How a String Monitoring Box Works in Residential Solar Systems
How a String Monitoring Box Works in Residential Solar Systems
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
- Enclosure
- PV fuses
- Surge Protection Device
- DC Disconnector/Isolator:
- Cable Glands/Connectors
- Monitoring card
Suggested Articles

6 Upcoming Renewable Energy Events in India You Should Attend
The World Environment Expo, 2022 is a business platform that allows national and international equipment

What Does 1 kWp Mean in Solar Power Systems?
1 kWp is a standard unit used to measure the capacity of a solar power system under ideal conditions. This guide explains what 1 kWp means, how much energy it produces, and why it matters for system sizing.

Inverter Circuit Board Fault Guide for Solar PV Systems
A complete guide to identifying inverter circuit board faults in solar PV systems, recognizing when professional service is required, and following safe maintenance procedures.

Single Line Diagram (SLD) in Solar PV Systems: Complete Guide to Design, Symbols & Reading
Learn how to fetch a Bill of Material (BOM) for a solar PV system directly from design documents like SLD, layout, and GA drawings. This step-by-step guide helps installers and EPCs ensure accurate material estimation and efficient project execution.

Rajasthan Rooftop Solar Subsidy: What Homeowners Need to Know
Rajasthan homeowners can save big with the 2025 rooftop solar subsidy. Learn about the updated rates, eligibility criteria, and benefits to make your switch to solar more affordable.

Solar PV Conduit & Cable Routing Plan Guide
A complete guide to preparing solar PV conduit and cable routing plans, including layout design, routing methods, and installation best practices.

How to Perform Cable Continuity Tests in Solar PV Systems
A complete guide to cable continuity testing for solar PV systems, ensuring safe, reliable, and properly connected electrical installations.

Complete Guide to Net Metering and Electricity Bill Savings
Learn how net metering lets you sell excess solar energy back to the grid, reducing your electricity bills and maximizing your solar investment.