The Toshiba XCMS-1124A (Part Number: 3Z2T0120-2) is a specialized AC current monitoring relay designed for industrial power systems to provide overcurrent protection, load monitoring, and equipment safety.
Product Parameters (Datasheet)
- Model Number: XCMS-1124A
- Part Number: 3Z2T0120-2
- Device Type: AC Current Relay (Monitoring/Protective)
- Input Current: Standard AC secondary input (typically 5A or 1A CT compatible)
- Rated Frequency: 50/60 Hz
- Contact Configuration: Multi-contact output for tripping and status signaling
- Mounting: Panel mount or standard industrial rack integration
- Housing: Robust, dust-resistant casing for industrial environments
- Adjustment: Potentiometer or DIP-switch based setpoints for trip current and time delay
Country of Origin
This precision protective relay is manufactured by Toshiba Corporation in Japan, adhering to high-level Japanese industrial standards (JIS) for power system reliability and electrical safety.
Application Fields
The XCMS-1124A is widely utilized in medium and high-voltage power distribution:
- Motor Protection: Detecting locked rotor conditions or phase unbalance in large AC motors.
- Transformer Monitoring: Providing secondary-side overcurrent protection for distribution transformers.
- Switchgear Systems: Serving as a primary sensing element for circuit breaker trip logic.
- Manufacturing Plants: Monitoring heavy machinery load to prevent thermal damage from continuous overcurrent.
Product Usage Instructions
- Wiring: Connect the Current Transformer (CT) secondary leads to the relay input terminals. Ensure all connections are secure to prevent open-circuit CT hazards.
- Setting the Trip Point: Adjust the “Current Set” dial to the desired percentage of the rated current based on your equipment’s thermal curve.
- Time Delay: Set the “Time Delay” (if applicable) to allow for temporary inrush currents, such as those occurring during motor startup.
- Integration: Wire the output contacts into the control circuit of the main contactor or the shunt trip coil of the circuit breaker.
- Testing: Perform a secondary injection test with a portable current source to verify the relay operates within the calibrated tolerance.
Product Technical Description
The XCMS-1124A functions as an electromagnetic or solid-state comparator (depending on the specific revision) that monitors the magnitude of the AC current waveform. Technically, it rectifies or samples the input signal and compares it against a stable internal reference. When the monitored current exceeds the user-defined threshold for a duration longer than the set time delay, the relay energizes its internal coil, switching the output contacts to initiate a protective action. Its high accuracy ensures that it distinguishes between normal load fluctuations and genuine electrical faults.
Q&A (Common Questions)
Q: Can this relay be used on DC circuits? A: No, the XCMS-1124A is specifically designed for AC Current monitoring. Using it on DC will result in inaccurate readings or failure to trip.
Q: Does it require an external power supply? A: This depends on the specific “A” variant; many Toshiba XCMS relays are “self-powered” from the current circuit, while some electronic versions require a separate auxiliary control voltage.
Q: What is the significance of the 3Z2T0120-2 number? A: This is the specific Toshiba manufacturing code that defines the internal hardware revision and the specific current range calibration for this unit.
Q: Is there a manual reset button? A: Most XCMS-1124A models feature a physical reset button or a latching mechanism that requires manual intervention after a trip to ensure the fault is acknowledged.
Similar Model Recommendations
- Toshiba XCMS-1121A (Basic single-phase variant)
- Toshiba XCMS-1124B (Updated revision with different contact materials)
- Toshiba XCMS-1324A (Three-phase monitoring version)
- Toshiba IVG series (Voltage-specific monitoring relays)
- Toshiba UCG series (Ground fault specific relays)
Find more details on the Toshiba XCMS-1124A and explore our complete catalog of protective relays and power monitoring components.
