Flowserve NRS 1-51 - Manual (Page 5)

5
Directives and Standards
Pressure Equipment Directive (PED) 97/23/EC
The level switch NRS -5 in conjunction with level electrode NRG ...-5 is EC type approved
according 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.
VdTÜV Bulletin “Wasserstand 100” (= Water Level 100)
The level switch NRS -5 in conjunction with the level electrodes NRG ...-5 and NRG ...- is 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 switch NRS -5 is certified acc. to IEC 6508 only if used in combination with level elec-
trode NRG ...-5. This standard describes the functional safety of safety-related electrical/electronic/
programmable electronic systems.
The equipment combination NRG ...-5 + NRS -5 corresponds to a type B subsystem with Safety
Integrity Level (SIL) 3.
ATEX (Atmosphère Explosible)
According to the European Directive 94/9/EC the level switch NRS -5 must not be used in potentially
explosive areas.
Note
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!
LV (Low Voltage) Directive and EMC (Electromagnetic Compatibility)
The level switch NRS -5 meets the requirements of the Low Voltage Directive 006/95/EC and the
EMC Directive 004/08/EC.