KEPCO RKW 600W User Manual

OPERATOR’S MANUAL

RKW 600W SERIES

POWER SUPPLY

SINGLE OUTPUT, UNIVERSAL INPUT

KEPCO INC.

An ISO 9001 Company.

IMPORTANT NOTES:

1) 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.

2) Data subject to change without notice.

SINGLE PHASE, 0.99 POWER FACTOR

MODEL

RKW 600W SERIES

POWER SUPPLY MODELS

RKW 3.3-150K, RKW 5-120K, RKW 12-53K,
RKW 15-43K, RKW 24-27K, RKW 28-23K,
RKW 48-13K

KEPCO®

©2010, KEPCO, INC
P/N 228-1499-R5

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

email: [e-mail] ! World Wide Web: http://www.kepcopower.com

THE POWER SUPPLIER™

TABLE OF CONTENTS

SECTION PAGE

1. Introduction ........................................................................................................................................................ 1

1.1 Scope of Manual ..................................................................................................................................... 1

1.2 Description .............................................................................................................................................. 1

2. Specifications..................................................................................................................................................... 1

3. Operation ........................................................................................................................................................... 5

3.1 Voltage Adjustment ................................................................................................................................. 7

3.2 Remote Voltage Control.......................................................................................................................... 7

3.3 Remote Turn On-Turn Off ....................................................................................................................... 7

4. Alarm Functions ................................................................................................................................................. 8

4.1 Overvoltage And Overtemperature Protection ........................................................................................ 8

4.2 Overcurrent Protection ............................................................................................................................ 8

4.3 Fan Failure .............................................................................................................................................. 8

4.4 Optical Coupler Output Alarm Circuit ...................................................................................................... 8

5. Load Connection................................................................................................................................................ 9

5.1 Connecting The Load Using Local Sensing ............................................................................................ 9

5.2 Connecting The Load Using Remote Sensing ........................................................................................ 9

5.3 Parallel Connection ............................................................................................................................... 10

5.3.1 Current Balancing............................................................................................................................ 10

5.3.2 Master-Slave Configurations ........................................................................................................... 10

5.3.2.1 Master-Slave, Multiple Loads .................................................................................................... 11

5.3.2.2 Master-Slave, Single Load......................................................................................................... 11

5.4 Series Connection ................................................................................................................................. 11

5.5 Preliminary Electrical Check.................................................................................................................. 12

6. Fan Maintenance ............................................................................................................................................. 12

LIST OF FIGURES

FIGURE TITLE PAGE

1 Mechanical Outline Drawing Of The RKW 600W Power Supply ................................................................ 4

2 Power Rating Vs. Temperature................................................................................................................... 5

3 Mounting Positions For The RKW 600W Power Supply ............................................................................. 5

4 Locations Of Operating Controls, Indicators and Terminals ....................................................................... 6

5 Connections For Remote Voltage Control .................................................................................................. 7

6 Output Alarm Circuit, Optically Isolated ...................................................................................................... 8

7 RKW 600W Power Failure Timing Diagram................................................................................................ 9

8 Correct and Incorrect Methods of Load Connection ................................................................................... 9

9 Parallel Connection with Current Balancing.............................................................................................. 10

10 Parallel Connection, Master-Slave, Multiple Loads .................................................................................. 11

11 Parallel Connection, Master-Slave, Single Load....................................................................................... 11

12 Series Connection..................................................................................................................................... 12

13 Functional Checkout ................................................................................................................................. 12

LIST OF TABLES

TABLE TITLE PAGE

1 Output Ratings and Specifications ..............................................................................................................1

2 Power Supply Ratings and Specifications ..................................................................................................2

3 Function of Controls, Indicators and Terminals ..........................................................................................6

i RKW 600W 060110

1. INTRODUCTION

1.1 SCOPE OF MANUAL

This Operator's Manual covers the installation and operation of the Kepco RKW 600W Series of
PFC (Power Factor Corrected), RoHS (Reduction of Hazardous Substances) compliant, 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
RKW Power Supply. This information can be found on the nameplate of the unit.

1.2 DESCRIPTION

The Kepco RKW 600W Series consists of seven models of switching power supplies, each with a
single output as shown in Table 1. Units may be operated with a nominal 100V a-c to 240V a-c
(input voltage range 85 to 265 Va-c), 50-60 Hz (input frequency range 47-66Hz). They will also
operate on 110V to 370V d-c input. The RKW 600W Series employs a light weight ferrite core with
140 KHz switching frequency. Regulation is provided by pulse width modulation. A FET power
stage, operating in the flyback mode provides a smooth isolated d-c output. A thyristor circuit pre­vents excessive turn-on current surge. Overvoltage, overcurrent, overtemperature, fan failure and
power failure protections and an isolated remote TTL ON-OFF control are provided. An LED “out­put voltage ON” light and an output voltage adjust trimmer are visible on the terminal side of the
case. Units are manufactured on a steel frame with a steel cover.

2. SPECIFICATIONS

Table 1 contains specifications and operating limits of individual RKW 600W Series models. Table
2 contains specifications and operating limits common to all RKW 600W Series Models. These
specifications are at nominal input voltages at 25°C unless otherwise specified.

TABLE 1. OUTPUT RATINGS AND SPECIFICATIONS

MODEL RKW 600W 3.3-150K 5-120K 12-53K 15-43K 24-27K 28-23K 48-13K

Output Volts d-c
Adjustment Range

Voltage Setting 3.3 ±0.03 5 ±0.05 12 ±0.12 15 ±0.15 24 ±0.24 28 ±0.28 48 ±0.48

Maximum

Output

Ratings

(A,W)

Overcurrent Protection

(Amps)

Current Short Circuit 180 160 65 55 35 29 19
OVP Threshold (Volts)

Efficiency

% typical

Ripple &

Noise

(mV, p-p)

(1) Square type. If overcurrent condition continues for approximately 30 seconds, the output is shut OFF. Recovery is by

removing and reapplying AC input power, or by reset (open and close) at RC terminal.

(2) When overvoltage is detected, output is shut OFF. Recovery is by removing and, after about 40 seconds, reapplying AC

input power, or by reset (open and close) at ±RC terminals (no delay).

(3) Ripple and noise specifications are within 1.5 times the indicated values for a temperature range of -10 to 0°C. Ripple and

noise levels above are satisfied when conditions are 0 to 100% load, 0 to 65°C (derated from 50 to 65°C per Figure 2),
and bandwidth ≤ 100MHz.

)

Amps 150 120 53 43 27 23 13

50°C

amb

Watts 495 600 636 645 648 644 624

60°C,

65°C,

(1)

AC Input 100V 74 76 80 81 82 82 84
AC Input 240V 78 81 84 85 86 86 87

ripple 80 80 150 150 200 200 300

(3)

ripple noise

Amps 120 96 42.4 34.4 21.6 18.4 10.4

amb

Watts 396 480 508.8 516 518.4 515.2 499.2
Amps 90 72 31.8 25.8 16.2 13.8 7.8

amb

Watts 297 360 381.6 387 388.8 386.4 374.4

(2)

3.3V 5V 12V 15V 24V 28V 48V

1.8-3.6 3.5-6.0 7.2-14.4 10.5-18.0 16.8-28.8 19.6-33.6 33.6-52.8

156-186 126-156 55.6-68.9 45.1-55.9 28.3-35.1 24.1-29.8 13.7-16.9

4.0 - 4.6 6.2 - 7.0 14.8 - 16.8 18.6 - 21.0 29.8 - 33.6 34.7 - 39.2 55.0 - 59.9

120 120 200 200 300 300 400

RKW 600W 060110 1

TABLE 2. POWER SUPPLY RATINGS AND SPECIFICATIONS

SPECIFICATION DESCRIPTION

Input Voltage Nominal: 100-120V a-c or

200-240V a-c

Range 110-370V d-c Polarity insensitive (0 to 100% load, -10 to 65°C) Safety

Input Source Frequency Nominal 50/60 Hz, Range 47-440 Hz. (At 440 Hz the leakage current exceeds the VDE leak-

age safety specification limit).

Input Current: (Maximum Load At
25°C with Nominal Output Voltage)

Input Protection A thyristor circuit reduces start-up surge. Units are protected against shorts by an input fuse.

Fuse value 15.0A At 250 Volts

Input Surge cold start,

interval > 30 sec

Leakage Current: 0.45mA typ., 0.75mA max. at 120V a-c, 60Hz (per IEC 950 and UL1950)

Power Factor 100V a-c 0.99 typical

Stabilization Typical Maximum

Remote Error Sensing: Compensation up to 0.4 Volts per load wire (0.15 Volts for RCW 3.3-70K, 0.25 Volts for RCW

Transient Recovery
characteristic

Start-up Time 100 - 120V a-c 350 msec maximum, 280 msec typical.

Output Hold-up Time 100 - 120V a-c 30 msec typical, 20 msec minimum.

Overvoltage Protection When the Power Supply goes into an overvoltage condition, the output is cut OFF. To restart

Remote Control ON/OFF: "High", 2.4V to 24V (or open), unit OFF- Fan Off ; "Low", 0.0V to 0.4V (or closed), unit ON.

Operating Temperature: -10 to 65°C (see Figure 2)

Startup Temperature -10 to -20°C (see Figure 2 )

Storage Temperature: -30°C to +75°C

(1) First surge only, not including current flow into EMI filter.

(1)

0.60mA typ., 0.75mA max. at 240V a-c, 60Hz (per IEC 950 and UL1950)

Source Effect (min - max)
(85 to 132 V a-c, 170 to 265V a-c)

Load Effect, measured at DC output
terminals (0%-100% load change)

Temperature Effect (–10° to 71°C) 0.5% 1.0%

Combined Effect (envelope, Source,
Load and Temperature)

Drift (from 1/2 to 8 hours at 25°C) 0.2% 0.5%

5-70K) (see Figure 8).

excursion ±4% maximum 50% to 100% load,

recovery time 1 ms maximum

(reset) the unit, it is necessary either to remove the a-c input power, wait about 40 seconds,
and then to reconnect the a-c input power, or reset using remote ON-OFF feature (see PAR.

3.3).

Source current is 1.6mA maximum, sink current 1.0 mA maximum. The ±RC terminals are iso­lated from the a-c input terminal and the DC output terminals. When remote ON/OFF is not in
use, ±RC terminals must be shorted (use shorting link supplied) for unit to operate.

100 - 120V a-c 8.4A rms max. (7.2A rms max for the 3.3V model)

200 - 240V a-c 4.2A rms max. (3.6A rms max for the 3.3V model)

100 - 120V a-c 15A typ., 30A max. first surge

200 - 240V a-c 30A typ., 60 max. first surge

200V a-c 0.95 typical

200 - 240V a-c 150 msec maximum, 100 msec typical.

200 - 240V a-c 40 msec typical, 20 msec minimum.

Range: 85-265V a-c
(0 to 100% load, -10 to 65°C)

agency approval applies only to a-c input operation.

0.1%

(0.15% for 3.3V Model)

0.3%

(0.45% for 3.3V Model)

±0.9%

(±1.1% for 3.3V Model)

(±2.2% for 3.3V Model)

transient time >50

0.2%

(0.3% for 3.3V Model)

0.6%

(0.9% for 3.3V Model)

±1.8%

µsec

2 RKW 600W 060110

TABLE 2. POWER SUPPLY RATINGS AND SPECIFICATIONS (CONTINUED)

SPECIFICATION DESCRIPTION

Isolation: (at 15-35°C ambient, 10­85% relative humidity)

Insulation Resistance: (at 15-35°C
ambient, 10-85% relative humidity)

Humidity: 10% to 95% relative humidity, noncondensing, Wet Bulb temper-

Vibration: 5-10 Hz., 10mm amplitude, 10-200 Hz.,

Shock:
(non-operating, 1/2 sine pulse,
three shocks on each axis, Power
Supply is fixed on its bottom side)

Safety: All units designed to meet UL1950, CSA Electrical Bulletin 22.2 No.950-95 (certified by UL),

EMI Conducted: Designed to meet: FCC Class B, VCCI-Class B, EN55011-B, EN55022-B.

EMI radiated: Designed to meet: FCC Class B, VCCI-Class B, EN55011-B, EN55022-B.

Input current harmonics: Designed to meet: EN61000-3-2.

ESD immunity: Designed to meet: EN61000-4-2, level 4. normal operation

Fast transient burst immunity: Designed to meet: EN61000-4-4 level 3. normal operation

Surge immunity: Designed to meet: EN61000-4-5, level 4. no damage

Power frequency magnetic field
immunity:

Radiated field immunity: Designed to meet: EN61000-4-3 level 3. normal operation

Conducted noise immunity: Designed to meet: EN61000-4-6 level 3. normal operation

Voltage dips interruptions and
variations:

Dimensions: 3.62 in. (92 mm) x 4.72 in. (120 mm) x 7.87 in. (200 mm)

Mounting: No. M4 tapped holes

Maximum Screw Penetration: 0.24 in. (6 mm)

Cooling: Forced air flow - one fan

Frame Material/Cover Material: Steel

Weight: 5.95 lbs. (2.7 Kg) typical, 6.61 lbs. (3.0 Kg) maximum

Between input and case 2000Va-c for 1 minute. Cutout current is 20mA

Between output and case 500Va-c for 1 minute. Cutout current is 100mA

Between input and output terminal 2000Va-c for 1 minute. Cutout current is 20mA

Between output and case, input and case, and input and output, 100 Megohms minimum
(500Vdc)

operating and non-operating

ature<35°C

non-operating, 1 hr. on each

acceleration 64.3ft./s

964.6ft./s

2

(294m/s2 ) (30g), 11ms ± 5 msec pulse duration

2

(19.6m/s2) (2g)

of 3 axes, Power Supply is
fixed on its bottom side)

and TÜV Rheinland EN60950 (ambient temp. 50°C max.). Meets Creepage and Clearance
requirements of Dentori, Appendix 8. RKW 600W units are CE marked per the Low Voltage
Directive (LVD), 73/23/EEC and 93/68/EEC. [The standards do not apply with DC input opera­tion]

Designed to meet: EN61000-4-8, level 4. normal operation

EN61000-4-11 normal operation

RKW 600W 060110 3

NOTES:

1.MOUNTING SCREW PENETRATION: 0.24 inches [6 mm] maximum

2.TOLERANCES: ±0.04” [±1.0 mm] unless specified.

3.Dimensions are in inches brackets are in millimeters.

4 WEIGHT: 5.95 lb. (2.70 Kg.) typ, 6.6 lb. (3.0 Kg) max.

FIGURE 1. MECHANICAL OUTLINE DRAWING OF THE RKW 600W POWER SUPPLY

4 RKW 600W 060110

FIGURE 2. POWER RATING VS. TEMPERATURE

FIGURE 3. MOUNTING POSITIONS FOR THE RKW 600W POWER SUPPLY

3. OPERATION

Figure 4 shows the location of all operating controls and input/output terminals followed by an
explanation of each. The unit is shipped with shorting links installed connecting the following ter­minals: +RC to –RC and REF to RV. A local sensing cable is also installed, connecting +DC
Output with +S and –DC Output with –S for local sensing.

NOTES:

1. +S and –S MUST be properly connected for the unit to operate. For local
sensing, leave local sense cable in place (refer to PAR. 5.1). For remote
sensing (at the load), refer to PAR. 5.2.

2. If remote ON/OFF is not being used, ±RC terminals must be connected
(use shorting link supplied) for unit to operate.

RKW 600W 060110 5

NOTE Unit is shipped with shorting links
(not shown) connecting +RC to –RC (see
PAR. 3.3) and REF to RV (see PAR. 3.2)
installed and with local sensing cable
installed (connects +DC Output to +S and
–DC Output to –S) (see PAR. 5.2

FIGURE 4. LOCATIONS OF OPERATING CONTROLS, INDICATORS AND TERMINALS

TABLE 3. FUNCTION OF CONTROLS, INDICATORS AND TERMINALS

FIG. 4

INDEX

NO.

1 Frame Ground (earth) Connect to earth ground. This terminal is connected to the case.

2 A-C Input (L, N) Connect to AC: 100 to 120V AC or 200 to 240V AC input line.

3 DC Output (+, –) Connect to load (see Figure 8).

4 Sense (+S, –S) Used to compensate for voltage drop in the connecting lines from the output ter-

5 Output Voltage Reference (REF) Using REF terminal (together with the RV terminal) allows all the output voltages

6 Output Voltage Adjust (RV) This terminal (together with the REF terminal) is used for remotely controlling

7 Current Balance (CB) This terminal is used when several power supplies are connected in parallel (see

8 Power Failure (PF) These terminals output an open logic signal if output voltage drops to 80 % or

CONTROL, INDICATOR,

TERMINAL

FUNCTION

minal to a load; they are connected to ± DC Output terminals for local sensing
(see Figure 8).

of slave power supplies to be controlled by one voltage adjustment of a master
power supply (normally connected to the RV terminal with a metal shorting link).

output voltage (see PAR. 3.2).

PAR. 5.3).

lower of a set voltage, or if output voltage is shut down due to overvoltage or
overcurrent protection, fan speed failure, or overheating. (see Figure 6).

9 Remote ON-OFF (+RC, –RC) Output is turned ON-OFF by shorting-opening the RC terminals (output OFF

10 Output Voltage Trim Adjust (Vadj) Adjusts output voltage.

11 Output Voltage On indicator

(green)

when open). RC terminals are isolated from input and output terminals. Nor­mally, ±RC terminals are shorted with a metal shorting link (see PAR. 3.3).

Green LED lights when output voltage is present.

6 RKW 600W 060110

3.1 VOLTAGE ADJUSTMENT

Output voltage can be manually adjusted with the voltage adjustment control, Vadj (see Figure 4).
To adjust voltage, first place the unit under an operating load, then monitor the (+)S and (–)S
Sense terminals with a precision voltmeter and turn the voltage control to the desired operating
value. Refer to Table 1 for the recommended Adjustment Range of all the RKW 600W Models .

NOTE: Actual output voltage can exceed recommended range values.

3.2 REMOTE VOLTAGE CONTROL

The unit is shipped with a shorting link in place between RV and REF terminals. Removal of this
link allows the output voltage to be adjusted by either a trimmer pot (resistance) or by an external
variable voltage source using the RV terminal.

NOTE: Specifications are met when voltage is within adjustment range in Table 1. If remote

voltage control is not implemented, the shorting link between RV and REF must be in
place.

Use either local sensing (PAR. 5.1) or remote sensing (PAR. 5.2). If remote sensing is used, the
impedance of the load wires connecting each power supply to the load should be the same. It is
possible that the overvoltage protection may be triggered if the external programming voltage
source is changed very quickly (using either the Vadj pot or the RV terminal) when the power supply
is at a low load condition.

RESISTANCE. Use a shielded wire, 2m maximum in length, for connection to the trimmer control.
Connect the external trimmer as shown in Figure 5 (A). Suggested value for the trimmer control is
5K ohms). With the external trimmer control at its maximum clockwise position, set the output volt­age to the desired maximum value by adjusting Vadj clockwise. The value should not be more
than 120% of Eo nominal (not more than 110% for the 48-volt model, not more than 3.6V for the

3.3-volt model).

VOLTAGE. By adjusting an external 0-6V voltage source (0-5.5V for the 48-volt model) from mini­mum to maximum, the maximum output voltage can be adjusted from 0 to 120% (the 48-volt model
can be adjusted from 0 to 110%; the 3.3-volt model can be adjusted to 3.6V). Remove the shorting
link between the REF and RV terminals. Connect the voltage source across the RV and (–)S termi­nals as shown in Figure 5 (B).

FIGURE 5. CONNECTIONS FOR REMOTE VOLTAGE CONTROL

3.3 REMOTE TURN ON-TURN OFF

When input source power is ON, the output may be turned ON or OFF with the remote control fea­ture using the ±RC terminals (see Figure 4). These terminals accept a logic level (2.4V to 24V
"high" and 0.0 to 0.4V "low"), or a contact closure. When the ±RC terminals are open, using either

RKW 600W 060110 7

a mechanical switch or a high level logic signal, the RKW 600W output is cut OFF. When the RC
terminals are shorted, the output returns to within specifications. At low level logic, the maximum
source current is 1.6mA, at high logic level the maximum sink current is 1.0mA. The RC terminals
must remain shorted if remote ON-OFF is not used. The RC terminals are isolated from both the
AC input and DC output terminals. Remote ON-OFF offers the advantages of low inrush current
and no delay on restarts.

4. ALARM FUNCTIONS

4.1 OVERVOLTAGE AND OVERTEMPERATURE PROTECTION

When the output voltage or the internal temperature of the RKW 600W Power Supply increases
beyond the specified values (see Table 1), the output is cut OFF and the fan turns OFF. Overvolt­age setting tracks output voltage up to maximum specified in Table 1. To restart (reset) the unit,
remove AC input power, wait about 40 seconds, then reconnect AC input power. The power sup­ply can also be reset with no delay using the remote ON-OFF feature (see PAR. 3.3).

If the Power Supply shuts down due to an increase in internal temperature, the restart cycle
(Power ON) should not begin until the temperature returns to within specifications.

The alarm circuit is a diode transistor optical coupler. The transistor is normally conducting. When
the alarm activates, the transistor cuts off and the collector emitter circuit opens (see PAR. 4.4).

4.2 OVERCURRENT PROTECTION

The overcurrent setting has a square type characteristic, and the unit is set to shut down if output
current exceeds specifications (see Table 1) for more than 30 seconds. To restart (reset) the unit,
remove AC input power, wait about 40 seconds, then reconnect AC input power. The power supply
can also be reset with no delay using the remote ON-OFF feature (see PAR. 3.3).

4.3 FAN FAILURE

A decrease in fan speed causes the output to shut down and the fan to turn OFF. Fan failure is indi­cated by an open circuit across the (±) PF terminals) (see PAR 4.1). To restart (reset) the unit
remove the AC input power, wait about 40 seconds, then reconnect AC input power. The power
supply can also be reset with no delay using the remote ON-OFF feature (see PAR. 3.3).

4.4 OPTICAL COUPLER OUTPUT ALARM CIRCUIT

When the output voltage falls to less than about 80 percent of programmed output voltage the
alarm is activated: a high logic level appears at the ±PF terminals (see Figures 6 and 7). The
default state of the alarm is logic low. The sink current is 50mA maximum, the maximum collector
to emitter saturation voltage is 0.40 Volts, and the collector to emitter voltage is 40 volts maxi­mum. The PF terminals are isolated from the AC input and DC output terminals. Insulation resis­tance between the PF terminals and the AC input terminals is the same as the insulation
resistance between the input and output. Insulation resistance between the PF terminals and the
output terminals is the same as the insulation resistance between the output and ground.

FIGURE 6. OUTPUT ALARM CIRCUIT, OPTICALLY ISOLATED

8 RKW 600W 060110

FIGURE 7. RKW 600W POWER FAILURE TIMING DIAGRAM

5. LOAD CONNECTION

5.1 CONNECTING THE LOAD USING LOCAL SENSING

To connect the load for local sensing, the local sensing cable supplied must be installed to con­nect the +S terminal with DC Output (+), and –S terminal with DC Output (–). The load is con­nected across DC output (+) and (–) (see Figure 8).

5.2 CONNECTING THE LOAD USING REMOTE SENSING

For remote sensing the load is connected as shown in Figure 8. Remote error sensing at the load
terminals compensates for voltage drop in the connecting wires as indicated in Table 2. For
remote sensing, the local sensing cable must be removed from the ±S and ±DC Output terminals.
NOTE: If the overvoltage protection trips too easily, install one external electrolytic capacitor, rated
470µF min. between the +DC Output and +S terminals and one between the –DC Output and –S
terminals.

FIGURE 8. CORRECT AND INCORRECT METHODS OF LOAD CONNECTION

RKW 600W 060110 9

5.3 PARALLEL CONNECTION

Identical RKW 600W Power Supplies can be connected in parallel (with or without N+1 redun­dancy). Current balancing per PAR 5.3.1 can be implemented. Parallel units can be configured in
a master-slave configuration so that all units can be adjusted using on Vadj control, either for mul­tiple loads (PAR 5.3.2.1) where current draw is dependant upon the individual loads, or for a sin­gle load (PAR 5.3.2.1), where current balancing (forced current sharing) per PAR 5.3.1 equalizes
the load among the parallel-connected units.

For a single remote ON-OFF signal to turn off all parallel-connected units, connect together all
+RC terminals and connect together all –RC terminals.

Figure 9 illustrates connection of up to four (maximum) power supplies in parallel. Output current
for a parallel connection operating into a single load must be equalized per PAR 5.3.1 after con­necting the CB terminals as shown in Figure 9. Refer to PAR. 5.3.1 for conditions required for
proper current equalization (balancing).

N+1 Redundancy. An N+1 system requires one additional power supply than necessary to supply
the load. If one of the parallel-connected units fail, the others will seamlessly provide power to the
load without down time. For N+1 redundancy, add isolation diodes as shown in Figure 9.

FIGURE 9. PARALLEL CONNECTION WITH CURRENT BALANCING

5.3.1 CURRENT BALANCING

Current balancing (equalization) conditions required for up to four RKW 600W units in parallel are:

1. Output current of each power supply should be within 20 to 90% of the total output current
rating.

2. The output voltage of any Power Supply individually must be within 2% maximum of the
other power supplyies’ output voltage setting.

Maximum Voltage Minimum Voltage–

------------------------------------------------------------------------------------------------------ - 2%=
Rated Voltage

variation of output voltage in each power supply

3. The expected current sharing is such that the output current variation for each power supply
is less than or equal to 10% of each power supply rated output current.

5.3.2 MASTER-SLAVE CONFIGURATIONS

Master-slave operation allows the output voltage of all the power supplies connected in parallel to
be adjusted using the Vadj control on the designated master power supply.

10 RKW 600W 060110

5.3.2.1 MASTER-SLAVE, MULTIPLE LOADS

Figure 10 shows the master-slave connection of three power supplies in parallel, each having an
independent load, with output voltage controlled by the Vadj control of the master power supply.
Use shielded wire (recommended) or twisted wires for connections to RV and –S terminals.

FIGURE 10. PARALLEL CONNECTION, MASTER-SLAVE, MULTIPLE LOADS

5.3.2.2 MASTER-SLAVE, SINGLE LOAD

Figure 11 shows the connection of three power supplies in parallel to a single load. The output
voltage of all power supplies is controlled by Vadj of the master. Current balancing must be imple­mented to equalize the load (see PAR. 5.3.1). NOTE: Use shielded wire (recommended) or
twisted wires for connections to RV and –S terminals. Match impedance of load wires between
each power supply and load by using the same wire lengths and wire sizes.

FIGURE 11. PARALLEL CONNECTION, MASTER-SLAVE, SINGLE LOAD

5.4 SERIES CONNECTION

Units may be connected in series to obtain higher voltages. When a number of power supplies are
operating in series, the current rating is to be limited to the rating of the power supply with the low­est rating. Each Power Supply in series should be protected by a diode connected in its non-con­ducting direction in parallel with the output as shown in Figure 12. The diode protects against
inadvertent shorting of the series connection. It should be rated for the maximum voltage and cur­rent of the series connection (typically, V
2 x I

of the series connection). This may require several diodes in parallel to meet high current

OUT

REVERSE

= 2 x V

of the series connection, I

OUT

FORWARD

=

requirements.

RKW 600W 060110 11

FIGURE 12. SERIES CONNECTION

5.5 PRELIMINARY ELECTRICAL CHECK

Connect an adjustable load across the power supply output terminals, on the right side terminal
barrier strip on the front panel (see Figure 4). The load must have a dissipation rating of at least
700 Watts. Connect a voltmeter and an oscilloscope across the power supply sense terminals +S
and –S. The oscilloscope must be isolated from the source and grounded at the load. Use an iso­lation transformer between the test equipment and the AC input power (see Figure 13).

Connect the AC input power to the line, neutral and ground terminals (see Figure 4). Turn input
power on and check the output voltage both with and without load. The output voltage can be
adjusted within the published range by using the front panel voltage control trimmer Vadj.

FIGURE 13. FUNCTIONAL CHECKOUT

6. FAN MAINTENANCE

Under most conditions the fan requires no maintenance. Do not use the fan in an environment of
high temperature and high humidity that exceeds the temperature and humidity limits given in the
Power Supply Specifications (see Table 2). Avoid an environment where corrosive gas may be
present. If the Power Supply is used in an open or dirty area, a filter should be installed on the air
intake side of the fan to prevent the inflow of dust particles. If the Power Supply is used in briny air
care should be taken to keep the salt from entering the Power Supply.

12 RKW 600W 060110

You must register your product to comply with the terms of the warranty. Either fill out the form
below and mail or fax to Kepco, or for rapid on-line registration go to:

http://www.kepcopower.com/warranty.htm

PRODUCT PURCHASED:

Model Number)______________________________________

Serial Number_______________________________________

PURCHASE INFORMATION:

Date Purchased:_____________________________________

Date Received:______________________________________

REQUEST ADDITIONAL INFORMATION

" Send complete Catalog

" Have Sales Engineer Call

Contact via: " E-Mail " Telephone " Fax " S-mail

REGISTER TO:

Registered by:________________________________________

Company Name:______________________________________

Street: ______________________________________________

City:________________________________________________

State:_______________________________________________

Country:_____________________________________________

Zip:_________________________________________________

E-mail: ______________________________________________

FAX:____________________________________________

Phone: _________________________________________

WHAT INFLUENCED YOUR CHOICE OF THIS POWER SUPPLY?

" Previous Experience (which Kepco Models do you have?)

______________________________________________________

" Kepco Catalog or Brochure?__________________________

" Sales Representative?

______________________________________________________

______________________________________________________

" Magazines (which ones?)_____________________________

______________________________________________________

" Trade Shows (which ones?)___________________________

" Directory?__________________________________________

Kepco 5 Year Warranty

This is to certify that we, KEPCO, INC., (hereinafter called “Company”), Flushing, NY
11355 USA, warrants for a period of FIVE YEARS, this instrument known as:

MODEL: __________________________________________

SERIAL NO. _________________________________________

The Company’s products are warranted for a period of five years from date of delivery to
be free from defects in materials and workmanship and to conform to the specifications
furnished or approved by the Company. Liability under this warranty shall be limited to
the repair or replacement of any defective product at Company’s option.

If any defect within this warranty appears within the warranty period, the Purchaser shall
promptly notify the Company in writing. No material will be accepted for repair or
replacement without written authorization of the Company.

" Web Site

" Other (please explain):_____________________________

What products would you like to see Kepco make?

____________________________________________________

____________________________________________________

____________________________________________________

CUT HERE

Upon such authorization, and in accordance with instructions of the Company, parts or
materials for which replacement is requested shall be returned to the Company for
examination, with shipping charges prepaid by the Purchaser. Final determination as to
whether a product is actually defective rests with the Company.

This warranty does not extend to any product which has been subjected to misuse,
neglect, accident, improper installation, or use in violation of instructions furnished by
the Company. The warranty does not extend to, or apply to, any unit which has been
repaired or altered outside of the Company’s factory by persons not expressly approved
by the Company.

THE WARRANTY HEREIN CONTAINED IS IN LIEU OF AND EXCLUDES ALL OTHER
WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, INCLUDING WITHOUT
LIMITATION THE WARRANTY OF MERCHANTABILITY.

THIS KEPCO PRODUCT IS WARRANTED FOR FIVE YEARS!

KEPCO, INC. # 131-38 SANFORD AVENUE, FLUSHING,
NY 11355 USA

MST SERIES 6/1/10 1

E-mail: [e-mail]

#

Tel. [phone] # Fax. [phone]

#

URL: http://www.kepcopower.com

KEPCO, INC.

131-38 SANFORD AVE.
FLUSHING, NY 11355 USA

FOLD HERE

Please

place

stamp

here

CUT HERE