The **M5CT-15-R/Q** is a high-performance current transformer manufactured by **METSE (Schneider Electric / Merlin Gerin)**. It belongs to the METSE series of measurement devices designed to transform high primary currents into standard lower currents (usually 5A) for use with power meters, relays, and monitoring equipment. ### 1. Technical Specifications The following table summarizes the key electrical and physical parameters of the M5CT series: | Parameter | Specification | | :--- | :--- | | **Model** | M5CT-15-R/Q | | **Primary Current ($I_{pn}$)** | 1500 A (standard for this series) | | **Secondary Current ($I_{sn}$)** | 5 A | | **Accuracy Class** | Class 0.5 or 1.0 (typical) | | **Burden / Power Output** | 10 VA to 15 VA | | **Max. Voltage Rating** | 0.72 kV | | **Frequency** | 50/60 Hz | | **Mounting Type** | DIN Rail or Busbar mounting | --- ### 2. Core Electronic Components and Design The M5CT-15-R/Q is a **passive electromagnetic component**. It does not contain integrated circuits (ICs) but relies on high-quality materials to ensure measurement precision: * **Toroidal Core:** Made of high-permeability grain-oriented silicon steel. This ensures low magnetic loss (hysteresis) and prevents saturation during overcurrent conditions. * **Secondary Winding:** Comprised of many turns of high-grade copper wire. The "5A" output is derived from the turns ratio ($N_1/N_2 = I_2/I_1$). * **Encapsulation:** The internal components are protected by a flame-retardant (UL94-V0) polycarbonate plastic housing, providing electrical insulation and physical durability. * **Terminals:** Features "Q" (Quick-connect) or "R" (Screw-type) terminals for secure connections to measurement devices like the **PowerLogic** series meters. --- ### 3. Application Use Cases This specific part is used in industrial electrical distribution for: 1. **Energy Billing:** Providing accurate current data to utility-grade meters. 2. **Load Monitoring:** Tracking power consumption in Large Switchboards or Motor Control Centers (MCCs). 3. **Protection:** Interfacing with overcurrent protection relays to trigger circuit breakers during faults. --- ### 4. Wiring Diagram (Simplified) When connecting the M5CT-15-R/Q, ensure the polarity (P1/P2 and S1/S2) is correct to avoid phase errors in power calculations. ```text L1 (Source) ----------------- [ P1 ] ----------------- L1 (Load) [ ] <-- CT Body Meter Input (S1) <----------- [ S1 ] Meter Input (S2) <----------- [ S2 ] ``` > **Warning:** Never leave the secondary terminals (S1, S2) open-circuited while the primary current is flowing. This can induce dangerously high voltages that may damage the CT or harm personnel.