The measurements that turn suspicion into diagnosis.
Thermal images and monitoring data tell you something is wrong. Electrical field testing tells you what, where and how bad. Sinovoltaics performs IV curve tracing, insulation resistance, bypass-diode and PID verification at module and string level - by qualified skilled persons under EN 50110-1 national regimes, with results interpreted against your plant’s design values and factory data
[Request an electrical testing scope]
What electrical field testing covers
Electrical field testing measures the actual electrical behaviour of PV modules, strings and balance-of-system components - IV characteristics, insulation resistance, diode function and ground continuity - to localise faults, quantify losses and verify safety before they escalate.
Test scope:
- IV curve tracing - module- and string-level current-voltage characteristics vs STC-corrected design values: quantifies power loss, localises mismatch, confirms degradation
- Insulation resistance (RISO) - localises insulation faults in modules, strings and DC cabling; the test behind unexplained inverter isolation trips
- Bypass-diode testing (LBPD) - finds lost bypass diodes, a hidden fire risk invisible to standard inspections until shading triggers overheating
- PID verification - confirms potential-induced degradation electrically, complementing its EL and thermal signatures
- BOS electrical checks - combiner boxes, connectors, cable terminations, earthing and continuity: where a leading share of field failures actually starts
Deliverables: test report per string/module with pass-fail against design values, fault localisation maps, severity-ranked repair list, safety findings flagged immediately.
Qualified persons, national rules
Electrical testing on operating plants is regulated work. All Sinovoltaics field engineers operate as qualified skilled persons under the national implementation of EN 50110-1 where they work (NEN 3140, DIN VDE 0105-100 and equivalents), with documented authorisation levels for LV and HV environments. Your site rules, our discipline - no exceptions.
One visit, three methods
Electrical testing rarely travels alone. The standard diagnostic chain:
- Thermography screens the full plant and flags anomalies
- Electrical testing measures the flagged strings and quantifies the loss
- EL imaging proves the cell-level cause and - via the factory baseline - its origin
Booked together, one mobilisation covers all three. That is also exactly what the Annual Plant Health Program does, every year.
When you need this
- Inverters trip on isolation faults and O&M can’t localise the cause
- Monitoring shows string-level underperformance without visible damage
- You suspect PID, diode failures or connector degradation
- Acceptance testing: verifying the plant electrically matches its design
- Safety verification after repairs, retrofits or storm events
