ALSTOM MCGG22D1CB0753C – Feeder overcurrent and ground fault protection relay
Brand / ModelALSTOM MCGG22D1CB0753C (MCGG22 family)
Product TypeNon‑directional overcurrent and earth‑fault protection relay (IDMT + definite‑time)
HS Code8536.49.00 (Protection relays, for a voltage not exceeding 1000 V)
Power RequirementsAuxiliary supply typically 110–250 V DC (other ranges may exist depending on option code)
CT / InputsPhase and earth CT inputs, usually 1 A / 5 A selectable or by variant; binary inputs for controls (varies by build)
OutputsTrip and alarm relay contacts; typical changeover relays suitable for breaker tripping and signaling
CommunicationNot standard on base MCGG22; certain variants may include RS‑485 (option dependent)
Operating TemperatureTypically −10 °C to +55 °C (series baseline)
Dimensions & WeightCompact draw‑out case (approx. 4U panel height); weight around 3–4 kg depending on options
Installation MethodPanel/flush‑mount in switchgear cubicle; front test access with draw‑out chassis
The ALSTOM MCGG22D1CB0753C is a proven non‑directional overcurrent and earth‑fault protection relay, widely used on MV/LV feeders, incomers, and motor circuits.
From my experience, it’s often specified as a direct replacement in legacy GEC/ALSTOM/AREVA panels where utilities and industrial plants want to keep wiring unchanged and downtime minimal.
You might notice that it balances simplicity with dependable protection—IDMT and definite‑time curves, high‑set stages, and straightforward draw‑out maintenance.
Key Features
Feeder protection, kept practical – Non‑directional overcurrent and earth‑fault functions for MV/LV panels, typically with IDMT and definite‑time elements.
Multiple curve selections – IEC/IEEE‑style IDMT curves are usually available, so coordination with upstream/downstream devices is straightforward.
High‑set stages – Instantaneous high‑set OC/EF generally included to clear severe faults quickly.
CT flexibility – Typically supports 1 A and 5 A CT inputs, simplifying retrofit on existing switchgear.
Draw‑out case – Front access for testing and rapid swap; in many cases it’s a like‑for‑like fit with legacy panels.
Rugged build – Designed for substation and plant environments; stable operation over a wide temperature range.
MCGG22D1CB0753C
Technical Specifications
Brand / Model ALSTOM MCGG22D1CB0753C (MCGG22 family)
Product Type Non‑directional overcurrent and earth‑fault protection relay (IDMT + definite‑time)
HS Code 8536.49.00 (Protection relays, for a voltage not exceeding 1000 V)
Power Requirements Auxiliary supply typically 110–250 V DC (other ranges may exist depending on option code)
CT / Inputs Phase and earth CT inputs, usually 1 A / 5 A selectable or by variant; binary inputs for controls (varies by build)
Outputs Trip and alarm relay contacts; typical changeover relays suitable for breaker tripping and signaling
Communication Not standard on base MCGG22; certain variants may include RS‑485 (option dependent)
Operating Temperature Typically −10 °C to +55 °C (series baseline)
Dimensions & Weight Compact draw‑out case (approx. 4U panel height); weight around 3–4 kg depending on options
Installation Method Panel/flush‑mount in switchgear cubicle; front test access with draw‑out chassis
MCGG22D1CB0753C
Application Fields
Commonly found in utility substations, industrial plants, mining, oil & gas skids, and data center power rooms. In many cases, engineers choose the MCGG22 to:
Protect MV/LV radial feeders, ring‑main units, and transformer secondaries.
Provide backup protection to downstream MCCBs/ACBs or motor protection relays.
Retrofit legacy GEC/AREVA installations without re‑engineering CT ratios or wiring looms.
Standardize maintenance across mixed‑vintage switchboards.
A maintenance lead I worked with mentioned that the draw‑out design “saved us at least half a day every time we needed to verify trip settings,” which seems to be a fair summary of the practical benefits here.
Advantages & Value for Procurement
Drop‑in replacement potential – Minimizes wiring changes on existing GEC/ALSTOM panels; reduces outage windows.
Reliable, no‑nonsense protection – Stable IDMT characteristics help coordination; high‑set provides fast fault clearing.
Compatibility – Works with common 1 A / 5 A CTs and standard trip coils; no exotic accessories needed.
Lifecycle support – Straightforward testing and spare strategy; from my experience, keeping one spare per board is usually enough.
Cost control – Lower engineering overhead versus a full digital retrofit when the goal is continuity and uptime.
Installation & Maintenance
Mounting – Install in a clean, ventilated switchgear cubicle; allow front clearance for draw‑out and test access.
Wiring – Use shielded cont
