Keysight Technologies RP7900 Series, Operating And Service Manual

Page: 69 / 318

Bus Bar Connections
SHOCK HAZARD, LETHAL VOLTAGES Many models generate voltages greater than 60
VDC, with some models rated at 950 VDC! Ensure that all instrument connections,
load wiring, and load connections are either insulated or covered using the safety
covers provided, so that no accidental contact with lethal voltages can occur.
The following factors should be considered when wiring the load to the power supply:
l
Load wire current carrying capacity
l
Load wire insulation rating (must be equivalent to the maximum output voltage)
l
Load wire voltage drop
l
Load wire noise and impedance effect
Wire Size
FIRE HAZARD To satisfy safety requirements, load wires must be large enough not to
overheat when carrying the maximum short-circuit output current. If there is more than
one load, then any pair of load wires must be capable of safely carrying the full-rated
current of the unit. Paralleled load wires may be required for larger-ampacity models.
The following table lists the characteristics of AWG (American Wire Gauge) copper wire.
AWG Equivalent mm2 Nearest Metric size Ampacity (Note 1) Resistance (Note 2)
18 0.82 1.0 mm2 up to 14 A 6.385 Ω
16 1.31 1.5 mm2 up to 18 A 4.016 Ω
14 2.1 2.5 mm2 up to 25 A 2.525 Ω
12 3.3 4 mm2 up to 30 A 1.588 Ω
10 5.3 6 mm2 up to 40 A 0.999 Ω
8 8.4 10 mm2 up to 60 A 0.628 Ω
6 13.3 16 mm2 up to 80 A 0.395 Ω
4 21.2 25 mm2 up to 105 A 0.248 Ω
2 33.6 35 mm2 up to 140 A 0.156 Ω
1/0 53.5 50 mm2 up to 195 A 0.098 Ω
2/0 67.4 70 mm2 up to 225 A 0.078 Ω
3/0 85 95 mm2 up to 260 A 0.062 Ω
4/0 107 120 mm2 up to 300 A 0.049 Ω
6.2/0 (350 MCM) 177 185 mm2 up to 420 A N/A
Note 1 Ampacity is based on a single conductor in free air, 26-30 °C ambient temperature with the conductor rated at 60 °C. Ampacity
decreases at higher temperatures.
Note 2 Resistance is in ohms/1000 feet, at 20 °C wire temperature.
Keysight RP7900 Series Operating and Service Guide 69
2 Installing the Instrument