ELRH5-I-SC-24DC/500AC-2 PHOENIX

A Phoenix Contact Basis Unit acts as the passive backplane interface that attaches directly to a standard DIN rail. It allows active electronic modules, such as digital or analog I/O function modules, communication interfaces, and power measurement units, to be plugged in and removed easily without disturbing the surrounding wiring. The base unit routes both the internal communication bus and the internal power distribution (such as 24 VDC supply and logic voltages) continuously from one module to the next through integrated side connectors. Field wiring connects directly to the push-in or screw terminal blocks integrated on or attached to the basis unit, enabling hot-swappable module replacement and reducing downtime during maintenance.

Product Parameters

• Product Type: Base Element / Bus Base Module for Modular I/O and Housing Systems

• Mounting Type: Standard NS 35 DIN Rail Mounting

• Connection Technology: Push-in Spring Connection or Screw Connection options

• Nominal Current Capacity: Typically up to 8 A or 10 A across power distribution contacts depending on specific series

• Nominal Voltage: Up to 24 VDC for logic supply and up to 230 VAC for specific power terminals

• Housing Material: High-grade Polyamide PA 6.6, flame-retardant class V0 according to UL 94

• Operating Temperature Range: -25°C to 60°C (-13°F to 140°F) for standard industrial environments

• Storage Temperature Range: -40°C to 85°C (-40°F to 185°F)

• Degree of Protection: IP20 protection rating when fully assembled with functional modules

• Backplane Bus Interface: Integrated multipole side contacts for internal communication and logic power pass-through

Product Advantages

Phoenix Contact Basis Units provide exceptional modularity, allowing control system designers to scale I/O counts and mix different signal types precisely to match application requirements.

The underlying separation of the mechanical base and functional electronics permits permanent panel wiring to be completed and tested prior to installing the sensitive electronics, greatly accelerating installation timelines.

Maintenance is significantly simplified because individual electronic modules can be swapped quickly without disconnecting any signal wires from the terminal blocks.

The integrated backplane bus eliminates the need for complex external jumper wiring between adjacent modules, reducing cabinet clutter and potential wiring errors.

The rugged DIN-rail latching mechanism and vibration-resistant connection technology ensure reliable operation even in harsh industrial environments with high mechanical stress.

Important Considerations and Precautions

Always verify the total current consumption passing through the base unit power contacts to ensure it does not exceed the maximum bus current rating specified by Phoenix Contact.

Ensure that end clamps are installed on both sides of the modular assembly on the DIN rail to prevent lateral movement and maintain firm electrical contact across the backplane bus connectors.

Before inserting or removing functional modules from the basis unit, double-check whether the specific system series supports hot-swapping or requires the main power supply to be turned off first.

Protect the exposed backplane contacts from dust, moisture, and conductive debris during installation before the electronic modules are snapped into place.

Use appropriate conductor cross-sections and strip lengths matching the terminal specification to ensure secure clamping and optimal current carrying capability.

Product Applications

Phoenix Contact Basis Units are widely deployed across various automation and industrial control infrastructure applications.

• Industrial Control Cabinets: Building distributed I/O racks connected to central PLCs or industrial PCs in factory automation systems.

• Process Automation: Modular signal collection and conditioning in chemical, water treatment, and oil and gas processing plants.

• Machine Building: Compact I/O node assembly directly on automated packaging lines, assembly machines, and robotics cells.

• Energy and Infrastructure: Interfacing sensors and actuators in power distribution cabinets, solar generation monitoring, and wind turbine control systems.

• Building Management Systems: Interfacing HVAC controls, lighting systems, and energy monitoring hardware into centralized automation networks.