KEPCO RA 19-4C Operator Manual - Manual (Page 53)

RA 19-4C 121013
2-35
The following standard wiring configuration is recommended by Kepco as being compliant with
applicable national and international safety standards. Please consult local electrical codes for
wire current ratings and other specific requirements:
• Connect Terminal G of each RA 19-4C input power terminal block to safety ground
• Connect a separate wire pair from each side of the input power to the L/N terminal pair of
the input power terminal block.
• In North America where 115/230V a-c source power is used, Kepco recommends the
use of a Kepco line cord (P/N 118-1145, North American style plug, 30A maximum, 6
ft. long). European applications may require the use of Kepco line cord P/N 118-1146
(250V, 32A maximum).
• Wire size is determined by the maximum rated source current for each HSF power sup-
ply and the number of power supplies installed. For lower system power configurations,
smaller wire can be used; contact Kepco Applications Engineering for assistance.
2.11.2.1 EMI COMPLIANCE
Depending on the application and system environment, special source power considerations
may be required to meet listed Input EMI specifications for HSF power supplies, particularly
FCC Class B. It may be necessary to add external source power filtering, such as installing
snap-on ferrite beads on the line cord wires of the RA 19-4C as close to the input a-c terminal
block as possible. Another option is to add an in-line cabinet-mounted EMI filter (available from
a number of manufacturers) between the source power and the RA 19-4C line cord. For addi-
tional assistance, contact Kepco Applications Engineering.
2.11.3 CONTROL SIGNAL CONNECTIONS
Access to the control signal (I/O) connector for each HSF power supply is provided via four 15-
pin D-subminiature connectors on the rear panel of the rack adapter (see Figure 1-4). Four mat-
ing connectors (Kepco P/N 142-0449) are provided in a plastic bag. Consult PAR. 2.4 and the
HSF operator's manual for instructions on wiring and use of these control lines.
2.11.4 OUTPUT LOAD CONNECTIONS
Load connections to the rack adapters are achieved via four pairs (DC OUTPUT + and –) of out-
put terminals located on the rear panel assembly. Wire gage may be between 22 GA and 6 GA
depending on ring lug used; torque to 20 lb-in (2.3 N•M) maximum.
2.11.4.1 REDUCING RIPPLE AND NOISE
Ripple and noise are measured under nominal load conditions to provide the rated output volt-
age/current of the HSF power supply. Measurement of ripple/noise is illustrated in Figure 2-23. It
is most important to minimize impedance between the power supply output and the load. As the
length of load wires increases, ripple and noise may increase proportionally, therefore length
and placement are critical for minimum ripple and noise. A filter consisting of a 50
µF electrolytic
capacitor in parallel with a 0.01 µF capacitor must be used to eliminate unwanted ripple and
noise pickup on the load wire during measurements. For noise-sensitive applications the load
wires and sense wires must be twisted.