Delta Elektronika SM 700 Series User manual

SM 700 - series •SM 1540-D
•SM 7020-D
•SM 3004-D

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 SAFETY INSTRUCTIONS Page 2 - 1
Safety Instructions
Caution
The following safety precautions must be observed during all phases of operation, service and
repair of this equipment. Failure to comply with the safety precautions or warnings in this document
violates safety standards of design, manufacture and intended use of this equipment and may
impair the built-in protections within.
Delta Elektronika shall not be liable for user’s failure to comply with these requirements.
Installation Category
The Delta Elektronika power supplies have been evaluated to installation category II.(Over voltage
category II)
Grounding
This product is a safety Class 1 instrument. To minimize shock hazard, the instrument chassis
must be connected to the AC Power Supply mains through a tree or four conductor power cable for
resp. a single or three phase unit, with the ground wire firmly connected to an electrical ground
(safety ground) at the power outlet.
For instruments designed to be hard-wired to supply mains, the protective earth terminal must be
connected to the safety electrical ground before another connection is made. Any interruption of
the protective ground conductor, or disconnection of the protective earth terminal will cause a
potential shock hazard that might cause personal injury.
Fuses
Fuses must be changed by authorized Delta Elektronika service personnel only, for continued
protection against risk of fire.
Input Ratings
Do not use an AC Supply which exceeds the input voltage and frequency rating of this instrument.
The input voltage and frequency rating of the Delta Elektronika power supply series are stated in
de accompanying datasheet.
Live Circuits
Operating personnel must not remove the instrument cover. No internal adjustment or component
replacement is allowed by non Delta Elektronika qualified personnel. Never replace components
with the power cable connected. To avoid injuries, always disconnect power, discharge circuits and
remove external voltage sources before touching components.
Parts Substitutions & Modifications
Parts substitutions and modifications are allowed by authorized Delta Elektronika service personnel
only. For repairs or modifications the unit must be returned to a Delta Elektronika service facility.

DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 2 - 2 SAFETY INSTRUCTIONS 1989 rev. May 2008
Environmental Conditions
The Delta Elektronika power supplies safety approval applies to the following operating conditions:
Indoor use
Ambient temperature : −20 to 50 °C
Maximum relative humidity : 95%, non condensing, up to 40 °C
: 75%, non condensing, up to 50 °C
Altitude: up to 2000 m
Pollution degree 2
Caution risk of electrical Shock
!Instruction manual symbol. The instrument will be marked with this symbol when it is
necessary for the user to refer to the instruction manual
Protective ground conductor terminal
oOff (supply)
I On (Supply)
WEEE
(Waste Electrical & Electronic Equipment)
Correct Disposal of this Product
Applicable in the European Union.
This marking shown on the product, its packing or its literature indicates that
it should not be disposed with other wastes at the end of its working life, but
should be collected separately to recycle it responsibly to promote the
sustainable reuse of material resources.

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 DESCRIPTIONS Page 3 - 1
DESCRIPTIONS
1) OUTPUT
The SM7020-D and SM3004-D feature an
AUTORANGING faciliy where the power sup-
ply automatically switches over between two
current ranges. This switching, which is unno-
ticeable the user, results in a versatile power
supply with twice the output voltage range.
This means for the SM7020-D: the maximum
output power (700 W) is available at both 35 V
and 70 V. For the SM3004-D: 600 W at both
150 V and 300 V. Fig. 3 - 1 shows the output
ranges.
Note: the voltage and current settings will
never be altered by the AUTORANGING, only
the maximum attainable current will change.
E.g. on the SM3004-D, with an initial setting of
1.5 A. When the voltage is decreased from
200 V to 150 V the max. current output remains
1.5 A as originally set.
•DISPLAY CV/CC SETTING FUNCTION
The setting of the voltage and current control
can be observed on the front panel meters by
pressing the Display CV/CC Setting button.
This allows the current limit to be set when op-
erating in the CV mode without shorting the
output terminals, and the voltage limit to be set
when operating in the CC mode without open-
ing the load leads.
•OVERLOAD PROTECTION
The power supply is fully protected against all
overload conditions, including short circuit.
2) INPUT VOLTAGE
The power supplies have a wide input voltage
range. The 2 ranges (110 V / 220 V) are
selectable with a switch on the rear panel, see
fig. 3 - 2. In the 220 V position the units can also
be used as a DC/DC converter.
•nonstandard line input voltage
The units will still operate at a line input voltage
lower than standard, but with a reduction in
output power. Fig. 3 - 3 shows the max. output
current as a function of output voltage with AC
or DC line input voltage as a parameter.
Example: When the required output voltage is
12.5 V at a line input voltage of 150 V AC.
Fig. 3 - 4 shows the maximum current for the
SM1540-D to be 32.8 A.
fig. 3 - 1
The output ranges
Every point in hatched area can be used
SM1540-D SM7020-D SM3004-D
fig. 3 - 2
Input voltage selector at rear panel
fig. 3 - 3
Max. output current vs output voltage with AC or
DC line input voltage as a parameter
fig. 3 - 4
Example how to use the graph

DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 3 - 2 DESCRIPTIONS 1989 rev. May 2008
3) INPUT CURRENT
The input circuit has a large series choke to improve the waveform. The re-
sult is: a lower rms input current, less mains distortion and no large peak cur-
rents. The units also have an inrush current limiter and a soft start circuit, for
smooth switch on.
•FUSES- At 220 V: 8 A Slow blow, at 110 V: 16 A Slow blow.
4) STANDBY INPUT POWER
The unit consumes very little power when in standby. This makes it possible
to leave the input power on and use the Remote ShutDown input (pin 5 on
prog. connector rear panel) to disable the output.
5) EFFICIENCY
The efficiency is very high and constant over a wide output current range,
see fig. 3 - 5. High efficiency also means low power loss and low heat gener-
ation.
6) REGULATION
The load regulation should be measured directly on the output terminals.
A few cm of cable can have a voltage drop of several mV (at high current!).
7) RIPPLE & NOISE
The output ripple is very low with almost no spikes.
The ripple voltage has to be measured directly on the output terminals using
a probe with very short connections (to avoid pick up of magnetic fields). See
fig. 3 - 6 and fig. 3 - 7.
•LOW TEMPERATURE
At –20 °C the CV ripple increases to the following values:
8) PROGRAMMING INPUTS
The output voltage and current can be programmed by an external analog
voltage. This programming is very accurate and linear, (non-linearity <
0.15%). The levels are all standardized on 5 V. Always use a shielded cable
for programming.
The inputs have a protection circuit formed by a series resistor and a parallel
zener, see fig. 3 - 8. The capacitor limits the speed to a safe value. Note that
the analog inputs (and outputs) are not floating, but the common is con-
nected to the negative output terminal. Wrong connection of Ø can cause
earth loops which can trip the fuse. After removing the fault, the fuse will re-
set (PTC-fuse). To prevent earth loops, use isolated programming with the
ISO AMP MODULE (δ-product).
The programming mode (program and manual) can be selected by means of
the prog. switches which are situated below the programming connector,
see fig. 3 - 10.
9) IEEE488 / RS232 PROGRAMMING
The prog. connector on the power supply is both pin and level compatible
with the interfaces PSC-488 module and PSC-232 module (both δ-prod-
ucts).
Voltage and current can easily be programmed and read back, also the CC
and OVP status can be read by the computer. Always use a shielded cable
for programming.
10) MONITORING OUTPUTS
The monitor outputs give a voltage 0 - 5 V proportional to the output current
or voltage. The output current can easily be measured without an external
shunt using the I monitor, see fig. 3 - 9. The monitor outputs are buffered by
op-amp’s and protected by series resistors and parallel zeners see fig. 3 -
11. The table in fig. 3 - 12 shows the impedance levels of the monitoring out-
puts.
Note: in case of a pulsating load, the I monitor voltage will not exactly
fig. 3 - 5
Efficiency vc output current, SM7020-D
DC input, Vout = 70 V
SM1540-D SM7020-D SM3004-D
CV ripple (rms/pp)
@−20 °C
6 / 20 mV 10 / 35 mV no change
fig. 3 - 6
Measuring ripple voltage
WRONG !
fig. 3 - 7
Measuring ripple voltage
RIGHT !
fig. 3 - 8
Programming inputs
(internal circuit)
fig. 3 - 9
External meters
using monitor outputs

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 DESCRIPTIONS Page 3 - 3
match the output current. This is mainly caused by the current through
the output capacitors. Remote sensing will worsen this effect.
11) STATUS OUTPUTS
The status outputs have an open output voltage of 5 V and a short cir-
cuit current of 10 mA. This makes it possible to drive directly: an
opto-coupler, a TTL gate or a CMOS gate (put leakage resistor to Ø).
12) REMOTE SHUTDOWN (RSD)
A voltage of +5 V on the Remote ShutDown input on the programming
connector will switch off the power circuit of the unit. In standby mode
the power supply consumes very little power.
It is also possible to use a relay contact or a switch to shutdown the
unit: connect a switch between Vref and Rem. ShutD. (pin 9 and 5).
Note: The Remote ShutDown will also cause the OVP-led to burn and
the OVP-status will be high.
13) PROGRAMMING RESPONSE TIME
The response time is measured with a step waveform at the CV prog.
input. Programming from a low to a high output voltage is nearly load
independent, but programming down to a low voltage takes more time
fig. 3 - 10 Location of output terminals, Sense Block, analog prog.
connector and PROG. / MAN. switches on rear panel
(SM3004-D has no sense block).
fig. 3 - 11
Buffered monitor outputs (internal circuit)
Output pin Ro Io max
Vref 9 15 Ohm 10 mA
Vmon 10 20 Ohm 10 mA
Imon 2 20 Ohm 10 mA
+12V 7 500 Ohm 25 mA
Ø 1 1.2 Ohm
fig. 3 - 12 Outputs on programming connector
pin description
1Ø, return of reference, prog. inputs and
monitor outputs.
2current monitor output (0 - 5V)
3current programming input (0 - 5V)
4CC status output, logic 1 = CC mode
(5 V / 10 mA)
5Remote ShutDown
6M/S parallel, slave enable (only for
autoranging)
7+12 V output (Ri = 500 Ohm)
8Ø, return of status outputs, +12 V and
remote ShutDown
9reference voltage 5.1 V
10 voltage monitor output (0 - 5V)
11 voltage programming input
(0 - 5V)
12 PSOL status output (optional)
13 OVP status output, logic 1 = OVP mode
(5 V / 10 mA)
14 NC
15 NC
fig. 3 - 13
Connections ANALOG PROG. CONN.
fig. 3 - 14 External potmeters

DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 3 - 4 DESCRIPTIONS 1989 rev. May 2008
on lighter loads. This is caused by the output capacitors, which
can only be discharged by the load because the power supply
cannot sink current.
14) PROGRAMMING BANDWIDTH
For small signals the bandwidth is 50 Hz, but for large signals
there is a limitation in the maximum amplitude of the output wave-
form. The output capacitors limit the max. slew rate. Fig. 3 - 15
shows the maximum peak to peak output voltage swing as a
function of frequency, with the load as a parameter. The higher
the load resistance the lower the max. amplitude. The measure-
ments were carried out using a sine wave. The DC level of the
output is 50 % of the max. output voltage. On the SM7020-D and
SM3004-D measurements were also carried out at 25 % of the
max. output voltage.
15) RECOVERY TIME
Fig. 3 - 16 shows the recovery time for the SM7020-D at 25 °C, a
50 – 100 % load step and at maximum output voltage. At –20 °C
the recovery time increases by 100 μs.
16) NOISE SUPPRESSION (input / output)
The input / output noise suppression is measured with a pulse
generator (a) in series with the line input or (b) between input and
case (earth). The generator should produce a high energy pulse
of about 300 V. If there is an electrical connection between the
output and the input through the oscilloscope, you will get a false
reading. The suppression for the SM3004-D is lower, but the rel-
ative disturbance on the output is comparable to the SM1540-D.
17) PULSATING LOAD
To avoid overheating the output capacitors, the AC component
of the load current should be limited. See fig. 3 - 17.
One method of decreasing the AC current through the output ca-
pacitor is by using a large external electrolytic capacitor in paral-
lel with the load. Care must be taken so that the capacitor in
combination with the lead inductance will not form a series reso-
nant circuit!
When using remote sensing on a pulsating load (for instance a
DC-motor), use a capacitor between S+ and + and between S-
and - and a series resistor in the sense leads. See fig. 3 - 18. Like
this the AC-component caused by the voltage drop across the
load leads, is filtered.
fig. 3 - 15
Max. peak to peak output voltage swing vs frequency
fig. 3 - 16
Recovery time SM7020-D
50 - 100 % load step, Vo = 70 V
fig. 3 - 17
Pulsating load current
fig. 3 - 18
Remote sensing on a pulsating load
SM1540-D SM7020-D SM3004-D
AC-level max. 10 Arms 5 Arms 1 Arms

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 DESCRIPTIONS Page 3 - 5
18) INSULATION
For safety the insulation of the separating components (trans-
formers) between input and output is tested at 3750 Vrms during
1 minute. This is tested before assembling.
Warning! The 3750 Vrms cannot be tested afterwards on the
assembled unit because the insulation between the compo-
nents on the input side to the case (like the bridge rectifier) is
specified at 2500 Vrms. Since the insulation output - case is low
(only 600 V DC) the insulation of the primary components to
case will break down when 3750 Vrms is applied between input
and output (2500 Vrms + 600 V DC < 3750 Vrms). See also
fig. 3 - 19.
Note: when testing the insulation, take care to charge and dis-
charge the capacitors between input - case and output - case
slowly (e.g. in one second). This to prevent high peak currents,
which could destroy the power supply. Make sure to have dis-
charged the capacitors completely before using it again.
19) RFI SUPPRESSION
Both the input and output have RFI filters, resulting in very low
conducted RFI to the line and load. Due to the output filter the
output voltage is very clean, having almost no spikes.
20) OPERATING TEMP
At full power the operating temperature range is –20 to +50 °C.
From 50 to 75 °C the output current has to be derated linearly to
20 % at 75 °C. See fig. 3 - 20. These temperatures hold for nor-
mal use, i.e. the air must be able to pass freely vertically along
and through the unit.
21) THERMAL PROTECTION
A thermal switch shuts down the output in case of insufficient
cooling. After cooling down the unit will start working again. In
this condition the OVP led on the front panel will burn, and the
OVP status output will be high.
22) HOLD - UP TIME
The hold - up time depends on the load, output voltage and line
input voltage. A lighter load, a lower output voltage or a higher
line input voltage all result in a longer hold - up time, see fig.
3 - 21. For example: the SM1540-D at 220 VAC input and 12 V /
40 A output will have a hold-up time of 50 ms.
23) TURN ON DELAY
The output voltage is available 0.5 sec after mains switch on.
24) INRUSH CURRENT
The inrush current is limited by a 50 Ohm PTC resistor, resulting
in a very low current during switch on. The input current during
switch on will be lower than during operation at full load.
fig. 3 - 19
Insulation test voltages
fig. 3 - 20
Operating temperature ranges
fig. 3 - 21
Holdup time vs Vout with line input
and Iout as parameter

DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 3 - 6 DESCRIPTIONS 1989 rev. May 2008
25) SERIES OPERATION
Series operation is allowed up to 600 V total voltage. The power supplies
can be connected in series without special precautions.
For easier control, Master / Slave operation is recommended (fig. 3- 23).
By using the Master / Slave series feature a dual tracking power supply
can be made with one unit as master and one as slave.
For series operation in combination with Power Sink option, all units must
have a Power Sink built inside otherwise no power can be absorbed.
26) PARALLEL OPERATION
Paralleling of the units has no limitations. The power supplies can be con-
nected in parallel without special precautions.For easier control, Master /
Slave operation is recommended (fig. 3 - 24).
Normal parallel operation of Fast Programming units can give problems,
each combination has to be tested first, in combination with the load !
For parallel operation in combination with Power Sink option, only one unit
can have a Power Sink. Refer to Power Sink manual for details and restric-
tions.
27) MASTER / SLAVE OPERATION
The Master / Slave feature makes it possible to use the power supplies as
building blocks to form one large unit, see fig. 3 - 23 and fig. 3 - 24.
The resulting combination of units behaves like one power supply and can
be programmed on the master. In the Master / Slave mode the autoranging
feature still works. Fig. 3 - 26 shows a computer controlled M / S parallel
combination.
Mixed parallel - series operation is also possible (fig. 3 - 25), to a maximum
of 600 V.Here the MASTER / SLAVE SERIES ADAPTER(δ-product) must
be used. For parallel operation connections can easily be made on the ana-
log programming connector.
In series mode the master controls one slave, which in turn controls the
second slave and so on. In parallel mode the master controls all the slaves.
The result is true current or voltage sharing in the parallel or series mode
respectively.
Note: Master / Slave parallel operation is not recommended for more
than 3 units or in combination with Fast Programming option.
Consult factory for a solution.
28) REMOTE SENSING
The voltage at the load can be kept constant by remote sensing. This fea-
ture is not recommended for normal use but only when the load voltage is
not allowed to vary a few millivolts. Always use a shielded cable for sens-
ing. Note that the SM3004-D has no remote sensing.
In order to compensate for the voltage drop across the load leads, the unit
will have to supply a higher voltage: Uout = (voltage drop across each lead)
+ (voltage across the load), see fig. 3 - 27. The OVP reads the voltage di-
rectly at the output and the setting must be increased by the total voltage
drop across the load leads.
The voltmeter is connected to the sense leads and therefore reads the volt-
age across the load and not the voltage on the output terminals.
The sense leads are protected for accidental interruption, in which case
the output voltage will go to a max. of 115% of the set value.
Warning: Do not interrupt the minus lead while the S– lead is still con-
nected to the load, during operation. It is possible that the capacitor C808
on P385 or P386 will be damaged.
For sensing on a pulsating load see par.17) of this chapter.
29) OVP
The Over Voltage Protector will protect your circuit from unwanted high
voltages.
A high output voltage could be caused by accidental interruption of leads,
accidentally turning up the voltage potmeter or a defect in the power sup-
ply. The OVP circuit uses a separate voltage devider connected directly to
the output terminals.
The OVP limits the output voltage to a value which can be set by the OVP
potmeter on the front panel. While doing this, press the DISPLAY OVP
SETTING button to read the limit value in the left display. The led on the
front panel will indicate whether the OVP has reached the limit. The OVP
status output will give a logic 1 (+5 V)
fig. 3 - 22
Dual tracking power supply
fig. 3 - 23
Master / Slave series operation
fig. 3 - 24
Master / Slave parallel operation
fig. 3 - 25
Master / Slave mixed Series-Parallel
fig. 3 - 26
The Master / Slave combination can also
be programmed with the interfaces
PSC-488 or the PSC-232

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 DESCRIPTIONS Page 3 - 7
Note: The Thermal ShutDown and Remote ShutDown will also cause the
OVP-led to burn and the OVP-status will be high.
When the OVP status output is used as an indication for accidental inter-
ruption of leads, a defect in the power supply etc., it is recommended to set
the limit well above the working output voltage to avoid accidental limiting.
The recommended OVP set voltages can be read from the following table:
Example: For a SM7020-D set at 24 V output voltage it is recommended to
set the OVP on 24 + 3 = 27 V.
30) POTENTIOMETERS
•Standard: -CV and CC potentiometers with knobs at front panel,
OVP potentiometer with screwdriver adjustment at
the front panel.
•Option P001: -Screwdriver adjustment for CV, CC and OVP at the
front panel, fig. 3 - 28.
•Option P002: -Screwdriver adjustment for CV, CC and OVP at the
rear panel (no potentiometers at front panel),
fig. 3 - 29.
31) COOLING
The cooling is by natural convection, no noisy blowers are present. The
unit should have sufficient free space to let the air flow vertically through the
unit. See fig. 3 - 30. A distance of minimum 5 cm around the unit is recom-
mended.
For long life the temperature of the air entering the unit, should be below
35 °Cunder normal conditions.
Under extreme conditions it should be below 50 °C.
fig. 3 - 27
Remote sensing, voltage drop in load
leads subtracts from max. output
fig. 3 - 28
Optional screwdriver adjustment
at front panel
fig. 3 - 29
Optional screwdriver adjustment
at rear panel
fig. 3 - 30
Vertical airflow through the unit
Unit: SM1540-D SM7020-D
range 0 - 35 V
SM7020-D
range 35 - 70 V
SM3004-D
range 0-150 V
SM3004-D
range 150-300 V
Vovp Vout + 2 V Vout + 3 V Vout + 5 V Vout + 10 V Vout + 25 V

DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 3 - 8 DESCRIPTIONS 1989 rev. May 2008
CIRCUIT DESCRIPTION
The 220 V AC line voltage is rectified by a bridge
rectifier and smoothed by a large electrolytic capaci-
tor. The 50 Hz choke in the input circuit improves the
waveform of the input, so that no low frequency dis-
tortion is produced on the line voltage.
Carefully designed RFI filters protect the line and
the load from the high frequency interference pro-
duced inside the power supply.
When the unit is switched on, the electrolytic ca-
pacitor is charged via the resistor of the SOFT
START circuit, so no large inrush current will flow.
As soon as the voltage is sufficiently high the power
supply starts working and the series resistor is by-
passed by a triac.
The operating switching frequency of 100 kHz
has many advantages like small size, light weight,
low ripple and fast regulation.
The rectified 220 V (300 V DC) is chopped by the
transistors and transformed to a lower voltage. This
100 kHz power converter is of the feed forward type.
The regulation is achieved by pulse width modula-
tion.
Careful design, over-rating of vital components,
several built-in protections and cool operation (be-
cause of the very high efficiency) make the SM se-
ries very reliable power supplies which can be used
continuously at maximum rating.
fig. 3 - 31 Simplified functional diagram of SM1540-D, SM7020-D, SM3004-D

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 OPERATING MAINTENANCE TROUBLE SHOOTING CALIBRATING Page 4 - 1
OPERATING MANUAL
1) OPERATING THE UNIT FOR THE FIRST TIME
•Set the input voltage selector switch found on the rear panel to
the required input voltage (110/230 V). A wrong setting can seri-
ously damage the unit. Do not switch the selector switch when
the unit is in use.
•Check input fuses. For 110 V operation fuses have to be re-
placed. See text at rear panel.
•Check that there is no condensation on the unit. If there is, allow
some time to dry.
•Set the prog. switches on the rear panel on MANUAL.
•Check that there is a link between + and S+ and between – and
S– on the SENSE BLOCK (on rear panel).
SM3004-D has no remote sensing!
•Set OVP potentiometer (on front panel) to maximum (fully clock-
wise), Use a screwdriver to set the OVP voltage.
•With high output current (SM1540-D!) make sure to use low re-
sistive connections between the power supply and the load:
- Mount the cable lugs between the two nuts and washers .
- Only use nuts and washers supplied with the unit (tinned brass).
- Never use extra washers, spring washers , serrated locks etc.
•Switch on unit.
•Turn both the CV and CC potentiometer a few turns clockwise. A
voltage should now be present on the output.
•By pressing the DISPLAY CV/CC SETTING button the meters
will show the setting of the CV and CC potentiometer.
•By pressing the DISPLAY OVP SETTING button the volt meter
will show the setting of the OVP potentiometer.
•When the power supply is used on a fixed output voltage it is
highly recommended to set the Over Voltage Protector. As set
out in the following table:
SM1540-D SM7020-D
range 0 - 35V
SM7020-D
range 35 - 70V
SM3004-D
range 0 - 150V
SM3004-D
range 150 - 300V
Vout + 2V Vout + 3V Vout + 5V Vout + 10V Vout + 25V
Example: For a SM7020-D set at 24 V output voltage it is recom-
mended to set the OVP on 24 + 3 = 27 V.
•Check that the cooling of the unit is not obstructed.
2) ANALOG PROGRAMMING
•Put the appropriate switch(es) in the position PROGRAM.
•Connect the programming voltage source(s) (0 - 5 V) to the ANA-
LOG PROG. CONNECTOR on the rear panel (see fig. 4 - 1 and
fig. 4 - 2). Always use a shielded cable for programming.
•If only the voltage is programmed, the maximum current can still
be set with the CC potentiometer and vice versa. If this is not de-
sirable the CC or CV can be set with an external potentiometer, in
order to have a fixed setting.
•CAUTION: The analog inputs are not isolated from the output.
The Ø of the prog. input (pin 1) is internally connected to the S–,
the S– is connected to the negative output. To protect the internal
wiring a 650 mA self-resetting fuse is connected in series (F600
on P385, P386 or P387), see fig. 4 - 4.
For isolated analog programming the ISO AMP MODULE
(δ-product) is recommended to avoid earth loops.
•To avoid hum or noise, the programming cable may have to be
twisted in some cases.
•To program the unit by current instead of voltage, simply use a
parallel resistor as a current to voltage converter.
3) IEEE488 / RS232 PROGRAMMING
•With the external IEEE488 /RS232 interface PSC-488 module /
PSC-232 module (both δ-products) simply connect the prog.
connector of the power supply with the mating connector of the
PSC-488 / PSC-232 (pin compatible). Always use a shielded ca-
ble.
•Set both prog. switches to the position program.
•Both CV and CC can be programmed and read back. The CC and
OVP status can also be read by the computer.
fig. 4 - 1
Programming by voltage
left voltage -, right current programming
fig. 4 - 2
Programming by current
left voltage -, right current programming
fig. 4 - 3
Remote control
fig. 4 - 4
Internal circuit of programming inputs and outputs

DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 4 - 2 OPERATING MAINTENANCE TROUBLE SHOOTING CALIBRATING 1989 rev. May 2008
4) MONITORING OUTPUTS
•The 5 V level is compatible with most interfaces.
•The monitoring outputs can drive a meter directly, fig. 4 - 3.
5) STATUS OUTPUTS
•The status outputs have a separate Ø connection (pin 8) to
avoid unwanted offsets in the programming. This pin is pro-
tected with a 650 mA fuse (F601 on P385, P386 or P387).
6) REMOTE SENSING
•Not available on SM3004-D.
•Remove the links on the SENSE BLOCK (on rear panel) and
connect sense leads (thin shielded measuring wires) to S+
and S–. See fig. 4 - 5 and fig. 4 - 6.
•With remote sensing the voltage on the load can be kept con-
stant. The voltage drop in the load leads will be compensated.
This feature is not recommended for normal use, because it
can easily give problems.
•Max. 2 V per load lead can be compensated. Note that the
voltage drop in the leads decreases the max. output voltage
rating. In fig. 4 - 27 it can be seen that on a 15 V power supply
only 11 V will be available on the load when 2x 2 V compensa-
tion is used.
•In order to prevent interference it is advisable to twist the
sense leads. To minimize the inductance in the load leads
keep the leads close to each other. The inductance of the
loads leads could give a problem with pulsating loads. In this
case a large electrolytic capacitor in parallel with the load will
help. Check that the capacitor in combination with the load
leads does not form a resonant circuit resulting in a large AC
current flowing in the leads.
•Since the voltmeter is internally connected to the sensing ter-
minals, it will automatically indicate the voltage on the load.
Note that the voltage measured on the load will be lower than
on the output terminals.
•The Over Voltage Protector measures the voltage on the out-
put terminals, so the OVP setting should be increased by the
total voltage drop in the load leads.
7) BATTERY CHARGER
•The CV / CC regulated power supplies are ideal battery charg-
ers. Once the output is set at the correct voltage the battery
will charge constantly without overcharging. This can be use-
ful for emergency power systems.
•Protective measures
Use a CIRCUIT BREAKER in series in order to protect the
power supply from accidental reverse connection, see fig.
4 - 8. The circuit breaker should have a DC voltage rating 2x
the battery voltage. Use the very fast type (Z), a type meant for
protecting semiconductors.
The unit has a reverse diode in parallel with the output, this di-
ode and the wiring cannot withstand the thousands of am-
peres supplied by a wrongly connected battery.
Suggested Circuit Breakers for protection power supply
Model Type number
Circuit Breaker
Brand Remarks
SM1540-D S281 UC-Z 40 ABB
SM7020-D S281 UC-Z 20 ABB extra parallel
diode on output
= Option P021
SM3004-D S282 UC-Z 4 ABB 2 poles in series,
extra parallel
diode on output
= Option P022
fig. 4 - 5
Local sensing
fig. 4 - 6
Remote sensing with shielded wires
fig. 4 - 7
Remote sensing, voltage drop in load leads sub-
tracts from max. output
fig. 4 - 8
Charging battery with a circuit breaker in series
fig. 4 - 9
Protecting sense wires with diodes

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 OPERATING MAINTENANCE TROUBLE SHOOTING CALIBRATING Page 4 - 3
•Remote sensing cannot be recommended, because it easily
causes defects inside the power supply in case of wrong con-
nection.
If you really need remote sensing, please use the circuit in fig.
4 - 9. The internal circuit can be protected by relatively small
anti-parallel diodes. To protect the anti-parallel diodes, please
connect the fuses in series as indicated in fig. 4 - 9 . A practi-
cal choice for the fuses is 250 mA, the diodes can be any nor-
mal 3 or 5 A type.
•Note: The SM7020-D and SM3004-D need an extra parallel
diode on the output, without this diode the internal diode will
still blow. The diode should have a surge current rating of
resp. 2000 and 3000 amps during 1msec (IFSM = 2000 / 3000
A ). For the SM7020-D 2x BYT52PI200 and for the SM3004-D
2x BYT261PIV400 from ST will work. The SM7020-D with Op-
tion P021 and the SM3004-D with Option P022 have an extra
diode built-in.
fig. 4 - 10
Left: remote ShutDown with switch,
Right: Over Current Trip
8) REMOTE SHUTDOWN / OVER CURRENT TRIP
•The remote ShutDown can be operated with +5 V or a relay
contact, fig. 4 - 10.
•Using the remote ShutDown input, an Over Current Trip could
be made., fig. 4 - 10.
9) MASTER / SLAVE SERIES OPERATION
•For series operation the MASTER / SLAVE SERIES
ADAPTER (δ-product) must be used, see fig. 4 - 11.
The advantage is that the masters position can be the upper or
the lower unit (in particular for higher voltages; 150 V and
300 V). Other advantages are the fast and easy way of
connecting.
•First, connect output terminals and test system in normal se-
ries operation. Ensure that all (output) power connections are
reliable. An interruption of one of the power leads can cause a
fuse to blow in the unit, see ''trouble shooting''.
•The voltage drop in the connecting leads between the units
should be kept < 10 mV.
•Second, switch off all units. Connect units as shown in fig.
4 - 12. Use standard 15 pole (1:1) shielded cables.
•The max. number of slaves is only limited by the max. total
voltage of 600 V.
•The AUTORANGING feature still works
10) MASTER / SLAVE PARALLEL OPERATION
•Note: Master / Slave parallel is not recommended for more
than 4 units, consult factory for using more than 4 power
supplies in parallel.
•First connect output terminals and test system in normal paral-
lel operation. Ensure that all power connections are reliable. An
interruption of one of the (output) power leads can cause a fuse
to blow in the unit, see “trouble shooting”.
•Second, switch off all units. Plug in prog. connectors with the
connections according to fig. 4 - 13 (buss bar topology). Always
use a shielded cable. The shielding must be connected to the
case of the supply.
Disconnect the links between the S– and – of the slaves only.
fig. 4 - 11
The Master / Slave Series Adapter,
supplied by Delta Elektronika
fig. 4 - 12
Master / Slave series connection with
two M/S SERIES ADAPTERS

DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 4 - 4 OPERATING MAINTENANCE TROUBLE SHOOTING CALIBRATING 1989 rev. May 2008
If not removed the current sharing will not be proportional.
Both prog. switches of the slaves should be in the position
PROGRAM.
•The purpose of the link between pin 9 and 11 is to set the volt-
age limit of the slaves at maximum.
•an extra link on the slaves (between pin 6 and 8) is needed for
the AUTORANGING feature.
•Keep the load close to the master. Keep wiring between mas-
ter and slaves short. The voltage drop between a unit and the
buss bar should be kept < 10 mV.
•Accidental interruption of a negative load lead of a unit during
operation will cause fuse F600 to blow, see section ‘trouble
shooting’.
•The S- and S+ could be connected to the load if desired, but
this is not recommended because of the complexity.
11) MASTER / SLAVE MIXED SERIES / PARALLEL
OPERATION
•For complex combinations as mixed series - parallel always
use the MASTER / SLAVE SERIES ADAPTER (δ-product).
•See fig. 4 - 14 for an example of how to connect 2 units in se-
ries in parallel with 2 units in series, controlled by 1 master.
•On the parallel slave1, fully open the CV-potmeter.
•Note: A Master / Slave combination can always be pro-
grammed, also with the IEEE488 / RS232 controller
(PSC-488 module / PSC-232 module (both δ-products)).
fig. 4 - 13
Master / Slave parallel connections
fig. 4 - 14
Master / Slave mixed series - parallel connections with
two M / S SERIES ADAPTERS

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 OPERATING MAINTENANCE TROUBLE SHOOTING CALIBRATING Page 4 - 5
OPERATING AND STORAGE CONDITIONS
1) TEMPERATURE
•The operating temperature range at full load is -20 to +50 °C.
But this temperature range only holds when the perforated bottom
and cover are unobstructed and the temperature of the air enter-
ing is not higher than +50 °C. See fig. 4 - 15.
•Please note: a lower temperature extends the life of the
power supply.
•When the power supply is mounted in a cabinet please note that
the temperature of the air entering should be kept low. Also avoid
a short circuit in the airflow i.e. hot air leaving the perforated cover
entering the bottom again.
•The storage temperature range is -40 to +85 °C.
2) HUMIDITY
•During normal operation humidity will not harm the power supply,
provided the air is not aggressive. The heat normally produced in
the power supply will keep it dry.
•Condensation. Avoid condensation inside the power supply,
break-down could be the result.
Condensation can occur during a period the power supply is
switched off (or operating at no load) and the ambient temperature
is decreasing .
Always allow the power supply to dry before switching it on again.
3) GALVANIC INDUSTRY
•For using the power supplies in the galvanic industry it is strongly
recommended to take precautions against an aggressive environ-
ment.
•An aggressive environment with acid, salt, etc. can harm the elec-
tronic components. Sometimes even the copper traces of the
pc-boards dissolve.
•To avoid problems the power supplies should be mounted in a rel-
ative clean room, or mounted in a cabinet receiving clean air with
over pressure. Or a cabinet with a heat exchanger.
MAINTENANCE
1) GENERAL
•The SM-series power supplies normally need no maintenance or
calibration. Only care must be taken that the cooling of the unit is
not obstructed.
TROUBLE SHOOTING
1) GENERAL
•In case you need assistance for repairing a unit, please contact
our engineers using the address "S[email protected]".
•In case you want us to repair the unit, please first fill out the
RMA-form before sending the unit to us. Adding a detailed fault
description will help us to repair the unit as soon as possible.
On our website www.DeltaPowerSupplies.com the RMA-form
can be found under 'Support'.
2) NO OUTPUT (normal operation)
•Check input voltage selector at rear panel. Wrong selection can
cause serious damage to the unit. Do not operate the selector
switch when the unit is switched on.
•Check input fuses. For 110 V operation fuses have to be replaced.
See text at rear panel for values.
•Check position of prog. switches at the rear panel, they should be
on MANUAL.
•Check the connections on the SENSE BLOCK (at rear panel),
there should be a link between + and S+ and between – and S–.
fig. 4 - 15
Leave enough space below and above the unit
the let the air flow through it.
fig. 4 - 16
Location of the input Selector Switch and
the input fuses at the rear panel
switch
fuse
fuse

fig. 4 - 17
For normal operation links should be connected
between S+ and + and between S- and -
DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 4 - 6 OPERATING MAINTENANCE TROUBLE SHOOTING CALIBRATING 1989 rev. May 2008
•Set OVP potentiometer at front panel to max (fully clockwise).
•Switch on unit.
•Turn both the CV and CC potentiometer a few turns clockwise.
A voltage should be present on the output.
3) PROGRAMMING DOES NOT WORK OK
•Check position of prog. switches at rear panel.
•The unit works OK in manual control, but in programming
mode the output voltage / current has a large error.
Probably the fuse in series with Ø (pin 1) of prog. connector trip-
ped, the fuse (F600 = 650 mA) is a self-resetting type. See fig.4 -
18.
•To check the fuse (F600) measure the voltage between Ø and
the minus output, during the fault condition. The voltage should
only be a few mV, a high voltage means that an unwanted cur-
rent is flowing through pin 1 of the prog. connector.
Please check why current is flowing through pin 1, see also next
paragraph ‘programming offsets’ and fig. 4 - 19.
4) PROGRAMMING OFFSETS
•Unwanted offsets in the programming can be caused by
earth loops.
Fig. 4 - 19 shows a typical earthing problem. In case the load has a
connection to earth and the programming source as well, prob-
lems could occur. Improper choice of the earthing point of the load
can give a voltage drop of ΔV1. Connecting the minus or zero to a
separate earth connection can give a voltage drop of ΔV2. Be-
cause the internal wires of the programming input are thin, the
voltage drops ΔV1 and ΔV2 will be across the internal wiring as
well. Resulting in a error voltage in series with the programming
voltage.
•The best solution for this is using a floating programming source
with the help of the ISO AMP MODULE (δ-product) or a floating
load.
5) STATUS OUTPUTS FAIL
•Check fuse F601 in series with Ø (pin 8), see fig. 4 - 18. To check
the fuse (F601) measure the resistance between Ø and the minus
output, an open circuit means a blown fuse. F601 = 650 mA.
6) MASTER / SLAVE PARALLEL PROBLEMS
•Accidental interruption of a minus lead of a unit during operation
will cause fuse F600 to blow. See fig. 4 - 18. To check the fuse
(F600) measure the resistance between Ø (pin 1 of prog. conn.)
and the minus output, the fuse is a self resetting type.
F600 = 650 mA
•AUTORANGING behaves abnormally. Check link between pin 6
and 8 on the prog. connector of the slaves.
•Check link between pin 9 and 11 on the prog. connector of the
slaves
•Current sharing is not ok. Probably the links between S– and – of
the slaves are not removed.
7) OUTPUT VOLTAGE IS HIGHER THAN SET VALUE
•Check connections on SENSE BLOCK (on rear panel), For nor-
mal operation there should be a link between + and S+ and be-
tween – and S–. See also fig. 4 - 17. When remote sensing is
used, check the wires of the sensing.
8) OVP LED on.
•Check OVP setting.
•Overheating also causes the OVP led to be on (see fig. 4 - 21),
cooling down will reset the thermal protection.
•You are using Remote Sensing.
Even a short voltage pulse > 3 V between – and S – causes the
OVP circuit to limit the output voltage.
•Remote ShutDown voltage is applied to the prog. connector.
fig. 4 - 18 Location of programming fuses on
output board P385, P386 or P387.
fig. 4 - 19
Unwanted programming offsets

SM1540-D SM7020-D SM3004-D DELTA ELEKTRONIKA BV
1989 rev. May 2008 OPERATING MAINTENANCE TROUBLE SHOOTING CALIBRATING Page 4 - 7
9) NO LEDS on.
•Overheating can be the cause, cooling down will reset the thermal
protection.
•Check input power and input fuses (on rear panel)
10) CHECK POINTS IN CASE OF A SERIOUS FAILURE
•Check output diodes. Defective diodes give a short.
SM1540-D Check diodes D400 - D403
SM7020-D Check diodes D400 and D402 on P380
SM3004-D Check diodes D400 - D404, D410 - D414,
D420 - D424, D440 - D434 on P381
Replace defective parts.
•Fuse F300 is blown. Do not replace F300 until unit is repaired.
Probably defect on P378. First check output diodes, see above.
•Repairing P378.
Check diodes D301 - D308, check transistors Q300 - Q303.
When defective they usually give a short. Replace defective com-
ponents.
•If necessary, send P378 for repair.
Check fuses
on rear panel
No Output
No LED on
Replace P382
One or more
LED on
Check fuse F300
P377
Proceed with
section: Fuse
F300 is blown
Proceed with
section: Check
output diodes
BlownO.K.
The unit is not
overheated
fig. 4 - 20 Location of F300 on P377
F300
fig. 4 - 21 Location of OVP, CV and CC LED's
fig. 4 - 22 P378: indicated are the polarity of the diodes (K) and the FET's (G/D/S)

DELTA ELEKTRONIKA BV SM1540-D SM7020-D SM3004-D
Page 4 - 8 OPERATING MAINTENANCE TROUBLE SHOOTING CALIBRATING 1989 rev. May 2008
CALIBRATION
1) GENERAL
•The power supplies are factory cali-
brated and normally need no further
calibration.
2) METER CALIBRATION
•DIGITAL METERS
The zero indication can be calibrated
with R712 and R716, the full scale indi-
cation can be calibrated with R706 and
R708 on P388 (fig. 4 - 23).
3) SPECIAL CALIBRATIONS
•The following calibrations must be
done by qualified personnel only.
Wrong calibration causes malfunction.
These calibrations are only needed af-
ter special repairs.
Warning ! Damage caused by wrong
calibration is not warranted.
•CALIBRATING MAX. CURRENT
RANGE or CALIBRATING CC MONI-
TOR FULL SCALE.
The max. output current can be cali-
brated with R686. R686 is located on
P385, P386 or P387. See fig. 4 - 24.
Program CC input with exactly 5.00 V.
Set output voltage to a low value, en-
suring the power supply is in CC mode.
Measure the output current with an ac-
curate shunt. Calibrate the current with
R686 exactly on the rated max. cur-
rent.
Warning! Wrong calibration can dam-
age the unit.
•CALIBRATING THE CC MONITOR
OFFSET.
With R652 on P384 the offset of the CC
monitor voltage can be calibrated. See
fig. 4 - 25. The unit has to be unloaded,
the output voltage set on a low value.
Measure the offset voltage of the CC
monitor on the prog. connector. Cali-
brate the offset on a negative value be-
tween –10 mV and zero mV.
Warning! wrong calibration can
damage the unit.
SPARE PARTS
•When ordering spare parts please
state: Model, Serial number, Compo-
nent number and Component descrip-
tion.
example:
•Model SM7020-D
Serial no................814605900112
Component no. .....D402
Component descr..BYV52-PI-200
fig. 4 - 23 Meter calibration with 25-turn potmeters on P388
fig. 4 - 24 Calibrating max current P385, P386 or P387
fig. 4 - 25 After lifting P384, CC monitor can be calibrated

P.O. BOX 27
4300 AA ZIERIKZEE
NETHERLANDS
TEL. [phone]
FAX. [phone]
www.DeltaPowerSupplies.com
We
Delta Elektronika
P.O. BOX 27
4300 AA ZIERIKZEE
The Netherlands
declare under sole responsibility that the following Power Supplies:
SM 1540-D
SM 7020-D
SM 3004-D
meet the intent of Directives 2004/108/EC; 92/31/EEC; 93/68/EEC for Electromagnetic
Compatibility and
Directives 73/23/EEC; 93/68/EEC regarding Electrical Safety. (Low Voltage Directive)
Compliance was demonstrated to the following specification as listed in the official Journal
of the European Communities:
EN 61204-3 EMC, low voltage power supplies
EN 61000-6-3 Generic Emissions: (residential, light industrial)
EN 55022 Radiated and conducted, Class B
EN 61000-3-2 Power Harmonics
EN 61000-3-3 Voltage fluctuation and flicker
EN 61000-6-1 Generic Immunity: (residential, light industrial)
EN 61000-6-2 Generic Immunity: (industrial environment)
EN 61000-4-2 Electrostatic Discharge
EN 61000-4-3 Radiated electromagnetic fields
EN 61000-4-4 Electrical Fast Transients / Bursts
EN 61000-4-5 Surge Immunity
EN 61000-4-6 RF common mode, conducted
EN 61000-4-11 Voltage variations and dips
EN 60950 Safety of IT equipment
EN 61010 Safety of electrical equipment for measurement, control and laboratory use
EC Declaration of Conformity
Managing director