The **MA15FAX-R** is a high-performance surge protective device (SPD) manufactured by **Eaton (MTL Instruments)**. It is specifically designed to protect sensitive electronic equipment from voltage transients and electrical noise on AC power lines. --- ## Technical Overview The MA15 series is classified as a **Type 3 surge protector** or a "surge filter." Unlike standard surge strips, it combines surge suppression with high-frequency noise filtering. ### Key Specifications | Feature | Specification | | :--- | :--- | | **Nominal Voltage** | 120V AC (Standard for the 'FAX' variant) | | **Max Continuous Operating Voltage (MCOV)** | 140V AC | | **Max Surge Current** | 18kA (8/20µs waveform) | | **Operating Current** | 15 Amps | | **Mounting Type** | DIN Rail Mounting | | **Filtering Range** | 800Hz to 30MHz | --- ## Core Electronic Components & Functions The MA15FAX-R utilizes a hybrid circuit design to provide comprehensive protection: ### 1. Metal Oxide Varistors (MOVs) These are the primary surge suppression components. - **Function:** When a high-voltage spike occurs, the MOV's resistance drops instantly, shunting the excess energy to the ground. - **Protection:** It clamps the voltage to a safe level, preventing insulation breakdown in connected devices. ### 2. Multi-stage R-C Filtering Unlike simple SPDs, the "Filter" aspect of this device involves resistors (R) and capacitors (C). - **Function:** Attenuates Radio Frequency Interference (RFI) and Electromagnetic Interference (EMI). - **Benefit:** Reduces "electrical noise" that can cause data errors or malfunctions in PLCs and industrial computers. ### 3. Thermal Fusing - **Function:** Internal thermal disconnectors protect the device in "end-of-life" scenarios or sustained over-voltage conditions. - **Safety:** Prevents the device from overheating or catching fire if the MOVs are compromised. ### 4. Status Indication & Remote Monitoring - **LED Indicator:** A visual green LED indicates that protection is active. - **Remote Contacts (The '-R' Suffix):** The "R" in the part number stands for **Remote**. It includes a set of dry contacts (volt-free) that can be wired to a PLC or alarm system to notify maintenance staff if the surge protection has failed. --- ## Typical Applications Because of its DIN rail form factor and high-current capacity, it is commonly found in: * **Industrial Control Panels:** Protecting PLCs and I/O modules. * **SCADA Systems:** Ensuring clean power for telemetry equipment. * **Process Automation:** Shielding sensitive sensors from motor-induced noise.