IEC 62446-1 Summarized

IEC 62446-1 establishes the standard for testing, documenting, and maintaining grid-connected PV systems. We have summarized it below for easy processing and integration into your processes!

IEC 62446 Test



Challenges for Operative Systems


Grounding System Continuity Test

Ensure that parts of the PV system frame, rack, boxes are grounded.

Ohm-meter or continuity tester

No Problems

Check continuity of ground in any preventative maintenance inspection and before working on system.

Polarity Inspection

To ensure that (+) and (-) wires are not reversed


No Problems

This test should spot problems upon initial commissioning and not need to be repeated for preventative maintenance inspections- still we do find strings wired in reverse polarity that were not caught in commissioning in which case the string fuse is burned.

Combiner Box Test

Ensures fuses are OK and that current sums as intended.

Digital Multi-meter

Test usually entails shut down of system

While important in commissioning new system, not required for PM inspection as other tests can spot the common problems.

String Open Circuit Voltage (Voc)

Check string is wired correctly inlcuding number of modules.


Requires shut down of system and removal of fuse from fuse holder to create open circuit can damage aged fuse holders.

Measure operating voltage (Vmp) instead of Voc

String Short Circuit Current (Isc)

test instrument with a short circuit current measurement function (e.g. a specialized PV tester)

Requires "Short Circuit Switch Box" to contain switching arc; requires fuse removal from fuse holder.

Measure operating current (Imp) instead of Isc

Functional Test

Ensure operation of switches, breakers, ground fault, arc fault, other functions.

Not applicable

Requires system shut-down. Aged equipment is likely to fail when exercised.

Some tests, such as inverter shutdown and restart, might be OK, but not recommended to exercise all functions for PM inspection

Insulation Resistance Test

Ensure integrity of insulation on wiring.

Insulation Resistance Tester ("Megger")

Shock hazard; personnel protection; isolation of PV array from ground and from inverter and other equipment. High test voltages may damage devices (eg surge suppressors) or void warranties.

Usually not recommended for PM inspection of operating system- may be employed if wiring problems precipitate a need for it.

IEC 62446 Category II tests

I-V Curve Test

Expose details of current/voltage characteristics

I-V Curve Tracer

Requires system shut-down and same issues as Voc and Isc test.

Not required for PM inspection- Vmp and Imp measurements will expose most problems.

Infrared Scan Test

Identify PV modules or switchgear that is overheating due to improper operation.

Infrared Camera with good resolution

No Problems

Widely recommended in PM inspections. Can be used for PV modules, combiner boxes, connectors, batteries, and AC switchgear

Other Tests

Voltage to Ground-Resistive Ground System

Verify resistance to ground for modules with resistive grounding with manufacturer's recommendation

Loop Impedance Meter

Only for modules with resistive grounding systems. Requires sytem stut down and isolation of modules.

Not generally recommended, but may be required by module manufacturer.

Blocking diode test

Check polarity and voltage drop of diode

Diode Tester

Testing of bybass diodes in PV modules requires opening of junction box (potential leak) and requires module to be covered for measurement of bypass diode or may damage meter.

Not generally recommended, but may be conducted if module performance fails other tests.

Wet insulation test

Identify faults that occur only in wet condition

Insulation Resistance Tester ("Megger")

Time consuming and expensive; inconsistent results.

Not generally recommended

Shade evaluation

Measure shade of surrounding opbjects

Shading Profile Device (eg Solmetric Suneye)

No Problems

Not generally needed, but useful for establishing baseline and monitoring shade growth.

Grid Interface Tests

Check operation of grid-protecting and anti-export features

Special equipment to "inject" voltage and frequency profile into device

Requires sytem shutdown; may require service shut-down.

Not recommended unless required by Grid Operator for typical PM inspection.

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