zone 0, as IEC 60079-25 does next comments indeed, then it's not allowed to install that device in zone 0 (better wording is location requiring EPL "Ga"). For this conclusion, no Decision Sheet is necessary. Kiwa Unit -- Answer te A better prevention for the same Replace second part of the answer We will take the proposition into ExVision device to be installed in zone 0 into: account. NL (which seems to be the intention of the Decision Sheet) is to mark it Ex Conception Ex ia [ia Ga] IIC T .. ia [ia Ga] IIC Tx Gb; meaning this Gb is the best option if the surge device is allowed to be installed in protection device is designed to zone 1 or zone 2 only and has an protect the intrinsically safe circuits "ia" circuit that may be extending in the zone 0. into zone 0. The mentioned example (which indeed may be one of the options, but not the best) should require an additional Ex d enclosure. The use of EPLs, invented by IEC, is just the way to indicate the equipment protection level, and hence the allowed location, of a device. So use the EPL concept for that purpose.
zone 0, as IEC 60079-25 does indeed, then it's not allowed to install that device in zone 0 (better wording is location requiring EPL "Ga"). For this conclusion, no Decision Sheet is necessary. next comments Kiwa Unit ExVision NL -- Answer te A better prevention for the same device to be installed in zone 0 (which seems to be the intention of the Decision Sheet) is to mark it Ex ia [ia Ga] IIC Tx Gb; meaning this device is allowed to be installed in zone 1 or zone 2 only and has an "ia" circuit that may be extending into zone 0. The mentioned example (which indeed may be one of the options, but not the best) should require an additional Ex d enclosure. The use of EPLs, invented by IEC, is just the way to indicate the equipment protection level, and hence the allowed location, of a device. So use the EPL concept for that purpose. Replace second part of the answer into: Conception Ex ia [ia Ga] IIC T .. Gb is the best option if the surge protection device is designed to protect the intrinsically safe circuits in the zone 0. We will take the proposition into account.
ExTAG_427A_CC_Compilation.docx