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HARRIS
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WARNING: Disconnect and lockout AC primary power prior to servicing
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2.2.3.2 Air Conditioning
The heat load for planning air conditioning is 6,600 BTU for each PA, the control
cabinet heat load is 500 BTU. The best approach is to keep the room cool with a N+1
system and to minimize the air ducts used. The use of supply ducts is preferred over
ducting of return air.
2.2.4 Electrical Power
Two standards are commonly used as a source of data for AC power systems: the
National Electrical Code published by the National Fire Protection Association in the
United States, and the Canadian Electrical Code published by the Canadian Standards
Association. These standards should be followed since they are referenced in most state
and local codes.
The transmitter is designed to operate from 208, 220/240 or 480 volts, 60 Hz or 80/415
volts, 50 Hz. If voltage variations in excess of +/-10% are anticipated, the transmitter
power input must be equipped with automatic voltage regulators (optional) capable of
correcting the primary AC mains voltage.
The transmitter requires a relatively stable source of input power. For this reason, the
primary power for the transmitter should originate at the main power distribution
system and remain isolated from other electrical distributions.
All wiring and signal inputs are at the top of the cabinets. Overhead cabling is used. No
access is provided in the cabinet floors for under-floor or trench wiring.
AC power to the transmitter should be run in metallic conduit, connected to earth
ground for safety and to provide shielding against interference. All phases should be
run within the same conduit to cancel induced magnetic fields. The power run must be
terminated in a power distribution panel, whose enclosure must also be connected to
earth ground.
2.2.4.1 Circuit Breaker Selection
Refer to AC Distribution Diagram for the connection and breaker sizing information. It
is important that the circuit breakers withstand the listed inrush current. Each cabinet is
fed from the distribution panel through a separate circuit breaker. If fuses are used,
contact Harris Field Service for guidance on fuse sizing and phase loss protection.
NOTE:
Starting Surge Requirement
A short-duration starting surge, due to transformer inrush current, will last for a
portion of the first few cycles after power is turned on. During this surge, the
line voltage at the cabinets must not drop below 80% of the rated line voltage.