120 20195-100 Preliminary
Paragon4 – UHF, 700, & 800MHz User Manual
7
2.4 Electrical
Standard 120 VAC electrical power is required. It should be capable of providing at least 10A to
power Paragon4 unit (<6A) and ancillary equipment.
2.4.1 Standard Power Supply Configuration
Although the T809-10 is a high efficiency switched mode power supply, a considerable
amount of heat is generated during normal operation. While in use, ensure that an adequate
flow of cooling air is able to circulate around the power supply, and that the air intake vents
on the rear and sides of the unit are not inadvertently covered.
Caution:
Do not operate this unit in a completely enclosed cabinet.
The Radio assembly unit receives 13.8 VDC power inputs from two “T809 ” power supply modules
powered at 120 VAC. Normally used at room ambient temperatures, it can operate within its specifi-
cations over a range of –10 to +60 °C.
Note: Internal over-temperature protection shuts down the main transformer above 105° Celsius.
Both power supply modules are internally connected to ground via their individual, rear-connected,
seven-foot standard 120 VAC power cords. The Radio Assembly chassis requires a secure ground
connection. A threaded grounding binding post fitted with a knurled binding-nut is provided on the
chassis next to DC input 2.
•
For the Radio Assembly chassis, install the grounding lead’s lug over the binding post and firmly
hand-tighten the binding-nut.
•
If a –DC rail (0V) is installed as part of the system, the grounding leads may alternatively be fit-
ted to the rail terminal.
Caution:
Improper grounding between power supply case and rack frame may result in harmful voltage poten-
tials and/or miscellaneous power supply switching noise problems in both receivers and transmitter.
2.4.1.1
DC Power Supply Connection & Torque Settings
Warning:
Securing the DC Power Supply cable into the DC connector to provide a good electrical con-
nection is essential. Over time, the wires tend to compress in the DC connector resulting in an
increasingly poorer connection. Consequently, as high current is drawn, the connector heats up
increasing the resistance thereby causing still more heat until the connector eventually burns up.
Although screws securing DC cables to the Power Supply terminals are tightened to the torque set-
tings given below prior to new system delivery, they must be re-tightened as part of the commission-
ing process and re-tightening is also part of the regular maintenance schedule.
Prior to replacing a Power Supply module into an existing system, inspect the cable and re-terminate
the DC wires if the strands have previously been twisted together or show any sign of damage.
Cut the wire at the end of the insulation and then strip approximately .43 inch (11mm) of insulation
off the cable. DO NOT TWIST THE WIRE STRANDS. Insert the DC cable into the screw terminal
and tighten the screw to secure the cable as per the torque settings given below.
