Shunt-Based Current Measurement
Shunt-based sensing, rather than conventional Hall-effect sensors, gives the SMC linear and consistent current readings across every channel, with accuracy better than 0.75% of full-scale deflection.
Renewable & Solar Solutions
String Monitoring Card (SMC) for Solar PV String Current and Voltage Monitoring
The String Monitoring Card (SMC) from Sertel Electronics is a DC monitoring module with 16 or 24 channels, providing solar plant operators and SCADA systems a clear, string‐by‐string view of each photovoltaic array. Constructed as the SEPL300_SMC, it measures current, voltage, power and temperature on every string in real time, allowing a fault, shading loss, or underperforming panel to appear on a particular string well before it manifests as a reduction in overall plant yield.
16 or 24 String Channels
Up to 2100 V DC Input
30 A per String (80 A on Request)
RS-485 / Fiber Optic / Wireless, Modbus RTU
Key Features
Built for String-Level Visibility Across Every PV Array
A combiner box hides underperformance until it costs you generation. The String Monitoring Card puts a current, voltage and temperature reading on every string entering it, so operators can act on an individual string instead of estimating from an array-level total.
Multi-Protocol Communication
Every card ships with RS-485 (Modbus RTU) as standard, alongside an Optical Fibre interface and an optional Wireless LoRa module for sites where running a hardwired bus back to the data concentrator is difficult.
High-Voltage DC Compatibility
A selectable 0 to 1000 V DC or 0 to 1500 V DC input range, with DC voltage reading capability up to 2100 V DC, sizes the SMC for both legacy strings and today's higher-voltage PV arrays.
Automatic Fault Diagnosis
Onboard LED status indication, surge protection device (SPD) monitoring and switch status reporting flag a fault at the card itself, ahead of any downstream SCADA alarm.
Multi-Point Temperature Monitoring
One onboard sensor tracks internal enclosure temperature while a separate external RTD input, PT100 or PT1000, reads combiner box or ambient temperature independently.
Low-Power DIN Rail Design
Rated for industrial outdoor conditions from -30°C to +70°C, the SMC draws less than 3 W with RS-485 active and mounts directly to standard DIN rail inside the combiner box.
Applications
Where the String Monitoring Card Is Deployed
Built around a shunt-based, multi-channel current and voltage front end, the SMC extends beyond solar arrays to any installation where individual DC branches need to be tracked independently rather than as one combined feed.
Technical Specifications
Complete electrical, environmental and communication details for the SEPL300_SMC String Monitoring Card.
Input Voltage
| Parameter | Specification |
|---|---|
| Number of Channels | 1 channel |
| Measuring Range | 0 V to 1000 V DC or 0 V to 1500 V DC (selectable) |
Input Current
| Parameter | Specification |
|---|---|
| Number of Channels | 16-channel variant: 30 A per string. 24-channel variant: 25 A per string |
| Accuracy at FSD | Less than 0.75% of full-scale deflection |
| Measuring Side | Negative or positive (configurable) |
FAQ
Frequently Asked Questions
Ready to Monitor Every String in Your Array?
Talk to a Sertel engineer for a tailored channel configuration, Modbus register mapping guidance and pricing for the SEPL300_SMC String Monitoring Card.