KEPCO HSF-A Series User manual

IMPORTANT NOTES:
1) This manual is valid for the following Model and associated serial numbers:
MODEL SERIAL NO. REV. NO.
2) A Change Page may be included at the end of the manual. All applicable changes and
revision number changes are documented with reference to the equipment serial num-
bers. Before using this Instruction Manual, check your equipment serial number to identify
your model. If in doubt, contact your nearest Kepco Representative, or the Kepco Docu-
mentation Office in New York, [phone], requesting the correct revision for your par-
ticular model and serial number.
3) The contents of this manual are protected by copyright. Reproduction of any part can be
made only with the specific written permission of Kepco, Inc.
Data subject to change without notice.
KEPCO®
THE POWER SUPPLIER™
MODEL
OPERATOR’S MANUAL
KEPCO INC.
KEPCO, INC. 131-38 SANFORD AVENUE FLUSHING, NY. 11355 U.S.A. TEL [phone] FAX [phone]
email: [e-mail] World Wide Web: /www.kepcopower.com
An ISO 9001 Company.
HSF-A, 1500W
©2021, KEPCO, INC
P/N 243-1412
HSF-A 1500W SERIES
POWER SUPPLY
HSF-A 1500W SERIES
POWER SUPPLY
SINGLE OUTPUT POWER SUPPLIES
SINGLE PHASE, UNIVERSAL AC INPUT, OPTIONAL METER
HSF 24-50A (M), HSF 36-42A (M),
HSF 48-32A (M), HSF 60-25A (M)

iHSF 1500W 010421
TABLE OF CONTENTS
SECTION PAGE
LIST OF FIGURES
FIGURE TITLE PAGE
LIST OF TABLES
TABLE TITLE PAGE
1. Introduction ........................................................................................................................................................ 1
1.1 Scope of Manual............................................................................................................................................. 1
1.2 Description...................................................................................................................................................... 1
2. Specifications..................................................................................................................................................... 2
3. Features.......................................................................................................................................................... 5
3.1 DIP Switch Configuration................................................................................................................................ 5
3.2 Front Panel Access......................................................................................................................................... 6
3.3 Keying............................................................................................................................................................. 6
3.4 Output Voltage Control.................................................................................................................................... 7
3.4.1 Front Panel Voltage Control......................................................................................................................... 7
3.4.2 Remote Voltage Control............................................................................................................................... 7
3.5 Current Monitor (M Suffix only)....................................................................................................................... 7
3.6 Remote On-Off................................................................................................................................................ 8
3.7 Protection Circuits........................................................................................................................................... 8
3.7.1 Overvoltage And Overtemperature Protection............................................................................................. 8
3.7.2 Current Limit Setting and Excess Power Protection..................................................................................... 9
3.7.3 Fan Failure................................................................................................................................................... 9
3.8 Alarm Settings................................................................................................................................................. 9
3.8.1 Visual Alarm................................................................................................................................................. 9
3.8.2 Alarm Signals............................................................................................................................................... 9
3.8.2.1 Internal Isolated Relay Alarm.................................................................................................................... 9
3.8.2.2 Optically-Coupled Logical Alarm ............................................................................................................... 9
3.9 Retaining Latches ......................................................................................................................................... 10
4. Load Connection.............................................................................................................................................. 10
5. Connecting Multiple Power Supplies................................................................................................................ 10
1 RA 19-4C Rack Adapter I/O Connector...................................................................................................... 1
2 VSET (VCI) vs OVP Curve......................................................................................................................... 2
3 Power Rating Vs. Temperature, Load vs. Input Voltage............................................................................. 4
4 Mechanical Outline Drawing Of HSF 1500W Power Supply ...................................................................... 4
5 DIP Switch Configuration............................................................................................................................ 5
6 Front Panel Controls, Indicators and Test Points....................................................................................... 6
7 Connections For Remote Voltage Control.................................................................................................. 8
8 Correct and incorrect Methods of Load Connection................................................................................. 10
1 Rear Connector Pin Assignments ...............................................................................................................1
2 Output Ratings and Specifications ..............................................................................................................2
3 Power Supply Ratings and Specifications ..................................................................................................3

HSF-A 1500W 010421 1
1. INTRODUCTION
1.1 SCOPE OF MANUAL
This Operator's Manual covers the installation and operation of the Kepco HSF-A 1500W Series
of Switching Power Supplies. For service information, write directly to: Kepco Inc., 131-38 Sanford
Avenue, Flushing, New York, 11355, U.S.A. Please state Model Designation and Serial Number of
your HSF Power Supply (see nameplate of the unit).
1.2 DESCRIPTION
The Kepco HSF-A 1500 Watt Series are hot swappable, plug-in power supplies. Metered models
(M suffix) are completely interchangeable with the non-metered HSF-A 1500W Series. Four mod-
els may be selected for outputs of 24V, 36V, 48V or 60V. They employ forward conversion and
power factor correction and are designed to operate in a fault tolerant power system with a nomi-
nal a-c input of 100V a-c to 240V a-c (input voltage range 85 to 265V a-c), 50-60Hz (input fre-
quency range 47-63Hz). A built-in current balancing circuit and OR-ing diodes allow configuration
for hot-swap and parallel-redundant N+1 operation.
These power supplies are designed to be used with Kepco's Series RA 19-4C rack adapters. The
RA 19-4C rack adapter accepts up to four modules. All input/output connections are through a 24-
pin connector that plugs in to the rack adapter. All external connections are made through the rack
adapter’s I/O connector (see Figure 1).
An optional meter (M suffix) provides digital indication of voltage or current (switch selectable)
from the front panel. RoHS-compliant models indicated by HSF* (e.g., HSF 24*50AM).
FIGURE 1. RA 19-4C RACK ADAPTER I/O CONNECTOR
TABLE 1. REAR CONNECTOR PIN ASSIGNMENTS
Signal
Name Pin Function
Output + 1, 2, 4 DC output (+) applied to load.
Output – 3, 5, 6 DC Output (–) applied to load.
IMON+ 8 Current Monitor+ (used on C and M suffix only).
NO 10 Normally Open contact of alarm relay, referenced to AL COM, pin 14 (see PAR. 3.8.2).
IMON– 11 Current Monitor– (used on C and M suffix only).
COM 12 Signal Common - return for AUX 5V pin 15, RV pin 18 and CSB pin 17.
NC 13 Normally Closed contact of alarm relay, referenced to AL COM, pin 14 (see PAR. 3.8.2).
AL COM 14 Common contact of alarm relay (see PAR. 3.8.2).
AUX 5V 15 +5V supply for optional I2C communication when enabled by DIP switch SW1 position 1 Return is COM
(pin 12, 19, or 21) Caution: Not short circuit protected!
+PF 16 +Power Fail of open-collector alarm circuit. Used with COM, pin 19 (see PAR. 3.8.2).
CSB 17 Current Share Bus - Used whenever several power supplies are connected in parallel (see PAR. 5.).
RV 18 Remote Voltage - Return is COM (pin 12, 19, or 21) Used for remotely controlling the output voltage (see
PAR. 3.4.2)
COM 19 Signal Common - return for AUX 5V pin 15, RV pin 18 and CSB pin 17.
3044526
7
8
2
4
5
6
3
1
+IMON
CSB
-RC (COM)
ALARM (NO)
ALARM (NC)
REF
+PF
(NOT USED)
15
9
12
13
14
11
10
+RC
-IMON
(NOT USED)
ALARM (COM)
-PF
-COM (COM)
RV
NOTE: PINS 8 AND 10 ARE
DESIGNATED "COM" FOR
HSF-A 1500W ONLY.
SEE NOTE
SEE NOTE

2HSF-A 1500W 010421
2. SPECIFICATIONS
Table 2 contains specifications and operating limits of individual HSF-A 1500W Series models.
Table 3 contains specifications and operating limits common to all HSF-A 1500W Series Models.
These specifications are at nominal input voltages at 25°C and apply to all models unless other-
wise specified.
FIGURE 2. VSET (VCI) VS OVP CURVE
+RC 20 +Remote On-off used with –RC, pin 21, to allow remote turn-on turn-off of the unit (see PAR. 3.6)
COM 21 Signal Common - return for AUX 5V pin 15, RV pin 18 and CSB pin 17.
GND 22 AC input ground
N 23 AC Input neutral
L 24 AC input line
TABLE 2. OUTPUT RATINGS AND SPECIFICATIONS
MODEL HSF 24-50 HSF 36-42 HSF 48-32 HSF 60-25
Output Volts d-c (nominal) 24 36 48 60
Adjustment Range (Volts) Front panel Trimpot 0 - 30.5 0 - 36.8 0 to 49.4 0 to 62
Maximum Output Current
and Power Ratings (1)
(A,W)
90-100V a-c Input 90 - 100
100 - 264V a-c Input: 105
Overvoltage Protection Level(2) at output terminals Variable OVP, 120% ±7% of VSET
Current Limit Setting (Amps) 100 - 264V a-c Input: 52.5 43.7 32.8 26.2
Efficiency (%) Typical 89 89 90 91
Ripple & Noise(3) (mV, p-p) maximum 300 360 480 600
Sense Resistor (IMon) values
(Ohms) Metered models only 0.002 0.002 0.005 0.005
(1) See Figure 3 for power derating vs. temperature and input voltage.
(2) Protection type: Latch-style (recovery after reset AC power ON or inhibit)
(3) Ripple & noise are measured at 20MHz of bandwidth by using a 12" twisted pair wire terminated with a 1 uF ceramic capacitor.
TABLE 1. REAR CONNECTOR PIN ASSIGNMENTS (CONTINUED)
Signal
Name Pin Function

HSF-A 1500W 010421 3
TABLE 3. POWER SUPPLY RATINGS AND SPECIFICATIONS
CHARACTERISTIC SPECIFICATION CONDITION/NOTES
Input Voltage Range: 90-264V a-c, 127-370V d-c Up to t0% derating between 90 and 100V a-c
Input Source Frequency Range: 57-63 Hz
Input Current: 115V a-c 18A Maximum Load At 25°C
with Nominal Output Voltage
230V a-c 9A
Input Protection The internal power supply is protected against shorts by an input fuse.
Input Surge cold start, 115V a-c 30A Maximum Load At 25°C
with Nominal Output Voltage
inrush current 230V a-c 40A
Leakage Current: <2.5mA 240V a-c
Power Factor, 115V a-c 0.99
230V a-c 0.95
Voltage Stabilization Source Effect ±1%
Load Effect ±1%
Temperature Effect ±0.02% / °C
Combined Effect ±1.6% Typical, ±3.2% Maximum Source, Load and Temperature
Start-up Time 800 msec
Output Hold-up Time 14 msec 230V a-c at full load
Protection Overvoltage Variable OVP, 120 ± 7%, refer to VSET vs OVP curve Figure 2.
Protection type: Latch style, recovery after AC power cycle or inhibit
Overload 105% rated output power , protection type: constant current limit
Overtemperature 85 ± 5ºC detected on NTC Auto recovery after temperature goes down
Auxiliary Power Selectable +5V I 0.5A or +9V I 0.lA.
auxiliary output
Remote ON/OFF Control By external switch
Power OK signal Open drain signal low when PSU turns on,
Max. sink current 20mA, Max. drain voltage: 40V.
Parallel Current Share When connected In parallel, only one unit will operate if the total output load is less than
5% of the rated power.
Temperature Operating: -25 to +60°·C
Storage: -40 to +85°·C Refer to power rating curve, Figure 3.
Humidity Operating: 20 -90% RH
Storage: 10 to 95% RH non-condensing
Vibration 10 -500Hz, 2G 10min./1cyc1e, period
for 60min. each along X, Y. Z axes Compliance to IEC 68-2-6, IEC 68-2-84
Safety Standards Certified UL 60950-1; EN 60950-1
Withstand Voltage, input to output 3KV a-c (4,242V d-c)
input to ground 1.5KV a-c (2,121V d-c)
output to ground 0.5KV a-c (707V d-c)
Isolation Resistance, input to output 100M Ohms 1500V d-c
input to ground 100M Ohms 1500V d-c
output to ground 100M Ohms 1500V d-c
EMI Conduction and Radiation Certified EN 55022; EN 61204-3;
EN 61000-6-3
Harmonic Current Certified EN 81Q00.3.2; EN 61Q00.3.3
EMS Immunity Certified EN 55024; EN6 1204-3;
EN6 1000-6-1; IEC 61000-4-2, 3, 4, 5, 6, 8,11
Mounting: Plug-in
Cooling: Forced air flow - load/temperature controlled fan
Dimensions 5.22 in. (132.5 mm) x 4.288 in. (108.9 mm) x 16.86 in. (428.2 mm) (See Figure 4)
Weight 8.42 lbs (3.82 kg)

4HSF-A 1500W 010421
FIGURE 3. POWER RATING VS. TEMPERATURE, LOAD VS. INPUT VOLTAGE
FIGURE 4. MECHANICAL OUTLINE DRAWING OF HSF 1500W POWER SUPPLY
POWER RATING VS. TEMPERATURE
OutputPowerRating(%)
Ambient Temperature (°)
-10 0 10 20 30 40 50 60 90 -20
10
20
40
50
60
70
80
90
30
100
-25
LOAD VS. INPUT VOLTAGE
Load(%)
40
50
100
80
70
60
90
0100 110 120 264
Input Voltage (V a-c)
FRONT VIEW (M SUFFIX ONLY)
REAR VIEW
3044520 = PIN PRESENT
= PIN MISSING
KEYING
DETAIL "A"
24V 36V 48V
NOTES:
1. MATERIAL:
A) BACKPLATE 0.064" THK. ALUM. 5052-H32
B) PCB 0.063" THK FR-4
C) FRONT PANEL 0.090 THK. ALUM. 6061-T6
2. FINISH:
FRONT PANEL -KEPCO DUAL TONE GRAY
3. MODULE IS KEYED AS SHOWN IN DETAIL
4. DIMENSIONS ARE IN INCHES, [DIMENSIONS IN
BRACKETS ARE IN MILLIMETERS].
FRONT VIEW
KEPCO, INC. - PROPRIETARY DATA
SUBJECT TO TERMS OF USE AGREEMENT.
14.667 [372.5]
0.690 [17.5]
0.093 [2.4]
1.500
[38.1]
SEE DETAIL "A"
0.093
[2.4]
0.093 [2.4]
1.813" [46.04]
0.188 [4.8]
2.408 [61.2]
0.430 [10.9]
3.353
[85.2] 2.065
[52.5]
0.337 [8.5]
0.433" [11.00]
0.438 [11.1]
0.085 [2.2]
0.943 [23.9]
0.119" [3.03] 4.288 [108.9]
5.218[132.5]
2.144
[54.46]
5.218[132.5]
2.144
[54.46]
4.288 [108.9]
60V

HSF-A 1500W 010421 5
3. FEATURES
3.1 DIP SWITCH CONFIGURATION
The power supply incorporates one DIP switch, SW1 (see Figure 5), which must be configured
before the unit is installed in the rack adapter. The DIP switches control the following parameters:
• Position 1 - default: position 1 is OFF. When switch is ON, AUX 5V supply is made avail-
able on pin 15 (used for I2C communication).
• Positions 2 and 3 - default position 2 is OFF, position 3 is ON, allows output voltage set-
ting by front panel Vadj control (see PAR. 3.4.1).
When position 2 is ON and position 3 is OFF, front panel Vadj control is disabled and
allows HSF output voltage setting by either an external trimpot or voltage source (see
PAR. 3.4.2)
• Positions 4 and 5 - default position 4 is OFF, position 5 is ON - allows HSF output to be
reset after a fault using the front panel OUTPUT RESET switch and disables remote ON/
OFF control of HSF output. (see PAR. 3.6)
When position 4 is ON and position 5 is OFF, allows HSF output to be enabled/disabled
via mechanical switch or logic level (see PAR. 3.6); front panel OUTPUT RESET switch
is disabled.
• Positions 6 and 7 - default position 6 is OFF, position 7 is ON - allows alarm signals to be
produced from internal relay, Form C contacts (one NO, one NC) (see PAR. 3.8.2).
When position 6 is ON, connects +PF on RA 19-4C I/O connector to the internal not-iso-
lated alarm signal
• Position 8 - default position is ON - allows red LED front panel ALARM indicator to func-
tion (see PAR. 3.8.1). When switch is OFF, the front panel red ALARM indicator is dis-
abled.
FIGURE 5. DIP SWITCH CONFIGURATION
FACTORY DEFAULT SETTING:
- FRONT PANEL VADJ CONTROL
- REMOTE ON-OFF DISABLED
- FRONT PANEL RESET ENABLED
- RELAY ALARM SELECTED
- VISUAL ALARM ENABLED
3044518
DETAIL VIEW
3
3
SW1
6
6
7
87
8
5
45
4
ON
1
22
1
TAB
OFF

6HSF-A 1500W 010421
3.2 FRONT PANEL ACCESS.
The front panel provides a power ON/OFF switch controlling input power and a “VDC ON” indica-
tor which lights green when the unit is operating. The indicator lights red if the unit fails or if
RESET is pressed; it lights red for about 30 seconds if there is a power loss..
CAUTION: DO NOT repeatedly toggle the power ON/OFF switch as this may cause unit to
fault.
NOTE: The ON/OFF switch must be set to OFF before removing unit from rack adapter.
If remote on-off is not enabled (see PAR. 3.6), the OUTPUT RESET button restores output power
in the event that overcurrent or overvoltage protection has tripped, or thermal overload or fan mal-
function has occurred.
If remote voltage control (see PAR. 3.4.2) is not enabled, the front panel Vadj trimmer (see PAR.
3.4.1) provides adjustment of the output voltage within the limits specified in Table 1; test points
are available at the front panel for monitoring the DC output.
Figure 3.4 shows the location of all operating controls, indicators and test points followed by an
explanation of each.
3.3 KEYING
Keying of the power supply is established at the factory. The output voltage determines which key
pins are installed (see Figure 4, Detail A). When the proper holes in the rack adapter are blocked
by keying screws installed by the user, only a power supply of the correct voltage can be inserted
in the rack adapter slot. Refer to the RA 19-4C Manual for rack adapter keying instructions.
FIGURE 6. FRONT PANEL CONTROLS, INDICATORS AND TEST POINTS
• VDC ON/ALARM indicator. Lights green when unit is operating. When enabled by DIP switch config-
uration, lights red to indicate loss of output voltage (see PAR. 3.8.1).
• V.ADJ Output voltage adjustment trimmer: Adjusts output voltage within limits specified in Table 2
(see PAR. 3.4.1). Not functional if remote voltage control is enabled (see PAR. 3.4.2).
• DC output test points (+, –): Connect to voltmeter to monitor output voltage.
• OUTPUT RESET switch. Used to recycle power in the event of an alarm condition (see PAR. 3.7).
Not functional when remote on/off control is enabled (see PAR. 3.6).
• POWER ON/OFF rocker switch. Applies power to the unit.
Retaining Latches
POWER ON/OFF switch
OUTPUT RESET switch
TEST POINT (-)
TEST POINT (+)
V. ADJ Output Voltage Adjustment Trimmer
VDC ON/ALARM Indicator
3044519
Voltage/Current Meter
(M Suffix only)
Meter Mode switch
(M Suffix only)
V (Voltage) indicator
(M Suffix only)
A (Amperes) indicator
(M Suffix only)

HSF-A 1500W 010421 7
CAUTION: Power must be OFF before unit is removed from the rack adapter.
• Retaining Latches (2). Prevents inadvertent removal of unit from rack adapter (see PAR. 3.9)
• (M Suffix only) Voltage/Current meter: Monitors output voltage or current according to setting of
Meter Mode switch.
• (M Suffix only) Meter Mode switch: Set to V for display to show output voltage, set to A to show out-
put current.
• (M Suffix only) V indicator: Lights green to indicate meter is showing Volts.
• (M Suffix only) A indicator: Lights amber to indicate meter is showing Amperes.
3.4 OUTPUT VOLTAGE CONTROL
Output Voltage can be controlled from either the front panel (PAR. 3.4.1) or externally using a
trimpot or voltage source (PAR. 3.4.2).
3.4.1 FRONT PANEL VOLTAGE CONTROL
Output voltage can be manually adjusted with the voltage adjustment control, Vadj (see Figure 6
for location) when DIP switch SW1 position 3 is set to ON and position 4 is set to OFF shown in
Figure 5 (factory default) To adjust voltage, first place the unit under an operating load. Then mon-
itor the (+) and (–) test points on the front panel with a precision voltmeter and turn the voltage
control to the desired operating value.
3.4.2 REMOTE VOLTAGE CONTROL
For remote voltage control, set position 2 of the DIP switch to ON and position 3 to OFF (see Fig-
ure 5 for switch location). This removes control from the front panel Vadj control and allows the
output voltage to be adjusted by either an external trimmer pot (resistance) or by an external vari-
able voltage source connected across the rack adapter I/O connector pin 12 (RV, Remote Volt-
age) and pin 10 (COM, Common) as shown in Figure 7. At the rack adapter I/O connector use a
shielded wire 6.6 feet (2M) maximum in length, for connection of RV (pin 12), and COM (pin 10) to
the trimmer control or external voltage source.
NOTE: If remote voltage control is not implemented, the factory default for DIP switch posi-
tions 2 and 3 must be restored (Figure 5).
It is possible that the overvoltage protection may be triggered if the output voltage is decreased to a
low level very quickly when the power supply is at a low load condition.
RESISTANCE: Connect a 0 to 5kohm variable resistor as shown in Figure 7A to adjust the output
voltage from zero to nominal. The 1mA current source inside the unit provides polarization to RV,
allowing RV voltage to be adjusted from zero to 5V.
VOLTAGE. By adjusting an external 0 to 5V voltage source capable of absorbing current of 1mA or
more, the output voltage can be adjusted from 0 to 100% of nominal. Connect the voltage source
across the RV and COM pins as shown in Figure 7B.
3.5 CURRENT MONITOR (M SUFFIX ONLY)
Current monitor is via ±IMON assigned to pins of the RA 19-4C I/O connector (see Figure 1).
Monitored Output Current (Amps) = Voltage drop across Rs (Volts) x Rs (Ohms), where voltage
drop across Rs (see Table 2) is measured across ± IMON pins (requires millivoltmeter, range 0 to
200mV). Accuracy is ±3%; contact Kepco if greater accuracy is required. There is no isolation
between ±IMON, negative d-c output, /P_OK and RV signals.

8HSF-A 1500W 010421
FIGURE 7. CONNECTIONS FOR REMOTE VOLTAGE CONTROL
3.6 REMOTE ON-OFF
When power is ON at the source, the output may be turned ON or OFF using the +RC signal if the
remote ON-OFF feature is enabled. Note that when remote ON-OFF is enabled, the RESET OUT-
PUT switch does not function. The unit can be reset using the remote ON-OFF feature or by leav-
ing the unit OFF for at least 40 seconds
Remote ON-OFF is enabled by setting DIP switch position 4 to ON and position 5 to OFF. The
+RC signal, referenced to COM (at the rack adapter I/O connector, pins 15 and 10, respectively)
then turn the unit on or off. These pins accept a logic level (3.3 to 5V “high” and 0.0 to 0.4V “low”),
or a contact closure. When +RC to COM is open using a high level logic signal, the power supply
output is cut OFF. When +RC is shorted to COM, the output returns to within specifications. Posi-
tions 4 and 5 of the DIP switch must be restored to the factory default setting (Figure 5) if remote
ON-OFF is not used. The +RC pin is not isolated from the negative DC output pin.
3.7 PROTECTION CIRCUITS
The following protection features are implemented in the power supplies: overvoltage and over-
temperature (PAR. 3.7.1), current limit/excess power (PAR. 3.7.2) and fan failure (PAR. 3.7.3).
The power supply provides a configurable visual alarm (see PAR. 3.8.1) as well as an option to
use either relay contacts or logic levels for alarm signals (see PAR. 3.8.2)
3.7.1 OVERVOLTAGE AND OVERTEMPERATURE PROTECTION
When the output voltage of the power supply increases beyond the specified values (see Table 2),
the output is cut OFF and the fan turns OFF. To restart (reset) the unit, press and release the
OUTPUT RESET switch on the front panel or use the remote on/off feature (see PAR. 3.6).The
unit may also be restarted by turning the POWER ON/OFF switch to OFF, waiting at least 40 sec-
onds, then setting the POWER switch to ON.
When the internal temperature of the power supply increases beyond safe values, the output is
cut OFF and the fans turn OFF. The restart cycle (Power ON) should not begin until the tempera-
ture returns to within specifications. To restart (reset) the unit, set the POWER ON/OFF switch to
OFF, wait 40 seconds, then set the POWER switch to ON. The power supply cannot be reset
using the remote ON-OFF feature unless the power supply remains shut down for at least 40 sec-
onds.
REMOTE VOLTAGE
CONTROL USING
EXTERNAL RESISTANCE
RA 19-4C RA 19-4C
HSF SLOT 1
I/O 1
LOAD
J2 RV COM
J2
I/O 1
1012
VOLTAGE
SOURCE LOAD
REMOTE VOLTAGE
CONTROL USING
EXTERNAL VOLTAGE
-+ -+
COM
RV
1012

HSF-A 1500W 010421 9
3.7.2 CURRENT LIMIT SETTING AND EXCESS POWER PROTECTION
The output characteristic of the power supply is square type, with default current limit at 105% of
nominal current.
If a current limit lower than the default is needed, a 0.5 to 4.5 kohm resistor can be installed on the
main printed circuit board at location R9. A resistor of 1 kohms limits the current to about 20%, 2.5
kohms to about 50%, 4 kohms to about 80% of the unit’s nominal current.
In the rare case when both the output voltage and current are above their nominal values, excess
power protection may shut down the unit. This happens when the internal power module power
level exceeds 105% of nominal power or, respectively, 1530W for the 24V model or 1550W for the
36, 48, 60V models.
To restart (reset) the unit, press and release the OUTPUT RESET switch on the front panel or use
the remote on/off feature (see PAR. 3.6). The unit may also be restarted by turning the POWER
ON/OFF switch to OFF, waiting 40 seconds, then setting the POWER switch to ON.
3.7.3 FAN FAILURE
A fan failure causes the output to shut down and the fans to turn OFF. Fan failure and all the other
protection circuit operations produce an alarm (see PAR. 3.8.2). To restart (reset) the unit, press
and release the OUTPUT RESET switch on the front panel or use the remote on/off feature (see
PAR. 3.6). The unit may also be restarted by turning the POWER ON/OFF switch to OFF, waiting
40 seconds, then setting the POWER switch to ON. If fan rotation is out of specification the power
supply will not recover.
3.8 ALARM SETTINGS
3.8.1 VISUAL ALARM.
The front panel VDC ON/ALARM indicator can be configured to light red if a) the respective power
supply output voltage is lost, b) the unit is reset (local or remotely) or c) if the POWER switch is
set to OFF (indicator lights red for 30 seconds after setting to OFF). This feature is enabled when
DIP switch 1, position 8 set to ON (factory default, see Figure 5 for switch location).
3.8.2 ALARM SIGNALS.
Either of two options are available for signalling alarms: isolated relay contacts (factory default,
PAR. 3.8.2.1) or logic level alarm signals +PF (PAR. 3.8.2.2).
3.8.2.1 INTERNAL ISOLATED RELAY ALARM
The first option, the factory default setting, uses an isolated internal relay offering normally closed
(NC) and normally open (NO) contacts referenced to an isolated common (AL COM). These con-
tacts may be used to configure “close on failure” or “open on failure” alarm circuits. (Refer to the
Series RA 19-4C Manual for alarm configurations for multiple HSF power supplies.) Setting posi-
tion 6 to OFF and 7 to ON (factory default) selects this option. The NC (pin 6of the rack adapter I/
O connector) and NO (pin 7) signals are referenced to Alarm common (pin 14).
3.8.2.2 OPTICALLY-COUPLED LOGICAL ALARM
This ±PF signals, available in older non-A suffix HSF 1200/1500W models are not available in the
HSF-A 1500W series. Therefore DIP switch SW1 position 6 should always be set to OFF and
position 7 set to ON.

10 HSF-A 1500W 010421
3.9 RETAINING LATCHES
HSF-A 1500W series power supplies are provided with (2) retention latches located at each side
of the bottom edge of the front panel (see Figure 6). These latches work in conjunction with the
RA 19-4C rack adapters to prevent unauthorized or inadvertent module extraction from an operat-
ing power system. The latch is engaged by loosening the cap-head screw approximately 1/2 turn
CCW (use 5/32” hex key) and sliding the latch down to the bottom of the slot, then retightening the
cap-head screw CW until snug. DO NOT OVERTIGHTEN! To release, follow the same procedure,
except lift the latch to the top of the slot. Be sure to move the latch completely up or down to
ensure full engagement and disengagement of the latching mechanism. When the HSF-A power
supply is not installed in its plug-in rack adapter, it is recommended that the latch be secured in
the open (up) position to prevent damage.
NOTE: Retaining latches must not be used to secure the HSF power supply in the rack
adapter for shipping purposes. For shipping HSF units installed in the rack adapter, the
units must be secured by two flat head #8 screws (Kepco P/N 101-0188): FLP0, 8-32 X
0.375, ST at the top of the rack adapter.
4. LOAD CONNECTION
Connect the load to (+) and (–) terminals at the rear panel of the Rack Adapter. See Figure 8 for
the proper way to connect multiple loads.
FIGURE 8. CORRECT AND INCORRECT METHODS OF LOAD CONNECTION
5. CONNECTING MULTIPLE POWER SUPPLIES
All connections to multiple HSF-A power supplies must be made via the I/O mating connectors at
rear of the Rack Adapter and/or by the Rack Adapter DIP switches. These connections, including
the configuration of the internal HSF DIP switch, are described in the Rack Adapter Instruction
manual, and include:
• Using parallel configurations (for increased current or redundancy)
• Using series configurations (for increased voltage).
• Using open-on-fail or close-on-fail alarm schemes with multiple power supplies.