What Would be Low Voltage Circuit Protection Feature?
Fuses are not to be used for
protection of circuits below 1000V phase-to-phase, (Low Voltage).
All low voltage and DC
circuit protection is to be provided by molded case, or miniature circuit
breakers (MCCB).
Link carriers and bases shall
be of approved manufacture and of such form and material to protect
persons from shock and burns in normal service and maintenance. Links and fixed
contacts shall be shielded to prevent inadvertent contact with live metal
whilst the link is being inserted or withdrawn.
The labeling of carriers and
bases shall comply with IEC 269 Identification labels fixed to panels, boards and desks for MCBs and links shall describe
their duty, voltage, and rating.
Sponsored:
Sponsored:
What Would be the Miniature Circuit Breaker (MCB) Kinds and Features?
All miniature circuit breakers (MCBs) shall comply with IEC 157 and be fitted
with over-current releases of both the thermal and instantaneous types. All MCBs
supplied on this contract shall be to short circuit category P2 of IEC 157.
Single, two, or three pole
breakers may be used where appropriate, and a trip of one pole shall cause a
complete trip of all associated poles. In addition, the rating given of MCBs
supplied shall be confirmed as that appropriate to the enclosure provided.
The Contractor shall ensure
satisfactory time and current grading with other associated miniature circuit breakers or MCCBs.
Kind and Type Selection of Distribution Boards and Isolators
Distribution boards shall be
provided throughout the plant for local distribution of lighting, small power, and air conditioning supplies. The lighting and small power circuits may use a
common distribution board.
Distribution boards shall be
of 1 kV AC 1.2 kV DC rating and conform to IEC
439. All distribution boards shall be of the weatherproof enclosure type
and shall be arranged so that the door or cover can be locked in the closed
position.
All triple pole and neutral
boards shall provide satisfactory cable entry for all cables that could be
required for the number of circuit facilities provided and shall have the
neutral bar drilled for the full number of single-phase ways.
Each distribution board
supplied from a remote location shall have a load-breaking/fault-making
incoming isolating switch mounted adjacent to or as part of the distribution
board. Each distribution board shall have removable top and bottom (undrilled)
gland plates.
Each circuit in every
distribution board shall be numbered and identified by means of a schedule
attached to the interior of the door or cover of the board. The schedule shall
be legible and durable to the Engineer'’ approval.
Twenty-five percent spare
ways shall be provided for future use.
Sponsored:
Sponsored:
No comments:
Post a Comment
WAZIPOINT:
Thank you very much to visit and valuable comments on this blog post. Keep in touch for next and new article. Share your friends and well-wisher, share your idea to worldwide.