Triconex Trident, Planning And Installation Manual

Page: 150 / 274

134 Guidelines
Trident Planning and Installation Guide
Environment
This section provides general guidelines for controlling the controller’s
environment.
Controlling the Environmental
To minimize the expense and labor associated with system maintenance, observe
the following guidelines:
• Do not expose the system to metal chips, conductive particles, or dust (such
as that produced by drilling or filing metal-mounting panels). Modules are
enclosed for limited protection against these contaminants; nevertheless,
short circuits can be caused by particles. Similarly, heat-trapping layers of
dust can accumulate on a module and adversely affect its performance.
• Because the temperature in industrial environments is generally not
uniform, do not locate the controller’s enclosure near units that generate
large amounts of heat or operate at high temperatures; for example, large
motors.
• For extended operation, the system is designed for a maximum ambient
temperature of 70°C (160°F). Lower ambient temperatures increase the life
of the individual controller components and decrease the likelihood of
module failure, thereby lowering your maintenance costs.
For guidelines on wiring, see Appendix C, “Recommended Wiring Methods.”
Allowing for Adequate Cooling
Adequate convection or forced-air cooling should be provided. The following
general guidelines can be used for typical environments (50
°
C maximum ambient
temperature with 20
°
C internal temperature rise):
• In sealed environments, the external surface area of the enclosure should be
at least 0.009 m 2 /watt.
• In vented environments, the internal air flow should be at least 7 m 3 /watt.
Air flow should be directed to flow into vents at the bottom of the enclosure
(for example, a vent at the bottom of the door) and to exit at the top of the
enclosure (for example, a pagoda top).
• For maximum reliability of the system, the average ambient temperature
should be below 50°C (120°F). Heat load dissipation should be calculated
to include both logic power and field power. Using the following table, sum