrinsic safety circuit
Lo
Permissible capacitance of intrinsic safety circuit
Co
As a combination of intrinsic safety circuits connected with barriers and wiring, it is necessary to
meet the following conditions to keep the intrinsic safety performance.
Uo
≤
Ui
Io
≤
Ii
Po
≤
Pi
Lo
≥
Li+Lw
Co
≥
Ci+Cw
