Rockwell Automation 440C Guardmaster 440C-CR30 Configurable Safety Relay User Manual - Manual (Page 17)

Rockwell Automation Publication 440C-UM001C-EN-P - November 2014 17
Installation Chapter 2
Enclosure Considerations Most applications require installation in an industrial enclosure to reduce the
effects of electrical interference and environmental exposure. Pollution Degree 2
is an environment where normally only non-conductive pollution occurs except
that occasionally temporary conductivity that is caused by condensation can be
expected. Overvoltage Category II is the load level section of the electrical
distribution system. At this level, transient voltages are controlled and do not
exceed the impulse voltage capability of the product insulation.
This equipment is intended for use in a Pollution Degree 2 industrial
environment, in overvoltage Category II applications (as defined in
IEC 60664­1), at altitudes up to 2000 m (6562 ft) without derating. This
equipment is considered Group 1, Class A industrial equipment according to
IEC/CISPR 11. Without appropriate precautions, there could be difficulties
with electromagnetic compatibility in residential and other environments due to
conducted and radiated disturbances.
This equipment is supplied as open-type equipment. It must be mounted within
an enclosure that is suitably designed for those specific environmental conditions
that are present. It must also be appropriately designed to prevent personal injury
as a result of accessibility to live parts. The enclosure must have suitable
flame­retardant properties to prevent or minimize the spread of flame, complying
with a flame spread rating of 5VA, V2, V1, V0 (or equivalent) if non-metallic.
The interior of the enclosure must be accessible only by the use of a tool.
Subsequent sections of this publication contain more information regarding
specific enclosure type ratings that are required to comply with certain product
safety certifications.
For more information, see:
• Industrial Automation Wiring and Grounding Guidelines, publication
1770-4.1 , for more installation requirements.
• NEMA Standard 250 and IEC 60529, as applicable, for explanations of
the degrees of protection that is provided by different types of enclosure.
Preventing Excessive Heat For most applications, normal convective cooling keeps the controller within the
specified operating range. Verify that the specified temperature range is
maintained. Proper spacing of components within an enclosure is usually
sufficient for heat dissipation.
In some applications, other equipment inside or outside the enclosure produce a
substantial amount of heat. In this case, place blower fans inside the enclosure to
help with air circulation and to reduce “hot spots” near the controller.
More cooling provisions are necessary when high ambient temperatures are
encountered. Do not bring in unfiltered outside air. Place the controller in an
enclosure to help protect it from a corrosive atmosphere. Harmful contaminants
or dirt could cause improper operation or damage to components. In extreme
cases, you may need to use air conditioning to help protect against heat buildup
within the enclosure.