Flowserve NRG 16-51 - Manual (Page 5)

5
Directives and Standards
Pressure Equipment Directive (PED) 97/23/EC
The level electrode NRG ...-5 in conjunction with level switch NRS -5 is EC type approved accord-
ing to EN 95/EN 953. These Directives state, among other things, the requirements made on
limiting systems and equipment for steam boiler plants and (pressurised) hot-water installations.
ATEX (Atmosphère Explosible)
The level electrodes NRG ...-5, NRG ...- are simple items of electrical equipment as specified
in EN 60079- section 5.7. According to the European Directive 94/9/EC the equipment must be
equipped with approved Zener barriers if used in potentially explosive areas. Applicable in Ex zones
,  (999/9/EC). The equipment does not bear an Ex marking. The suitability of the Zener barriers is
certified in a separate document.
Note that the requirements of the IEC 6508 are not met if the NRG ...-5, NRG ...- + Zener
barriers + NRS -5 are interconnected!
VdTÜV Bulletin “Wasserstand 100” (= Water Level 100)
The level electrodes NRG -5, NRG ...- in conjunction with the level switch NRS -5 are type
approved according to the VdTÜV Bulletin “Water Level 00”.
The VdTÜV Bulletin “Wasserstand (=Water Level) 00” specifies the requirements made on water level
control and limiting equipment for boilers.
Functional Safety acc. to IEC 61508
The level electrode NRG ...-5 is certified acc. to IEC 6508 only if used in combination with level
switch NRS -5. This standard describes the functional safety of safety-related electrical/electronic/
programmable electronic systems.
The equipment combination NRG ...-5 + NRS -50 corresponds to a type B subsystem with Safety
Integrity Level (SIL) 3.