Introduction to the Honeywell 2MLR-DC42 Power Supply Module

The 2MLR-DC42 from Honeywell is a compact power supply module. This unit converts 24VDC input to a regulated 5VDC output. Engineers use the 2MLR-DC42 to power control system components. The module suits PLC racks, I/O modules, and other field devices. Its robust design ensures reliable DC power delivery. The 2MLR-DC42 fits perfectly in Honeywell control cabinets.

Technical Specifications

This section covers the detailed technical parameters of the 2MLR-DC42.

Input Specifications

The rated input voltage is 24 VDC. The acceptable input range spans 19.2 to 28.8 VDC. This wide range handles voltage fluctuations well. Inrush current peaks at 80A and drops quickly. Efficiency reaches 65% or higher during normal operation. The module allows instantaneous interruptions within 20 milliseconds.

Built-in Fuse Protection

The 2MLR-DC42 includes a built-in input fuse. Users cannot replace this fuse in the field. For AC power, the fuse is 250V at 3.15A (Time-lag type, UL approved). For DC power, the fuse is 125V at 10A (Time-lag type, UL approved). This protection prevents damage from overcurrent events.

Output Specifications

The output voltage is fixed at 5VDC with ±2% tolerance. Output current capacity reaches 7.5A continuously. Total output power is 37.5W at 55°C ambient temperature. Over current protection activates between 9.0A and 17.0A. This feature shuts down the output during fault conditions.

RUN Contact Specifications

The 2MLR-DC42 includes a purpose-built RUN contact. Rated switching voltage is 24VDC at 0.5A. Minimum switching load is 5VDC at 1mA. This contact indicates normal output status. Off→On response time is 10ms or lower. On→Off response time is 12ms or lower.

Relay Life Ratings

Mechanical life exceeds 20 million operations. Electrical life reaches 100,000 operations at rated switching current. This long life ensures reliable signal feedback. The 2MLR-DC42 provides years of maintenance-free service.

Status Indication and Wiring

LED Voltage Display

A green LED shows voltage status clearly. The LED lights up when output voltage is normal. Operators can check module status at a glance. This simple indicator saves troubleshooting time.

Wiring Specifications

Use cable sizes between 0.75 and 2 mm². Recommended clamped terminals are RAV1.25-3.5 and RAV2-3.5. These terminals secure wires firmly in place. Proper wiring ensures stable power delivery.

Environmental and Physical Data

The 2MLR-DC42 operates reliably in industrial environments. Dimensions measure 55mm wide by 95mm high by 110mm deep. The total weight is 417 grams. This compact size fits tight panel spaces. The module requires no forced air cooling under normal loads.

Installation Guidelines

Follow these steps to install the 2MLR-DC42 correctly.

1. Mount the Module: Secure the 2MLR-DC42 onto a DIN rail. Ensure the clip locks firmly in place.

2. Connect Input Power: Wire 24VDC to the input terminals. Observe correct polarity for safe operation.

3. Connect Output Load: Wire the 5VDC output to your control system. Do not exceed 7.5A current draw.

4. Wire RUN Contact: Connect the RUN contact to a monitoring input. This contact signals normal output status.

5. Power Up: Apply input voltage and check the LED. The 2MLR-DC42 is ready when the LED lights green.

Package Contents

Your 2MLR-DC42 shipment includes the following items:

• One Honeywell 2MLR-DC42 power supply module

• One installation instruction sheet

• One set of terminal number labels

• One anti-static protective bag

Common FAQs

1. Can I replace the built-in fuse on the 2MLR-DC42?
No, the fuse is not user-replaceable. If the fuse blows, you must replace the entire 2MLR-DC42 module.

2. What happens if output current exceeds 7.5A?
The over current protection will activate between 9.0A and 17.0A. This protection shuts down the output to prevent damage.

3. Does the 2MLR-DC42 accept both AC and DC input?
The 2MLR-DC42 is designed for 24VDC input only. Do not connect AC power to this module.

4. What does the RUN contact do on this power supply?
The RUN contact closes when output voltage is normal. It provides a dry contact signal for system monitoring.

5. Is the 2MLR-DC42 compatible with other Honeywell systems?
Yes, this power supply works with most Honeywell control platforms. Always verify voltage requirements before connection.

Conclusion

The Honeywell 2MLR-DC42 delivers reliable 5VDC power for industrial controls. Its wide input range handles voltage variations easily. Built-in fuses and over current protection ensure safety. The compact DIN rail design saves panel space. Choose the 2MLR-DC42 for your next Honeywell control system power need.