Two robots can both be called "explosion-proof" and hold certificates that are not accepted by the same authority. A CMA GR series robot carries an EU Type Examination Certificate under the ATEX directive; a SR series robot carries a Chinese explosion-proof certificate under GB/T 3836. Both are real certificates issued by accredited bodies. They answer to different legal systems, and only one of them satisfies an EU-directive project.
What the ATEX certificate is
An EU Type Examination Certificate is issued by a notified body — for the CMA GR series, CML B.V., notified body number 2776. The certificate states the equipment group and category, the marking, the standards applied, and any special conditions of use (the "X" suffix on the certificate number means such conditions exist and must be read).
The GR series certificates on file are: CML 20ATEX1065X (GR6150, 2900 mm), CML 23ATEX1156X (GR6150-1500), CML 17ATEX1114X (GR6100ST) and CML 17ATEX1115X (GR680ST). The first three carry gas group IIC; the last two carry IIB. Group is not a detail — a IIB certificate does not cover a hydrogen or acetylene atmosphere.
What the GB/T 3836 certificate is
The SR series holds explosion-proof certificate GYB23.3310X, issued under the Chinese GB/T 3836 standard series, valid from 18 December 2023 to 17 December 2028. The marking is Ex eb ib mb pxb IIC T4 Gb for gas and Ex tb ib mb pxb IIIC T135°C Db for dust, and the certificate covers SR models with 5, 8, 10 and 12 kg payload and 1600 to 3800 mm reach.
GB/T 3836 is technically aligned with the IEC 60079 series, which is why the marking looks familiar to a European reader. Alignment of the standard is not recognition of the certificate: a GB/T 3836 certificate is not an ATEX certificate and does not carry a notified body number.
How to read the marking
| Element | Example | What it tells you |
|---|---|---|
| Protection type | pxb | Pressurization — the enclosure is purged and kept above booth pressure |
| Additional types | eb ib mb | Increased safety, intrinsic safety, encapsulation applied to specific parts |
| Gas group | IIC / IIB | IIC covers the most easily ignited gases; IIB does not cover them |
| Temperature class | T4 | Maximum surface temperature 135 °C |
| Equipment protection level | Gb / Db | Gb = zone 1 gas; Db = zone 21 dust |
| Dust marking | IIIC T135°C | Conductive dust, 135 °C maximum surface temperature |
Which one your project needs
- A plant in the EU, or a plant whose specification cites Directive 2014/34/EU: an ATEX certificate is required. Choose a GR series model and check that the gas group on the certificate matches your solvent.
- A plant in Russia or the EAEU: the applicable scheme is TR CU 012/2011 with EAC marking. Neither ATEX nor GB/T 3836 substitutes for it; ATEX documentation usually shortens the EAC route because the test reports exist, but the certificate itself must be obtained for the customs union.
- A plant whose specification references GOST or ПУЭ zone classification: map your zone first (В-Iа corresponds broadly to zone 1), then confirm the protection type is accepted by your safety authority — see the note on pressurization below.
- A plant in a market that accepts IECEx or national certificates aligned to IEC 60079: GB/T 3836 documentation is usually a workable basis, but confirm with the authority before ordering.
Two things buyers get wrong
The first is the series-versus-variant question. Certificates are issued for a series with a defined scope. If your exact variant is not named in the scope, the honest answer is "coverage to be confirmed", not "certified". We publish the number and let your safety engineer read the scope.
The second is treating a certificate as a substitute for installation compliance. A pressurized robot needs a continuous protective gas supply, a purge cycle before energizing (15 minutes pre-purge on the SR series) and interlocks that cut power on pressure loss. The certificate covers the equipment; the installation is yours.
Frequently asked questions
Is a GB/T 3836 certificate valid in Europe?
No. GB/T 3836 is aligned to IEC 60079 in content, but it is a Chinese certificate without a notified body number and does not satisfy Directive 2014/34/EU. For an EU-directive project choose a CMA GR series model with an EU Type Examination Certificate.
What does the X at the end of a certificate number mean?
It means the certificate carries special conditions for safe use. Those conditions are part of the certificate and must be read and applied — typically covering purge gas quality, cable entry, and permitted ambient temperature.
Does an ATEX certificate cover the whole robot system?
It covers the equipment named in the certificate — the manipulator with its pressurization system. The control cabinet is normally IP54 and installed outside the hazardous zone, and the spray equipment, paint supply and booth are separately assessed.
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