Ⅰ.Introduction
The LNJBC-II Relay Protection Tester is a new generation of verification device developed based on the original JBC. The instrument's internal AC/DC voltage and current sources adopt the latest power technology, providing convenience for field personnel to apply the power instrument technology to other tests. While simplifying operation, this instrument also enhances functionality, allowing for the verification of various common relays. Its panel layout is compact and user-friendly, making it easy to operate and understand, thus earning widespread praise from users.


Ⅱ.Technical parameter
1.Output characteristic 
AC current： 
0～100A adjustable（200A customized） 
0～20A Adjustable
0～5A Adjustable
AC voltage：0～250V (adjustable) 
DC current：0～20A (adjustable) 
DC voltage：0～250V (adjustable) 
Fixed output DC voltage 24V 48V 110V 220V 
Time setting：0-9999.999s 
Resolution：0.1ms 

2.Power supply AC220V ± 5%, 50Hz ± 5%

3.Function
This instrument can calibrate the following types of relays or group protections: 
(1)Measuring relays: including current and voltage type relays, which can measure their starting value, return value, and coefficient.
(2) Time relay: It can measure its starting value, return value, and action time, with a time measurement error of no more than 0.2ms.
(3) Intermediate relay: Calibration of various intermediate relays with starting and holding coils, capable of measuring starting value, return value, holding value, and action time.
(4) Recloser relay: capable of conducting capacitor charging tests, charging time, reclosing time, and testing of intermediate components.
(5) Differential relay: capable of conducting DC excitation test, braking characteristic test, and volt ampere characteristic test.
(6) Various other uncommon relays.