Technical Specifications / Parameters Parameter Specification Manufacturer Order Code 1SVR040010R0000 Catalogue Type CC-U/STDR Brand / Series ABB CR-U Series (Universal Monitoring Relays) Device Type Universal Resistance Monitoring Relay Monitoring Function Monitors the ohmic resistance (R) of a two-wire loop connected to its input terminals. Measurement Principle Applies a constant DC measuring current and measures the resulting voltage drop to calculate resistance. Resistance Measurement Range Typically from a few ohms (Ω) up to several megaohms (MΩ). Specific ranges (e.g., 0-10kΩ, 0-1MΩ) are selectable via front switches or DIPs. 必须核实具体型号范围。 Number of Setpoints Two independent adjustable setpoints (High and Low), typically via potentiometers. Setpoint Logic Configurable to trigger when resistance is above a high limit, below a low limit, or inside/outside a window defined by the two limits. Output Relay 1 Changeover (CO) Contact (SPDT: 1 NO + 1 NC) • Contact Rating: Typically 6A / 250V AC (resistive load). Power Supply (Auxiliary) 24...240V AC/DC (wide-range, for relay electronics). Measuring Voltage/Current Uses a low, safe DC voltage/current for measurement to avoid influencing the monitored system (e.g., < 10V DC). Status Indication LEDs for Power, Alarm/Trip, and sometimes Measurement Active. Hysteresis Adjustable or fixed, to prevent output chatter near the setpoint. Mounting DIN Rail Mounting (35mm). Module Width 22.5 mm (1 module width). Operating Temperature -25°C to +55°C. Front Protection Degree IP40. Standards & Approvals IEC/EN 60255, UL 508, CSA C22.2 No. 14, CE, cULus. Typical Applications • Conductivity-based liquid level detection in tanks (probe resistance changes when immersed). • Moisture or humidity detection (with resistive humidity sensors). • Monitoring of heating elements for open circuit (infinite resistance) or degradation. • Ground electrode or bonding strap continuity checking. • Simple insulation monitoring of low-voltage circuits (e.g., detecting coolant leakage into a motor winding).