1. Overview:
1. Automatically cut off some user loads when connected to the power grid frequency; 2. Automatically disconnect according to frequency in interconnected systems; 3. To ensure the safety of large steam turbine generator units or provide power to important users, disconnect the generator units from the system when the grid frequency decreases; 4. Used in other industrial sectors for progressive frequency control.

2. Model parameters:
1. The frequency setting value error shall not exceed ± 0.015Hz, and the minimum frequency setting level difference shall be 0.0125Hz;
2. The frequency setting range is 45-49.7Hz, with one action frequency setting value;
3. The return coefficient is not greater than 1.002, and the return time is not greater than 60ms;
4. The working voltage of the input terminal of the device is AC 60-120V;
5. The setting range for delay action time is 80ms-99.99 seconds, and the maximum setting difference for delay is 10 milliseconds;
6. Preventive measures against misoperation;
Set the range of 45.2-50Hz for releasing frequency lock level setting
Equipped with slip locking circuit, with a setting range of 3-10Hz/S
Equipped with a low voltage lockout circuit for locking below 55V (SQP-1C/II also has a low current lockout);
There is a central alarm signal contact point.
7. Measures to prevent refusal of action:
There is a monitoring level for normal operation, which may trigger an alarm in case of internal faults;
Equipped with low-frequency test signals, transmission tests can be conducted during operation.
8. The operating environment temperature is -25~+50 ℃, and the relative humidity does not exceed 90%.
9. There are two pairs of export action contacts and one pair of central alarm signal contacts, both with a capacity of DC220V and 30W.

SZH-2A (SQP-1A/II) Digital Frequency Relay