Kikusui PWX750ML User Manual
PART NO. IB022997
Dec. 2014
PWX750ML
Installation
and Preparation
Basic Functions
External Control
Parallel/Series
Operation
Maintenance
Specifications
User’s Manual
Regulated DC Power Supply
PWX Series
1
2
3
4
5
6
Isolated Analog Interface
7
OPtions
Troubleshooting
App
PWX 1
Thank you for purchasing the PWX750ML Regulated DC
About the PWX750ML Manuals
Checking the Package Contents
Power Supply.
These manuals are intended for users of the Regulated DC
Power Supply and their instructors. It is assumed that the
reader has knowledge about electrical aspects of regulated
DC power supplies.
Documentation Structure
Safety information
This document contains general safety precautions for this
product. Keep them in mind and make sure to observe
them.
User’s manual (this manual, PDF)
This manual is intended for first-time users of this product. It
provides an overview of the product and notes on usage. It
also explains how to configure the product, operate the
product, perform maintenance on the product, specifications
the product, and so on. To effectively use the product features, read this manual from beginning to end.
We recommend that you read it thoroughly before using this
product for the first time.
If you forget how to use the product or if a problem occur s,
we recommend that you refer to this manual again.
Quick reference
This manual explains Panel description and operation
briefly.
Communication Interface Manual (HTML,
partially PDF)
This manual contains details about using commands to control the product remotely. It also contains details about the
multichannel function (Virtual Multi Channel Bus), which
makes it possible to control up to 31 PWXs from a single
PC.
The interface manual is written for readers with sufficient
basic knowledge of how to control power supplies using a
PC.
The command list is provided in PDF format.
PDF and HTML files are included in the accompanying CDROM.
Adobe Reader 6.0 or later is required to view the PDF files.
Microsoft Internet Explorer 6.0 or later is required to view
the HTML files.
Firmware versions that this manual covers
This manual covers firmware versions 2.2X.
When contacting us about the product, please provide us with:
The model (marked in the top section of the front panel)
The firmware version (see page 13)
The serial number (marked on the rear panel)
Trademarks
Microsoft, Windows, and Visual Basic are registered trademarks of Microsoft Corporation in the United States and/or
other countries.
All company names and product names used in this manual
are trademarks or registered trademarks of their respective
companies.
Copyrights
The contents of this manual may not be reproduced, in whole
or in part, without the prior consent of the copyright holder.
The specifications of this product and the contents of this manual are subject to change without prior notice.
© 2011 Kikusui Electronics Corporation
When you receive the product, check that all accessories are
included and that the accessories have not been damaged
during transportation.
If any of the accessories are damaged or missing, contact
your Kikusui agent or distributor.
We recommend that you save all packing materials, in case
the product needs to be transported at a later date.
Component Quantitiy
Power cord 1 pc.
Output terminal cover 1 set
J1 connector plug kit 1 set
Output terminal M6 bolt set 2 sets
Chassis connection wire 1 pc.
Packing list 1 pc.
Quick reference
Safety information 1 pc.
CD-ROM 1 disc
English: 1 pc.
Japanese: 1 pc.
If you find any misplaced or missing pages in the manuals,
they will be replaced. If the manual gets lost or soiled, a new
copy can be provided for a fee. To replace or purchase a manual, please contact your Kikusui agent or distributor. At that
time, inform your agent or distributor of the “Part No.” written
on the front cover of this manual.
Every effort has been made to ensure the accuracy of this
manual. However, if you have any questions or find any errors
or omissions, please contact your Kikusui agent or distributor.
After you have finished reading this manual, store it so that
you can use it for reference at any time.
2 PWX
The PWX750ML is a constant voltage (CV)/constant current
Product Overview
(CC) automatic crossover power supply that can output a wide
range of voltage and current within rated output power.
It can be controlled remotely through the standard-equipped
communication feature.
Model Maximum
operating
current
PWX750ML 28 A 0 V to 80 V 750 W
Operating
voltage
Power
Features
Communication feature
RS232C, USB, and LAN interfaces are all installed as standard.
The remote interfaces comply with IEEE Std 488.2 1992
and SCPI Specification 1999.0. Because the LAN interface
complies with the LXI standard, the construction of a highly
cost-effective system is possible. If you use the multichannel (VMCB) function, you can construct a multichannel
power supply system in which up to 31 PWXs are controlled
from a single PC.
Master-slave parallel operation
You can increase the PWX750ML’s output current by connecting up to four units in parallel. You can set one unit as
the master unit, and control the remaining units as slave
units.
Setting preset feature
You can save up to three sets of output settings (the combination of the voltage value and current value). You can simply select a set of output settings that you want to use rather
than having to specify each setting every time.
Automatic output on setting
You can set the PWX750ML so that when a protection function is activated and the output is turned off, output is automatically turned back on when the problem that caused the
protection function to be activated is fixed.
Set voltage/current limitation feature
You can apply limits to the voltage and current settings.
This prevents you from setting an appropriate value by mistake, which would cause the output to turn off.
Overcurrent protection (OCP) detection time setting
You can set a detection time, which is the amount of time
that an overcurrent must persist after the first detection of
the overcurrent before the overcurrent protection (OCP) is
activated. By setting the detection time, you can prevent an
alarm from occurring when an inrush current from the EUT
connected to the output causes an excessive current to flow
temporarily.
Bleeder on/off feature
You can turn the bleeder circuit on and off. Turn the bleeder
circuit off when you do not want the internal bleeder circuit
to sink output current. When you connect a battery, you can
prevent excessive electrical discharges by turning the
bleeder circuit off.
Compatibility with other products
You can set the command language and emulation that are
used during remote control. By setting the command language, you can enable the PWX to support the proprietary
commands of other products. By selecting the emulation,
you can remotely control products other than the PWX.
Isolated analog interface (factory option)
You can use isolated optical signals to set and monitor the
output voltage and current. The signal is isolated from the
reference potential of this product.
Y ou can use a voltage control (0 V to 5 V or 0 V to 10 V) or a
current control (4 mA to 20 mA).
PWX 3
When using this product, be sure to observe the “Saf ety
Safety Precautions
Precautions Concerning
Installation Location
Notations Used in This Manual
WARNING
CAUTION
See
Memo
Precautions” in the Safety information manual.
When installing this product, be sure to observe the
“Precautions Concerning Installation Location” in the
Safety information manual. The following precautions
pertain only to this product.
• When installing this product, be sure to observe the temperature and humidity ranges indicated below.
Operating temperature range: 0 °C to +50 °C
(32 °F to 122 °F)
Operating humidity range: 20 %rh to 85 %rh (no condensation)
• When storing this product, be sure to observe the temperature and humidity ranges indicated below.
Storage temperature range: -20 °C to +70 °C
(-4 °F to 158 °F)
Storage humidity range: 90 %rh or less (no condensation)
• In this manual, the PWX750ML Regulated DC Power Supply is referred to as the “PWX Series” or “PWX750ML.”
• The term “PC” is used to refer generally to both personal
computers and workstations.
• The screen captures used in this manual may differ from the
actual screens that appear on the PWX750ML. The screen
captures are merely examples.
• The following markings are used in this manual.
Indicates a potentially hazardous situation which, if
ignored, could result in death or serious injury.
Indicates a potentially hazardous situation which, if
ignored, may result in damage to the product or other
property.
Indicates information that you should know.
DESCRIPTION
Explanation of terminology or operation principle.
Indicates a reference to detailed information.
Indicates reference to detailed information operation manual.
CFxx:x
“CF” stands for a CONFIG parameter. The two digits after
CF indicate the CONFIG parameter number. The value
after the colon indicates the selected setting.
SHIFT+key name (blue characters below the
keys)
Indicates an operation that requires you to press a key
indicated in blue characters (below the key) while holding
down the SHIFT key.
Indicates useful information.
4 PWX
Contents
About the PWX750ML Manuals ..................2
Checking the Package Contents ................2
Product Overview .......................................3
Safety Precautions ......................................4
Precautions Concerning Installation Location
4
Notations Used in This Manual ...................4
Search by Topic...........................................7
Component Names......................................8
Installation and Prepara-
1
tion
Connecting the Power Cord............................. 12
Turning the Power On...................................... 13
Rack Mounting................................................. 14
Load Considerations........................................ 15
Load Cables..................................................... 17
Connecting to the Output Terminals................ 18
Sensing............................................................ 20
Basic Functions
2
Measured Value Display and Setting Display .. 24
Panel Operations............................................. 25
Output Operations............................................ 26
Operation Overview ............. ............................ 26
CV Power Supply and CC Power Supply ........ 27
Using the PWX750ML as a CV or CC Power Sup-
ply ....................................................................
Protection Functions and Alarms..................... 30
CONFIG Settings............................................. 36
Preset Memory Function............................ ...... 47
Locking Panel Operations (Key lock)............... 49
Bleeder On/Off Feature.................................... 49
Switching from Remote Mode to Local Mode .. 50
Factory Default Settings (Initialization) ............ 51
Turning the POWER switch on ................. 13
Turning the POWER switch Off................. 14
Local sensing............................................ 21
Remote sensing......... ... ............................ 21
29
Alarm occurrence and clearing alarms...... 30
Protection function activation .................... 31
CONFIG parameter details ....................... 39
Saving settings to preset memory............. 47
Recalling preset memory entries............... 48
3
4
5
6
7
External Control
Overview.......................................................... 54
About the J1 Connector................................... 54
Output Terminal Insulation............................... 56
When the output terminal is not grounded
(floating)....................................................
When the output terminal is grounded...... 57
Cautions when using the external voltage
(Vext) ........................................................ 58
Controlling the Output Voltage......................... 59
Control using an external voltage (Vext)... 59
Control using an external resistance (Rext)60
Controlling the Output Current......................... 61
Control using an external voltage (Vext)... 61
Control using an external resistance (Rext)62
Controlling the Output On and Off States........ 63
Controlling Output Shutdown........................... 65
Controlling the Clearing of Alarms................... 66
External Monitoring.......................................... 67
56
Parallel/Series Operation
Master-Slave Parallel Operation...................... 70
Features of the PWX750ML during master-
slave parallel operation.............................
Connection (master-slave parallel operation) .
72
Settings (master-slave parallel operation) 74
Starting master-slave parallel operation .. 75
Series Operation.............................................. 76
Features of the PWX750ML during series op-
eration.......................................................
Connection (series operation)................... 78
Settings (series operation)........................ 79
Starting series operation..................... ... ... 79
70
76
Maintenance
Calibration........................................................ 82
Calibration overview.................................. 82
Calibration procedure................................ 83
Specifications
Isolated Analog Interface
Introduction...................................................... 96
Isolated Analog Interface Connector ............... 97
Setup and Operation........................................ 98
PWX 5
Appendix
A Options ......................................100
B Troubleshooting........................102
6 PWX
Search by Topic
Troubleshooting
See “Troubleshooting” on page 102
• I want to check the accessories. →See “Checking the Package Contents”
or the included packing list.
p.2
• The installation space is limited, so I want
to check the installation conditions.
→
See the included “Safety Precautions”
document, or the electronic version of
the document on the CD-ROM.
–
• How do I connect the AC power supply?→“Connecting the Power Cord” p.12
• What kind of load cables should I use?
→
“Load Cables” p.17
• How do I ensure stable voltage when the
cables connected to the load are long (the
distance to the load is long)?
→
“Sensing”
p.20
• How do I rack mount the PWX750ML?
What kind of parts are needed?
→
“Rack Mounting”
p.14
• How do I use remote sensing to stabilize
the PWX750ML?
→“Sensing”
p.20
• How do I set the protection functions to
prevent damage to the load?
→“Protection Functions and Alarms”
p.30
• After a protection function has been acti-
vated, how do I restart tests automatically
when the cause of the alarm is fixed?
→“Alarm occurrence and clearing alarms”
p.30
• How do I set the communication condi-
tions for remote control?
→See the Communication Interface Man-
ual on the CD-ROM.
–
• How do I check the settings in preset
memory?
→“Recalling preset memory entries”
p.48
• How do I reset the PWX750ML to its fac-
tory default settings?
→“Factory Default Settings (Initialization)”
p.51
• How do I use the multichannel (VMCB)
function to construct a multichannel power
supply system?
→See the Communication Interface Man-
ual on the CD-ROM. –
• How do I use the PWX750ML as a con-
stant voltage power supply (CV mode)?
→“Using the PWX750ML as a CV or CC
Power Supply”
p.29
• How do I use the PWX750ML as a con-
stant current power supply (CC mode)?
• How do I operate the PWX750ML at a
specific current? How do I save current
values to the preset memory?
→“Preset Memory Function”
p.47
• How do I control the output voltage with
an external DC voltage?
→“Overview”
p.54
• How do I monitor the output voltage and
output current?
→“External Monitoring”
p.67
• How do I use parallel operation to
increase the current capacity?
→“Master-Slave Parallel Operation”
p.70
• How do I prevent the settings from being
changed?
→
“Locking Panel Operations (Key lock)”
p.49
• How do I clean the PWX750ML? →See the included “Safety Precautions”
document, or the electronic version of
the document on the CD-ROM.
–
• How do I calibrate the PWX750ML? →“Calibration” p.82
Preparation
Setup
Operation
Maintenance
PWX 7
Component Names
Display area
5
16 17 18 19 20 21
67 8 9 10 11
23
15
4
1
Display area
1312 14
Front Panel
8 PWX
No.
See
Name Function
1 POWER switch
CURRENT knob Used to set the current value or select a parameter number in the CONFIG settings. p.25, p.36
2
FINE Used to make fine current value adjustments. p.25
VOLTAGE knob Used to set the voltage value or change the value of a CONFIG parameter. p.25, p.36
3
FINE Used to make fine voltage value adjustments. p.25
4 Air inlet (louver) Air inlet for cooling the inside of the PWX750ML. –
5 OUTPUT key Used to turn output on and off. p.26
SET key Used to set and confirm the output voltage and output current (the key has an LED). p.24
6
ALM CLR key Used to release protection functions that have been activated (the key has an LED). p.31
• OVP keys
OCP
7
A Used to recall and save the value of preset memory A (the key has an LED). p.47
CONFIG key Used to configure the various operating conditions (the key has an LED). p.36
8
B Used to recall and save the value of preset memory B (the key has an LED). p.47
PWR DSPL key Used to display the output power on the ammeter (the key has an LED). p.24
9
C Used to recall and save the value of preset memory C (the key has an LED). p.47
LOCAL key Used to switch between local mode and remote mode (the key has an LED). p.50
10
LOCK key
11 SHIFT key Used to enable the functions that are written in blue characters below the key. –
12 Ammeter Displays the current, power, or the parameter number of a CONFIG parameter. p.24, p.36
13 CC LED Lights in red during constant current mode. p.29
14 Voltmeter Displays the voltage, the value of a CONFIG parameter, or the cause of an alarm.
15 CV LED Lights in green during constant voltage mode. p.29
16 OUTPUT LED
17 ALARM LED
18 PRESET LED
19 LOCK LED Lights in green when the keys are locked. p.49
20 REMOTE LED Lights in green during remote control. –
21 LAN LED
Flip the switch to the ( ) side to turn the power on. Flip it to the ( ) side to turn the
power off.
Used to set and display the overcurrent protection (OCP), overvoltage protection
(OVP), undervoltage limit (UVL) trip points (the key has an LED).
Used to lock the operation of all keys other than the OUTPUT key (the key has an
LED).
Lights in green when output is turned on. Blinks orange when output is on and a protection function has been activated.
Lights in red when a protection function has been activated, However, does not light
when a undervoltage limit (UVL) protection has been activated, Blinks red when the
power limit (POWER LIMIT) has been activated.
A: Lights in green when the memory A values are being recalled or saved.
B: Lights in green when the memory B values are being recalled or saved.
C: Lights in green when the memory C values are being recalled or saved.
Lights and blinks when the LAN interface is in use.
• No fault status: Lights in green.
• Fault status: Lights in red.
• Standby status: Lights in orange.
• WEB identify status: Blinks green.
p.13
p.32
p.49
p.24, p.30,
p.36
p.26, p.30
p.30
p.47
–
PWX 9
Rear Panel
* The serial number is displayed on the side of the product next to the AC inlet.
634
7
8 9 10
2
5
1
See
No.
Name Function
1 DC OUTPUT Output connector p.18
2 USB USB port for controlling the PWX750ML remotely
3 RS232C RS232C port for controlling the PWX750ML remotely
4 LAN Ethernet port for controlling the PWX750ML remotely
5 Air outlet Air outlet for cooling the inside of the PWX750ML –
6 AC INPUT AC inlet p.12
7 Chassis terminal Connector for grounding the output –
Sensing terminal connec-
8
tors
9 J1 External control connector p.54, p.69
10 Option slot Slot for the isolated analog interface option (factory option) p.95
Terminals to connect the sensing cables p.20
Interface
Manual
10 PWX
Installation and Preparation
This chapter describes how to turn on the
PWX750ML, what kind of load cables to
use, and how to connect cables to the output connectors.
Connecting the Power Cord
WARNING
Risk of electric shock.
• This product is a piece of equipment that conforms to IEC Safety Class I (equipment
that has a protective conductor terminal). Be sure to earth ground the product to
prevent electric shock.
• The product is grounded through the power cord ground wire. Connect the protective conductor terminal to earth ground.
• Use the supplied power cord to connect to the AC line. If the supplied power cord cannot
be used because the rated voltage or the plug shape is incompatible, have a qualified engineer replace it with an appropriate power cord that is 3 m or less in length. If obtaining a
power cord is difficult, contact your Kikusui agent or distributor.
• The power cord with a plug can be used to disconnect the PWX750ML from the AC power
line in an emergency. Connect the plug to an easily accessible power outlet so that the plug
can be removed from the outlet at any time. Be sure to provide adequate clearance around
the power outlet.
• Do not use the supplied power cord for other devices.
This product is a piece of equipment that conforms to IEC Overvoltage Category II (equipment that consumes energy supplied from a fixed installation).
Check that the AC power line meets the nomin al input rating of the prod-
1
uct.
The product can receive a nominal line voltage in the range of 100 Vac to 240 Vac at
50 Hz or 60 Hz.
Check that the POWER switch is turned off.
2
Connect the power cord to the AC inlet on the rear panel.
3
Insert the power plug into a grounded outlet.
4
12 PWX
Turning the Power On
WARNING
CAUTION
See
See
See
Firmware version display
(Version 1.00 in this example)
Rated voltage and rated current display
(The PWX750ML is being used in this
example.)
Build number display
(Build number BLD 0120 in this example.)
Interface display
(The LAN interface is selected in this
example.)
Turning the POWER switch on
Risk of electric shock. Regardless of whether load cables are connected to the output
terminals, be sure to attach the OUTPUT terminal cover before turning the POWER
switch on.
You can use the CONFIG settings to set how the PWX750ML starts when you turn the
POWER switch on. Depending on the setting, the output may be turned on automatically
when the POWER switch is turned on. In case that you connect a load without setting OVP
and OCP to the appropriate values, the load may be damaged if output automatically turns
on at the PWX750ML power-on.
1
p.51
p.39
p.19
When you turn the POWER switch on for the first time after purchase, the PWX750ML starts
with its factory default settings. Subsequent times that you turn the PWX750ML on, it starts
with the panel settings (excluding the output on/off setting) that were in use immediately
before the POWER switch was turned off.
You can use the CONFIG settings (CF02) to select how the PWX750ML starts when the
POWER switch is turned on.
Check that the power cord is connected correctly.
1
Check that the OUTPUT terminal cover is attached.
2
When the product is shipped from the factory, the OUTPUT terminal cover is not
attached.
Turn the POWER switch on ( ).
3
All the LEDs light, and then the voltmeter and the ammeter display the following
sequence of information: the rated voltage and rated current, the firmware version
number, the build number, and then the selected interface. Each item is displayed for
approximately 1 second.
After a few seconds, the PWX750ML enters the operation standby state (the output
value is displayed).
Installation and Preparation
Inrush current
When the POWER switch is turned on, an inrush current of up to 70 A flows. Check that sufficient current capacity is available in the AC power line or the switchboard, particularly if you
are using multiple PWX750ML and turning on their POWER switches simultaneously.
PWX 13
Rack Mounting
See
CAUTION
See
Rubber foot
Screw (4 locations)
M3 screw
Max. depth: 8 mm [0.31 inches]
(
)
Turning the POWER switch Off
Flip the POWER switch to the ( ) side to turn the PWX750ML off.
The PWX750ML saves the panel settings (except the output on/off setting) that were in use
immediately before the POWER switch was turned off.
p.39
You can use the CONFIG settings (CF02) to select how the PWX750ML starts when the
POWER switch is turned on.
If the POWER switch is turned off immediately after the settings have been changed, the last
settings may not be stored.
After you turn the POWER switch off, wait at least 10 seconds after the panel display turns
off before you turn the POWER switch back on. Repeatedly turning the POWER switch on
and off at short intervals can cause damage to the inrush current limiter. Furthermore, this
will shorten the service life of the POWER switch and the internal input fuse.
Rack Mounting
p.100
You can mount one or two PWX750MLs side by side to a rack. You can use brackets or slide
rails to mount the PWX750ML to a rack.
Remove the rubber feet before you mount the PWX750ML to a rack.
If you are mounting two PWX750MLs side by side, install the optional support board to sup-
port the two PWX750MLs.
Attach the optional support angles (KRB1-PWX SUPPORT ANGLE) to support the
PWX750ML.
We recommend that you keep all pieces that you have removed from the PWX750ML. You
will need these pieces if you remove the PWX750ML from the rack.
If you remove the PWX750ML from the rack, re-attach the original rubber feet.
When using several PWX750ML power supplies together, such as for master-slave parallel
operation or series operation, mount them to a rack before use.
You can mount the PWX750ML to the Kikusui KRC series and KRO series racks.
Removing the rubber feet
Loosen the screws to remove the rubber feet (in four locations).
14 PWX
Load Considerations
Set constant current
Ammeter reading (mean value)
Set constant current
Ammeter reading (mean value)
CAUTION
Note that the output will become unstable if the following types of loads are connected.
Loads with peak current or pulse-shaped current
The PWX750ML only indicates mean values. Even when the indicated value is less than or
equal to the set constant current, the peak values may exceed the set constant current. If this
happens, the PWX750ML is instantaneously put into constant-current mode, and the output
voltage drops.
For these types of loads, you must increase the set constant current or increase the current
capacity.
Load current with peaks Pulse-shaped load current
1
Installation and Preparation
Loads that generate reverse current to the power supply
The PWX750ML series cannot absorb reverse current from the load. Therefore, if a regenerative load (such as an inverter, converter, or transformer) is connected, the o utput voltage
increases and becomes unstable. This can cause a malfunction.
For these types of loads, connect a resistor (RD) as shown in the following figure to bypass
the reverse current. However, the amount of current to the load decreases by Irp.
EO
Equivalent circuit of the PWX750ML
+IO
0
Output current
-IO
RD
Reverse current
IO
RD (in Ω) ≤
Irp
Use a resistor with sufficient rated power for RD. If a resistor with insufficient rated power for
the circuit is used, resistor R
D will burn out.
＋
Load
Regenerative load
EO (in V)
Irp (in A)
RD: Reverse current bypass dummy load
E
O: Output voltage
Irp: Maximum reverse current
PWX 15
Load Considerations
CAUTION
Loads with accumulated energy
Connecting a load with accumulated energy, such as a battery, to the PWX750ML may cause
current to flow from the load to the internal circuit of the PWX750ML. This current may damage the PWX750ML or reduce the life of the load.
For this type of load, connect a reverse-current-prevention diode (DRP) between the
PWX750ML and the load in series as shown in the following figure.
This cannot be used in conjunction with remote sensing.
D
RP
DRP: Reverse-current-protection diode
PWX750ML
Load with accumulated energy
• To protect the load and the PWX750ML, use a DRP that conforms to the fol lowing
specifications.
Reverse voltage withstand capacity:
At least twice the rated output voltage of the PWX750ML.
Forward current capacity:
Three to ten times the rated output current of the PWX750ML.
A diode with small loss.
• Be sure to take into account the heat generated by D
RP. DRP will burn out with inadequate
heat dissipation.
16 PWX
Load Cables
WARNING
Risk of fire.
• Use load cables whose capacity is adequate for the PWX750ML’s rated output current.
• The output connector and its surrounding area become hot. Use cables whose covers have heat resistance at 85 °C and higher.
Risk of electric shock.
• Use load cables whose rated voltage meets or exceeds the PWX750ML’s isolation
voltage.
The cables’ allowable current depends on the insulation’s maximum allow-
able temperature.
A cable’s temperature is determined by the resistive loss based on the current, the ambient
temperature, and the cable’s external thermal resistance. The following table shows the current capacity of heat-resistant vinyl wires that have a maximum allowable temperature of
60°C, assuming that a wire is stretched out horizontally in air in an ambient temperature of
30°C. The current capacity must be reduced under certain conditions, such as when vinyl
cables that have a low heat resistance are used, when the ambient temperature is 30 °C or
greater, or when cables are bundled together and little heat is radiated.
Nominal cross-sectional
area [mm
2 14 (2.08) 27 10
3.5 12 (3.31) 37 -
5.5 10 (5.26) 49 20
8 8 (8.37) 61 30
14 6 (13.3) 88 50
22 4 (21.15) 115 80
30 2 (33.62) 139 38 1 (42.41) 162 100
50 1/0 (53.49) 190 60 2/0 (67.43) 217 80 3/0 (85.01) 257 200
100 4/0 (107.2) 298 125 - - 344 150 - - 395 300
200 - - 469 -
2
]
AWG (reference crosssectional area) [mm
2
Allowable current1 [A]
(Ta = 30 °C)
]
Kikusui-recommended
current [A]
1
Installation and Preparation
1 Excerpt from Japanese laws related to electrical equipment.
Taking measures against noise
When connecting wires that have the same heat resistance, separating the wires as much as
possible to increase heat radiation enables a greater amount of current to flow . However, wiring the + (positive) and - (negative) output wires of the load cable side by side or bundling
them together is more effective against unwanted noise. The Kikusui -recommended cu rrents
shown in the above table are allowable currents that have been reduced in consideration of
the potential bundling of load cables. Use these values as a guidel ine when connecti ng load
cables.
Limitations of the remote sensing function
All wires have resistance. As the wire becomes longer or the current becomes larger, the voltage drop in the wire becomes greater. This results in a smaller voltage being applied at the
load end. The PWX750ML has a sensing function that compensates for this voltage drop up
to approximately 4 V for a single line. If the voltage drop exceeds this level, use wires that
have a greater cross-sectional area.
PWX 17
Connecting to the Output Terminals
WARNING
- terminal
Chassis terminal
+ terminal
Screw (M3)
Screw (M4)
Chassis connection wire
Use an M3 screw and an
M4 screw to connect the
wire.
Crimping terminal
Bolt (M6)
Spring washer
Washer
Nut
Use the M6 bolt set to
connect the cables.
Risk of electric shock.
• Turn the POWER switch off before you touch the OUTPUT terminals.
• Even if you turn the output off or turn the POWER switch off, if the bleeder on/off setting (CF11) is set to “oFF,” the voltage that was present when the output was on will
remain at the output terminals. Set the bleeder on/off setting to “on” before you
touch the output terminals.
• Regardless of whether load cables are connected to the output terminals, be sure to
attach the OUTPUT terminal cover before turning the POWER switch on.
Turn the POWER switch off.
1
Check that there is no voltage across the output terminals.
Connect one end of the included chassis connection wire to the chassis
2
terminal, and then connect the other end of the wire to the negative or
positive output terminal.
Use the screw that is attached to the PWX750ML to connect the wire to the chassis
terminal. Use the screw that is attached to the output terminal to connect the wire to
the output terminal.
Attach crimping terminals to the load cables.
3
The output terminals have bolt holes (M6) for connecting the load cables. Use crimping terminals that are designed for M6 bolts.
Use the included bolt set to connect the load cables to the output termi-
4
nals.
Connect the positive cable to the positive output terminal and the negative cable to
the negative output terminal.
18 PWX
Memo
Both the top and bottom
Remove the screws, and
then line up the cover.
Memo
Push this part toward the panel.
Continue sliding the cover until
you hear a click.
Top cover
Bottom cover
Line up the two halves so
that the protruding parts of
the top cover are in front of
the protruding parts of the
bottom cover.
After you have lined up the top
and bottom covers, use the
screws to fix them in place.
Screws (M3)
of the OUTPUT terminal
cover are the same
shape.
Connecting to the Output Terminals
Attaching the OUTPUT terminal cover
Remove the screw that is attached next to the output terminals on the
1
PWX750ML.
Use this screw to attach the OUTPUT terminal cover.
Place the bottom half of the OUTPUT terminal cover underneath the load
2
cables connected to the output terminals.
1
Installation and Preparation
It is easier to slide the
OUTPUT terminal cover
in place if you make the
load cables perpendicular
with the PWX750ML.
Align the hooks of the top half of the OUTPUT terminal cover with the
3
bottom half of the OUTPUT terminal cover.
Pushing the top half of the OUTPUT terminal cover toward the rear
4
panel, slide the top half of the OUTPUT terminal cover onto the bottom
half.
Continue sliding the cover until you hear a click.
Push the OUTPUT terminal cover against th e rear panel, and then use
5
screws to fix the cover in place.
Make sure that both screws are securely fastened.
PWX 19
Sensing
84-61-7305
Connector
P1-000-109
Terminal cover
WARNING
Strip 7 mm (0.28 inches) of the
cable covering, and then insert
the cable here.
Incorrect
Incorrect
Correct
The wire itself is
in contact with
the chassis.
Wire scraps are
in contact with
the chassis.
Strip gauge
7 mm (0.28 inches)
Use this screw to fix the
cables in place so that they do
not come loose.
Local sensing jumpers
Terminal Function
-S Negative remote sensing terminal
-LS
Negative local sensing terminal
Connected to the negative output
terminal
— Not connected
+LS
Positive local sensing term inal
Connected to the positive output
terminal
+S Positive remote sensing terminal
Sensing
cable
AWG28 to AWG16
When the PWX750ML is shipped from the factory, terminal cover and connector are attached
to the sensing terminals. For safety reasons, when not using the sensing terminals, be sure to
attach to terminal cover.
If they are damaged or lost, contact your Kikusui agent or distributor.
Connecting the sensing cables
Risk of electric shock and damage to internal circuits.
• Never wire the sensing terminals while the POWER switch is turned on.
• Use sensing cables whose rated voltage is higher than the PWX750ML’s isolation
• The sensing terminals are at approximately the same electric potential as the nega-
• Even if you turn the output off or turn the POWER switch off, if the bleeder on/off set-
• Regardless of whether local sensing or remote sensing is used, be sure to attach the
voltage. Protect the uncovered sections of the shielded cable by using insulation
tubes whose withstand voltage is greater than the PWX750ML’s isolation voltage.
tive output terminal. Insert the cables so that the wire strands do not touch the chassis when they stick out of the sensing terminal. Also, insert the cables so that the
stripped wires do not stick out of the terminal.
ting (CF11) is set to oFF, the voltage that was present when the output was on will
remain at the output terminals. Set the bleeder on/off setting to on before you touch
the sensing terminals.
sensing terminal cover before turning the POWER switch on.
If the sensing cables come loose, the output voltage across the load may become unstable,
and an excessive voltage may be applied to the load. If an approp riate OVP trip point is set,
the OVP will trip before an excessive voltage is generated.
When you are finished with remote sensing, return the PWX750ML to local sensing mode.
20 PWX
Local sensing
See
By factory default, the PWX750ML is set to local sensing (the rear panel sensing connector is
hard wired). The sensing point during local sensing is the output terminal. This meth od does
not compensate for the voltage drop in the load cable, so use this method when the load current is small or when you do not need to consider the load effect voltage.
Sensing
1
PWX
Remote sensing
Remote sensing is a feature that stabilizes the output voltage across the load by reducing the
influence of voltage drops and other effects caused by the load cable resistance.
p.17
You can use the PWX750ML’s remote sensing feature to compensate up to 4 V for a single
line. Select a load cable that has sufficient current capacity to prevent the voltage drop in the
load cable from exceeding the compensation voltage.
When you perform remote sensing, set the voltage of the sensing point (across the load) so
that it does not exceed the rated output voltage. If you are performing remote sensing with
the voltage close to the maximum output voltage, the output is limited by the maximum output
voltage (105 % of the rated output voltage). Electrolytic capacitors may be required at the
sensing point (across the load).
To reduce the effect of noise, use twisted-pair wires or 2-core shielded wires. When you are
using shielded wires, connect the shield to the ground of the PWX750ML or the load.
Output terminal
Chassis terminal
Sensing terminal
+S
+LS
-LS
-S
Use twisted-pair wires for the load cables.
Make the cables as short as possible.
+
Load
–
Installation and Preparation
PWX
Output terminal
Chassis terminal
Sensing terminal
+S
+LS
-LS
-S
PWX 21
Use twisted-pair wires for the load cables.
Make the cables as short as possible.
+
+
Load
–
For the sensing cables, use twisted-pair
wires or shielded wires.
C
–
Connect an
electrolytic
capacitor
across the load
as necessary.
Sensing
Load
S
+
–
C
+
–
+S
–S
+
–
Turn the POWER switch off.
1
Remove the sensing terminal cover and sensing connect or from the rear
2
panel sensing terminals.
Remove the local sensing jumpers from the sensing connector.
3
Remove 7 mm of the wire covering. Connect the negative sensing cable
4
to -S and the positive sensing cable to +S.
Use cable screws to securely fix the cables in place so that they do not come loose.
Firmly attach the sensing terminal cover and sensing connector to the
5
rear panel sensing terminals.
Turn the POWER switch on.
6
Electrolytic capacitor to connect across the load
If the wiring inductance component is large, the following symptoms may appear.
• The PWX750ML oscillates
If the wires used to connect to the load are long, the wiring inductance and capacitance
can cause phase shifting at a level that can not be ignored. This may lead to oscillation.
• The output fluctuates
If the load current changes drastically in a pulse-shaped pattern, the output voltage may
become large due to the wiring’s inductance component.
You can reduce the inductance component by twisting the load ca bles, which stabilizes the
voltage. However, if this does not rectify the problem, connect an electrolytic capacitor across
the load.
Electrolytic capacitor to use
Capacity: 0.1 μF to a few hundred μF
Withstand voltage: At least 120 % of the rated output voltage of the PWX750ML
If you are inserting a mec hanical switch between the PWX7 50ML and the
load
If you want to connect and disconnect the load using a mechanical switch that is i nserted
between the PWX750ML and the load, be sure to include swi tches in the sensing cables as
shown in the following figure and turn on and off the load cable and the sensing cables simultaneously. Before you turn the mechanical switch on or off, be sure to turn the output or the
POWER switch off.
22 PWX
Basic Functions
This chapter describes how to turn the output on and off and the basic operation s that
you can perform from the front panel.
Measured Value Display and Setting Display
See
Lit
The voltage and current displays have the following two states.
• Measured value display
• Setting display
In addition to the voltmeter and ammeter, the PWX750ML can display the power, the set OVP
or OCP, and the system configuration.
Measured value display
The present output voltage and load current are displayed. In this situation, the SET key LED
is off.
p.29
You can change the output voltage and output current in the measured value display.
Power display
In the measured value display, press PWR DSPL to display the output power on the ammeter.
The output power is calculated from the measured output voltage and the me asured output
current.
When the power is being displayed, the PWR DSPL key lights. Press PWR DSPL again to
turn off the LED and return to the measured value display.
Lit
Setting display
Press SET to light its LED and display the present output voltage and output current settings.
Press SET again to return to the measured value display.
When you recall a preset memory entry, the values stored in the preset memory entry are displayed on the panel.
24 PWX
Panel Operations
Decrease IncreaseIncrease Decrease
See
Memo
Overvoltage protection and overcurrent protection setting display
Press OCP•OVP to light its LED and display the present overcurrent protection and overvoltage protection settings.
Lit
System configuration setting display
Press CONFIG to light its LED and display the present system configuration settings.
Panel Operations
Measured value display, setting display, and set OVP/OCP display
Turn the VOLTAGE knob to change the voltage. Turn the CURRENT knob to change the current.
2
Lit
Basic Functions
p.32
When you set a value, it is
convenient to first use
normal resolution to set
the value roughly and
then switch to fine
resolution to set it
precisely.
Press SET to switch to the setting display, and then change the output voltage and output
current while you view their actual settin g s.
You cannot set the output voltage to a value that is 95% of the OVP trip point or higher. You
cannot set the output current to a value that is 95% of the OCP trip point or higher.
The displayed current or voltage may not change even if you turn the CURRENT or VOLTAGE knob. In this situation, the values are being changed at a finer resolution that which is
being displayed. The display will change when the amount that you change the value by
reaches the smallest display digit of the set voltage or current.
Fine adjustment
You can change the resolution of the VOLTAGE and CURRENT knobs.
Hold down SHIFT while you turn the VOLTAGE knob or CURRENT knob to make small
changes to the value.
PWX 25
Output Operations
See
Lit
Output on
See
See
CAUTION
See
Output current (A)
Output voltage (V)
90
80
70
60
50
40
30
20
10
0
0 5 10 15 20 25 28 30
Rated output current: 28 A
Rated output power: 750 W
Rated output voltage: 80 V
PWX750ML operating range
The output turns on and off each time you press OUTPUT. When output is on, the OUTPUT
LED in the display area lights. When the output is off, the OUTPUT LED in the display a rea
turns off.
When the output is on, output is generated at the present set values.
If you change the settings while the output is on , the chang es are a pplied immedi ately to the
output. If the output is off, the setting display will appear (the SET key lights) as soon as you
change the settings. Then, you can press OUTPUT to output using the new settings.
p.42, p.63
You can use external control to turn the output on and off.
Y ou ca n use the CONFIG settings to set the output -on startup state (C F12: prioritize CC or CV).
Output on or off when the PWX750ML turns on
p.51
p.32
In the factory default settings, output is off when the PWX750ML turns on. Using a CONFIG
parameter (CF02:Forc), you can set the PWX750ML so that output is turned on at power on.
If you set the PWX750ML so that output is turned on at power on, be sure to check the OVP
trip point setting before you turn the PWX750ML off.
If you change the load, it may be damaged if the PWX750ML’s OVP and OCP settings are
not correct.
Operation Overview
The PWX750ML is a constant voltage (CV)/constant current (CC) regulated DC power supply
that can output a wide range of voltage and current within rated output power.
If you configure the settings so that “output voltage × output current” is less than or equal to
the rated output power, the PWX750ML operates as a traditional constant-voltage (CV)/constant-current (CC) power supply.
p.35
If you configure the settings so that “output voltage × output current” is greater than the rated
output power, the actual output is limited by the power limit (POWER LIMIT: approximately
105% of the rated output power), and the output voltage and output current change depending on the load value.
26 PWX
CV Power Supply and CC Power Supply
0
ImaxIs
Vs
Vmax
Output current Iout
Crossover point
A = CV mode area
B = CC mode area
Vs = Set voltage
Is = Set current
Rc = Vs/Is (Ohm’s Law)
RL = Load resistance
Vmax = Maximum settable voltage
Imax = Maximum settable current
RL = Rc
RL > Rc
RL < Rc
p
q
A
B
Output voltage Vout
A
B
A
B
The PWX750ML has features that enab le it to function as a constant-voltage source and constant-current source even when the load is changed. The constant-voltage source operation
is referred to as constant-voltage (CV) mode. The constant-current source operation is
referred to as constant-current (CC) mode. The operation mode is determined by the following three values.
• The set output voltage (Vs)
• The set output current (Is)
• The load resistance (R
The operation modes are described below.
L)
2
Basic Functions
The above figure shows the PWX750ML operation modes. The load resistance is denoted as
RL. The resistance, which is denoted as Rc, is calculated from the set voltage and current (Rc
= Vs/Is). The power supply is designed so that it operates in CV mode in area and CC
mode in area . The boundary is the line defined by R
which the output voltage and the set voltage are equal and the output current and the set current are equal. If load resistance RL is greater than resistance Rc, the operating point is in
area , and the PWX750ML operates in CV mode (point p). In this case, the set current Is
equals to the current limit.
When operating in CV mode, the output voltage is maintained at the set voltage. Output current I is determined by the equation I = Vs/R
The actual current that flows is not necessarily equal to the specified value.
For loads in which transient peak current flows, current Is must b e set so that the p eak va lue
does not reach the current limit.
Conversely, if load resistance R
and the PWX750ML operates in CC mode (point q). In this case, set voltage Vs equals to the
voltage limit.
When operating in CC mode, the output current is maintained at the set curren t. Output voltage V is determined by the equation V = Is × RL and is a voltage that is less than voltage limit
Vs. The actual voltage that is applied is not necessarily equal to the specified value.
For loads that generate transient surge voltage, Vs must be set so that the surge voltage
does not reach the voltage limit.
L is less than resistance Rc, the operating point is in area ,
L and is a current that is less than current limit Is.
L = Rc. This line represents the load at
Crossover point
The PWX750ML switches automatically between CV mode a nd CC mode according to the
changes in the load. A crossover point is the point at which the mode switches.
For example, when operating in CV mode, if the load changes and the output current reaches
the current limit, the PWX750ML automatically switches to CC mode to protect the load. Like-
PWX 27
wise, when operating in CC mode, if the output voltage reaches the voltage limit, the
PWX750ML switches to CV mode.
CV Power Supply and CC Power Supply
CV mode and CC mode operation example
This section uses a power supply with a rated output voltage of 100 V and a rated output current of 10 A as an example.
A load resistance (RL) of 8 Ω is connected to the output terminals of the power supply. The
output voltage and output current are set to 30 V and 5 A, respectively. In this case, Rc = 30
V/5 A = 6 Ω. Because 8 Ω is greater than 6 Ω (RL > Rc), the power supply operates in CV
mode. When you want to increase the voltage in CV mode, you can increase the voltage up
to the voltage defined by the following equation: Vs = Is × R
obtain Vs = 5 A × 8 Ω = 40 V. If you try to increase the voltage above this point, the crossover
point is reached, and the power supply automatically switches to CC mode. To maintain operations in CV mode, increase the current limit.
Next, a load resistance (R
The output voltage and output current are set to 30 V and 5 A, respectively. In this case, Rc =
30 V/5 A = 6 Ω. Because 5 Ω is less than 6 Ω (RL < Rc), the power supply operates in CC
mode. When you want to increase the current in CC mode, you can increase the current up to
the current defined by the following equation: Is = Vs/R
= 30V/5Ω = 6 A. If you try to increase the current above this point, the crossover point is
reached, and the power supply automatically switches to CV mode. To maintain operations in
CC mode, increase the voltage limit.
L. Substituting the values, we
L) of 5 Ω is connected to the output terminals of the p ower supply.
L. Substituting the values, we obtain Is
28 PWX
Using the PWX750ML as a CV or CC Power Supply
See
See
See
See
When using the PMX750ML as a constant-voltage power supply, the set current is the limit to
the current that can flow through the load.
When using the PMX750ML as a constant-current power supply, the set voltage is the limit to
the voltage that can be applied to the load.
If the specified limit is reached, the PMX750ML automatically switches its operation mode.
When the PMX750ML switches its operation mode, the lit LED in the display area (CV LED or
CC LED) changes to indicate the switch.
Turn the POWER switch off.
1
2
p.18
p.25
p.24
Connect the load to the output terminals.
2
Turn the POWER switch on.
3
If the OUTPUT LED in the display area is lit, press OUTPUT to turn the output off.
Press SET to change to the setting display.
4
The SET key lights.
Turn the VOLTAGE knob to set the voltage.
5
6
7
Even when the output is on, you can set the voltage and current by carrying out step 5 and
step 6 while checking the actual output voltage or current.
You can set the voltage that is actually output while checking the power.
Voltage range: 0 V to 84 V
Turn the CURRENT knob to set the current.
Current range: 0 A to 29.4 A
Press OUTPUT to turn output on.
The SET LED turns off, and the OUTPUT LED in the display area lights. The voltage
and current are generated from the output terminals. When the PMX750ML is operating as a constant-voltage power supply, the CV LED in the display area lights. When
the PMX750ML is operating as a constant-current power supply, the CC LED lights.
Basic Functions
p.42
PWX 29
You can use the CONFIG settings to set the output-on startup state (CF12: priori tize CC or
CV).Set this according to the operation mode that you are using. You can prevent overshoot
from occurring when the output is turned on by prioritizing CV when using the PWX series as
a constant-voltage power supply and by prioritizing CC when using the PWX series as a constant-current power supply.
When used as a slave device, CC is automatica lly prioritized. To use the PWX series as a
standalone unit or master unit after using it as a slave unit, set the operation mode that you
want to use. If you do not set the operation mode, CC will be prioritized.
When the output is turned on, the internal capacitors ar e ch arged . Depen din g on the set cu rrent, the PMX750ML may enter CC mode for an instant.
Protection Functions and Alarms
Lit
Lit
Blinking (in orange)
Alarm indication when
OHP has been activated
Alarm indication when OHP has been
activated with the output on
See
The PMX750ML is equipped with the following protection functions.
• Overvoltage protection (OVP) • Overvoltage protection 2 (OVP2)
• Overcurrent protection (OCP) • Undervoltage limit (UVL)
• Overheat protection (OHP) • Fan failure protection (FAN)
• Incorrect sensing connection protection (SENSE)
• Low AC input protection (AC-FAIL) • Shutdown (SD)
• Power limit (POWER LIMIT) • Communication monitoring (WAT CHDOG)
Alarm occurrence and clearing alarms
Alarm occurrence
When a protection function has been activated, the PMX750ML behaves as follows.
p.40
• The output turns off.
For the overheat protection (OHP), fan failure protection (FAN), and low AC input protec-
tion (AC-FAIL) functions, you can use the CONFIG settings to select to turn the output on
automatically when the problem that caused the alarm is fixed (CF03: Auto) or to leave
the output turned off when the problem that caused the alarm is fixed (CF03: SAFE). This
parameter is the same for the OHP, FAN, and AC-FAIL alarms. You cannot set this
parameter separately for each protection function.
• The ALARM LED in the front panel display area lights to indicate that an alarm has
occurred. The voltmeter indicates the cause of the alarm.
• The ALARM LED in the front panel display area blinks (only when the power limit has
been activated).
• The OUTPUT LED in the front panel display area blinks (only when a protection function
has been activated when the output is on).
If a protection function is activated w hen the output is on, the ALARM LED lights and the
OUTPUT LED blinks in orange.
If the PWX750ML is set so that output turns on automatically after the problem that
caused the alarm is fixed (CF03: Auto), the output is turned on and the OUTPUT LED
lights automatically when the problem that caused the alarm is fixed.
If the PWX750ML is set so that output remains off even after the problem is fixed (CF03:
SAFE), output remains off even after the problem that caused the alarm is fixed.
• The alarm sign al is generated from pin 14 of the J1 connector (when the OVP/ OVP2/
OCP/ OHP/ FAN/ SEN/ AC-F AIL/ SD/ WATCHDOG has been activated).
When a CONFIG parameter is being displayed, only the ALARM LED turns on; the cause of
alarm is not displayed. To view the cause of the alarm, exit from the CONFIG parameter display.
30 PWX
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