9 wire selection, Wire current capacity – AMETEK ReFlex User Manual
Page 247
DC Power Supplies
ReFlex Power™
6-44
M380056-01 Rev K
signal will open the sense / output isolation relays, and turn off the front-panel
output indicator. The condition of the ENA signal is stored in the FAULTS
register; it could be queried using the SCPI command, STAT[n]:MOD:FAUL?.
6.4.9
W
IRE
S
ELECTION
Input/output wiring must have a current carrying capacity compatible with the
current rating of the ReFlex Power™ system. The maximum current rating of a
wire is dependent on the materials used in its construction, and is primarily
limited by the insulation. The current must be limited so that the temperature rise
of the wire does not result in an operating temperature that exceeds the rating of
the wire.
W
IRE
C
URRENT
C
APACITY
Table 6-14 shows maximum current ratings, based on a cable of three
conductors, that will produce an approximate 30ºC temperature rise above
ambient. When wiring must operate in areas with an elevated ambient
temperature or bundled with other wiring, heavier gauges or higher temperature-
rated wiring should be used.
Although wire with higher temperature rated insulation will allow operation at
higher currents, the total voltage drop would also be increased for a given wire
gauge. For applications where voltage characteristics, such as regulation, are
important, it may be necessary to size the wire based on total voltage drop
instead of temperature rise.
Table 6-14. Wire Data
AWG
COPPER AREA,
CM
2
RESISTANCE,
Ω/M AT 20°C
RESISTANCE,
Ω/M AT 100°C
CURRENT RATING,
A FOR 30ºC RISE
6
0.133
0.0013
0.0017
54
8
0.0837
0.0021
0.0028
40
10
0.0526
0.0033
0.0044
27
12
0.0331
0.0052
0.0069
21
14
0.0208
0.0083
0.011
16
16
0.0131
0.0132
0.0174
12
18
0.00823
0.0209
0.0276
10
20
0.00518
0.0333
0.044
7.5
22
0.00326
0.053
0.07
5.5