The JL-8CG rail type inverse time overcurrent relay is divided into inverse time overcurrent relay and timed overcurrent relay, and is currently the latest product on the market. The function is based on the same principle as before, reducing the volume by two-thirds, greatly facilitating customer selection. The new overcurrent relay has a novel style and excellent performance. Easy to use and intuitive. It is actually the most ideal product to replace all overcurrent relays.
Rail type overcurrent relay (hereinafter referred to as relay). It is composed of conventional integrated circuits and digital circuits, and its I-t delay characteristics comply with the national society IEC255-4 standard. At the same time, considering the interchangeability of domestic electromagnetic (GL type) inverse time overcurrent relays, non-standard inverse time characteristic relays can also be provided according to actual system operation requirements. Each relay in this series is equipped with a low overrunning quick disconnect outlet. When combined with other types of relays, it can form different types of protection functions. Therefore, it can be applied to relay protection of various types of power equipment.
At present, the transmission systems with voltage levels below 35kV in China's power system generally use current protection devices with incomplete star connections, and overcurrent protection is mostly used. Among them, overcurrent protection is generally time limited or inverse time limited. Considering the traditional practice of relay protection in China, this relay adopts two-phase current protection, which can be selected with reverse time limit or fixed time limit. Both overcurrent and rapid break of the two phases can be independently set, with overcurrent and rapid break independent tripping outlets and alarm signal output contacts.
working principle
The CT secondary current forms a weak voltage through the converter, and the inverse time starting current is set, filtered, rectified, filtered, and automatically extracts the maximum fault phase current, which is sent to level detection to form an open circuit. The characteristic quantity is inserted into the circuit to form different types of inverse time characteristic curves. The V-F circuit is sent to the timer, and when it is consistent with the set delay, the circuit sends a pulse signal to the amplifier to drive the KF inverse time outlet relay. Quick break setting and automatic extraction of maximum fault phase current to be sent to the integration level detector. After discrimination with the preset level, a pulse signal is sent to the amplifier to drive the KS quick break output relay.

The JL-8CG rail type inverse time overcurrent relay has the following characteristics:
1. No DC auxiliary power supply;
2. Completely using dial switches for setting, convenient and intuitive;
3. Has strong anti-interference ability;
4. There is no mechanical jamming phenomenon in the original electromagnetic overcurrent relay;

Main parameters of JL-8CG rail type inverse time overcurrent relay
Product features: All products meet the following technical parameters [except for products with special requirements]
1. Return time: In the method of cutting off the circuit, the relay is powered off, and the return time of the relay is not more than 30mS; except for power-off delay time relays
2. The allowable range of voltage variation for the power supply is 0.8 to 1.1 times the rated voltage, and the power supply circuit can also be wide;
3. Contact capacity: The output contact of the relay can disconnect up to 250V, and the DC inductive load circuit with a time constant of 5 ± 0.75mS is 50W; the AC circuit with a voltage not exceeding 250V is 50VA. The relay can be connected for a long time for 5A.
4. Power consumption: not exceeding 5W at rated voltage.
5. Environmental temperature: -10 ℃~+50 ℃.
6. The conductive terminals of the dielectric strength relay are connected together to withstand an AC voltage of 2000V (effective value) between exposed non charged metal parts or casings, and tested for 1 minute without insulation breakdown or arcing. 7. The conductive terminals of the insulation resistance relay are connected together, and the insulation resistance between the exposed non-metallic parts and the shell is measured with a megohmmeter with an open circuit voltage of 500V, and the insulation resistance is not greater than 300M Ω.
8. The contact points of the electric life relay are connected to a circuit load with a specified capacity, and the electric life is 100000 times.
9. Anti interference performance: Relay interference complies with DL478-92 "General Technical Conditions for Static Relay Protection and Safety Automatic Devices".

JL-8CG rail type inverse time overcurrent relay