KEPCO HSF-PFC 100W User Manual

INSTRUCTION MANUAL

KEPCO

An ISO 9001 Company.

KEPCO SINGLE OUTPUT 100 WATT

HOT SWAP PLUG-IN POWER SUPPLIES

I — INTRODUCTION

The Kepco HSF-PFC 100 Watt series hot swappable, high
frequency switching, plug-in power supplies with built in
power factor correction employ forward conversion and are
designed to operate in a fault tolerant power system with
either a-c or d-c input. A negative temperature coefficient
(NTC) thermistor limits start-up surge. A built-in forced cur­rent share circuit and OR-ing diodes allow configuration for
hot-swap and parallel-redundant N+1 operation.

These power supplies are designed to be installed in
Kepco’s RA 19-(X)B Rack Adapters (Figure 2). RA 19-6B
accepts up to six 150W units, RA 19-7B accepts up to three
150W units, and up to four 50W or 100W units and RA 19­8B accepts up to eight 50W or 100W units. The applicable
RA 19-(X)B Operator Manual can be downloaded from the
Kepco web site at:

www.kepcopower.com/support/opmanls.htm#ra19-xb

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.

HSF-PFC

100W SERIES

Seven models may be selected for outputs of 3.3, 5, 12, 15,
24, 28, or 48V (see Table 1 or 2).

When the input is cut off, the output is maintained for 20
milliseconds minimum. If the power supply shuts down due
to an output overvoltage condition, it is then necessary to
turn the unit off and wait approximately 30 seconds mini­mum before turning the unit on again.

Specifications for each model of the HSF-PFC 100 Watt
Series are listed in Section III, on page 4 (standard models)
and Section IV, on page 6 (suffix C, T, X and Y).

OPTIONS. Options are identified by suffix: T (-PFCT) offers improved efficiency and less weight; C (-PFCC) offers current monitoring via an integral current sensing resistor (includes option T); X (-PFCX) offers remote on/off (includes option T); and Y (-PFCY) includes options C, X and T.

II — FEATURES

FRONT PANEL ACCESS. The front panel provides a

power ON/OFF switch controlling input power and a “VDC
ON” light which indicates when the unit is operating. NOTE:

The ON/OFF switch must be set to OFF before remov­ing unit from (or inserting into) rack adapter.

The front panel “MASTER ON” LED lights when 1) the unit
operates independently, or 2) the unit is used in parallel
redundant configurations while a) the output current is
within 10% to 100% of nominal and the unit is functioning
as a master or b) the output current is less than 10% of
nominal. In parallel redundant configurations, the module
with the highest voltage functions as the master. The other
units are slaves, and track the output voltage of the master.
Refer to Current Share Bus (CSB) on page 3 for details.
(The MASTER ON LED is not used on 3.3V model; it is
always off.)

KEPCO, INC.  131-38 SANFORD AVENUE  FLUSHING, NY. 11355 U.S.A.  TEL [phone]  FAX [phone]

http://www.kepcopower.com  email: [e-mail]

©2013, KEPCO, INC 1
Data subject to change without notice 228-1533 REV 15

The front panel Vadj trimmer provides adjustment of the
output voltage within the limits specified in Table 1 or 2; test
points connected to the +S and –S lines are available at the
front panel for measuring the output voltage.

FORCED CURRENT SHARE CIRCUIT. (Not avail­able on 3.3V model.) When units are configured for N+1 parallel redundant operation, it is desirable for current to be divided equally among the paralleled supplies. When the CSB (Current Share Bus) lines of paralleled units are con­nected together, the load current is forced to divide equally between all paralleled units. If one unit fails, the remaining units continue to supply the load, and the load current is divided equally among the remaining operating units. The failed unit is automatically isolated from the circuit by a built-in isolation diode. Refer to Current Share Bus (CSB) on page 3 for details.

I

1

I

2

t

3043527

T

D=(t/T)

The standard 24V Model (no options) can supply Peak
current listed in Table 1 if the four conditions listed below
are met. These models include thermal protection, volt­age shutdown type. Restart by removing a-c input; after
sufficient cooling, reapply a-c input (wait at least 30 sec­onds).

1. Time: t ≤ 10 Seconds

2. I

≤ Peak Current (Amperes)

1

3. Effective Current:

2

≤ Rated current (Amperes)

DI

1

ID–()I

2

×+

2

4. Effective Power P ≤ Maximum Power (Watts)
(output RMS current x output voltage)

FIGURE 1. 24V MODEL PEAK CURRENT REQUIREMENTS (

REMOTE ON-OFF. Remote on-off (X and Y models only) is via ±RC assigned to pins of the RA 19-(X)B I/O connector: off = no voltage, short circuit, or 0 to 0.8V, on =

4.5 to 12.5V (or 12.5 to 24.5V via 1.5K Ohms). To reverse
on-off polarity contact Kepco. There is no isolation
between ±RC, d-c output and alarm circuit. Refer to the
applicable RA 19-(X)B Manual for details.

CURRENT MONITOR. Current monitor (C and Y models only) is via ±IMON assigned to pins of the RA 19­(X)B I/O connector. Monitored Output Current (Amps) = Voltage drop across R R

is the sum of RS (see Table 2) + trace resistance to

EQ

(mVolts) / REQ (mOhms) where

EQ

point where current monitor is connected, approximately
4mOhms. The voltage drop across R

is measured

EQ

across ± IMON pins (requires millivoltmeter, range 0 to
250mV). Accuracy is ±10%; contact Kepco if greater
accuracy is required. There is no isolation between
±IMON, alarm circuit and d-c output. Refer to the applica­ble RA 19-(X)B Manual for details.

ALARM CIRCUIT. Any condition which causes the unit to be out of specified voltage/current ranges (includ­ing overvoltage, overcurrent, overtemperature, open sense line, ac input line failure, etc.) results in an alarm. All models include an isolated internal relay offering nor­mally closed and normally open contacts referenced to an isolated common. These contacts are rated for 1A at 30V d-c and 0.5A at 125V a-c. These contacts may be used to configure “close on failure” or “open on failure” alarm cir­cuits (see Figure 3 for typical alarm circuits). Refer to the applicable RA 19-(X)B Manual for details about the follow­ing: 1) normally open (close on failure) contacts are not available if ±RC is used on X and Y suffix models, 2) alarm signals are not isolated on C, X and Y models and

3) alarm configurations for multiple power supplies.

KEYING. Keying of the power supply is established at the factory. The output voltage determines which keyway is open. When the corresponding rack adapter key (pin) is installed by the user, only a power supply of the correct voltage can be inserted in the rack adapter slot.

FIGURE 2. HSF-PFC 100 WATT POWER SUPPLIES (8) INSTALLED IN RA 19-8B RACK ADAPTER

KEPCO, INC.  131-38 SANFORD AVENUE  FLUSHING, NY. 11355 U.S.A.  TEL [phone]  FAX [phone]

http://www.kepcopower.com  email: [e-mail]

2 228-1533 REV 15 083013

CONNECTIONS: The 24-pin I/O connector is designed to mate with the corresponding connector in the Series RA 19-(X)B Rack Adapter. (See Rack Adapter manual for pin assignments.)

(+) SENSE, (–) SENSE: These lines are provided to compen-

sate for voltage drops in the load connecting wires. The

Sense lines must be connected to their respective (+)
and (–) output terminals, either at the load or at the rack

adapter (see Rack Adapter Manual). The connection
ensures the most accurate error tracking. Maximum volt­age drop compensation in the load connecting wires for
each model is calculated as the difference between the
minimum overvoltage (see Table 1 or 2) and the maximum
adjustment range (see Table 1 or 2), divided by two to give
the voltage drop compensation per lead. Higher compen­sation values are possible if output voltage is decreased
below the maximum adjustment range shown in Table 1 or

2.

NOTE:

The Sense lines must be connected for

the power supply to work properly!

OUTPUT (+), OUTPUT (–): These lines are the power supply

d-c output lines which are connected to the load.

to parallel many units and still keep all units within 250 mV
of each other. Adjust the outputs using Vadj trimmer on
front panel.

• Optimum difference among output voltages of par­alleled units: 40mV

• Maximum difference among output voltages of
paralleled units: 250 mV

• Minimum difference among output voltages of par­alleled units: 25 mV

ALARM: The Alarm NC (normally closed) - Open on Fail-

ure and Alarm NO (normally open) - Close on Failure lines
are relay contacts referenced to Alarm Common. If the unit
fails, the path between Alarm NC - Open on Failure and
Alarm Common opens, the path between Alarm NO - Close
on Fail and Alarm Common is a short circuit. Figure 3 illus­trates typical Close on Fail and Open on Fail circuits to give
a failure indication if any one of a number of power supplies
fail. See RA 19-(X)B Manual for limitations applicable to C,
X and Y suffix models described in “Alarm Circuit.” on
page 2.

INPUT POWER: Line (either a-c or d-c source power), Neu-

tral and Ground (chassis)

CURRENT SHARE BUS (CSB): (Not available on 3.3V

model.) Connecting the CSB lines of power supplies oper­ating in a parallel configuration causes output current to be
shared equally. (See Rack Adapter Manual for additional
information on parallel configurations.). For current sharing
to work properly the outputs of all paralleled units must be
within 250 mV (max) of each other and each unit must be
operating at between 10% to 100% of rated output current.
If current to the load goes below 10% for each unit in cur­rent share mode, all MASTER ON lights may go on (see
load effect specifications); this indicates that forced current
share is no longer working, units are simply in automatic
current share mode. (If forced current sharing at less than
10% nominal current per supply is needed, contact Kepco
application engineering.) Remote sensing is recom­mended. For master/slave operation to work properly each
unit should be adjusted to 40 mV (optimum) less than the
next paralleled unit. Unit 1 is adjusted to V

– 40mV, and unit 3 to V

V

OUT

– 80mV, etc. If the master

OUT

, unit 2 to

OUT

fails, the unit 2 will become the new master. The 40 mV dif­ference can be reduced to a minimum of 25 mV as needed

FIGURE 3. TYPICAL ALARM CIRCUIT DIAGRAMS

KEPCO, INC.  131-38 SANFORD AVENUE  FLUSHING, NY. 11355 U.S.A.  TEL [phone]  FAX [phone]

083013 228-1533 REV 15 3

http://www.kepcopower.com  email: [e-mail]