ABB 266D Series Short Form Instruction Manual page 15

... "EX SAFETY" ASPECTS AND "IP" PROTECTION (EUROPE)
b) Certificate ATEX II 1/2 G Ex ia IIC T6 and II 1/2 D Ex iaD 21 T95°C
FM Approvals certificate number FM09ATEX0024X respectively FM09ATEX0069X
This ATEX Category depends on the application (see below) and also on the intrinsic safety level of the transmitter supply
(associated apparatus) which can sometimes suitably be [ib] instead of [ia]. As it is well known, the level of an intrinsic safety system
is determined by the lowest level of the various apparatus used, i.e., in the case of [ib] supply, the system takes over this level of
protection.
The meaning of ATEX code is as follows:
II : Group for surface areas (not mines)
1/2 : Category - It means that only a part of the transmitter complies with category 1 and a second part complies with category 2 (see
next application sketch)
G : Gas (dangerous media)
D : Dust (dangerous media)
T50°C: Maximum surface temperature of the transmitter enclosure with a Ta (ambient temperature)
+40°C for Dust (not Gas) with a dust layer up to 50 mm depth.
T95°C: As before for Dust for a Ta +85°C
(Note: the number close to the CE marking of the transmitter safety label identifies the Notified Body which has responsibility for the
surveillance of the production)
The other marking refers to the protection type used according to relevant EN standards:
Ex ia : Intrinsic safety, protection level "a"
IIC : Gas group
T6 : Temperature class of the transmitter (which corresponds to 85°C max)
with a Ta (ambient temperature) +40°C
T4 : Temperature class of the transmitter (which corresponds to 135°C max)
with a Ta (ambient temperature) +85°C
About the applications, this transmitter can be used in Zone "0" (Gas) classified areas (continuous hazard) with its "process part" only,
whereas the remaining part of the transmitter, i.e. its enclosure, can be used in Zone 1 (Gas), only (see sketch below).
Reason of this is the process part of the transmitter (normally called primary transducer) that provides inside separation elements to
seal off the electrical sensor from the continuously hazardous process, according to the EN 60079-26 and EN 60079-1. About Dust
application, the transmitter is suitable for "Zone 21" according to the EN 61241-0 and EN 61241-11 as it is shown on the relevant part
of the sketch:
APPLICATION FOR PRESSURE TRANSMITTER EX ia CATEGORIES 1/2G and 1/2D
Application with Gas
Tank
Zone "0"
dangerous
medium
(process)
Separation elements
Note: the transmitter can be connected to either [ib] or [ia] supply
(associated apparatus)
Zone "1"
266 Tx category
1/2G Ex ia
Primary
transducer
(Note: see the
certification for
exceptions)
Zone 0 / Zone 1
Application with Dust
Silo
Zone "20"
dangerous
medium
(process)
Note: the protection is mainly assured by the "IP" degree associated
to the low power from supply. This can either be [ia] or [ib]
2600T Series Pressure transmitters 266 models | SOI/266-XC 15
Zone "21"
266 Tx category
1/2D Ex ia