DRDN20-24 Emerson MEAN WELL Power Module Datasheet

Emerson DRDN20-24 DRDN20 DIN Rail Redundancy Module

The Emerson DRDN20-24, also cataloged as the DRDN20-24 DIN Rail Redundancy Module, operates as a dedicated hardware component for power supply decoupling within 24 VDC nominal infrastructure networks. The device utilizes integrated diode or MOSFET ORing logic to auction input power between two independent parallel DC sources, routing continuous output current to downstream industrial automation loads.

Hardware Specifications

Industrial Network & Power Component Properties

The Emerson DRDN20-24 incorporates strict protocol isolation attributes, establishing galvanic isolation limits up to 500 V between the input supply channels and the chassis frame. This specific architectural segregation blocks reverse-current propagation, ensuring that a dead short or internal component failure on power supply unit A does not clamp or degrade the DC bus voltage of power supply unit B. The mechanical module envelope features a high DIN-rail mounting stability profile, mitigating risk of electrical trace fracturing under extreme thermal dissipation profiles up to +80 deg C. Dual input channels continuously balance output load distribution, ensuring minimal protocol conversion latencies or voltage dips during an active supply line transfer.

Frequently Asked Questions

Q: What is the behavior of the output bus voltage during a sudden total failure of the primary power source?

A: The passive ORing circuitry switches paths based on voltage differentials. Because both input supplies are continuously connected to the internal node, the transition to the operational backup source occurs with zero millisecond delay, preventing downstream PLC or DCS cards from resetting.

Q: Can this redundancy module combine a 12 VDC supply and a 24 VDC supply to achieve power backup?

A: No, the module requires balanced nominal inputs matching the 19–29 VDC rating on both channels. Connecting asymmetric voltages will cause the internal diode logic to permanently select the higher voltage source, overriding the redundant balancing paths and risking overvoltage diagnostic faults.

Q: Is a common ground wire terminal connection mandatory across both input power supplies?

A: Yes, the negative return lines (V-) from both feeding power supplies must be tied to a common negative bus reference point. This alignment ensures correct voltage balancing measurements across the internal decoupling components.

Field Installation Guidelines

• DIN Rail Attachment and Spacing: Snap the module securely onto standard TS-35/7.5 or TS-35/15 symmetric DIN rails. To preserve optimal thermal heat sink dissipation profiles, maintain a minimum lateral ventilation gap of 20 mm from adjacent active heat-generating electronic modules.
• Input and Output Power Wiring: Use copper field wiring rated for the full 20 A current capacity. Strip insulation to factory specifications and secure conductors into the screw terminal clamps using the designated tightening torque; loose wires create localized heating zones and voltage drops.
• Surge Protection and Grounding: Route the chassis earth terminal directly to the central panel cabinet ground busbar using a thick, low-impedance conductor. Ensure this path remains clean and free of paint to maximize surge voltage protection limits against ambient inductive spikes.