loop powered displays, hand held terminals etc. connected to the hazardous location terminals of the associated apparatus in Zone 0, 1 or 2 should all meet the requirements for ‘ia’. The only additional consideration if the design fully meets the requirements for ’ia’ then the use of non-linear elements is that Intrinsically safe systems utilizing surge suppression techniques shall be supported by an adequately documented analysis of the effect of indirect multiple earthing, taking into account the criteria set out in clause 12 of 60079-25. The capacitance and inductance of the surge suppression devices shall be considered in the assessment of the intrinsically safe system. the safety. But if the surge protection devices certified with a resulting Ex marking string of “Ex ia IICT ... Ga”, the user would have the wrong impression of installing the devices in zone 0 which could cause danger. 2）CQM received the certification application for surge protection device with Marking Ex ia ... Ga, and for this matter, the applicant provided a IECEx CoC issued by an ExCB as evidence. Such DS could help ExCBs to adopt a consistent approach to the problem. Kiwa Unit ExVision NL Ge Kiwa does not really see the need of this decision sheet. Even if the device is marked Ex ia IIC Tx Ga, but the installation standard prohibits the installation in Reject the draft Decision Sheet. But if ExCBs/ExTLs agree that the DS is needed, because there are designers/installers that look at labels, not in standards, then see The same as above.
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.
Kiwa Unit ExVision Background ed Sentence "... taken into consider when assessing of the …" is not correct change to: " ... taken into consideration when assessing of the …" We will take the proposition into account. LCIE FR If the surge protective device is assessed according to the standard IEC 60079-11 and meets every requirement, nothing prevents to issue an IECEx certificate with the marking Ex ia IIC Ga T .... The matter should be transfer to MT of IEC 60079-11 and IEC 60079-25 in order to align requirements. In addition, as a provisional measure, it shall be required to add : condition for safe use to CoC : the surge protection device must be installed outside but as near to the boundary of Zone 0 as is practicable, preferably within 1 m a marking on the product : WARNING: SURGE PROTECTION DEVICE MUST BE INSTALLED OUTSIDE THE ZONE 0 – SEE INSTRUCTIONS Further step for MT.
NANIO CCVE (ExCB and ExTL) Tech We support the draft Decision sheet in principle, but we consider that the issue related to surge protection devices should be put in a broad perspective and we propose to discuss additional issues. The proposed draft Decision sheet is attached. To consider the draft Decision sheet attached. Annex A of this document. We will take the proposition into account. NEPSI CN T If the certification is requested based on IEC 60079-11, the example of marking can be as Ex ia IIC TX Gb; If the certification is requested for use in Zone 0, the example of making can be as Ex d+ia IIC TX Ga NEPSI CN If the certification is requested based on IEC 60079-11, the example of marking can be Ex ia IIC TX Gb; If the certification is requested for use in Zone 0, the example of making can as Ex d+ia IIC TX Ga
SGS Baseefa GB General Change answer from: No, because the device with Ex ia IIC T… Ga may be allowed to be installed in Zone 0, which does not agree with the relevant provisions on the surge protection device of IEC 60079-25 and could cause danger. Conception Ex d [ia Ga] IIC T .. Gb is one of the options if the surge protection device is designed to protect the intrinsically safe circuits in the zone 0. Change To: Yes. An IECEx Certificate can be issued marked Ex ia IIC T* Ga. When the device is not operating as a surge protector, it can be connected into an Ex ia IIC circuit in zone 0 as it does not affect the intrinsically safe circuit. However, as a surge protector, it should be installed according to national installation conditions i.e. IEC 60079-14. Concept Ex d [ia Ga] IIC T* Gb is just one of the options if the surge protection device is designed to protect the intrinsically safe circuits in the zone 0. We don’t accept this proposition as the same reasons to FME(GB). TIIS JAPAN G TIIS supports ExTAG/417/CD without any comments . TRA AU General The question is not correct, because IECEx certificate is not necessary for Revise the question to: Is a marking of Ex ia IIC T.. Ga We will take the proposition into account and make editorial
- [Ex ia Ga] IIА/IIВ/IIC T…; - Ex ia IIC T…Gb; - Ex ia [ia Ga] IIB T… Gb. QUESTION 2: Is the requirement for the limitation of the current through the device in normal operation to less than 10 microamperes the only requirement and surge protection devices meeting this requirement can be connected to intrinsically safe circuits? ANSWER 2: No, the requirement for the limitation of the current through the device to less than 10 microamperes in normal operation is necessary, but not sufficient to connect such devices to intrinsically safe circuits. QUESTION 3: Clause 12 IEC 60079-25:2010 states that surge protection devices shall be installed outside Zone 0. Is it permitted to assign EPL Ga to surge protection devices? ANSWER 3: No, it is not permitted assign EPL Ga to surge protection devices, as they are not intended to be installed in Zone 0 according to IEC 60079-25.