Honeywell 2MLR-AC13 Power Supply Module

The Honeywell 2MLR-AC13 is a high-capacity AC-to-DC power supply module designed for HC900, ControlEdge, and MasterLogic-200 (ML200R) system architectures. It converts an 85–132 V AC nominal grid input into a regulated 5 VDC backplane bus voltage, delivering up to 8.5 A (46.75 W) to energize local controller CPUs, communication modules, and I/O assemblies.

Power Conversion and Protection Characteristics

The module converts single-phase AC utility voltage into a tightly controlled 5 VDC output with a ±2% tolerance under load. Operating with an efficiency rating of at least 65%, the module tolerates momentary AC line interruptions up to 20 ms without dropping backplane rail power, ensuring continuous operation during transient line sags. Internal protection circuits include over-current protection set between 9.3 A and 17.0 A, which safely limits power delivery during fault conditions.

Non-replaceable internal time-lag fuses are integrated on both the AC input side (250 V / 3.15 A) and the DC output path (125 V / 10 A) to prevent board-level damage during severe electrical surges.

System Diagnostics and Signaling

A front-panel Voltage Status LED provides visual verification when the 5 VDC rail output remains within normal working boundaries. For remote hardware monitoring, an onboard relay RUN contact rated at 24 VDC and 0.5 A changes state based on power status, changing state with an Off-to-On response time under 10 ms and On-to-Off under 12 ms.

The low-ripple 5 VDC output helps stabilize system backplane communications, ensuring consistent execution timing for analog and process I/O modules, which retain their independent channel-to-channel electrical isolation.

Technical Specifications

Field Installation Guidelines

• Route AC line power input conductors separately from low-voltage DC signals and instrumentation cabling to prevent electromagnetic noise coupling.
• Secure power field wiring into the terminal block using 0.75–2 mm² cross-section conductors with clamped ring or spade connectors (RAV1.25-3.5 or RAV2-3.5).
• Terminate shielded cabling grounds at a single common earth point to mitigate ground loops and circulating currents.
• Maintain unobstructed air circulation around the rack assembly to facilitate passive heat dissipation.
• Verify RUN contact load currents and polarity prior to powering up the system.

Frequently Asked Questions

Q: Can the 2MLR-AC13 power module be replaced while the chassis is powered?

A: No, the chassis must be fully de-energized before inserting or removing the module to prevent electrical damage or system faults.

Q: How does the module react to short-term AC line drops?

A: It maintains continuous regulated 5 VDC backplane output through voltage sags or interruptions lasting up to 20 ms.

Q: Can the internal protection fuses be changed in the field if blown?

A: No, both the AC input fuse and DC output fuse are internal, non-replaceable safety components.