2.10
DATA TRANSMISSION CONVERTER
Data transmission converters shall be used to connect equipment using EIA
ANSI/TIA/EIA-485-A data transmission when necessary and as shown.
Converters shall operate full duplex and support two wire circuits at
speeds up to 2 megabytes per second and have a built in 120 Ohm terminating
resistor. Converters shall be mechanically, electrically, and optically
compatible with the system.
2.11
ENCLOSURES
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NOTE: If all FO devices will be located in
enclosures of other systems, then paragraph
ENCLOSURES can be deleted. Otherwise, paragraph
ENCLOSURES must remain and enclosure locations must
be shown on the drawings.
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Enclosures shall conform to the requirements of NEMA 250 for the types
specified. Finish color shall be the manufacturer's standard, unless
otherwise indicated. Damaged surfaces shall be repaired and refinished
using original type finish.
2.11.1
Interior
Enclosures installed indoors shall meet the requirements of NEMA 250 Type
12 or as shown.
2.11.2
Exterior
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NOTE: For exterior applications where corrosive
environments exist, Type 4X will be specified. Type
4X metallic enclosures should be used for security
applications where physical hardening is required.
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Enclosures installed outdoors shall meet the requirements of NEMA 250 Type
4 unless otherwise specified or shown.
2.11.3
Corrosive Environment
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NOTE: Show corrosive locations on the drawings.
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Enclosures in a corrosive environment shall meet the requirements of NEMA
250, Type 4X.
2.11.4
Hazardous Environment
Enclosures in a hazardous environment shall be installed and shall meet the
requirements as specified in paragraph ENVIRONMENTAL REQUIREMENTS.
2.12
TAMPER AND PHYSICAL PROTECTION PROVISIONS
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NOTE: Tamper and physical protection provisions are
SECTION 16768A
Page 21
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