1. Product overview

The CG2078 Cable Termination Fault Monitor for Ring Main Units is specifically designed for cable terminations in RMUs (Ring Main Units). It adopts direct temperature sensing via sensors and electric field energy harvesting technology, enabling remote, real-time online monitoring of potential faults such as abnormal temperature rise. The system provides early warnings to prevent sudden power outages, thereby enhancing the operation and maintenance efficiency of the distribution network.

2. Functions & features

· Precise monitoring and intelligent control
Temperature measurement range: -40 ~125℃ with an accuracy of ±1.5%, and an FS resolution of 0.1℃

Monitoring & control mode: the temperature sensor and ultra-low-power sampling/transmitter circuit are embedded inside the plugging head, powered by electric field energy harvesting. The temperature sensor directly contacts the metal connection point, ensuring high-precision measurements. A microprocessor chip samples and processes the temperature signal before wirelessly transmitting it to an external receiver module. It supports multi-channel monitoring (3–24 temperature measurement points).

- Intelligent early warning and alarm

Configurable alarm thresholds: user-customizable high-temperature alarm thresholds. Alarm triggers when any phase temperature exceeds ambient temperature by the preset threshold, or temperature difference between any two phases surpasses the configured limit

Multi-level alarm: notify maintenance personnel through audible/visual alerts and real-time data transmission

·Flexible adaptation

The sensor installation requires no modification to the cable accessory's original mechanical dimensions or standard installation procedures, while fully preserving the inherent insulation strength of cable joints. Custom-engineered plugging adapters are compatible with various specifications of cable joints.

The main unit supports DIN rail mounting for quick and tool-free installation.

3. Technical specifications

I. Technical specifications of wireless temperature sensor

1) Temperature sensor temperature range: -40 ~125℃, with an accuracy of ±1.5% and an FS resolution of 0.1℃

2) Power supply method for temperature sensor: electric field energy harvesting

3) Sampling interval: 1 time/min

4) Sampling method: the sensor is in direct contact with the metal connection to improve sampling accuracy.

5) Temperature sensor wireless communication frequency: 433MHz, with the transmission power of <10mW <10mW

6) Temperature sensor protection rating:: sensor IP65

7) Installation and dimensional diagrams (customized plugging heads available for different sizes)

II. Main technical specifications of the main unit

1) Working power supply: AC 85-265V 50HZ or DC 110-340V or DC24V (optional)

2) Power consumption: less than 10W

3) Alarm output relay: 1 x relay normally open (NO) contact（AC220V/3A）

4) RMU bay configuration: flexible 1-8 bays (6 bays standard), 3 temperature monitoring points per bay

5) Alarm parameter settings:(1) any phase temperature exceeds ambient temperature by more than the set threshold

(2) The temperature difference between any two phases exceeds the set threshold.

6) Display unit: 4.7-inch color TFT-LCD screen

7) Screen Saver Mode: Activates after 10 seconds of inactivity, exits upon any key press

8) Alarm event logging: 50 records

9) Operating conditions: operating temperature: -20°C to +125°C; storage temperature: -40°C to +125°C

              Humidity: no more than 95%RH.

10) Communication interface (downstream): 433MHz Wireless;

11) Communication interface (upstream): RS-485 Bus;

12) Installation method: 35 mm rail installation;

13) External dimensions: 156*91*60mm;

14) Cutout dimensions: 151*80

4. Applications

Urban distribution network ring main unit (RMU): Preventing fault-induced outages caused by cable termination breakdown   

Industrial parks/Data centers: ensuring stable operation of critical power equipment   

Rail transit / tunnel power supply: long-term online monitoring in harsh environments   

Aging grid renovation: compensating for manual inspection blind spots and reducing O&M costs