KEPCO RA 60 Rev 1, 2, 3 - Manual (Page 18)

2-6
RA60 SERIES 090910
2.6.2 SOURCE POWER CONNECTIONS
When used in conjunction with Kepco HSP series power supplies, these rack adapters can be
operated from either single-phase or three-phase a-c source power without adjustment or modi-
fication. Voltage and frequency limits are determined by the source power rating of the HSP
power supplies. Operation from d-c power is also available; please contact factory for limitations
imposed when using d-c source power.
The rear panel of RA 60 Series rack adapters (Figure 2-2) includes seven terminal blocks to
allow for connection of single-phase a-c, three-phase a-c (4-wire or 5-wire) and d-c input power.
These terminal blocks are labeled L1, N1, L2, N2, L3, N3, and G. Wires must be sized according
to expected current. Each terminal block will accommodate up to #6 AWG (16mm²) or equiva-
lent conductor size; torque to 15 lb-in (1.5 N•M) maximum. Their functions are:
• Terminal G is the safety ground connection for the rack adapter. It is connected to the rack
adapter chassis as well as to the safety ground terminal of the source power connector of
each of the three power supply mounting positions. Regardless of the type of source power
provided, Terminal G must be connected to safety ground in order to ensure proper ground-
ing of the HSP power supplies when installed. The conductor used to connect Terminal G to
safety ground must be sized to support the total fault current of all of the power supplies
installed in the rack adapter; for HSP series power supplies, the ground fault current rating
is 20 amperes per power supply. Consult local electric codes for the proper wire size to
carry the required fault current.
• Terminal pairs L1/N1, L2/N2, L3/N3 are connected to the high-side and low-side contacts
of the source power connectors for each of the three power supply mounting positions (1, 2
and 3) of the rack adapter (see Figure 2-2). Each terminal pair (Lx/Nx) is isolated from the
remaining two pairs, facilitating redundant source power connections if desired. The con-
ductor used to connect terminals Lx and Nx to source power must be sized for the 16
ampere maximum source current drawn by HSP Series power supplies; Kepco recom-
mends #14 AWG (2.5mm²) or equivalent minimum conductor size to support this current.
2.6.3 SOURCE POWER CONFIGURATIONS
The following standard wiring configurations are recommended by Kepco as being compliant
with national and international safety standards. It is the user's responsibility to ensure that all
applicable local electric codes are met. The minimum and maximum limits for source power volt-
age are defined in HSP series power supply specifications.
CAUTION
UNDER NO CIRCUMSTANCES SHOULD THE STEADY-STATE SOURCE VOLTAGE
APPLIED ACROSS ANY Lx/Nx PAIR EXCEED 277V rms!