Moeller ZB12 Series, Hardware And Engineering

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05/05 AWB2300-1527D/GB
1 ZB12 and ZB 32 overload relays
Preface In addition to the type of protection specified in the
standards EN 60079-14 and VDE 0165 Part 1, further
provisions have been made to ensure the safety from ignition
for motors operated in potentially explosive atmospheres.
EN 50019 demands additional measures for operating
motors with "increased safety" type of protection "e".
These measures provide a higher degree of safety and
prevent impermissible high temperature and development of
sparking and arcing on the motors, which usually does not
occur under normal operating conditions. The motor
protective equipment used for this is operated at a location
separate from the EEx e area and must be certified by an
accredited certification authority.
The guidelines on the application of Directive 94/9/EC (ATEX
100a) on the approximation of the laws of the Member
States concerning equipment and protective systems
intended for use in potentially explosive atmospheres has
been enforced since 30
th
June 2003.
The motor-protective relays ZB12 and ZB32 are certified by
PTB according to the 94/9/EC (ATEX 100a) Directives.
a The EU Certification of Conformity numbers are:
ZB12: PTB 04 ATEX 3022
ZB32: PTB 04 ATEX 3022
Overview of the devices
Figure 1: ZB12 overload relay