Phoenix Contact CBMC E4 24DC/1-4A NO Circuit Breaker

CBMC E4 24DC/1-4A NO: four-channel electronic circuit breaker for 24 V DC loads

The Phoenix Contact CBMC E4 24DC/1-4A NO (order no. 2906031) is the low-current member of this family: one DIN-rail module that protects four independent 24 V DC outputs, each adjustable from 1 A to 4 A. The designation reads as CBMC for the family, E4 for electronic tripping on four channels, 24DC for the nominal voltage, 1-4A for the setting range, and NO for the N/O remote-indication contact. It targets signal-level and control-level branches such as sensor supplies, small I/O groups, indicator circuits and relay coils, where a 10 A breaker would be too coarse to give meaningful protection.

Seven Star LLC supplies this module in Oman and the GCC as an independent supplier in Muscat, and can quote it alone or together with the matching 24 V DC supply.

Technical specifications of the CBMC E4 24DC/1-4A NO

How the CBMC E4 24DC/1-4A NO protects each output channel

Every channel measures its own load current and compares it with the value you set. An overload between 1.2 and 2.0 times nominal opens the channel after one second, while a short circuit above twice nominal is cleared within 10 ms. The module then holds the channel off for a 5 second cool-down, and the red LED shows that state. Green means the channel is carrying load, yellow means it is above 80 % of the setpoint, and a flashing yellow LED indicates programming mode. Supply voltage supervision switches the outputs off below 17.8 V DC and above 30.5 V DC.

Compared with the 10 A sibling, the fail-safe element is smaller (4 A per channel) and the whole module is limited to 16 A at IN+ rather than 40 A. That makes it the better fit when a small supply feeds many light branches, because the electronic limit and the integrated fuse sit much closer to the real load.

Where the CBMC E4 24DC/1-4A NO fits in a 24 V DC system

This module normally sits behind a 24 V DC supply rated up to about 16 A, such as a 24 V, 10 A or 20 A unit feeding a small cabinet. Typical downstream branches are PLC input modules, field-bus couplers, proximity sensors, solenoid-valve islands and HMI panels. For higher branch currents the 1-10 A version (2906032) is the natural step up, and the IO-Link version (2910411) adds digital status reporting. In a cabinet with mixed loads it is common to combine one 1-10 A module for heavy branches with this 1-4 A module for light ones, so each branch has a setpoint close to its real consumption.

Selection and ordering checklist

• Check that no branch needs more than 4 A and that the sum of all branches stays within 16 A at IN+.
• Confirm the 18 to 30 V DC supply window holds under all operating states.
• Confirm the largest input capacitance per channel against the 30000 μF limit.
• Decide on a collective N/O alarm to the PLC or an IO-Link variant.
• Check the listing you need: UL 508, UL 2367 and NEC Class 2 are shown for this device.
• Plan for spare modules if the branches protect safety-relevant instrumentation.

Installation, commissioning and maintenance

Mount the module on a 35 mm DIN rail with room for the supply and load wiring. The supply connects to push-in IN+ and IN-, and each load connects to its own OUT terminal. Connect the negative pole to IN- so the internal electronics are powered, and do not return load currents to the supply through IN-. Set each channel in programming mode, then lock the setpoints. Commission channel by channel and note the LED state; a persistent yellow LED means the setpoint is close to the real load and should be raised or the load reduced.

During maintenance, check the remote contact, read the LED pattern after any trip, and avoid simply resetting a channel that trips repeatedly; the manufacturer states that repeated hard short circuits can reduce the melting integral of the backup fuse.

Typical applications in Oman and the GCC

Across Oman and the GCC, this size of electronic breaker suits instrumentation cabinets at gas-processing and water-treatment sites, remote terminal units on pipelines, and small control panels in power and desalination plants. The branch-level protection is particularly useful where technicians work in hot, dusty areas and need a clear LED indication of which sensor circuit has failed, without opening fuse holders. Mounting in ventilated enclosures with a 60 °C ceiling is realistic for most indoor control rooms in the region.

Comparison with sibling devices

Information to send with an RFQ

• Full part number and quantity.
• Total expected current and the number of branches.
• Supply unit model and voltage tolerance.
• Required approvals (UL, NEC Class 2).
• Panel ambient temperature.
• Delivery location and date.

Documents and quotation

Send us the part number CBMC E4 24DC/1-4A NO and the quantity you need, and we will confirm which official documents are available for this device. Seven Star LLC is an independent supplier in Muscat and quotes for projects across Oman and the GCC; we do not act on behalf of the manufacturer.

Please also tell us the delivery location and required timeline so that availability can be checked before you commit to a project schedule.