ABB CME Current Measuring Relay

The ABB CME current measuring relay is a compact DIN rail monitoring relay that provides overload, under-load, and phase asymmetry protection for three-phase motors and other electrical loads, using three internal current measuring transformers to monitor each phase independently. The CME monitors current within a user-set band — an overload threshold and an underload threshold — and trips its single SPDT output relay when the measured current exceeds or falls below these limits for a configurable time delay from 0 to 30 seconds. Phase asymmetry detection operates by comparing the three phase currents, triggering an alarm when any phase differs from the average by more than approximately 30%, providing protection against the gradual current imbalance caused by supply asymmetry or developing winding faults before they escalate to a full phase failure.

The CME occupies a single 22.5 mm DIN rail module and accepts supply voltage from 24 V DC to 240 V AC, making it power-supply agnostic and simplifying panel design in facilities that mix 24 V DC control and 230 V AC auxiliary power. Its direct current measurement range spans 0.1 A to 10 A, covering small fractional-horsepower motors directly without CTs, while a 5 A CT input option extends the range to larger motors measured through external 1000/5 A or larger CTs. The LED indication on the front face shows operate status and fault type, allowing technicians to identify overload versus underload trip without a multimeter. While not a replacement for a full electronic motor protection relay in critical applications, the CME provides a highly cost-effective monitoring layer for non-critical motors in pump, fan, and conveyor applications where a simple current band alarm is sufficient protection.

In Saudi Arabia's industrial and utility sectors, the CME current relay is the standard current monitoring device for small to medium non-critical motors at ARAMCO facility service pumps, SEC substation cooling fans, water authority sump pumps, and building services equipment where current monitoring adds a diagnostic layer without the cost of a full motor protection relay. Building management contractors across Riyadh and Jeddah install CME relays on chiller auxiliaries, cooling tower fans, and domestic water pump motors to detect dry-running (underload trip) and motor overload conditions that would otherwise go undetected until motor failure. Process facilities use CME relays on agitators, mixers, and conveyor feeders to detect jam conditions (overload) and empty-bin conditions (underload) for process control interlock functions.

Razz Middle East stocks CME relays in all current range variants and supplies both single units for maintenance replacement and bulk quantities for panel builders across Saudi Arabia, with same-day dispatch and SAR pricing on all orders.