5.1 Introduction:
Power and control cables are the nerves of any process plant in industrial segment.
Operational reliability of process plant depends upon accurate cable laying method
during project stage. The maintenance of cables after completion of the project is
a challenging task for an electrical and instrument engineer.
A right cable Laying depends upon good cable routing and good quality of cable
tray systems. The good cable tray installation with good quality cable trays protect
cables from mechanical damages, dust deposition and electro motive forces
developed due to mutual induction effect
5.2 Type of Cable Trays:
There is various type of cable trays used in project engineering depending upon
project requirement. Different type of cable trays is used for different requirements.
Following are the major cable trays used in industries:
a) Molded Fiber Cable Trays
These cable trays are used generally in high humidity and salty areas. The
steel fabricated cable trays get corroded near sea shore. Sodium chloride reacts
with steel equipment’s in compositions with water which lead fast corrosion of
ferrous metals. The fiber molded cable trays are most suitable for these areas.
These are rust free and lighter in weight. Sometime these cable trays are also
used in chemical / refinery industries. The molded fiber is preferred in coastal
area along with specific industries due to non-reactivity and low flammable
properties. Following are the key features of these cable trays:
- Available with competitive price in market,
- Lighter in weight result easy handling,
- Easy in installation due to easy cutting, making bends and joints etc.,
- Quick delivery period,
- Available with excellent tensile and bending strength,
- No inflammables in case of fire in the plant,
- Shock proof when ground fault is taking place,
- Corrosion and rust proof with water and salt,
- Accurate engineering is required before procurement otherwise shortfall or
surplus dump may be possible at end of the project.
b) Fabricated Steel Cable Trays
These cable trays are used generally in low humidity areas. The steel fabricated
cable trays are gets corrode hence not used in coastal area. These cable trays
are generally used for cement, steel, power and non-corrode chemical
industries, refineries. Following are the key features of these cable trays: