OPERATOR’S MANUAL
RTW 300W 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
RTW 300W SERIES
POWER SUPPLY MODELS
RTW 3.3-70KC, RTW 5-60KC, RTW 12-25KC,
RTW 15-20KC, RTW 24-13KC, RTW 28-11KC,
RTW 48-6.5KC
KEPCO®
©2012, KEPCO, INC
P/N 228-1544R4
KEPCO, INC. ! 131-38 SANFORD AVENUE ! FLUSHING, NY. 11355 U.S.A. ! TEL (718) 461-7000 ! FAX (718) 767-1102
email: hq@kepcopower.com ! 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. Installation ......................................................................................................................................................... 1
4. Operation........................................................................................................................................................... 5
4.1 Voltage Adjustment......................................................................................................................................... 7
4.2 Remote Voltage Control ................................................................................................................................. 7
4.3 Remote Turn On-Turn Off............................................................................................................................... 7
5. Alarm Functions................................................................................................................................................. 8
5.1 Overvoltage Protection ................................................................................................................................... 8
5.2 Current Limit ................................................................................................................................................... 8
5.3 Optical Coupler Output Alarm Circuit.............................................................................................................. 8
5.4 Undervoltage .................................................................................................................................................. 8
6. Load Connection ............................................................................................................................................... 8
6.1 Connecting the Load Using Local Sensing..................................................................................................... 8
6.2 Connecting the Load Using Remote Sensing................................................................................................. 8
6.3 Parallel Connection......................................................................................................................................... 9
6.3.1 Current Balancing...................................................................................................................................... 10
6.3.2 Master-Slave Configurations...................................................................................................................... 10
6.3.2.1 Master-Slave, Multiple Loads.................................................................................................................. 10
6.3.2.2 Master-Slave, Single Load...................................................................................................................... 11
6.4 Series Connection ........................................................................................................................................ 11
6.5 Preliminary Electrical Check......................................................................................................................... 12
6.6 Accessories .................................................................................................................................................. 12
LIST OF FIGURES
FIGURE TITLE PAGE
1 Mechanical Outline Drawing of the RTW 300W Power Supply (Cover Removed) .................................... 4
2 Power Rating vs. Temperature .................................................................................................................. 5
3 Mounting Positions for the RTW 300W 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 Correct and Incorrect Methods of Load Connection .................................................................................. 9
8 Parallel Connection with Current Balancing............................................................................................. 10
9 Parallel Connection, Master-Slave, Multiple Loads.................................................................................. 10
10 Parallel Connection, Master-Slave, Single Load ...................................................................................... 11
11 Series Connection.................................................................................................................................... 11
12 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
4 Mating Connectors .....................................................................................................................................7
i RTW 300W 101212
1. INTRODUCTION
1.1 SCOPE OF MANUAL
This Operator's Manual covers the installation and operation of the Kepco RTW 300W 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 RTW Power Supply. This information can be found on the nameplate of the unit.
1.2 DESCRIPTION
The Kepco RTW 300W 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; units also operate
up to 440Hz although leakage current, power factor and efficiency specifications may not be met).
They will also operate on 110V to 370V d-c input. The RTW 300W Series employs a forward converter operating at 140 KHz. Regulation is provided by pulse width modulation. A power stage
with a MOSFET on each side of the primary winding, operating in the forward mode provides a
smooth isolated d-c output. A thyristor circuit prevents excessive turn-on current surge. A boost
converter operating at about 90KHz provides Power Factor Correction (PFC). Overvoltage protection, an isolated remote TTL ON-OFF control, an LED “output voltage ON” light and an output voltage adjust trimmer are provided. RTW 300W are low-profile convection-cooled units,
manufactured on an aluminum frame. Models with suffix KC include a cover; for applications
where a cover is not needed, contact Kepco for further information.
2. SPECIFICATIONS
Table 1 contains specifications and operating limits of individual RTW 300W Series models. Table
2 contains specifications and operating limits common to all RTW 300W Series Models. These
specifications are at nominal input voltages at 25°C unless otherwise specified.
3. INSTALLATION
Refer to Figures 1 and 3.
TABLE 1. OUTPUT RATINGS AND SPECIFICATIONS
MODEL RTW 300W 3.3-70KC 5-60KC 12-25KC 15-20KC 24-13KC 28-11KC 48-6.5KC
Output Volts d-c
Adjustment Range (Volts) 1.8 - 3.6 3.5 - 5.6 7.2 - 14.4 10.5 - 18.0 16.8 - 26.4 19.6 - 33.6 33.6 - 55.0
Voltage Setting (Volts) 3.3 ±0.03 5 ±0.05 12 ±0.12 15 ±0.15 24 ±0.24 28 ±0.28 48 ±0.48
Maximum Output Rating (Watts) 231 300 300 300 312 308 312
Output Current (max.) (Amps)
Current Limit Setting (Amps)
Current Short Circuit (Amps) 87 78 36 29 25 17.5 11.5
OVP Setting (Volts)
Undervoltage
Protection
Efficiency
% typical
Ripple &
Noise
(mV, p-p)
Acceptable Output Capacitor (µF)
(1) Square type.
(2) When overvoltage is detected, output is shut OFF. Recovery is by removing and reapplying power after about 30 seconds or by
opening and reclosing the ±RC pins of connector CN 2 or CN3
(3) Ripple and noise specifications are 1.5 times indicated values for temperature range of -10 to 0°C. Ripple and noise levels
above are satisfied when conditions are 0 to 100% load, 0 to 50°C (for 50 to 71°C see Figure 2), and bandwidth ≤ 100MHz.
(4) When output falls below rated output by the percent listed, for the time listed, output is shut OFF. Recovery is by removing and
reapplying power or by opening and reclosing the ±RC pins of connector CN 2 or CN3.
(5) Minimum output current is 0 Amps.
(6) Start-up time will change if this capacitor is added.
(4)
(3)
(5)
(1)
(2)
% Output 60 60 20 20 20 20 20
Time (Sec) 3 3 15 15 15 15 15
AC Input 100V 83 84 83 85 85 85 86
AC Input 200V 86 87 86 88 88 88 89
Ripple 80 80 100 100 150 150 200
Ripple noise 120 120 150 150 200 200 300
3.3V 5V 12V 15V 24V 28V 48V
70 60 25 20 13 11 6.5
73.5 - 84 63 - 72 26.3 - 30 21 - 24 13.7 - 15.6 11.5 - 13.2 6.8 - 7.8
4.0 - 4.6 6.2 - 7.0 14.8 - 16.8 18.6 - 21.0 29.8 - 33.6 34.7 - 39.2 55.5 - 59.9
(6)
10,000 10,000 10,000 10,000 10,000 10,000 10,000
RTW 300W 101212 1
TABLE 2. POWER SUPPLY RATINGS AND SPECIFICATIONS
SPECIFICATION DESCRIPTION
Input Voltage Nominal:
Range:
Input Source Frequency Nominal:
Range:
Input Current: (Maximum Load At
25°C with Nominal Output Voltage)
Input Protection A limiting resistor in series with a resistor fuse (in parallel with a thyristor circuit) reduces start-
Input Surge cold start,
interval > 30 Sec
Leakage Current: 0.3mA typ., 0.5mA max. 100V a-c, 60Hz (per Den-An)
Power Factor 0.99 typical 100V a-c
Stabilization Typical Maximum
Remote Error Sensing: Compensation up to 0.4 Volts per load wire (0.15 Volts for 3.3V model, 0.25 Volts for 5V
Transient Recovery
characteristic
Start-up Time 220 mSec typical,
(1)
100 to 120V a-c, 200 to 240V a-c
85-265V a-c
110-370V d-c Polarity insensitive. (0 to 100% load, -10 to 71°C, derated
50-to 60 Hz
47-440 Hz.
4A rms max.
(3.6A rms max for the 3.3V model,
6A rms typ. for 24V model)
2A rms max.
(1.8A rms max for the 3.3V model,
3A rms typ. for 24V model)
up surge. Units are protected against shorts by an input fuse. Fuse value 10.0A at 250 Volts
(Littelfuse P/N 0215010.MXF4P, Kepco P/N 541-0144).
15A typ., 20A max. first surge 100 - 120V ac
30A typ., 40 max. first surge 200- 240 V ac
0.4mA typ., 0.7mA max. 240V a-c, 60Hz (per IEC 950 and UL1950)
0.93 typical 240V a-c
Source Effect (min - max) (85 to
132 V a-c, 170 to 265V a-c)
Load Effect, measured at sensing
terminals (0%-100% load change)
Temperature Effect (–10° to 71°C) 0.5% 1.0%
Combined Effect (Source, Load
and Temperature)
Drift (from 1/2 to 8 hours at 25°C) 0.2% 0.5%
model) (see Figure 7). Transient recovery specs may not be satisfied if remote sensing used.
excursion ±4% maximum 50% to 100% rated output
recovery time
350 mSec maximum
120 mSec typical,
200 mSec maximum.
0 to 100% load, -10 to 71°C. Output power derated to 90%
of max. for input voltage between 85 and 90V a-c when
mounting positions B or C are used (see Figure 3).
CAUTION: Operation with input voltage outside specified
range may damage unit.
per Figure 2.) Safety ratings apply for a-c input operation
only.
Units operate up to 440 Hz, however the leakage current
exceeds the UL leakage safety specification limit, and
power factor and efficiency specifications may not be met.
100 - 120V a-c
200 - 240V a-c
0.1% 0.2%
0.2% 0.4%
±0.9% ±1.8%
1 mS maximum
100V a-c
240V a-c
current;
transient time >50
µSec
(1) First surge only, not including current flow into EMI filter
2 RTW 300W 101212
TABLE 2. POWER SUPPLY RATINGS AND SPECIFICATIONS (CONTINUED)
SPECIFICATION DESCRIPTION
Output Hold-up Time 30 mSec typ. (25 mSec typ. for 5V
and 15V models), 20 mSec min.
40 mSec typ. (30 mSec typ. for 5V
and 15V models), 25 mSec min.
Overvoltage Protection When the Power Supply goes into an overvoltage condition, the output is cut OFF. To restart
(reset) the unit, it is necessary to remove, then reconnect the a-c input power after about 30
seconds, or to open and then reclose the RC terminals.
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.
When remote ON/OFF is not in use, ±RC pins of connector CN2 or CN3 should be shorted
(use connector supplied) for unit to operate.
Operating Temperature: -10 to 71°C (see figures 2 and 3)
Startup Temperature -20 to -10°C (see Figure 2)
Storage Temperature: -30°C to +75°C
Humidity: 10% to 95% relative humidity, noncondensing, Wet Bulb tem-
perature </=35°C
Vibration: 5-10 Hz., 10mm amplitude,
10-200 Hz., acceleration 64.3ft./s
Shock: Acceleration: 1929.1ft./s
2
(588m/s2 ) (60g),
Pulse Duration: 11ms ± 5 mSec
Withstanding voltage : (at 15-35°C
ambient, 10-85% relative humidity)
2000Va-c for 1 minute. Cutout current is 10mA Between input and ground
500Va-c for 1 minute. Cutout current is 40mA Between output and ground
3000Va-c for 1 minute. Cutout current is 10mA Between input and output
Insulation Resistance: (at 15-35°C
ambient, 10-85% relative humidity)
Between output and ground, input and ground, and input and output, 100 Megohms minimum
(500Vdc)
Safety: UL60950-1 First Ed., CSA Electrical Bulletin 22.2 No.60950-1, and TÜV Rheinland
EN60950-1:2001, Assistance for Den-AN
CE marked per the Low Voltage Directive (LVD), 73/23/EEC and 93/68/EEC. The standards do
not apply with DC input operation
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
ESD immunity: Designed to meet EN61000-4-2, level 4 normal operation
Electrical fast transient burst: EN61000-4-4 level 3 normal operation
Surge withstand: EN61000-4-5, level 4 no damage
Power Frequency Magnetic Field: EN61000-4-8, level 4 normal operation
Radiated susceptibility: EN61000-4-3 level 3 normal operation
Conducted susceptibility: EN61000-4-6 level 3 normal operation
Voltage dips interruptions and
EN61000-4-11 normal operation
variations
Input harmonics current: Designed to meet EN61000-3-2
Dimensions: 4.72 in. (120 mm) H x 1.57 in. (40 mm) W x 9.84 in. (250 mm) L
Mounting: Four No. M4 tapped holes on the sides and the bottom
Maximum Screw Penetration: 0.24 in. (6 mm)
Cooling: Convection
Frame Material Aluminum
Weight 2.87 lbs. (1.3Kg) maximum
(2) Meets the creepage and clearance requirement of Den-An Appendix 8 (100V a-c only).
100V a-c
240V a-c
2
( 19.6m/s2) (2g)
(2)
(ambient temp.50°C max.). RTW 300W units are
operating and non-operating
non-operating, 1 hr. on each
of 3 axes, sweep time 10 minutes
(non-operating, 1/2 sine
pulse, three shocks on each
axis)
RTW 300W 101212 3
4 RTW 300W 101212
FIGURE 1. MECHANICAL OUTLINE DRAWING OF THE RTW 300W POWER SUPPLY (COVER REMOVED)
FIGURE 2. POWER RATING VS. TEMPERATURE
FIGURE 3. MOUNTING POSITIONS FOR THE RTW 300W POWER SUPPLY
4. 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 a shorting connector installed connecting: +RC to
–RC and local sensing cables connecting +DC Output with +S and –DC Output with –S for local
sensing.
NOTES:
a. +S and –S MUST be properly connected for the unit to operate. For local sens-
ing, leave local sensing cables in place (refer to PAR. 6.1). For remote sensing
(at the load), refer to PAR. 6.2.
b. If remote ON/OFF is not being used, ±RC pins of either connector CN2 or CN3
must be connected (use shorting connector supplied) for unit to operate.
RTW 300W 101212 5
1
2
3
4
5
6
7
8
3043020
+
+
–
–
CN1
PIN FUNCTION
1–PF
2+PF
CN2, 3
+S
–S
L
N
91011 12
NOTE Unit is shipped with a shorting connector on CN 2
which connects +RC to –RC (see PAR. 4.3) and with
5
15 121234234
CN3 CN2 CN1
FIGURE 4. LOCATIONS OF OPERATING CONTROLS, INDICATORS AND TERMINALS
local sensing cables installed (connects +DC Output to
+S and –DC Output to –S) (see PAR. 6.2).
PIN FUNCTION
1–RC
2+RC
3CB
4RV
5-S
TABLE 3. FUNCTION OF CONTROLS, INDICATORS AND TERMINALS
FIG. 4
INDEX
NO.
1, 2 DC Output (+, –) Connect to load (see Figure 7).
3 Output Voltage Trim Adjust (Vadj) Adjusts output voltage.
4, 5 Sense (+S, –S) Used to compensate for voltage drop in the connecting lines from the output terminal
6 Ground (earth) Connect to earth ground. This terminal is connected to the chassis.
7 A-C Input (L) Connect to AC: 100 to 240V input line.
8 A-C Input (N) Connect to AC: 100 to 240V input line.
9 Output Voltage On indicator
10, 11 Connector CN3, CN2
CONTROL, INDICATOR,
TERMINAL
(green)
(See Table 4 for mating connector
part numbers.)
FUNCTION
to a load; they are connected to ± DC Output terminals for local sensing (see Figure
7).
Green LED lights when output voltage is present.
–RC (pin 1) and +RC (pin 2) provide Remote ON-OFF. Output is turned ON-OFF by
shorting-opening the RC pins (output OFF when open). Normally, ±RC pins are
shorted with a shorting connector (see PAR. 4.3).
CB (Current Balance, pin 3) is used when several power supplies are connected in
parallel (see PAR. 6.3).
RV (Remote Voltage, pin 4) is used for remotely controlling output voltage (see PAR.
4.2).
–S (pin 5) –Signal common functions as the common return for connection of multiple
units. (see PAR’s 6.3 and 6.4.)
12 Connector CN1 –PF (pin 2) and +PF (pin 1) output an open logic signal if output voltage drops to 80%
or lower of a set voltage, or if output voltage is shut down due to overvoltage or overcurrent protection. (see Figure 6).
Local Sensing Cable Kit Connects ± DC Output to ±S for local sensing (see Figure 7).
Shorting Connector Connects –RC (pin 1) and +RC (pin 2) of connector CN2 or CN3 when not using
remote ON-OFF.
6 RTW 300W 101212
TABLE 4. MATING CONNECTORS
Connector
Number
CN1 B2B-XH-2 XHP-2
CN2, CN3 B5B-XH-2 XHP-5
(1) JST= Japan Solderless Terminal Mfg. Co.
Connector
Part Number
Socket Housing
Part Number
Contact
Part Number
SXH-001T-P0.6
SXH-001T-P0.6
MFR
JST
JST
(1)
(1)
4.1 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 (turn clockwise to increase voltage). Refer to Table 1 for the recommended Adjustment
Range of all the RTW 300W Models
4.2 REMOTE VOLTAGE CONTROL
Output voltage can be adjusted by an external voltage source using the Output Voltage External
Adjustment function (RV) of connector CN2 or CN3. An RV voltage of approx. 5V can produce the
rated output voltage. First monitor the ±S terminals and use the Vadj control to establish the minimum output voltage desired (output voltage decreases when trimmer Vadj is turned counterclockwise). Then connect the external voltage source across the RV and –S pins of CN2 or CN3 as
shown in Figure 5, using either twisted or shielded wires not more than 2 meters in length.
Optional Cable Kit 219-0493 (PAR. 6.6) may facilitate connections. Specifications are met when
voltage is within adjustment range shown in Table 1.
FIGURE 5. CONNECTIONS FOR REMOTE VOLTAGE CONTROL
4.3 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 pins of connector CN2 or CN3 (see Figure 4). These pins accept a logic level
(2.4V to 24V “high” and 0.0 to 0.4V “low”), or a contact closure. When the ±RC pins are open,
using either a mechanical switch or a high level logic signal, the RTW 300W output is cut OFF.
When the RC pins are shorted or at a low logic level, the output returns to within specifications. At
low level logic, the maximum source current is 1.6mA and at high level the maximum sink current
is 1.0mA. The RC pins must remain shorted if remote ON-OFF is not used; use the shorting connector provided with the unit. Optional Cable Kit 219-0493 (PAR. 6.6) may facilitate connections.
RTW 300W 101212 7
5. ALARM FUNCTIONS
5.1 OVERVOLTAGE PROTECTION
When the output voltage of the RTW 300W Power Supply increases beyond the specified values
(see Table 1), the output is cut OFF. To restart (reset) the unit, remove, then reconnect AC input
power after about 30 seconds; or open and then reclose the RC pins (see PAR. 4.3).
5.2 CURRENT LIMIT
The unit does not shut down if output current exceeds specifications (see Table 1). Instead, the
unit continues to operate, supplying the maximum current, while output voltage is reduced accordingly as long as the output voltage does not drop lower than the undervoltage protection value
(see Table 1).
5.3 OPTICAL COUPLER OUTPUT ALARM CIRCUIT
When the output voltage falls to less than about 80 percent of rated output voltage the alarm is
activated: a high logic level appears at the ±PF pins of connector CN1 (see Figure 6). 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 pins are isolated from the AC input and DC output terminals.
FIGURE 6. OUTPUT ALARM CIRCUIT, OPTICALLY ISOLATED
5.4 UNDERVOLTAGE
If the output voltage of the power supply falls below a preset percentage of the rated output voltage, the power failure alarm will go to the high logic state and the output is cut OFF. Table 1 lists
the percentage and the time duration each model will tolerate the undervoltage condition before
the output is shut off.
6. LOAD CONNECTION
6.1 CONNECTING THE LOAD USING LOCAL SENSING
To connect the load for local sensing, connect the +S to (+) terminal and –S to (–) terminal. The
load is connected across DC output (+) and (–) terminals (see Figure 7).
CAUTION: For 3.3V and 5V models use both (+) and both (–) output terminals to reduce cur-
rent carried through any one terminal. If current on a single terminal exceeds 40
Amperes, the terminal will overheat and damage the electrolytic capacitor.
6.2 CONNECTING THE LOAD USING REMOTE SENSING
For remote sensing the load is connected as shown in Figure 7. Remote error sensing at the
load terminals compensates for a voltage drop in the connecting wires as indicated in
Table 2. For remote sensing, the twisted-wire sensing cables shown in Figure 7 must
be removed from the +S to (+) and –S to (–) terminals.
8 RTW 300W 101212
NOTE: To prevent oscillations, install one external electrolytic (do NOT use tantalum) capaci-
tor, rated 470µF min. between the (+) and +S terminals and one between the (–) and –
S terminals (see Figure 7).
FIGURE 7. CORRECT AND INCORRECT METHODS OF LOAD CONNECTION
6.3 PARALLEL CONNECTION
RTW 300W Power Supplies can be connected in parallel (with or without N+1 redundancy). Use
twisted or shielded wire for connection to RV and –S terminals. The impedance of the load wires
between each power supply and load should be the same as close as possible.
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 8 illustrates connection of up to four
(maximum) power supplies in parallel. Output current for a parallel connection operating into a
single load is equalized by connecting the CB and –S terminals as shown. Refer to PAR. 6.3.1 for
conditions required for proper current equalization (balancing). Optional Cable Kit 219-0497 (PAR.
6.6) may facilitate connections.
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 continue to provide power to the
load without down time. For redundancy, add isolation diodes as shown in Figure 8.
RTW 300W 101212 9
6.3.1 CURRENT BALANCING
Current balancing (equalization) conditions required for up to four RTW 300W 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 supply 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.
FIGURE 8. PARALLEL CONNECTION WITH CURRENT BALANCING
6.3.2 MASTER-SLAVE CONFIGURATIONS
Master-slave operation allows the output voltage of all the power supplies connected in parallel to
be adjusted at the same time by using the Vadj control on the designated master power supply.
6.3.2.1 MASTER-SLAVE, MULTIPLE LOADS
Figure 9 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. If
optional Cable Kit 219-0493 (PAR. 6.6) is used, the wire at pin3 (CB) must be cut. NOTE: Vadj
control of all slave units must be set to maximum counterclockwise for this configuration to operate properly.
3. SET VADJ OF SLAVE UNITS TO MAXIMUM
COUNTERCLOCKWISE.
FIGURE 9. PARALLEL CONNECTION, MASTER-SLAVE, MULTIPLE LOADS
10 RTW 300W 101212
6.3.2.2 MASTER-SLAVE, SINGLE LOAD
Figure 10 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 is implemented
to equalize the load current (see PAR. 6.3.1). Vadj control of all slave units must be set to maximum counterclockwise for this configuration to operate properly. 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.
Optional Cable Kit 219-0497 (PAR. 6.6) may facilitate connections.
FIGURE 10. PARALLEL CONNECTION, MASTER-SLAVE, SINGLE LOAD
6.4 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 parallel with
the output as shown in Figure 11. The diode protects against reverse voltages. It should be rated
for typically, V
REVERSE
≥ 2 x ΣV
of the series connection, I
OUT
FORWARD
≥? 2 xI
OUT
connection. Optional Cable Kit 219-0497 (PAR. 6.6) may facilitate CN2/CN3 connections, however the wire at pin 3 (CB) must be cut.
of the series
FIGURE 11. SERIES CONNECTION
RTW 300W 101212 11
6.5 PRELIMINARY ELECTRICAL CHECK
Connect an adjustable load across the power supply output terminals, on the top side of the front
panel (see Figure 4). The load must have a dissipation rating of at least 300 Watts. Connect a
voltmeter and an oscilloscope across the power supply output terminals (should be linked to the
respective sensing 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 12).
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 12. FUNCTIONAL CHECKOUT
6.6 ACCESSORIES
Two optional cable kits are available for Series RTW 300W.
Kit 219-0493, used to facilitate remote operation of a single unit, consists of two cables. The
cables are one meter long, each having the power supply mating connectors wired to one end and
unterminated wires at the other end. One cable is for Power Fail connector CN1, and one is for
connector CN2 or CN3.
Kit 219-0497, used to facilitate connecting two units in parallel, consists of two cables. The Power
Fail cable for CN1 is one meter long, and has the power supply mating connector wired to one
end and unterminated wires at the other end. The parallel cable for connector CN2/CN3 is approximately 30 cm (12 inches) long, with power supply mating connectors at both ends. For each additional unit to be connected in parallel, an additional Kit 219-0497 is needed to make the CN2 to
CN3 connection. Parallel units may be controlled remotely by connecting cable 518-0110 from Kit
219-0493 to CN2 on the master; all shorting connectors supplied with the units must be removed.
12 RTW 300W 101212
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 10/12/12 1
E-mail: hq@kepcopower.com
#
Tel. 718-461-7000 # Fax. 718-767-1102
#
URL: http://www.kepcopower.com
KEPCO, INC.
131-38 SANFORD AVE.
FLUSHING, NY 11355 USA
FOLD HERE
Please
place
stamp
here
CUT HERE
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