ALSTOM MCGG22D1CB0753C – Feeder Overcurrent & Earth-Fault Protection Relay for Switchgear Modernization and Maintenance

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.

Order Placement Process and Guarantees

• Warranty: 365 days
• Delivery: typically 1 week for in‑stock; no more than 1 month at the latest
• Payment: 50% advance payment; full payment before delivery
• Express options: FedEx, UPS, DHL

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.

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

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 control wiring for auxiliary circuits where practical; verify CT polarity and shorting links before energization.
• Grounding – Bond auxiliary 0 V and case earth as per site earthing scheme to minimize nuisance pickup.
• Commissioning – Secondary injection to validate IDMT curve and pickup; confirm trip/alarm mapping to breaker coils and annunciation.
• Routine care – Annual function tests are typical; keep terminals clean, check tightness, and record settings to a panel log.
• Firmware/Calibration – If your variant includes digital elements, retain a copy of setting files; older static versions usually need only verification, not firmware updates.
• Safety – Always short CTs before removing the relay from its draw‑out case; isolate auxiliary supplies prior to service.

Quality & Certifications

• Conformance with IEC protection principles (IDMT/DT coordination) customary for the MCGG series.
• CE marking is present on later revisions; RoHS applicability may vary by vintage.
• Manufacturer’s warranty on new units varies by supply; we provide a 365‑day warranty on delivery.

Common Supporting Components

• Secondary injection test plug/block for draw‑out verification (model varies by case size and build).
• Protection‑grade CTs (5P/10P) at 1 A or 5 A to match settings and fault levels.
• Shunt trip and closing relays/contactors compatible with the breaker coil voltage.
• Annunciator modules or mimic lamps for clear trip/alarm indication on the panel door.

If you’d like, I can cross‑check the option code “D1CB0753C” against your existing panel drawings to confirm the auxiliary supply, contact mapping, and any communication option—this typically speeds up replacements and avoids re‑wiring on site.