Omron S82K Manual

Power Supply Technical Information 1
Power
supplies
Power Supply
Technical Information
Power Supply Overview
■What is a Power Supply?
Commercial AC power distributed from power plants cannot be
supplied directly to the ICs and other electronic components built
into electronic devices in automated office and factory equipment
without destroying the components due to the high voltage of
commercial AC power. Devices called power supplies or
regulated DC power supplies are therefore required to convert
commercial AC power into regulated DC power to drive ICs and
other electronic components.
■Regulated DC Power Supplies
The methods for controlling Regulated DC Power Supplies can
be largely classified into the following two types. Switch-mode
power supplies and linear power supplies are generally referred
to as power supplies. Currently, switch-mode power supplies are
the most prevalent.
●Switch-mode Power Supplies
Switch-mode power supplies convert commercial AC power into
the required high-frequency DC power using the high-speed
switching of semiconductors. Switch-mode power supplies are
so compact, light, and efficient that they are used as power
supplies by most electronic devices.
Advantages
Disadvantages
■Power Supply Selection
●Basic Selection Points
Factors to consider when selecting a Power Supply are provided
in the following diagram.
Switch-mode
Power
Supplies
Linear Power
Supplies
Regulated
DC Power
Supplies
Detection
circuit
Pulse width
modulator
Converts AC into DC
by rectifying and
smoothing AC.
DC OUT
AC IN
Steps down the voltage with a high-
frequency (40 to 200 kHz) transformer.
The primary and secondary sides are
insulated from each other.
Controls the high-frequency
switching pulse width and
frequency to stabilize the output.
•Highly efficient.
•Compact, and light.
•A wide input voltage range.
•Switching noise is generated.
•Large inrush current on primary side.
(1) Input Voltage
Each Power
Supply has an
input voltage
range. Select the
Power Supply
according to the
available input
voltage.
(3) Safety Standards
Power Supplies
with UL, CSA, or
VDE approval, or
CE Marking are
available.
(4) Shape and Mounting Method
Power Supplies of various shapes
are available. Use the most
suitable Power Supply according to
the application. Various mounting
brackets are also available.
(2) Output Capacity (Voltage ×Current)
The maximum load capacity must be
less than the maximum output
capacity of the Power Supply.
Power Supply
Load

2Power Supply Technical Information
Glossary
Note. As a general rule, the ambient temperature is measured at 50 mm from the Power Supply.
●Input Voltage
The input voltage is the input voltage and corresponding
frequency range at which the rated operations and performance
can be maintained. The AC input voltages shown are effective
values. An input voltage of 100 VAC is input when the input
voltage selector terminals are shorted with a short bar and an
input voltage 200 VAC is input when these terminals are open.
Main applicable models: S82K (90 W, 100 W),
S82J (300 W, 600 W)
Note. Models equipped with 100/200 VAC selection are delivered set to 200-
VAC input. Therefore, be sure to thoroughly check the input voltage
selector terminals before use. Using the incorrect voltage, whether 200
VAC or 100 VAC, will cause the Power Supply to malfunction.
●Input Current
Standard Switch-mode Power Supplies rectify AC input current.
Usually, rectification is achieved using capacitor inputs and a
smoothing capacitor through which a reactive current is allowed
to flow. Therefore, the input current depends on the output
power, input voltage, power factor, and efficiency, as follows:
The power factor of a Switch-mode Power Supply is usually
between 0.4 and 0.6. For details on efficiency, refer to the
information in the datasheet for each model.
Item Description Details
Efficiency (%) The output power divided by the effective input power. The higher the effi-
ciency, the smaller the internal power loss of the Power Supply. ---
Input
condition
Voltage range The voltage applied to the AC input terminals. The voltage fluctuation range
is indicated in parentheses. ---
Frequency The frequency of the voltage applied to the AC input terminals. ---
Current The current value flowing to the AC input terminals. This value is the station-
ary current and will fluctuate depending on the load. Refer to Input Current on page 2.
Power factor The effective input power divided by apparent power ---
Harmonic current The harmonic current component excluding the fundamental wave included
in the current waveform.
Refer to Harmonic Current Suppression on
page 8.
Leakage current The current leaking to the ground from the input lines through the casing of
the Power Supply. Refer to Leakage Current on page 3.
Inrush current The peak current that flows when the input is turned ON. Refer to Inrush Current on page 3.
Output
character-
istics
Voltage adjustment range The range in which the output voltage can be adjusted using the Output
Voltage Adjuster (V.ADJ).
Refer to Voltage Adjustment Range on
page 3.
Ripple noise voltage
The compound value of the ripple that appears between the output termi-
nals and high-frequency noise. This value is expressed as a peak to peak
(p-p).
Refer to Ripple and Noise on page 3.
Input variation influence The variation in the output voltage when the input voltage gradually varies
within the input voltage fluctuation range.
Refer to Input Variation Influence on page
4.
Load variation influence
(rated input voltage)
The variation influence in the output voltage when the output current gradu-
ally varies within the specified load range.
Refer to Load Variation Influence on page
4.
Startup time The time from when the input voltage is turned ON until the output voltage
reaches 90% of the rated output voltage. ---
Output hold time The time after the input voltage is shut off during which the output voltage
maintains the constant-voltage precision range. ---
Functions
Overload protection Prevents damage to the Power Supply if the output current exceeds the
rated current (including output short-circuits). Refer to Overcurrent Protection on page 4.
Overvoltage protection Detects excessive voltage between output terminals and turns OFF outputs. Refer to Overvoltage Protection on page 5.
Parallel operation Increases capacity through parallel connection of multiple Power Supplies. Refer to Parallel Operation on page 6.
Serial operation Increases output voltage through serial connection of multiple Power Sup-
plies. Refer to Series Operation on page 7.
Other
Ambient operating
temperature
The allowable range for the ambient temperature in which continued opera-
tion is possible. The ambient temperature is the temperature not affected by
the heat generated by the Power Supply itself. (See note.)
Refer to Precautions Common to all Power
Supplies on CD.
Storage temperature
The allowable range for the ambient temperature in which performance will
not deteriorate due to long-term storage. The Power Supply itself is in a
non-operational state.
Refer to Precautions Common to all Power
Supplies on CD.
Ambient operating
humidity
The allowable ambient humidity range in which the product can be used
continuously.
Refer to Precautions Common to all Power
Supplies on CD.
Dielectric strength Test for confirming the insulation strength by applying a specified voltage
between two specified points for a specified length of time. Refer to Dielectric Strength on page 4.
Insulation resistance DC resistance indicating insulation characteristics between two specified
points.
Refer to Insulation Resistance Test on page
4.
Vibration resistance The vibration resistance characteristics. ---
Shock resistance The shock resistance characteristics. ---
Conducted emission Noise voltage that is generated in the Power Supply’s AC input terminals. ---
100 V 200 V
678
SHORT
100-120V
VOLTAGE SELECT
OPEN
200-240V
Terminals short-circuited
usin
g
the short bar.
678
SHORT
100-120V
VOLTAGE SELECT
OPEN
200-240V
Short bar removed and
terminals open.
Input current = Output voltage
Input voltage ×Power factor ×Efficiency
Input Rectifier/Smoothing Circuit
Input fuse Inrush current protection circuit
Input
smoothing
capacitor

Power Supply Technical Information 3
Power
supplies
●Internal Fuse
If the internal fuse has blown, it is very likely that internal circuits
of the Power Supply have been damaged and that parts other
than the fuse will also need to be replaced. If the fuse has blown,
consult your OMRON representative.
If the fuse has blown, short-circuit current will not continue to
flow on the primary side (i.e., the external side) of the Power
Supply. There is, however, no protection function for the input
power lines.
●Inrush Current
When a Switch-mode Power Supply is turned on, a surge of
current flows into the input smoothing capacitor to charge the
capacitor. This current surge is called the “inrush current.” The
inrush current varies depending on the application timing and the
presence of an inrush current protection circuit, but is usually
several to several tens of times greater than the steady-state
input current.
When two or more Switch-mode Power Supplies are connected
to the same input, the total current is the sum of the currents for
each Power Supply. Therefore, check the fusing characteristics
of fuses and operating characteristics of breakers making sure
that the external fuses will not burn out and the circuit breakers
will not be activated by the inrush current. The inrush current
pulse width can be considered to be about 5 ms. (Refer to the
following diagram.)
In particular, models with 100-to-240 VAC input have higher
inrush current energy than models with single rated inputs or
models with switching inputs. Therefore, consider the
coordination with the breaker.
The following table provides guidelines for fuse and breaker
selection.
Note. The duration of the inrush current is 5 ms max. Therefore, the fusing
characteristics require the inrush current to flow sufficiently for up to 5 ms.
●Leakage Current
Switch-mode Power Supplies have an internal noise filter circuit
that prevents switching noise from being fed back to the input
lines and protects the internal circuit from external noise.
Leakage current is largely due to the current that flows through
the capacitors (C1or C2) of the input filter circuit.
Depending on the Power Supply’s configuration, leakage current
can be reduced by incorporating an internal filter circuit.
The ACG terminal on the S82W Power Supply, which is
connected between capacitors C1and C2of the filter circuit, is
short-circuited to the terminal by the short bar. Leakage
current can be reduced by removing the short bar.
When the leakage current poses a problem, such as when using
more than one Power Supply, remove the short bar from each
Power Supply.
To prevent electric shock, however, be sure to ground
the terminal.
In this case, however, the input filter cannot function effectively,
resulting in greater
output ripple noise
and feedback noise.
To suppress this
noise, connect an
external noise filter
circuit as shown
below.
Leakage current cannot be reduced in Power Supplies
without an ACG terminal due to the filter circuit
configuration.
●Ripple and Noise
Since Switch-mode Power Supplies operate at high frequencies
(i.e., as high as 20 kHz or more), the DC output will contain ripple
and noise. The following figure shows a representative waveform
for ripple and noise.
Since ripple and noise contain high-frequency components, the
ground line of the oscilloscope must be shortened when making
measurements. If the ground line is too long, it acts as an
antenna which is influenced by radian waves and, consequently,
the correct values of ripple and noise cannot be measured.
●Voltage Adjustment Range
The range over which the output voltage can be adjusted while
maintaining specific output characteristics.
Note 1. The output voltage can effectively be converted to a value above the
specified range. When adjusting the voltage, however, check the actual
output voltage and make sure it is within the specified output voltage
range.
Note 2. Make sure that the output voltage ×output current does not exceed the
rated output capacity and that the output current does not exceed the
rated output current.
Note 3. Do not apply unnecessarily strong force to the Output Voltage Adjuster
(V.ADJ). Doing so may damage the V.ADJ.
Selection points External fuses Circuit breakers
Rated voltage Sufficient for the input voltage of the Power Supply
Rated current Same as that of internal fuses Sufficient for the rated cur-
rent of the Power Supply
Inrush current Must not be burnt or tripped at the Power Supply inrush current
(pulse width: approx. 5 ms).
Fuse type Normal burning or semi-time lag. ---
Input
voltage
Input
current
Inrush current (at cold start)
Burnout time
Current
5 ms
Fuse Burnout Vs. Circuit-breaker
Characteristics Curve AC input
Rating
Inrush current
5 ms
Input
C2
C1
ACG
Model with A
CG
Terminals
ACG
AC Input Noise
filter
ACG ACG
Input
C2
C1
Model without ACG
Terminals
Ripple
Input cycle of commercial
power source
Switching cycle
Noise Ripple
and noise

4Power Supply Technical Information
●Input Variation Influence
The variation in the output voltage occurring when only the input
voltage is changed slowly over the input range while maintaining
constant output conditions.
●Load Variation Influence
The variation in the output voltage occurring when the output
current is changed slowly over a specified range while
maintaining constant input conditions.
●Temperature Variation Influence
The variation in the output voltage occurring when only the
ambient operating temperature is changed.
●Dielectric Strength
When a high voltage is applied between the input terminals and
the case (PE terminal), electric energy builds up across the
inductor L and capacitor C of the internal noise filter. This energy
may generate a voltage surge when a high voltage is applied to
the Power Supply by a switch or timer, and as a result, the
internal components of the Power Supply may be damaged. To
prevent voltage impulses when testing, decrease the applied
voltage using the variable resistor on the dielectric strength
testing equipment, or apply the voltage so that it crosses the zero
point when it rises or falls.
Some models of OMRON Switch-mode Power Supplies have
surge absorbers between the input lines and between the input
terminals and the ACG terminal. When testing the dielectric
strength of these models, remove the short bar from the PE and
ACG terminals. With the short bar attached to the terminals, the
applied voltage may be cut off by the testing equipment.
(See following diagram.)
●Insulation Resistance Test
To protect the Power Supply from an input voltage surge, surge
absorbers are inserted between the input lines and between the
input terminals and the ACG terminal. When testing the
insulation resistance of the Power Supply, remove the short bar
between the PE and ACG terminals on the front panel.
Otherwise, the measured resistance will be lower than the actual
value. (See following diagram.)
●Overcurrent Protection
Applicable Models: All Models
This protection function prevents damage to the Power Supply
itself due to overcurrent (including output short-circuits). The
protection function is activated and the output current is limited
when the load current is greater than the overcurrent detection
value (this value depends on the model).
The output voltage will also drop according to the overload (load
impedance).
The drop level depends on the overload conditions and load line
impedance.
The following table shows the six types of output voltage drop
characteristics for main models when the overcurrent protection
function is operating.
These drop characteristics can be seen as indicating the limit on
the output current that can be supplied to the load effectively in
the process in which the output voltage starts when the AC input
turns ON. When connecting a load (with built-in DC-DC
converter) that starts operating from a low voltage or a capacitive
load in which inrush current can flow easily, consider the trend in
overcurrent protection drop characteristics and the startup
characteristics on the load side when selecting the Power
Supply.
Generally, an inverted L voltage drop is considered favorable at
startup.
Input side Output side
Input S
V
V
PS
S
Input
ACG
AC1
PE
Input side Output side
Input
Input
S
V
V
PS
S
(M: Insulation resistance meter)
ACG
PE
M
Overcurrent drop char-
acteristics
Relationship between output voltage
and output current Trend Main models
Gradual current/
voltage drop
When a voltage drop occurs, the output current
also gradually drops, and the output returns to
the normal level automatically (automatic recov-
ery) when the overcurrent status is cleared.
S82K
3 W, 7.5 W, 15 W
S8VS
15 W
Inverted L voltage drop
When a voltage drop occurs, the output current
remains essentially constant. The output
returns to the normal level automatically (auto-
matic recovery) when the overcurrent status is
cleared.
S82J
100 W (5 V, 12 V, 15 V), 150 W, 300 W
S82K
90 W, 100 W
S8TS
S8T-DCBU-02
S8VS
240 W
S8VM
50 W, 100 W, 150 W (12, 15, 24 V)
Output current (%)0 10050
Output voltage (V)
0 10050
Output voltage (V)
Output current (%
)

Power Supply Technical Information 5
Power
supplies
Note 1. Loads with built-in DC-DC converters (PLCs, digital panel meters and other electronic devices) and capacitive loads are connected, the overcurrent protection
function will be activated at startup, which may prevent the Power Supply’s output from turning ON.
Note 2. Continuing to use the Power Supply with an output short-circuit or in overcurrent status may cause the internal parts to be deteriorated or damaged.
Note 3. If a load short-circuit occurs, the actual drop in voltage depends on the impedance of the load lines being used.
Note 4. Even if the inclination of the drop characteristics is the same, the actual characteristics (output current/voltage, etc.) depend on the model.
Note 5. Specific precautions apply to some models. For details, refer to the separate information in the datasheet for each model.
●Overvoltage Protection
Main applicable models: S82J (100 W/5 V, 24 V output,
300 W, 600 W), S8TS,
S8VM, S8VS, S8T-DCBU-02
This protection function detects overvoltage and interrupts
output to prevent sensors or other loads from being subjected to
excessive voltage due to failure of the Power Supply’s internal
recovery circuit.
To resume operation, turn OFF the input power, and wait for a
fixed period of time before turning ON the input power again.
Note 1. When the overvoltage protection circuit operates, the Power Supply
itself may be malfunctioning. When restarting the input power after the
overvoltage protection circuit has operated, turn the input power ON
with the load line disconnected and check the output voltage.
Note 2. The overvoltage protection circuit may operate if surge or other external
overvoltage (e.g., from the load) is applied to the output side.
Models with the Zener-diode clamp system do not restart after
the protection circuit operates. Send the product for repair.
* For further details, refer to the datasheet for individual models.
Overcurrent drop char-
acteristics
Relationship between output voltage
and output current Trend Main models
Voltage/current drop
Intermittent operation
When a voltage drop occurs, the output current
also gradually drops, and the load of the Power
Supply itself is reduced (automatic recovery)
using intermittent output when the voltage drops
to a certain level or lower.
S82J
10 W, 25 W
Inverted L voltage drop
Intermittent operation
When a voltage drop occurs, the output current
remains essentially constant. The load of the
Power Supply itself is reduced (automatic recov-
ery) using intermittent output when the voltage
drops to a certain level or lower.
S8VS
30 W, 60 W, 90 W, 120 W, 180 W
S8VM
50 W, 100 W, 150 W (5 V)
Gradual current in-
crease/
voltage drop
Intermittent operation
When a voltage drop occurs, the output current
increases as the voltage drops, maintaining con-
stant power, and the load of the Power Supply
itself is reduced (automatic recovery) using
intermittent output when the voltage drops to a
certain level or lower.
S82J
50 W, 100 W (24 V)
S82K
30 W, 50 W
S8VM
15 W, 30 W
Inverted L voltage drop
Shut off
When a voltage drop occurs, the output current
remains essentially constant. If, however, the
overcurrent status continues for longer than a
fixed time, the output will be interrupted and the
power will need to be turned ON again to
recover.
S82J
600W
Intermittent operation
010050 Out
p
ut current
(
%
)
Output voltage (V)
500 100
Intermittent operation
Output current (%)
Output voltage (V)
500 100
Intermittent operation
Output current (%)
Output voltage (V)
50
Output interrupted
0100 Output current (%)
Output voltage (V)
Output voltage (V)
Overvoltage operation
Voltage adjustable
range
Rated output
voltage
0 V

6Power Supply Technical Information
●Remote Sensing Function
Remote sensing can be used to compensate for a voltage drop
on the load lines. (The compensation range is ±10% of the rated
output voltage.)
To use remote sensing, remove the short bars from the remote
sensing terminals (short-circuited in standard shipments) and
wire as shown in the following diagram.
Make sure that the remote sensing screws are not loose. Loose
screws will prevent output of the output voltage.
To ensure stable operation, it is advisable to thicken the load
connection line and compensate for the amount of voltage drop
using the Power Supply’s voltage adjuster (V.ADJ).
The output voltage of the Power Supply can be varied using an
external variable resistor connected between terminals +V and
+S (except for S8VM).
●Remote Control Function
The output voltage of the Power Supply can be turned ON and
OFF from an external signal while the input voltage is being
applied to the Power Supply. To use this function, remove the
short bars from the remote control terminals (short-circuited in
standard shipments) and connect the switch or transistor as
shown in the following diagram. The output voltage will stop
when the remote control terminals are open.
If the remote control screws become loose, output voltage may
not be produced. Make sure that the screws are tight.
When a transistor is used, make sure that the collector-emitter
voltage VCE of the transistor is 20 V or higher and that the
collector current ICis 5 mA or higher.
●Parallel Operation
•Connect Power Supplies in parallel to increase the
output current if sufficient output current for the load
cannot be obtained from one Power Supply.
List of Connection Methods and Main Models that
Support Parallel Operation of Outputs
•Up to two of the same model can be connected in parallel for
the S82K (100 W), up to four of the same model can be
connected in parallel for the S8TS and S8T-DCBU-02, and up
to five of the same model can be connected for the S82J (300,
600 W).
•The above table lists the main models for which parallel
connection is possible. Refer to the datasheet for each model
for details.
Attempting parallel connection for models that do not support it
may result in an unbalanced load current, possibly causing the
rated output current to be exceeded, so the parallel connection
is not possible.
•Use the same length and thickness of load connection line to
ensure that the voltage drop between each Power Supply and
load is the same.
●N+1 Redundant Operation
Applicable Models: S8TS
Redundant operation is used in parallel connections of N Power
Supplies (single operation when N = 1) of the same model,
where a redundant Power Supply is added to the number of
Power Supplies (N) in parallel operation (N+1), thereby
improving the reliability of the system.
V. ADJ DC ON
Load
Load connection line
Remove
the short
bars.
Remote sensing connection line
(2-conductor shielded cable)
Note 1. When the voltage
drop in the load
lines is large, the
overvoltage
protectionfunction
may activate due
to the increase in
voltage to correct
the voltage drop,
so be sure to use
as thick as a wire
as possible.
Note 2. Be sure that
VOUT ×IOUT does
not exceed the
rating of the
Power Supply.
V. ADJ DC ON
Remove
the short
bar.
VR
The output voltage
variable range is ±10%.
Model Connection method
S82K-10024
S8T-DCBU-02 Only connect the +V and −V outputs in parallel
S82K
(100 W (- P type only)
S82J (300, 600 W)
Connect the +V and −V outputs in parallel and
set the parallel operation selection switch to
PARALLEL.
S8TS (12 V, 24 V) Connect the bus line connector.
Remove
the short
bars.
Tr SW
INPUT
I 1
I 2
I L
I L= I 1+ I 2
INPUT
Load

Power Supply Technical Information 7
Power
supplies
●Series Operation
•Connect the Power Supplies in series to increase the
output voltage.
List of Main Models that Support Series Connection of
Outputs
•The above table lists the main models for which series
connection is possible. Refer to the datasheet for each model
for details.
If models that do not support series connection are used, one
of the Power Supplies may not operate when the AC Power
Supply is turned on, possibly damaging internal circuits over a
period of time.
•If models with different power ratings or rated voltages are
wired in series, keep the current flowing to the load below the
rated output current for the Power Supply with the lowest
power rating.
•If the load is short-circuited when using an S82J-05024@@,
S82J-10024@@, S8VM, S8VS, or S8TS-02505@, reverse
voltage will occur inside the Power Supply, which may cause
Power Supply deterioration or damage. It is recommended to
connect the diodes (D1and D2) as shown in the above
diagram.
Guidelines for the type, dielectric strength, and forward current
of the diodes are as follows:
●Backup Operation
•Two Power Supplies can be wired in parallel even
though each has a sufficient power rating. This can be
done to ensure (back up) Power Supply even if one of
the Power Supplies fails.
(Backup operation is possible for all Power Supplies
with single outputs.)
Use the same model of Power Supply for A and B.
•Select the Power Supplies A and B so that either has a
sufficient power rating for the load.
•Be sure to connect diodes to both Power Supplies A and B, as
shown in the diagram, so that the Power Supply backing up
the faulty Power Supply is not affected.
Guidelines for the type, dielectric strength, and forward current of
the diodes are as follows:
•Increase the output voltage settings of Power Supplies A and
B just enough to allow for the voltage drop (VF) on diodes D1
and D2.
Also, make sure that the diodes are sufficiently cooled so that
their temperatures remain below the catalog value.
This is necessary to control the power loss (output current of
Power Supply IOUT ×diode forward voltage VF) resulting across
the diodes.
•Some power loss to the load will occur due to the load power
and diodes. Therefore, do not exceed the rated power (rated
output voltage ×rated output current) of the Power Supply.
●Creating ± (Positive/Negative) Outputs
•The floating output (the primary and secondary circuits are
separated) enables creating ±outputs using two Power
Supplies. To create ±outputs, connect two of the same model
of Power Supply as shown in the diagram.
•All models of Power Supply can be used to create ± outputs. If
there is the possibility that another load is wired in series, such
as a Servomotor or operation amplifier, as shown in the
diagram, connect bypass diodes D1and D2as shown in the
diagram. Without these diodes, the Power Supplies may not
start when power is turned ON, possibly damaging internal
circuits over a period of time.
No diodes are required for models that support series
operation.
•Guidelines for the type, dielectric strength, and forward current
of the diodes are as follows:
Model Power ratings Rated output voltage
S82K 90, 100 W 24 VDC
S82J 100 W 5, 12, 15, 24 VDC
50, 150, 300, 600 W 24 VDC
S8TS 25, 30, 60 W 5, 12, 24 V
S8VS 15, 30, 60, 90, 120, 180, 240 W 24 VDC
S8VM 15, 30, 50, 100, 150 W 5, 12, 15, 24 VDC
INPUT V1
D1
VL
V2D2
VL=V1+V2
INPUT
Load
•Type: Schottky barrier diodes.
•Dielectric strength (VRRM): Twice the rated output voltage of
the Power Supply or higher.
•Forward current (IF): Twice the rated output current of the
Power Supply or higher.
Power Supply A
Power Supply B
D
1
D 2
Load
•Type: Schottky barrier diodes.
•Dielectric strength (VRRM): The rated output voltage of the
Power Supply or higher.
•Forward current (IF): Twice the rated output current of the
Power Supply or higher.
INPUT
V
0 V
V
V
V
VV
INPUT
Load
Load
INPUT
D 2
D 1
INPUT
Load
Load
Load
•Type: Schottky barrier diodes.
•Dielectric strength (VRRM): Twice the rated output voltage of
the Power Supply or higher.
•Forward current (IF): Twice the rated output current of the
Power Supply or higher.

8Power Supply Technical Information
■Harmonic Current Suppression
●What is Harmonic Current?
Most switch-mode power supplies incorporate capacitors. As a
result, the input voltage sine wave is transformed into steep input
current pulses.
If this current is provided to the power-receiving equipment of
factories or buildings, the equipment will generate excessive heat
that may damage the equipment itself, while also consuming
unnecessary energy. This has become a public problem as well.
●Harmonic Current Control
As an international standard, IEC555-2 was enacted for the
limitation of harmonic current emission. IEC1000-3-2, as a
revised standard replacing IEC555-2, was established in 1994.
In conformance with the IEC1000-3-2, EN61000-3-2 was
established and will come into effect in European countries in
January 2001 Power Supplies with a capacity of 75 W or higher.
In Japan, the Ministry of International Trade and Industry
provided some guidelines for the suppression of harmonics
generated from electrical household appliances and electrical
equipment. Japanese manufacturers have been voluntarily
issuing and abiding by the guidelines.
•Main Applicable Models
S82K-P@@@24 (200-V Series only)
S8TS
S8VS
S8VM
Note. Buzzing Noise when Turning ON Input
A noise may occur when turning ON the input of models incorporating
harmonic current suppression circuits. This is a transient noise that
occurs only until the internal voltage has stabilized and does not indicate
any problem in the product.
Main Applicable Models: S8TS
S8VS (120, 180, 240 W)
S8VM (50, 100, 150 W)
■Life Expectancy
The life of a Power Supply is determined by conducting a
temperature rise test of the built-in aluminum electrolytical
capacitors, when using the Power Supply in a standard
installation at the rated input voltage under an ambient
temperature of 40°C and a load rate of 50%. The calculated life
expectancy functions as a guide only is not a guaranteed value.
Use this information as reference for performing maintenance
and replacement.
Note. The life expectancy of the fan in models with fans is not included.
(Main Models)
Eight years or longer: S82K
Ten years or longer: S82J, S8TS, S8VS, S8VM
Input voltage
Input curren
t

Power Supply Technical Information 9
Power
supplies
Power Supply Precautions for Correct Use
■Installation
●Mounting Methods
The standard mounting methods should
be used to ensure proper heat
dissipation. If other mounting methods
must be used, the ambient temperature
must be lowered or the load rate must
be reduced to prevent temperature
increase inside the Power Supply
caused by poor heat dissipation.
Refer to the information in the table on
the right.
DIN-rail Mounting Models: Main Models
Screw Mounting Models: Main Models
*1. The 300-W model can be used under given
conditions.
*2. The 600-W model can be used.
Yes: Can be used
No: Cannot be used.
Conditional: Can be used at an ambient tempera-
ture of 50°C (up to 50% of load rate).
Mounting direction Standard Horizontal Face-up Face-down
Model
S82K OK No Conditional No
S8TS OK No No No
S8VS(15, 30W) OK No OK No
S8VS (60, 90, 120,
180, 240 W) OK No No No
S8T-DCBU-01 OK No No No
S8T-DCBU-02 OK No No No
S8VM OK No No No
Mounting direction Standard Horizontal Face-up Face-down Horizontal
Model
S82J Yes Yes *1 Conditional *2 Conditional *2 No
S8VM Yes Yes Yes No No
●Installation Space
When mounting two or more Power
Supplies side by side, be sure to provide
spacing between them as indicated in
the table on the right or greater.
Note. Be sure to provide an installation space that
allows for shielding (including ducts).
AA
BC
Fan
Fan
S82J
BC
Front panel
Front panel
Spacing Required Between Power Supplies (Unit: mm)
* Ambient temperature of 50°C: 100 mm
Model Dimension A Dimension B Dimension C
S82J 20 20 (300, 600 W) 20 (300, 600 W)
S82K 10 --- ---
S8VS 20 --- ---
S8VM 20 --- ---

10 Power Supply Technical Information
●Wiring in Consideration of Voltage Drop
Make the input and output wiring as thick and short as possible to minimize voltage drop.
Selection of Wires
Select wires for the Power Supply carefully. Refer to this table when selecting the wires.
Recommended Maximum Current: Current The table is applicable to wires with 1 to 4 conductors. Keep the cur-
rent value to within 80% of the values shown in this table when using wires
having 5 or more conductors. The following chart shows the voltage drop per
meter in terms of the relationship between the current and conductor diame-
ter. Make sure that the current value does not exceed the recommended
maximum current value.
Voltage Drop per Meter (UL1015 Vinyl-sheathed Wires for Heat-resistant
Equipment)
Note. The current indicates the allowable current. In practice, application must be below the recommended current
values.
AWG No.
Cross-
sectional
area
(mm2)
Configura-
tion
(number of
conduc-
tors/mm)
Voltage drop per 1 A
(mV/meter)
Recommended maximum current (A)
UL1007
(300 V 80°C)
UL1015
(600 V 105°C)
30 0.051 7/0.102 358 0.12 ---
28 0.081 7/0.127 222 0.15 0.2
26 0.129 7/0.16 140 0.35 0.5
24 0.205 11/0.16 88.9 0.7 1.0
22 0.326 17/0.16 57.5 1.4 2.0
20 0.517 26/0.16 37.6 2.8 4.0
18 0.823 43/0.16 22.8 4.2 6.0
16 1.309 54/0.18 14.9 5.6 8.0
14 2.081 41/0.26 9.5 --- 12.0
12 3.309 65/0.26 6.0 --- 22.0
10 5.262 104/0.26 3.8 --- 35.0
LoadPower Supply
Voltage drop due to wiring
VO
IO
VL
(1)Select a wire diameter suitable for the load current IO.
(2)Make sure that the Power Supply’s output voltage VOdoes not exceed the specified
output fluctuation range.
(3)Consider the allowable current for load short-circuits (guideline: 1.6 times the Power
Supply’s rated output current or higher).
Voltage drop (mV)
1,000
AWG28
(See note.)
700
500
300
100
70
50
30
10
0.1 0.3 0.5 0.7 1 3 5 7 10 30 50 70 100
Current (A)
AWG26
AWG24
AWG22
AWG20
AWG18
AWG16
AWG14
AWG12
AWG10
●Extending the Operating Life
•The life of a Power Supply is
determined by the life of the
electrolytical capacitors used inside.
Here, Arrhenius’ Law applies, i.e., the
life will be halved for each rise of 10°C
and will be doubled for each drop of
10°C. As a result, the life of the Power
Supply can be increased by reducing
its internal temperature.
•Internal Temperature Reduction
The temperature inside a Power
Supply will remain constant when the
heat generation is equal to the heat
dissipated. The internal temperature
will rise if not enough heat is
dissipated, i.e., the Power Supply
must be mounted to allow proper heat
dissipation.
Due consideration must be given so
that the operating ambient
temperature of the Power Supply falls
within the range specified by the
derating curves.
Heat Dissipation with Natural Air Cooling
•Provide air holes and an ambient
atmosphere that allows air convection
•Use a metal plate as the mounting
panel.
•It is recommended that forced cooling
be used as much as possible.
•The calorific (heating) value of the
Power Supply can be expressed in the
following equation.
●Maintenance
Slits are provided in the Power Supply
case to allow heat generated internally
to dissipate externally. It is thus possible
for foreign matter and dirt to enter the
Power Supply and reduce or interrupt
the output. When performing periodic
maintenance, always vacuum away any
foreign matter and dirt from inside the
Power Supply.
Calorific
value (W) = Input power −Output power
=Output power −Output power
Efficiency