A "protection technique" is a specific process which negates one of the three components of combustion.
 

Group II

Applicable Zone	Protection Technique	Relevant Standard		Description
		Equipment	Installation
Zones 1 & 2	Exd	AS 2380.2	AS 2381.2	Flameproof Enc.
Zones 1 & 2	Exe	AS 2380.6	AS 2381.6	Increased safety
Zones 0 - ia           1 - ib           2 - ib	Exi	AS 2380.7	AS 2381.7	Intrinsic safety
Zones 1 & 2	Exm	AS 2431	-	Encapsulated app.
Zones 2	Exn	AS 2380.9	AS 1076.7	Non-sparking
Zones 1 & 2	Exo	IEC 79-6	-	Oil immersion
Zones 1 & 2	Exp	AS 2380.4	AS 2380.4	Pressurised rooms & encl.
Zones 1 & 2	Exq	IEC 79-6	-	Sand filled
Zones 0, 1 & 2	Exs	AS 1826	AS 1076.8	Special protection
Zones 1 & 2 Zones 20, 21 & 22	Exv  D.I.P	AS 1482 AS/NZS 61241.3	- AS/NZS 61241.3	Ventilation Dust ignition proof
Zones 20, 21 & 22	Exi	AS 2380.7	AS 2381.7	Intrinsic safety
Zones 20, 21 & 22	Exm	AS 2431	-	Encapsulation
Zones 20, 21 & 22	Exp	AS 2380.4	AS 2380.4	Pressurised rooms & encl.

The Australian standards are based on international Electrotechnical Commision (IEC) standards and are similar to Cenelec and British standards in respect of Zone classification, Gas groups, Temperature ratings and Testing Methods. This is illustrated in the table below.

ITEMS AUSTRALIA IEC CENELEC USA Class "1" ZONE Classification ZONE 0 ZONE 0 ZONE 0 DIVISION 1 ZONE 1 ZONE 1 ZONE 1   ZONE 2 ZONE 2 ZONE 2 DIVISION 2 Applicable Standards for various explosion protection techniques Exd 2380-2 79-1 EN50018 UL698 Exe 2380-6 79-7 EN50019 - Exn 2380-9 79-15 EN50021 CSA22213 Exp 2380-4 79-2 EN50016 NPF496 Exi 2380-7 79-1 EN50020 ANS14913 Gas groups and representative gases II A Ammonia, Butane, Propane, Pentane, Benzine, Acetone, Hexane, Heptane, Iso-octane, Decane, Cyclohexane, Methanol. D Acetone, Propane, Ethane, Butane II B Butadine, Ethylene Oxide, Town Gas, Coke-oven Gas. C Acetaldehyde, Ethylene II C Hydrogen, Acetylene. B Hydrogen, Butadine, Ethylene oxide   A Acetylene Temperature rating (Limit of Temp. rise over ambient of 40 ºC) Max ignition temp (ºC) T1 T2 T3 T4 T5 T6 450 300 200 135 100 85 Max ignition temp (ºC)  T1 T2 T2A T2B T2C T2D T3 450 300 280 260 230 215 200 T3A T3B T3C T4 T4A T5 T6 180 165 160 135 120 100 85   DEGREES OF PROTECTION   Weather proof IP 54            Nema 3 Water Tight IP 65            Nema 4 Dust Tight IP 66            Nema 4x Immersion Proof IP 67            Nema 6 Explosion Proof Exd            Nema 7 Dust Ignition Proof D.I.P            Nema 9

Note : The information shown here is subject to change and should always be verified against the current Australian Standard.
  

Method	Symbol	Type of protection
Exclusion	D.I.P	Dust-excluding ignition proof
	Exm	Encapsulation
	Exn	Non-sparking (hermetically sealed devices, sealed devices and restricted breathing)
	Exp	Pressurised enclosure /rooms
	Exq	Sand-filled  (powder filling)
Explosion containment	Exd	Flameproof enclosure
Energy limitation	Exi	Intrinsic safety
Dilution	Exv	Ventilation
Avoidance of ignition source	Exe Exn	Increased safety Non-sparking (inherently non-sparking)

Ex protection techniques

Type of Protection Principle Symbol Typical Application Flameproof Enclosure d Power Apparatus, Switchgears, Motors (all devices able to ignite flammable mixtures in normal operations) Powder Filling q Capacitors, Electronics Pressurised Apparatus p Power Apparatus (requires special measures to maintain safety features) Oil Immersion o Transformers Encapsulation m Measuring and Control Systems (avoiding hot spots on printed boards) Increased Safety e Terminal and Connection Boxes, Squirrel cage Motors, and Lighting (no incendiary or hot surfaces in normal operations) Intrinsic Safety i Terminal and Connection boxes, Data Processing (small electrical values)

Degree of protection of the enclosures for electrical equipment in accordance with the IEC 529 and EN 60529 standards.

IP Tests   0   No Protection 1 Protected against solid bodies larger than 50mm (e.g. accidental contact with the hand) 2 Protected against solid bodies larger than 12.5 mm (e.g. finger of the hand) 3 Protected against solid bodies larger than 2.5 mm (tools, wires) 4 Protected against solid bodies larger than 1 mm (fine tools, small wires) 5 Protected against dust (no harmful deposit) 6 Completely protected against dust

IP Tests   0   No Protection 1 Protected against vertically-falling drops of water (condensation) 2 Protected against drops of water falling at up to 15º from the vertical 3 Protected against drops of rain water at up to 60º from the vertical 4 Protected against projections of water from all directions 5 Protected against jets of water from all directions 6 Completely protected against jets of water of similar force to heavy seas 7 Protected against the effects of immersion 8 Protected against effects of prolonged immersion under specific conditions

Note

1. The explosion protection certification of the equipment alone does not necessarily mean it has an adequate degree of protection for specified weather or environment. Hence it is necessary to check the IP rating of the equipment before selection for a particular environment.
2. All GOVAN equipment is tested and certified for minimum IP 65 rating.