KEPCO KLR User Manual

QUICK START GUIDE

KEPCO

An ISO 9001 Company.

KLR

KLR POWER SUPPLY

This guide gives a brief introduction to the KLR Power supply, shows simple load connections, and
allows you to verify the power supply is working. The guide also shows you how to use the front panel
controls to perform the most commonly used functions.

Refer to the KLR User Manual for full specifications, installation considerations and operating instruc­tions. An Installation/Operation Summary includes hyperlinked references to detailed procedure, but
which can be printed as a handy reference.

Refer to the KLR Developer’s Guide for a full description of the digital interfaces, their associated driv­ers, and the SCPI command language.

The User Manual and Developer’s Guide can be downloaded from the Kepco web site at
www.kepcopower.com/support/. Drivers can downloaded from www.kepcopower.com/drivers/.

CONTENTS

DESCRIPTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

OPTIONS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

UNPACKING. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

EQUIPMENT SUPPLIED. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2

ACCESSORIES. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

SAFETY. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

PRELIMINARY OPERATIONAL CHECK. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

INSTALLATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Input Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Load Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Local Sensing (Factory Default). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Remote Sensing Select. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Analog I/O Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

GPIB Connections. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

RS 232 Connections (Standard Models). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

LAN Connections (E-Series Models). . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

OPERATION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Turning The Power Supply On. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Enabling/disabling Output Power. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Checking Or Changing Voltage/current Setpoints. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Limit Model Setting. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Setting Voltage Or Current. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Last Setting Recall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Viewing/changing Overvoltage or Overcurrent Protection Values. . . . . . . . . . . . . . . . . . . . . . . . 10

KLR OUTLINE DIMENSIONS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

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

©2013, KEPCO, INC
Data subject to change without notice

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228-1689 REV 1 091713

DESCRIPTION. Five KLR Models and five KLR E-Series Models are available, as listed in Table 1.

The standard Models are GPIB and RS 232 compatible; the KLR E-Series Models (identified by the E
suffix) are GPIB and LAN (ethernet, LAN) compatible. The only difference between standard and E­Series models is that LAN replaces the RS 232 interface on E-Series models. All models allow remote
analog programming as well as local control. For each model a multitude of limit models can be config­ured. Limit models allow the unit to be configured to maximum settings below the rated voltage and/or
rated current. When a limit model is established the unit will not accept programming values above the
user-defined limits.

OPTIONS. The Rapid Output Discharge Circuit (RODC) option (suffix R) is available on all KLR mod-

els. This circuit rapidly discharges the output capacitance, thus significantly reducing response time to
reductions in output voltage (see KLR User Manual for details).

TABLE 1. MODEL PARAMETERS

Model number

KLR 20-120

KLR 40-60

KLR 75-32

KLR 150-16

KLR 300-8

(1) Bandwidth: 20MHz; low frequency ripple may be higher at loads less than 30 Watts.
(2) Specifications apply to both standard and E Series (Suffix E) models.

(2)

(2)

(2)

(2)

(2)

Rated

Vol tag e

Range

0-20V 1.5A 0-120A 100 mV 87%

0-40V 0.8A 0-60A 80 mV 88%

0-75V 0.4A 0-33.3A 80 mV 87%

0-150V 0.2A 0-16A 100 mV 88%

0-300V 0.1A 0-8A 150 mV 89%

Minimum

Programmable

current

Rated

Current

Range

Ripple and

noise

(1)

p-p

Efficiency

@230 Va-c

UNPACKING. This instrument has been thoroughly inspected and tested prior to packing and is

ready for operation. After careful unpacking, inspect for shipping damage before attempting to operate.
Perform the PRELIMINARY OPERATIONAL CHECK. If any indication of damage is found, file an imme­diate claim with the responsible transport service.

EQUIPMENT SUPPLIED. See Table 2.

TABLE 2. EQUIPMENT SUPPLIED

ITEM

Jumper (24 AWG or larger bus wire) for local sensing connections 172-0638 2

Analog I/O port mating connector 142-0528 1

Nut with captive lockwasher (on output studs of 20V and 40V models only) 102-0175 2

Quick Start Guide* 228-1689 1

* User Manual and Developer’s Guide are available as free downloads from:
www.kepcopower.com/support/opmanls.htm#klr
Drivers are available as free downloads from
www.kepcopower.com/drivers/drivers-dl3.htm#klr

PART NUMBER QUANTITY

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ACCESSORIES. See Table 3.

TABLE 3. ACCESSORIES

ITEM FUNCTION

Line Cord Set (250V/20A) 2.5m long cord set, provides for source power

Line Cord Set (250V/15A) 2.5m long cord set, provides for source power

Source power connector

IEEE 488 (GPIB) Cable, 1m long Connect KLR Power Supply to GPIB bus. SNC 488-1

IEEE 488 (GPIB) Cable, 2m long Connect KLR Power Supply to GPIB bus. SNC 488-2

IEEE 488 (GPIB) Cable, 4m long Connect KLR Power Supply to GPIB bus. SNC 488-4

Chassis Slide (2 required per
power supply)

Analog Connector Backshell Locks analog port mating connector to KLR via jackscrews. 108-0204

Loop Back Test Connector Used for verification of RS 232 operation. 195-0112

Null Modem Cable, 10 ft. Connect RS 232 port with controlling computer, DB9F to DB9F, 10 feet

Null Modem Cable, 1 ft. Used for Master/Slave connections. Connects RS 232 ports of stacked

LAN Patch cable Connects KLR LAN port to LAN, 10 ft long. 118-1115

Support bracket, rear Provides extra support to rear of rack-mounted unit if needed. Two

connection. Mates with NEMA 6-20R receptacle
(see adjacent figure). Supports rated load power
over mains voltage range of 180-265V a-c.

connection. Mates with NEMA 6-15R receptacle
(see adjacent figure). Supports rated load power
over mains voltage range of 180-265V a-c.

Mates with a-c input connector J1 (see Figure 1-2) for user-wired
source power connection. Supports rated load power over mains volt-

age range of 180-265V a-c.

Allows rack-mounted units to slide in and out. 108-0239

long.

power supplies, DB9F to DB9F, one foot long.

brackets required per unit. Each bracket requires 2 screws and 2
washers. See Figure 4, sheet 1, Detail “C” for requirements.

NEMA 6-20R 118-1235

G

W

NEMA 6-15R 118-1137

KEPCO

PART NUMBER

142-0381

(Jonathan

375-QD Series)

118-1176

118-1220

128-2306

SAFETY. See Table 4

TABLE 4. SAFETY SYMBOLS

SYMBOL MEANING

CAUTION: RISK OF ELECTRIC SHOCK.

CAUTION: REFER TO REFERENCED PROCEDURE.

!

WARNING INDICATES THE POSSIBILITY OF BODILY INJURY OR DEATH.

CAUTION INDICATES THE POSSIBILITY OF EQUIPMENT DAMAGE.

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PRELIMINARY OPERATIONAL CHECK. A simple operational check after unpacking and

before equipment installation is advisable to ascertain whether the power supply has suffered damage
resulting from shipping.

NOTE: This test must be performed with all I/O ports disconnected, and ANALOG I/O SETTINGS

switch positions 3, 4 and 5 set to OFF (up).

1 With POWER circuit breaker set to OFF position, connect the power supply to source power (see

See “Input Connections.” on page 5.).

2 With no load connected, set POWER circuit breaker to the ON position. Each time the unit is turned

on an internal self-test is performed (see “Turning The Power Supply On.” on page 7). After the test
has been successfully completed, the status display reads SET (setpoint mode), the DC VOLTS dis­play reads 0 Volts and the DC AMPERES display reads minimum Amperes (see Note 1, below).

NOTES: 1. A minimum programmed current (actual value depends on model) is required to ensure proper

operation of the power supply under all load conditions. Programmed current is automatically set
to be at least the minimum current.

2. If an error indication is blinking in the Status display, refer to User Manual for an explanation of
error codes.

3 Rotate VOLTAGE adjust knob clockwise. Verify that DC VOLTS display increases in large (X 100)

increments.

4 Press and rotate VOLTAGE adjust knob clockwise. Verify the DC VOLTS display increases in finer

increments than step 3, then release knob.

5 Adjust VOLTAGE adjust knob clockwise until Status display reads >MAX. Tap either VOLTAGE or

CURRENT adjust knob once to enter values. Verify Status display is blank

6 Connect a digital voltmeter (DVM) to the (M+) and (M–) terminals on the rear panel.

7 Press and release DC OUTPUT switch to enable the output. Verify DC OUTPUT indicator lights.

8 Compare the programmed output voltage value (step 5) with the voltage reading of the DVM; the dif-

ference between the two should not exceed 0.05% of the maximum voltage of the unit.

9 Compare the voltage reading of the DC VOLTS display with that of the DVM; the difference between

the two should not exceed 0.1% of the maximum voltage of the unit.

10 Enter different value for output voltage, then repeat steps 4 and 5 using different values for pro-

grammed voltage.

11 Disable the output by pressing and releasing DC OUTPUT switch; verify front panel DC VOLTS and

DC AMPERES displays read 0.0V and minimal current and the DC OUTPUT indicator is off.

12 Set POWER ON/OFF circuit breaker to OFF and disconnect from source power, load and test equip-

ment.

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INSTALLATION. Install units in a 19 inch-wide rack. Optional slides may be used. Leave the front

and rear panels clear of obstructions to ensure adequate cooling. For parallel, series and master-slave
configurations, refer to the User Manual.

INPUT CONNECTIONS. Operation at rated load power (2400W) over the full rated source voltage range (180

- 265V a-c) requires a branch service rating of 20 Amperes; Kepco recommends use of #12 AWG (2,0 mm
mary wiring. For operation at output power of 2000W or less, or with source voltage not less than 200V a-c, branch
service may be reduced to 15 Amperes using #14 AWG (1,6 mm

2

) wiring. Line cords and a user-wireable

2

) for pri-

source power connector are available as accessories (see Table 3). Plug the (wired) source power con­nector or line cord into the source power inlet connector at the rear panel.

LOAD CONNECTIONS. Connect the load to the (+) and (–) DC OUTPUT terminals on the rear panel

(Figure 2). (+M) and (–M) outputs are for local connection of error sense leads.

Configuration of local sensing is facilitated by pre-installed jumpers which configure the unit for local
sensing as shown in Figure 2.

NOTE: Output Sense lines must be connected for proper operation, either locally, or at the load

(remote).

POWER ON/OFF

Turns unit on/off.

Circuit Breaker

gives input
protection.

DC VOLTS

Display shows

output voltage or

voltage setpoint.

(Also used for

special functions).

CV

indicator lights

green when
operating in

constant voltage

mode

LAN

indicator

lights green

when LAN

interface is

in use

[E-Series Models]

CC

indicator lights

amber when

operating in

constant current

mode

DC AMPERES

display shows

actual output

current or

current set point

(Also used for

special functions.)

DC OUTPUT
indicator lights
green to show
output enabled

VOLTAGE

control/momentary

switch

Rotate to set

output voltage.

Tap to enter

SETPOINT mode.

(Also used for

other functions.)

FIGURE 1. KLR SERIES, FRONT PANEL CONTROLS AND INDICATORS

FUNCTION

momentary switch

Used to access

calibration,

GPIB address,

RS232 baud rate

(Standard models),

Limit Model and
Utility functions.

Requires a thin tool

(e.g., end of paper

clip) to press

switch.

Status

Display normally

blank. Shows

active function or

blinks for error

messages.

PROTECT

momentary switch

Used to set

overvoltage and

overcurrent

protection limits.

Requires a thin

tool (e.g., end of

paper clip) to
press switch.

CURRENT

control/momentary

switch

Rotate to set

output current.

Tap to enter

SETPOINT mode.

(Also used for

other functions.)

DC OUTPUT

on/off switch

enables or

disables output.

(Also used to

accept front panel

inputs.)

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LOCAL SENSING (FACTORY DEFAULT). Unit is shipped with local sensing jumpers installed: +S

connected to +M and –M connected to –S (see Figure 2).

FIGURE 2. KLR SERIES, REAR PANEL VIEW, JUMPERS INSTALLED FOR LOCAL SENSING

REMOTE SENSING SELECT. First remove the factory-installed local sensing jumpers between +S

and +M and between –M and –S. Then connect the +S and –S lines at the load, observing proper polar­ity (see Figure 3). A high frequency bypass network consisting of two capacitors connected across the
error sensing point as shown in Figure 3 is recommended to reduce noise in the sense loop.

FIGURE 3. REMOTE SENSING

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ANALOG I/O CONNECTIONS. The Analog I/O Port connector, located on the rear panel of the KLR

power supply (see Figure 2), provides access to analog programming inputs, status signal outputs and
an external trigger input available for use with SCPI *TRG and TRIG commands.

GPIB CONNECTIONS. Your computer must have a GPIB interface card installed. Connect the power

supply to the computer’s GPIB interface card. Use a standard GPIB interface cable at the GPIB port on
the rear panel (see Figure 2). The default GPIB address is 6. Refer to the User manual to change it from
the front panel, or to the Developer’s Guide to change it using SCPI commands.

RS 232 CONNECTIONS (STANDARD MODELS). Connect the KLR to a modem using a Null Modem

patch cable at the RS 232 port located on the rear panel (See Figure 2). A Null Modem cable is not
required for older MAC computers with D-sub serial port in which the RXD and TXD line transposition is
accomplished via external hardware. The default baud rate is 38400. Refer to the User manual to
change it from the front panel, or to the Developer’s Guide to change it using SCPI commands.

LAN CONNECTIONS (E-SERIES MODELS). The LAN interface allows the KLR to communicate via a

built-in web port (using web pages from a standard browser), as well as through other built-in LAN ports.
Connect the KLR to the LAN via the RJ 45 LAN port located at the rear panel (See Figure 2). Refer to the
User manual to configure the LAN interface from the front panel or through the web interface. Refer to
the Developer’s Guide for the associated SCPI commands

OPERATION. Additional features covered in the User Manual are: Quick Boot (eliminating the power-

up displays), use of the internal relay, operation via the LAN interface or analog signals and setting
coarse/fine adjustment preference of the VOLTAGE and CURRENT controls. An Installation/Operation
Summary is also included in the User manual. The Developer’s Guide covers the GPIB and RS 232 and
LAN interfaces, including the use of the drivers available from www.kepcopower.com/drivers/.

TURNING THE POWER SUPPLY ON. To turn the power supply on, set POWER ON/OFF circuit

breaker (Figure 1) to ON. If an error occurs, an error code is displayed in the status display (see User
Manual.)

!

CAUTION: DO NOT attempt to “tease” the switch contacts closed by repetitive press-and-

release action. The circuit breaker is “trip-free” design; if overload exists, contacts
cannot be held closed by actuator. After turning the unit off, allow at least 5 seconds
before turning the unit on again.

1 When the power supply is turned on, it performs a self-test and displays the following information:

• Status display flashes KLR for 2 seconds while DC VOLTS and DC AMPERES displays show the max-
imum voltage and current capability of the unit.

• Status display flashes

• Status display flashes
installed.

• Status display flashes LMT for 2 seconds while DC VOLTS and DC AMPERES displays show the max-
imum voltage and current allowed for a previously programmed Limit model.

• Status display flashes
ously stored OVP and OCP trigger levels.

LAN for 2 seconds if unit is an E-Series model

RODC for 2 seconds if unit has the Rapid Output Discharge Circuit option

PROT for 2 seconds while DC VOLTS and DC AMPERES displays show previ-

2 After a successful self test, the default conditions upon power up are as follows:

• Status display shows SET,

• Output is disabled (green DC OUTPUT indicator is off).

• DC VOLTS and DC AMPERES displays show programmed output conditions: 0 Volts, minimum
Amperes (if DIP switch position 3 was ON when the unit was turned off, previously saved setpoint val­ues are displayed).

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NOTE: A minimum programmed current is required to ensure proper operation of the power supply under all

load conditions. Programmed current is automatically set to be at least the minimum current (actual
value depends on model, see Table 1).

• Since the output is off, Constant Voltage (CV) mode indicator (green LED) and Constant Current (CC)
indicator (amber LED) are off.

ENABLING/DISABLING OUTPUT POWER. When the power supply is turned on, the output is auto-

matically disabled (DC OUTPUT LED is off), the DC VOLTS and DC AMPERES displays show the pro-
grammed output voltage and current set points and “

SET” appears in the status display.

1 To enable the output, first exit

SET mode by tapping either the VOLTAGE or CURRENT control, then

press and release the DC OUTPUT switch. The associated green LED lights to indicate output
power is applied to the load. Each time you exit

SET mode, the setpoint values are stored for possible

recall if the power supply is turned off or the output is disabled.

2 To disable the output, press and release the DC OUTPUT switch again. The DC OUTPUT indicator

goes off.

NOTE: While in the setpoint mode (Status display reads

SET) the output cannot be turned on (press-

ing DC OUTPUT has no effect). If output was on while setpoint mode was entered, pressing
DC OUTPUT will disable the output.

CHECKING OR CHANGING VOLTAGE/CURRENT SETPOINTS.

CAUTION: When the output is disabled, the DC VOLTS and DC AMPERES displays show the

actual output voltage and current. Before enabling the output ALWAYS check the set­points to avoid possible damage to the load.

1 Tap either the VOLTAGE or CURRENT control. The status display reads SET, and the DC VOLTS

and DC AMPERES displays show the stored setpoints.

2 To accept the displayed value, tap the associated adjustment control again. To change the value,

rotate the control (press the control in while rotating for fine adjustment; or see User Manual to set
coarse/fine preference), then tap the adjustment control again to accept the new setting.

NOTE: Before changing the setpoint, note the displayed setpoint. If you decide not to change the

value after rotating the control, you must rotate the control to the value noted, then tap the
adjustment control to accept.

LIMIT MODEL SETTING. The limit model establishes a maximum programmable voltage and current

for the unit within the

maximum voltage and current ratings listed in Table 1. The unit will not accept pro-

grammed values beyond these values.

1 Using a thin tool (e.g., a paper clip), press the FUNCTION switch until the status display reads

LMT.

The DC VOLTS and DC AMPERES displays show the programmed maximum voltage and current of
the limit model.

2 To exit, rotate either VOLTAGE or CURRENT control until Status display reads

EXIT, then tap DC

OUTPUT switch. To change the limit model settings refer to the User Manual.

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SETTING VOLTAGE OR CURRENT. The VOLTAGE and CURRENT controls adjust output voltage

and current limit, respectively, when the unit is in constant voltage (CV) mode and adjust voltage limit
and output current, respectively, when the unit is in constant current (CC) mode. The mode (CV or CC) is
determined by the load together with the programmed settings. As long as the voltage across the load
produces a current that is less than the programmed Current setpoint, the unit operates in CV mode
(voltage programmed to voltage setpoint, current limited by current setpoint). If the load changes to the
point that current through the load reaches the current setpoint, the unit automatically enters CC mode
(current programmed to current setpoint, voltage limited by voltage setpoint).

Output voltage or current can be set at the front panel in two ways: Real-time adjustment or Setpoint
adjustment.

Real-time Voltage/Current Adjustment. Rotating the associated control will change the output voltage or current in real-time only if the output is enabled. If the unit is in constant voltage mode (CV indicator lit) the DC VOLTS display shows the actual output voltage as the VO LTAG E control is rotated. Similarly, if the unit is in constant current mode (CC indicator lit) the DC AMPERES display shows the actual output current as the CURRENT control is rotated.

• If the unit is in CV mode, rotating the CURRENT control will affect the current limit even though the DC

AMPERES display does not change since it is showing actual output current. Similarly, rotating the
VOLTAGE control while in CC mode affects the voltage limit. To change the limits to a precise value,

refer to SETPOINT ADJUSTMENT.

• Voltage and current settings are not allowed to exceed either a) the limit model setting or b) 80% of the
protection value. Attempts to set voltage or current beyond these limits will not be accepted. The status
display shows either >MAX for limit model, >OVP for voltage protection, or >OCP for current protection
to indicate which limit is being exceeded.

Setpoint Voltage/Current Adjustment.

1 Tap either the VOLTAGE or CURRENT control to initiate setpoint adjustment (status display reads

SET). The previous setpoint is visible on the corresponding DC VOLTS or DC AMPERES display.

2 Rotate the corresponding control to change the setpoint as viewed on the corresponding LED dis-

play. Tap the adjustment control again to accept the new setting.

• In the setpoint mode, both coarse and fine adjustment (depending on whether the control is pressed in
while rotating) is available. The coarse adjustment is approximately 100X the fine adjustment resolu­tion. Refer to User Manual to set coarse/fine preference.

• Setpoint adjust can be done with output either on or off, however the output can not be enabled while
setpoint is active.

• Voltage and current settings are not allowed to exceed either a) the limit model setting or b) 80% of the
protection value. Attempts to set voltage or current beyond these limits will not be accepted. The status
display shows either

>MAX for limit model, >OVP for voltage protection, or >OCP for current protection to

indicate which limit is being exceeded.

• If you decide not to change the value after rotating the control, the previous setpoint value will be
restored after about 20 seconds of inactivity. Then tap either adjustment control to accept.

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

091713 228-1689 REV 1 9

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LAST SETTING RECALL. KLR is capable of saving the last setpoint values for voltage and current

prior to unit shutdown, and recalling them when the unit is next turned on. Enable this function prior to
power-up by setting Analog I/O Switch 3 to the ON (down) position (see Figure 2). Upon next power-up,
each setpoint entry for voltage and current is stored in non-volatile memory, with latest settings displac­ing prior ones. When the power supply is turned off, the last settings are saved and automatically
retrieved at next power-up as the starting setpoints.

• Recall is for SETPOINT ADJUSTMENTS only; output changes entered as REALTIME ADJUSTMENTS
are not saved.

• To disable this function, turn the unit off and set Analog I/O Switch 3 to the OFF (up) position. At next
power-up, the stored value buffer is cleared and setpoints will default to zero volts and minimum cur­rent.

• If the limit model for the power supply is altered, the last settings are reset to zero volts and minimum
current.

VIEWING/CHANGING OVERVOLTAGE OR OVERCURRENT PROTECTION VALUES.

Overvoltage and Overcurrent protection values can be individually programmed. The range for overvolt­age and overcurrent values are 0.2 to 1.2 x E

max and 0.72 to 1.2 x IOmax.

O

If the output voltage/current exceeds the overvoltage/overcurrent protection value, the protection circuit
latches the output off, flashes an overvoltage (OVP) or overcurrent (OCP) protection error message on
the status display and sets a status bit that can be retrieved through the RS 232, GPIB or LAN port. The
unit must be cycled on and off to restore the output.

• The maximum values are 1.2 x EOmax for overvoltage protection (OVP), and 1.2 x IOmax for overcur­rent protection (OCP).

• A built-in feature prevents the unit from encroaching upon the above margins for OVP and OCP. For exam-
ple, if OVP and OCP are set to 12V and 72A, respectively, programming of the output is automatically
limited to 10V and 60A.

• When a limit model is defined, OVP and OCP are automatically set 20% and 20%, respectively, above
the maximum programmable values established by the limit model. If OVP or OCP are lowered by the
user, valid settings will actually be lower than the limit model limits because values within 20% of OVP
or 20% of OCP are prohibited.

• If either adjustment exceeds maximum programmable volts or amps, or if the adjustment is within 20%
of OVP or 20% of OCP, the status display will show

>MAX.

1 Using a thin tool (e.g., end of paper clip), press and hold the PROTECT switch. The output is

switched off, setting voltage to zero Volts, and current to a minimal value, and the status display
shows

PROT. The DC VOLTS and DC AMPERES displays show the corresponding overvoltage and

overcurrent protection setpoints while the PROTECT switch is held in.

2 To change the values, operate the corresponding adjustment control while holding the PROTECT

switch in. When the PROTECT switch is released, the protection values showing in the DC VOLTS
and DC AMPERES displays are entered as the new protection values.

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

10 228-1689 REV 1 091713

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FIGURE 4. KLR OUTLINE DIMENSIONS (SHEET 1 OF 2)

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

091713 228-1689 REV 1 11

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

FIGURE 4. KLR OUTLINE DIMENSIONS (SHEET 2 OF 2)

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

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

12 228-1689 REV 1 091713