TDK-Lambda DPP240-24-1 Industrial Switching Power Supply

Product Positioning: DPP Series Single-phase AC-DC DIN Rail Mount Industrial Switching Power Supply (NRND, Not Recommended for New Design)

NRND = Not Recommended for New Design. The manufacturer recommended replacement model is DRB240-24-1. (Note: Pin assignment, mounting and function compatibility are not fully guaranteed; engineering verification is required.)

✅ Model Definition

DPP: DIN rail mounting power supply series

240: Rated power 240W

24: Output voltage DC24V

1: Single-phase AC input (suffix 3 = 3-phase input, DPP240-24-3)

📌 Core Electrical Specifications

📏 Mechanical Dimensions & Installation

DIN rail (TS35) snap-on mounting, enclosed metal housing, natural convection cooling (fanless)

Width: 83 mm

Height: 125 mm

Depth: 126 mm

🧾 Terminal Definition (Screw Terminals)

1. DC Good relay
2. DC Good relay
3. V+
4. V+
5. V-
6. V-
7. PE Protective Earth
8. L Line
9. N Neutral

🛠️ Typical Application Scenarios

Industrial automation control cabinets, PLCs, sensors, solenoid valves, building automation, test & measurement equipment, factory 24V DC bus power supply.

⚠️ Key Notes

1. Status: NRND. Available as spare parts for legacy projects; DRB240-24-1 is recommended for new projects. Installation dimensions, terminal layout, DC-Good signal and parallel function differences must be verified.
2. Parallel operation: Set identical output voltage for all units and toggle switch to parallel mode; single-unit mode provides better load regulation accuracy.
3. Heat dissipation: Keep ventilation clearance on all sides; derating required for high ambient temperature.
4. Certifications: UL/EN/IEC62368-1, industrial safety certification.

🔧 Troubleshooting

No output: Measure L/N input voltage; check upstream circuit breaker and fuse; verify PE grounding; check green LED indicator on power supply.

Voltage drop under load: Overload, incorrect parallel switch setting, loose terminals; verify output current ≤10A.

DC Good inactive: Power supply enters latch-off protection; troubleshoot short circuit / overvoltage on downstream circuit.

Excessive ripple: Check grounding, add electrolytic / ceramic capacitor on output side, inspect cable shielding.

📎 Domestic Alternatives (DIN rail 240W 24V/10A, same specification)

Phoenix Contact QUINT-PS/1AC/24DC/240, Mean Well SDR-240-24, Delta DRP-240-24

TDK-Lambda DPP240-24-1 Complete Installation Guide

Suitable for TS35/7.5 or TS35/15 standard DIN rail. Never mount upside down (output terminals must not face down). Natural convection cooling, ventilation clearance required on all sides.

1. Pre-installation Preparation

1.1 Tools & Materials

Phillips screwdriver (for terminal screws)

Torque wrench (recommended)

Cables: AWG24～AWG10 (screw terminal version)

Standard TS35 DIN rail inside control cabinet

Upstream circuit breaker/fuse, PE protective earth wire

1.2 Safety Preconditions

Perform work in power-off state; confirm upstream power is fully disconnected

Class I equipment. PE protective earth must be reliably connected, otherwise electric shock hazard exists

Inspect power supply for damage and terminal oxidation before installation

2. DIN Rail Mechanical Installation Steps
3. Hook the top clip of the power supply onto DIN rail;
4. Press the power supply body inward until the bottom clip clicks and locks;
5. Shake slightly to confirm secure fixation on rail;
6. Removal: Use flat screwdriver to pry down the bottom spring clip and pull the unit outward.

Heat dissipation requirement: Minimum 25mm ventilation gap on top, bottom, left and right. Do not mount close to heat-generating components such as contactors and PLCs. Enclosure covering and upside-down mounting are prohibited. (Correct orientation: output terminals upward)

3. Terminal Wiring (Screw Terminal Version)

Terminal numbering (from left to right):

1,2: DC Good relay dry contact (power status passive contact, connect to PLC/alarm circuit)

3,4: V+ DC24V output positive

5,6: VDC24V output negative

7: PE Protective Earth

8: L Line

9: N Neutral

Torque Specification (per manufacturer manual)

Input terminals (L/N/PE): Max torque 1.0 N·m

Output terminals (V+ V-, DC Good): Max torque 0.65 N·m

Do not over-tighten to avoid screw slipping or terminal base cracking. All conductor strands must be fully inserted into terminals; no exposed copper strands to prevent short circuit.

Wiring Sequence

1. Connect PE (Terminal 7) for reliable earthing first;
2. Then connect output side: V+, V-, DC Good signal;
3. Finally connect input side L and N;
4. After wiring, check for short circuit and poor contact.
5. DIP Switch Setting (Single / Parallel Mode)

Single/Parallel DIP switch on front panel:

Single (Single Unit): Factory default setting, high load regulation accuracy. Must use this setting for standalone operation.

Parallel: Up to 3 DPP240 units for power expansion. Parallel requirements:

1. All units set DIP switch to Parallel;
2. Output cables of all units must have identical wire gauge and length;
3. System minimum load ≥10% rated current, maximum load ≤90%;
4. Pre-adjust all power supplies to the same output voltage.

Voltage adjustment: Front panel potentiometer, adjustable range DC22.5～28.5V

5. Power-on Commissioning Procedure
6. Under power-off condition, use multimeter to confirm no short circuit on input and output loops;
7. Verify DIP switch position;
8. Close upstream breaker and power on;
9. Observe green LED of power supply; measure output voltage to confirm set value;
10. Check DC Good relay: contacts close when power supply healthy; contacts open during fault / protection;
11. Perform loaded test, check temperature rise, confirm no abnormal overheating.
12. Prohibited Installation Practices (Important)
13. ❌ Upside-down mounting (output terminals down), which damages convection cooling and triggers over-temperature protection or permanent damage;
14. ❌ No 25mm ventilation clearance around unit;
15. ❌ PE earth connection omitted;
16. ❌ Parallel operation with cables of unequal length or load less than 10%;
17. ❌ Improper terminal torque; loose or exposed copper strands;
18. ❌ Use in high humidity, corrosive and dusty environment without protective enclosure.
19. Common Installation Issues
20. No green LED after power-on: Check L/N input voltage, upstream breaker, internal fuse (internal fuse cannot be replaced by user; unit must be returned for repair if damaged)
21. Voltage drop under load: Loose terminals, insufficient wire gauge, incorrect parallel switch setting, load exceeds 10A;
22. Power supply overheating: Insufficient ventilation gap, nearby heat sources, high ambient temperature, derating required.

TDK-Lambda DPP240-24-1 Outline Dimensions

Nominal dimensions (DIN rail clip protrusion excluded)

Width(W): 83 mm (3.27 inch)

Height(H): 125 mm (4.92 inch)

Depth(D): 126 mm (4.96 inch)

Weight: approx. 1000g (1kg)

Mounting rail: Standard TS35 (7.5 / 15mm) DIN rail

Cabinet Layout Notes

1. 83mm width occupies large horizontal space in control cabinet. Compare with alternative DRB240-24-1 (width approx. 41mm). DPP series is wider;
2. Heat dissipation clearance: minimum 25mm on all sides;
3. Depth 126mm. When designing cabinet depth from backplate to door, extra space for front terminal wiring must be reserved.

Reference Comparison (Alternative Model DRB240-24-1)

DRB240-24-1: 41 × 120 × 125 mm, nearly half the width. Large difference in installation space, cannot be directly drop-in replacement.

TDK-Lambda DPP240-24-1 Power Factor

Typical Power Factor PF = 0.7 (230VAC input, full load)

This power supply does not integrate active PFC circuit, adopting conventional rectifier topology, resulting in relatively low power factor.

Supplementary Description

1. Test condition: AC230V, full rated output; PF value decreases under 115VAC low input voltage.
2. Note: 0.7 is typical value not minimum; power factor further drops under light load.
3. System Impact:

If project requires strict harmonic and power factor compliance (e.g. EN61000-3-2), add external PFC filter at input front end.

Alternative model DRB240-24-1 of same power level has better PF performance.

4. Reference input current (full load):

230VAC: approx. 1.5A

115VAC: approx. 4.0A