KEPCO RA 19-4C User manual

©2022, KEPCO, INC 1
Data subject to change without notice 228-1671 REV 2
KEPCO, INC.  131-38 SANFORD AVENUE  FLUSHING, NY. 11355 U.S.A. TEL [phone]FAX [phone]
www.kepcopower.com email: [e-mail]
QUICK START GUIDE
KEPCO An ISO 9001 Company.
RA 19-4C
Rack Adapter
RA 19-4C
RACK ADAPTER
I — INTRODUCTION
SCOPE OF MANUAL. This Quick Start Guide covers
installation and operation of the Kepco RA 19-4C Rack
Adapter for two common configurations. For the full capa-
bilities and specifications of the RA 19-4C and to take
advantage of the many choices and features not covered in
this Quick Start Guide, the user is urged to download the
complete Operator’s Manual from the Kepco web site at
www.kepcopower.com/support/opmanls.htm#ra19-4c.
DESCRIPTION. Kepco RA 19-4C rack adapters are
specifically designed for up to four 300W, 600W, 1200W/
1500W HSF power supplies, both with -A suffix and older
legacy models (non-A suffix).
The rack adapter is user-configurable for parallel, series, or
independent power supply operation. Forced current shar-
ing and OR’ing diodes for N+1 redundancy are built into the
HSF power supplies. Redundant a-c inputs are provided to
deliver independent source power to each power supply in
a redundant pair. User-configurable keying can ensure that
only the correct power supply can be installed in a keyed
slot. Input/output connections between RA 19-4C and HSF
power supply are via HSF connectors that plug into corre-
sponding connectors of the RA 19-4C. All connections are
made at the rear panel (see Figure 1).
FIGURE 1. REAR PANEL CONNECTIONS, TYPICAL FOR EACH SLOT
II — PRE-INSTALLATION
NOTE: Either local or remote sensing MUST
be used except for HSF 1200W/1500W
(legacy non -A suffix) models.
DIP SWITCHES. The DIP switches (Figure 1) are
arranged as follows: DIP 1 is for PS1 sense lines; DIP 2 is
for PS2 sense lines and for paralleling PS1 and PS2. DIP 3
is for PS3 sense lines and for paralleling PS2 and PS3. DIP
4 is for PS4 sense lines and for paralleling PS3 and PS4.
Table 1 describes the function of each DIP switch position.
INDEPENDENT OPERATION. The RA 19-4C rack
adapter is shipped with the DIP switches of all slots config-
ured for independent operation (see Figure 1) and local
sensing.
PARALLEL OPERATION. The most common use for
the RA 19-4C rack adapter is with two or more identical
HSF modules adjusted to the desired output voltage, con-
nected in parallel to a single load with forced current shar-
ing to increase current output, increase reliability and/or
provide redundancy. Only adjacent slots can be connected
in parallel using DIP switches.

2228-1671 REV 2 110122
KEPCO, INC.  131-38 SANFORD AVENUE  FLUSHING, NY. 11355 U.S.A. TEL [phone]FAX [phone]
http://www.kepcopower.com email: [e-mail]
Figure 3 shows HSF’s in slots 3 and 4 connected in paral-
lel with forced current sharing and a close-on-fail alarm
circuit. Both HSF modules are configured for output volt-
age to be adjusted from the front panel trimpot (factory
default setting). See Operator Manual for other output
voltage adjustment options.
Configure DIP 4:
1. Set positions 1 and 2, to OFF to disable local sensing
for slot 4.
2. Set positions 3 and 4, to ON. This connects sense lines
(+S to +S and –S to –S) for slots 4 and 3.
3. Set position 5, to ON. This connects the current share
bus (CB) for slots 4 and 3.
4. Set positions 6 and 7 to ON. Position 6 connects the
normally open ALARM (N.O.) lines and position 7 con-
nects the ALARM (COM) (common) for slots 4 and 3,
implementing a close-on-fail alarm circuit (see equiva-
lent schematic shown in Figure 3. If either PS3 or PS4
fails, a contact closure provides continuity across pins 7
and 14 of both I/O 4 and I/O 3.
5. Set position 8 to OFF. This position is only set to ON for
open-on-fail alarm circuits.
6. Set position 9 to OFF. Isolates RV (remote voltage)
lines between slot 4 and 3, however RV is not used
(output voltage is controlled by the front panel trimpot).
7. Set position 10 to ON. This connects the common lines
(-COM) for slots 4 and 3.
TABLE 1. REAR PANEL DIP SWITCH FUNCTIONS
DIP
SWITCH
POSITION FUNCTION DIP SWITCH SETTINGS
1, 2
Local /
Remote
Sensing
Selection
Position 1 connects V+ to S+, Position 2 connects V– to S– .
Both required ON (factory default) for independent operation with Local Sensing. and for the first slot of a parallel config-
uration.
Both required OFF for:
a) Independent configurations using Remote Sensing.
b) All series connections.
c) All parallel configurations (except for the first slot); use switch positions 3, 4 set to ON to parallel sense connections
from the first slot.
3, 4
Connect
Sense
+ and –
in parallel
Position 3 connects +S to adjacent slot +S, Position 4 connects –S to adjacent slot –S.
Both required OFF (factory default) for all configurations except parallel configurations using DIP switch settings to con-
nect the sense leads in parallel.
Both required ON for parallel configurations using DIP switch settings to connect the sense leads in parallel.
5
Current
Balance
(forced
current
share)
Required ON for parallel operation with forced current share (connects current share lines in parallel) unless connec-
tions are made via external wires
Required OFF (factory default) for independent and series configurations.
6, 7 Close on
Failure
Alarm
When set to OFF (factory default), individual power supplies produce closure between I/O connector N.O. and COM
pins upon failure .
When set to ON, parallels N.O pins of adjacent slots to allow a single alarm to provide failure indication (contact closure
between N.O. pin and COM pin) if any one of many power supplies fails.
8Open on
Failure
Alarm
When set to OFF (factory default), individual power supplies produce open between I/O connector N.C. and COM pins
upon failure.
When set to ON, connects N.C to COM between adjacent slots so that individual alarms are connected in series. This
allows a single alarm to provide failure indication (contact open between N.C. pin and COM pin) if any one of many
power supplies fails.
9Remote
Voltage When both set to OFF (factory default), allows independent voltage control of each power supply When both set to ON, enables control of multiple supplies from one power supply designated as the Master.
Required OFF (factory default) for independent and series configurations.
10 -Common

KEPCO, INC.  131-38 SANFORD AVENUE  FLUSHING, NY. 11355 U.S.A. TEL [phone]FAX [phone]
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110122 228-1671 REV 2 3
Configure DIP 3:
1. Set positions 1 and 2, to ON. This connects +S to +V
and –S to –V for slot 3, establishing local sensing for slot
3.
2. Set positions 3 and 4, to OFF. This isolates sense lines
(±S) between slots 3 and 2.
3. Set position 5 to OFF. This isolates the current share
bus (CB) between slots 3 and 2.
4. Set position 6 and 7, to OFF. This isolates the ALARM
(N.O.) and ALARM (COM) lines between slots 3 and 2.
5. Set position 8 to OFF. This position is only set to ON for
open-on-fail alarm circuits.
6. Set position 9 to OFF. Isolates RV (remote voltage) lines
between slot 3 and 2, however RV is not used (output
voltage is controlled by the front panel trimpot).
7. Set position 10 to OFF. This isolates common (-COM)
lines between slots 3 and 2.
SERIES OPERATION. See Operator Manual for
series operation details.
ALARMS. For independent configurations, Close on
Fail contact closure is across I/O connector pins 7 (ALARM
N.O.) and 14 (ALARM COM). Open on Fail circuits are
across I/O connector pins 6 (ALARM N.C.) and 14 (ALARM
COM). Figure 3 shows a parallel close-on-fail circuit for
slots 3 and 4 using the DIP switches to make the connec-
tions. See Operator Manual for other options.
III — INSTALLATION
MOUNTING RACK ADAPTER: The rack adapter
mounts directly to EIA-RS 310D standard 19" racks via the
two mounting ears; two screws are required per mounting
ear for proper support. CAUTION: RACK ADAPTER
SHOULD BE MOUNTED BEFORE INSTALLING POWER
SUPPLIES. Install each HSF power supply in desired slot
and secure using two retaining latches as described by the
applicable HSF Power supply manual. Make sure the two
latches are in the open position before installing HSF mod-
ules.
The rack adapter is supplied with six cable clamps
equipped with release levers that can be snapped into
holes provided in the rear panel (see Figure 1) to support
the weight of the input, output and signal cables.
OPTIONAL PROTECTIVE COVER: A clear plastic
cover (Kepco P/N 137-0145) is available as an accessory
to protect the rear terminals against accidental contact.
See Operator Manual for details.
OPTIONAL BUS BAR: Bus bars which connect output
terminals for parallel or series operation are available as
accessories. See Operator Manual for details.
OPTIONAL KEYING: HSF power supplies are keyed
by voltage at the factory. The keyway is established by
installing screws (4-40 x 0.75 in. thread-forming, Kepco P/
N 101-0480, provided) into the corresponding holes as
indicated in Figure 2 so that the only holes open match the
power supply pins. DO NOT OVERTIGHTEN these screws
(max torque 5 in.-lbs. (0.6 N x m). User-modified keying
can differentiate between modules with same keyways
(e.g., 36V and 48V) or between identical HSF models but
with different adjustments; see Operator Manual for
details.
FIGURE 2. RACK ADAPTER KEYING
OPTIONAL I/O CONNECTOR: Mating Europlugs
(Kepco P/N 142-0544) for the Alarm I/O Euroheaders are
available as accessories for the Sense connections (±S)
and independent Alarm connections.
OPTIONAL A-C CONNECTIONS: Two line cords are
available as accessories. 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 applica-
tions may require the use of Kepco line cord P/N 118-1146
(250V, 32A maximum).
INSTALLATION/REMOVAL OF HSF POWER SUP-
PLIES: Use two retaining latches on each HSF power
supply to install or remove power supply to/from desired
slot in accordance with the applicable HSF Power supply
manual. Refer to RA 19-4C Operator Manual for keeping
= SCREW TO BE INSTALLED
AT REAR PANEL.
= NO SCREW INSTALLED.
DESIRED VOLTAGE 5V 12V15V 24V 28V 36V 48V

4228-1671 REV 2 110122
KEPCO, INC.  131-38 SANFORD AVENUE  FLUSHING, NY. 11355 U.S.A. TEL [phone]FAX [phone]
http://www.kepcopower.com email: [e-mail]
the power supplies secure under severe shock or vibra-
tion conditions.
FIGURE 3. SLOTS 3 AND 4 CONFIGURED FOR PARALLEL OPERATION, WITH CLOSE ON FAIL ALARM CIRCUIT
IV — WIRING
A-C WIRING: It is the user’s responsibility to obey all
local, national and international safety rules regarding
field-wired apparatus and the grounding of the metal
cover and case of any instrument connected to the a-c
power source. Grounding is an intrinsic part of the safety
aspect of the unit.
SOURCE POWER: Source power requirements are
determined by the HSF power supply (see HSF power
supply Instruction Manual); no adjustment or modification
of the rack adapter is required.
Source power can also be custom configured via jumpers
on the internal PC board. Contact Kepco Applications
Engineering for further details.
Wire size range for each terminal block is AWG 20-10/
IEC, rigid: 0.5 - 6mm2, or flexible (stranded): 0.5 - 4mm2;
torque to 6 lb-in (0.6 N•M) maximum. CAUTION: DO NOT
EXCEED MAXIMUM TERMINAL BLOCK RATING OF
500V AT 36A. The terminals are labeled L, N, and G.
Their functions are:
• Terminal G (Ground) is the safety ground con-
nection for the RA 19-4C.
• Terminals L (Line Phase) and N (Neutral) are
connected to the input power entry connectors.
Source power is provided to the power supplies
indicated by the label on the rear panel.
CONTROL SIGNALS: Access to all the control sig-
nals for each HSF power supply is provided via four 15-
pin D-subminiature I/O connectors on the rear panel of the
rack adapter (see Figure 1). Four mating connectors
(Kepco P/N 142-0449) are provided in a plastic bag. Basic
functions (Sense and Alarm) are also available via the 5-
pin ALARM I/O Euroheader.
OUTPUT LOAD: Load connections to the rack adapt-
ers are achieved via four pairs (DC OUTPUT + and –) of
output 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. 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 50mF electrolytic capacitor in parallel with a 0.01mF
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 and/or shielded.