ABB Bailey NMMU01 Mounting Unit

This mounting unit provides a secure backplane for ABB Bailey INFI 90 I/O modules. The ABB Bailey NMMU01 accepts up to eight modules in a single mechanical assembly. A printed circuit backplane distributes power and communication signals to all inserted modules. Consequently, plant engineers can build scalable control cabinets using standardized mounting units.

Technical Specifications of the Mounting Unit

The ABB Bailey NMMU01 measures 300 mm in width and 360 mm in height. Its depth reaches 60 mm for standard panel or rack mounting. The unit weighs approximately 3.2 kg including the backplane and metal chassis. A single ground lug provides a common connection point for system grounding. The rear side features two 50-pin expansion connectors for ribbon cable links. This design stores no energy whatsoever. Therefore, the mounting unit contains no capacitors, batteries, or any other storage elements.

Parameter	Specification
Brand	ABB Bailey
Full Model	NMMU01
Category	Mounting Unit (Backplane Chassis)
Dimensions (W x H x D)	300 mm x 360 mm x 60 mm
Weight	Approximately 3.2 kg
Module Slots	8 positions
Slot Type	INFI 90 standard
Backplane Layers	6-layer PCB
Expansion Ports	2 x 50-pin ribbon connectors
Grounding Point	Single copper lug
Energy Storage	None
Supply Voltage	24V DC and 5V DC via backplane
Mounting Type	6 screw positions

Functional Features and System Integration

The ABB Bailey NMMU01 routes all power and fieldbus signals to each slot evenly. You can mix analog, digital, and specialty modules within the same mounting unit. The backplane provides automatic addressing based on physical slot position. A keying bar prevents incorrect module insertion into the wrong slot. Consequently, this mounting unit simplifies cabinet assembly and reduces wiring errors.

Installation and Configuration

You must mount this unit on a flat panel using six M5 screws. The ABB Bailey NMMU01 requires a 24V DC power supply for field circuits. Two ribbon cables can link multiple mounting units for expanded I/O capacity. The unit includes numbered slot labels for easy module identification. Always verify backplane integrity before inserting any modules into the chassis.

Maintenance and Operational Benefits

Because the ABB Bailey NMMU01 stores no energy, it requires no discharge time before handling. Technicians can replace individual modules without removing the mounting unit from the cabinet. The open frame design allows natural convection cooling for all inserted modules. Consequently, this mounting unit provides reliable service with minimal maintenance requirements.