Intro4u2u

Disadvantages of this Technique

High energy consumption applications
are not applicable to this
technique because the energy is limited
at the source (or barrier). This
technique is limited to low-energy applications
such as DC circuits,
electro-pneumatic converters, etc.
Type n Technique:
This technique allows for the incorporation
of circuits in electrical instruments
that are not capable of igniting
specific flammable gases or
vapor-in-air mixtures under normal operating
conditions. This type of protection
is not available from CENELEC.
Advantages of this Technique

This technique uses electronic
equipment that normally does not develop
high temperatures or produce
sparks strong enough to ignite the
hazardous environment.

Cost is lower than other hazardous
environment protection techniques
because there is no need for
flameproof housings or energy limiting
barriers.

This technique provides a degree
of protection of IP54.
Disadvantages of this Technique

This technique is applicable to
Zone 2 locations only.

Constraints are placed on control
room to limit energy to field wiring
(normal operation is open, short or
grounding of field wiring) so that arcs
or sparks under normal operation will
not have enough energy to cause ignition.