Rockwell Automation Publication 440R-UM013E-EN-P - March 2017 15
Installation Chapter 2
This equipment is supplied as open-type equipment. The relays must be
mounted within an enclosure that is suitably designed for those specific
environmental conditions that are present and appropriately designed to help
prevent personal injury as a result of accessibility to live parts. The enclosure
must have suitable flame-retardant properties to help prevent or minimize the
spread of flame, in compliance 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
additional 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 additional installation requirements.
• NEMA Standard 250 and IEC 60529, as applicable, for explanations of
the degrees of protection provided by different types of enclosure.
Prevent Excessive Heat
For most applications, normal convective cooling keeps the relay 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 can
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.
Additional 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.
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