Yokogawa RAKD - Manual (Page 47)

<8. EXPLOSION-PROTECTED TYPE INSTRUMENTS>
8-1
IM 01R01B30-00E-E 5th edition January 01, 2013 -00 All Rights Reserved. Copyright © 2003, Rota Yokogawa
8. Explosion-protected Type Instruments
8.1 General
To ensure intrinsically safety, it is not permitted to repair or to modify the electronic transmitter and the limit
switches
The RAKD with electronic transmitter type "E" as well the limit switches (option/ K_) are intrinsically safe devices.
The RAKD with option /KS1 is ATEX certified for hazardous areas of zone 1 (category 2) and zone 2 (category
3). It is not homologated for zone 0 areas (category 1) (option /KS1 for category 2 and 3, option /KS3 and /KN1
only for category 3G). The classification in brackets is given according to the EU regulation ATEX, 94/9/EG.
The limit switches but not the electronic transmitter are ATEX dust proof certified (option /KS2).
The RAKD with option /KS1 and /ES1 are certified for hazardous areas of EPL Gb.
The RAKD with option /KS3 and /ES3 are for use in hazardous areas of EPL Gc.
The RAKD with option /FS1 is FM- certified for USA and Canada for hazardous classified locations Class I,
Division 1, Groups A, B, C, D.
The RAKD with option /NS1 is NEPSI- certified.
The RAKD must be connected to an intrinsically safe, certified power supply with a maximum voltage and
output power below the maximum values of the RAKD (refer to Technical data, section 7). The combined
internal inductance and capacity of the RAKD and connecting cables must be less than the permitted external
inductance and capacity of the power supply. Accordingly, the limit switches and the pulse output have to be
connected to intrinsically safe, certified isolating switching amplifiers. The relevant maximum safety values must
be heeded at all times. Power supply and transmitter relay are assigned devices and should be installed outside
any hazardous zone.
Especially in the case of high fluid temperatures, heated metering tubes or heat radiation by heat tracing, make
sure that the temperature in the indicator housing does not exceed the permissible maximum ambient
temperature of the transmitter (refer to Technical data, section 7).
To ensure intrinsically safety, it is not permitted to repair or modify the measuring transmitter.
WARNING