What is a string monitoring box in home solar system?
A string monitors system is the advanced version of AJB. AJB with string monitor unit is called SMB (string monitoring box). A string monitor system has the main objective to monitor the individual string current & common bus voltage on real time basis. It also has the temperature measurement facility for the keeping a check on the temperature inside the box. The string current, voltage & temperature are measured & communicated through a RS-485/Zigbee over Modbus protocol. It should be compatible with SCADA system. It helps in easy detection & identification of fault in any string. After getting the location of the fault through a computer we can rectify the same easily.
There are two types of string monitoring systems.
- Shunt based
- Hall effect type
The main components of SMBs are
- PV fuses
- Surge Protection Device
- DC Disconnector/Isolator:
- Cable Glands/Connectors
- Monitoring card