Industrial Enclosed Switching Power Supply – S Series
DAPPRA S Series — Conventional Single-Output Enclosed Switching Power Supply (40W–350W)
DAPPRA Enclosed Industrial Power Supply
S Series — Conventional Single-Output Enclosed Power Supply
The DAPPRA S Series is a conventional single-output enclosed switching power supply series designed for general industrial and commercial applications requiring a single fixed DC output.
The S Series features an enclosed metal chassis, selectable AC input by switch, free air convection or forced air cooling depending on the model, and complete protection functions. It serves as a cost-effective power supply solution for basic industrial applications.
The S Series covers power ratings from 40W to 350W with output voltages from 3V to 48V. Fanless models (S-40 to S-150) are ideal for quiet, low-maintenance installations, while fan-cooled models (S-240, S-320) deliver higher power in a compact chassis.
40–350 W
Output Power
3–48 VDC
Output Voltage
Selectable
AC Input by Switch
Fanless / Fan
Cooling Options
Overview
S Series Overview
The DAPPRA S Series is a conventional single-output enclosed switching power supply series designed for general industrial and commercial applications. The series includes multiple power ratings from 40W to 350W with single-output configurations ranging from 3V to 48V DC.
The S Series uses an enclosed metal chassis with perforated ventilation and selectable AC input by switch. Small and medium power models (S-40, S-50, S-100, S-150) use free air convection cooling without a fan, while higher power models (S-240, S-320) use forced air cooling with built-in DC fan and Fan ON/OFF control. The series provides short circuit, overload, and over voltage/over temperature protection depending on the model.
Key Features
S Series Key Features
Engineered for conventional, cost-effective enclosed power supply applications.
Selectable AC Input by SwitchThe S Series uses selectable AC input of 85–132 VAC / 170–264 VAC via an external switch. Some models also support 240–370 VDC input when the switch is set on 230 VAC position. The S-240 uses auto-switch 88–132 VAC / 176–264 VAC.
Enclosed Metal Chassis with Cooling VentsThe fully enclosed metal chassis with perforated ventilation holes provides heat dissipation and electrical safety. Suitable for standalone mounting inside industrial equipment and control cabinets.
Fanless or Fan-Cooled OptionsS-40, S-50, S-100 and S-150 use free air convection cooling without a fan. S-240 and S-320 use forced air cooling with built-in DC fan and Fan ON/OFF control (fan turns ON at RTH3 ≥50°C or RT1 ≥40°C depending on the model).
Wide Output Voltage RangeAvailable in 3V, 5V, 7.5V, 10V, 12V, 13.5V, 15V, 18V, 24V, 27V, 30V, 36V and 48V output options depending on the model, covering a broad range of industrial and commercial loads.
Complete Protection FunctionsShort circuit protection, overload protection (105–150% rated output power) are built in. Higher power models (S-240, S-320) also provide over voltage and over temperature protection.
LED Indicator for Power OnFront-panel LED indicates power-on status for quick visual diagnosis.
Fixed Switching FrequencySwitching frequency varies by power rating: S-40 = 75 kHz, S-50 = 27 kHz, S-100 = 25 kHz, S-240 = 75 kHz, S-320 = 90 kHz.
Designed for General Industrial ApplicationsThe S Series is designed referring to UL1012 and FCC Part15 J Conduction Class B for smaller models. The S-240 and S-320 are approved to UL60950-1 and TUV EN60950-1, providing a solid compliance foundation for industrial control systems and general equipment.
Model Selection
S Series Model Selection
Select the appropriate S model according to the required output power, output voltage and cooling requirement.
The S Series is available in power ratings from 40W to 350W, with output voltages ranging from 3V to 48V. Fanless models (S-40 to S-150) are ideal for quiet, low-maintenance installations, while fan-cooled models (S-240, S-320) deliver higher power in a compact chassis.
Model Code
S–100–24
SSeries prefix — DAPPRA S Series Conventional Single-Output Enclosed Switching Power Supply.
Example: S-100-24 = S Series, 100W output power, 24V DC output.
S-50 — 50W Single Output
Model
Output Voltage
Output Current
Rated Power
Efficiency
Dimensions
S-50-5
5 VDC
10 A
50 W
71%
159 × 97 × 38 mm
S-50-12
12 VDC
4.2 A
50.4 W
78%
159 × 97 × 38 mm
S-50-15
15 VDC
3.4 A
51 W
78%
159 × 97 × 38 mm
S-50-24
24 VDC
2.1 A
50.4 W
82%
159 × 97 × 38 mm
S-50: 85–132 VAC / 170–264 VAC selected by switch, or 240–370 VDC. Fixed switching frequency 27 kHz. Operating temperature -10 to +60°C. Fanless. Designed refer to UL1012 and FCC Part15 J Conduction Class B.
S-100 — 100W Single Output
Model
Output Voltage
Output Current
Rated Power
Efficiency
S-100-3
3 VDC
20 A
60 W
70%
S-100-5
5 VDC
20 A
100 W
78%
S-100-7.5
7.5 VDC
13.6 A
102 W
80%
S-100-10
10 VDC
10 A
100 W
80%
S-100-12
12 VDC
8.5 A
102 W
81%
S-100-15
15 VDC
6.7 A
100.5 W
81%
S-100-18
18 VDC
5.6 A
100.8 W
82%
S-100-24
24 VDC
4.5 A
108 W
84%
S-100-27
27 VDC
3.7 A
99.9 W
84%
S-100-36
36 VDC
2.7 A
97.2 W
84%
S-100-48
48 VDC
2 A
96 W
84%
S-100: 85–132 VAC / 180–264 VAC selected by switch, or 255–370 VDC. Fixed switching frequency 25 kHz. Operating temperature -10 to +60°C. Fanless. Dimensions 199 × 98 × 38 mm. Designed refer to UL1012 and FCC Part15 J Conduction Class B.
S-240 — 240W Single Output with Fan
Model
Output Voltage
Output Current
Rated Power
Efficiency
Cooling
S-240-5
5 VDC
40 A
200 W
78%
Fan
S-240-7.5
7.5 VDC
30 A
225 W
80%
Fan
S-240-12
12 VDC
18 A
216 W
82%
Fan
S-240-15
15 VDC
15 A
225 W
83%
Fan
S-240-24
24 VDC
10 A
240 W
84%
Fan
S-240-30
30 VDC
8 A
240 W
85%
Fan
S-240-48
48 VDC
5 A
240 W
85%
Fan
S-240: 88–132 VAC / 176–264 VAC auto switch, or 248–370 VDC. Built-in passive PFC choke. Fixed switching frequency 75 kHz. Fan ON at RT1 ≥40°C, OFF at ≤35°C; output shutdown at ≥70°C. Dimensions 190 × 93 × 65 mm. Safety: UL60950-1, TUV EN60950-1 (except for 7.5V).
S-320 — 320W Single Output with Fan
Model
Output Voltage
Output Current
Rated Power
Efficiency
Cooling
S-320-5
5 VDC
50 A
250 W
77%
Fan
S-320-7.5
7.5 VDC
36 A
270 W
80%
Fan
S-320-12
12 VDC
25 A
300 W
82%
Fan
S-320-13.5
13.5 VDC
22 A
297 W
83%
Fan
S-320-15
15 VDC
20 A
300 W
84%
Fan
S-320-24
24 VDC
12.5 A
300 W
86%
Fan
S-320-27
27 VDC
11 A
297 W
86%
Fan
S-320-48
48 VDC
6.5 A
312 W
86%
Fan
S-320: 88–132 VAC / 176–264 VAC by switch. Fixed switching frequency 90 kHz. Fan ON/OFF auto control. Dimensions 215 × 115 × 50 mm. Safety: UL60950-1.
Other S Series Power Ratings
Power Rating
Cooling
Description
S-40
Fanless
40W single-output enclosed power supply, 75 kHz switching frequency, 129 × 98 × 38 mm
S-150
Fanless
150W single-output enclosed power supply, 115/230 VAC selectable by switch, 199 × 110 × 50 mm
S-350
Fan
350W single-output enclosed power supply
Please refer to the specific model datasheet for complete specifications.
Dimensions
S Series Dimensions
Enclosed metal chassis with perforated ventilation design. All dimensions in mm, tolerance ±1 mm.
S-40
Length (L)
129 mm
Width (W)
98 mm
Height (H)
38 mm
Housing
Enclosed metal chassis
Cooling
Free air convection (fanless)
S-50
Length (L)
159 mm
Width (W)
97 mm
Height (H)
38 mm
Housing
Enclosed metal chassis
Cooling
Free air convection (fanless)
S-100
Length (L)
199 mm
Width (W)
98 mm
Height (H)
38 mm
Housing
Enclosed metal chassis
Cooling
Free air convection (fanless)
S-150
Length (L)
199 mm
Width (W)
110 mm
Height (H)
50 mm
Housing
Enclosed metal chassis
Cooling
Free air convection (fanless)
S-240
Length (L)
190 mm
Width (W)
93 mm
Height (H)
65 mm
Housing
Enclosed metal chassis
Cooling
Forced air (built-in DC fan)
S-320
Length (L)
215 mm
Width (W)
115 mm
Height (H)
50 mm
Housing
Enclosed metal chassis
Cooling
Forced air (built-in DC fan)
Installation
S Series Installation
The S Series uses an enclosed chassis design for standalone mounting inside industrial equipment. Adequate ventilation clearance is required.
01 / 06
Chassis Mounting
Mount the unit on a flat metal surface using the mounting holes on the chassis base. Ensure the unit is securely fixed to prevent vibration and movement. Recommended mounting screws: M3 or M4 depending on the model.
02 / 06
Ventilation Clearance
Always allow good ventilation clearances around the unit: at least 5 mm on left and right, 40 mm above and 20 mm below, to prevent overheating.
03 / 06
Airflow Direction
For fan-cooled models (S-240, S-320), ensure the airflow direction is not blocked. The built-in fan pulls air through the chassis from the vented sides.
04 / 06
FG Must Be Connected to PE
The FG (Frame Ground) terminal must be connected to PE (Protective Earth) for safety and to ensure proper EMC performance.
05 / 06
Operating Temperature Limits
All S Series models operate from -10°C to +60°C with derating above +50°C. Do not install near fire sources or high ambient temperature locations.
06 / 06
Indoor Use Only
Install the unit only in a dry, well-ventilated location. Do not install in places with high moisture or near water. The unit is designed for indoor industrial use.
The S Series requires adequate ventilation clearance. Ensure the perforated ventilation openings and the fan intake/exhaust are not blocked. Do not install in orientations other than the recommended position.
Wiring & Terminal
S Series Wiring & Terminal
The S Series uses screw-type terminal blocks for input and output connections. Use copper wire only and ensure all strands enter the terminal connection securely.
Terminal Pin Assignment
S-40 / S-50 — 5 Pins
Pin No.
Assignment
1
AC/L
2
AC/N
3
FG (Frame Ground)
4
DC OUTPUT -V
5
DC OUTPUT +V
FG must be connected to PE (Protective Earth) for safety and EMC performance.
S-100 — 7 Pins
Pin No.
Assignment
1
AC/L
2
AC/N
3
FG (Frame Ground)
4, 5
DC OUTPUT -V
6, 7
DC OUTPUT +V
S-150 / S-240 / S-320 — 9 Pins
Pin No.
Assignment
1
AC/L
2
AC/N
3
FG (Frame Ground)
4, 5, 6
DC OUTPUT -V
7, 8, 9
DC OUTPUT +V
Multiple DC output pins should all be connected to their respective output wires to prevent excessive current stress on a single contact.
Wiring Specification
Model Group
Torque
S-40 to S-100
5–6 kgf-cm (4.4–5.2 Lb-in)
S-150 to S-320
8–10 kgf-cm (7–9 Lb-in)
Use stranded copper wire only. Recommended screwdriver: 3 mm or 4 mm slotted type.
The FG pin must be connected to PE (Protective Earth). The number of output terminals varies by model — always verify the terminal label before wiring.
Output Voltage Adjustment
The S Series includes a front-panel DC output voltage adjustment potentiometer (+V ADJ) within the voltage adjustment range specified for each model, and a power-on LED indicator. Output current and output power must not exceed the rated value on its specification.
The actual wiring should follow the wiring diagram provided in the S Series installation manual. Use copper wire only and ensure all strands enter the terminal connection securely.
Safety & Compliance
S Series Safety & Cautions
Read and follow all safety instructions before installing, wiring, maintaining or modifying the S Series power supply.
Risk of electrical shock and energy hazard. All failure should be examined by a qualified technician. Do not remove the case of the power supply yourself.
Connecting both the primary and the secondary sides together is not allowed — risk of electric arcs and electric shock (danger to life).
Risk of burn hazard. Do not touch the unit in operation and shortly after disconnection.
Risk of fire and short circuit. The openings should be protected from foreign objects or dripping liquids.
The FG (Frame Ground) must be connected to PE (Protective Earth).
Output current and output power must not exceed the rated value on its specification.
Before commencing any installation, maintenance or modification work, disconnect the system from supply voltage. Make sure that inadvertent connection in circuit will be impossible.
For continued protection against risk of fire, replace only with the same type and rating of fuse.
The power supply is considered a component which will be installed into a final equipment. The final equipment must be re-confirmed that it still meets EMC directives.
Applications
S Series Industrial Applications
The S Series is suitable for general industrial and commercial applications requiring a single fixed DC output.
Industrial Control Systems
Factory Automation
Mechanical Equipment
Electrical Equipment
Electronic Instruments
LED Lighting
Communication Equipment
Security Systems
Test & Measurement
Next Step
Explore the S Series
Browse all S Series enclosed switching power supply products, or return to the Industrial Power Supply category page.
The DAPPRA S Series is a conventional single-output enclosed switching power supply series designed for general industrial and commercial applications requiring a single fixed DC output. It covers 40W to 350W with 3V to 48V output configurations.
What is the input voltage range of the S Series?
The S Series uses selectable AC input of 85–132 VAC / 170–264 VAC by switch, or 240–370 VDC on smaller models. The S-240 uses auto-switch 88–132 VAC / 176–264 VAC. The S-320 uses 88–132 VAC / 176–264 VAC by switch.
What is the switching frequency of the S Series?
The switching frequency varies by model: S-40 = 75 kHz, S-50 = 27 kHz, S-100 = 25 kHz, S-240 = 75 kHz, S-320 = 90 kHz.
Which S Series models use a built-in cooling fan?
The S-40, S-50, S-100 and S-150 models use free air convection cooling without a fan. The S-240 and S-320 models use forced air cooling with built-in DC fan and Fan ON/OFF control.
What protections does the S Series provide?
The S Series provides short circuit protection and overload protection. The higher power models (S-240, S-320) also provide over voltage protection and over temperature protection.
What is the operating temperature range of the S Series?
The S Series operates from -10°C to +60°C with derating above +50°C, depending on the model.
What certifications does the S Series have?
The S Series is designed referring to UL1012 and FCC Part15 J Conduction Class B for smaller models. The S-240 and S-320 are approved to UL60950-1 and TUV EN60950-1.
How do I choose the right S Series model?
Select the S model according to the required output power (40W to 350W), output voltage, whether fan cooling is required, and available mounting space.
