Seaward provides total test solutions so that Homeowners and Companies can comply with the demands of all types of safety legislation
Damage or corrosion to Cabling and connectors Caused by moisture can Decrease performance or Increase the risk of fire
Wires hanging below The panels or touching The roof or vegetation can Become damaged Presenting a shock hazard
Damage or corrosion to Cabling and connectors Caused by moisture can Decrease performance or increase the risk of fire
It`s important to identify electrical faults or wiring failures as early as possible, Periodic electrical testing verifies performance over extended periods.
Fires started by electrical faults in rooftop PV systems have been reported worldwide. Regular testing of PV system cabling and components reduces the potential risk of fire.
confirm continued safe operation and optimum energy output can be required by product warranties and component guarantees.
Poor insulation in underground cabling can cause electricity to leak to earth. This can significantly reduce the efficiency of the system.
Copies of all test and commissioning data should be provided to the customer as part of the system documentation when a PV system is installed
If the grounding system degrades over time there is a chance of electric shock
The international IEC 62446 standard recommends that periodic verification of an existing PV installation should be performed
In many cases simple electrical faults or wiring failures can cause a serious inefficiency in the ability of the panel to produce power. This is particularly important for installers working on ‘roof rental’ schemes where installation has been provided free of charge in return for receipt of the feed-in tariff payments. Although metering will always give an indication of system performance, effective electrical testing is also vital not only to prove the safe installation of a new system but also to verify ongoing functional performance.
The absolute minimum testing that needs to be undertaken involves continuity measurements, open circuit voltage, short circuit current, insulation and irradiance.
Other tests involving the use of I-V curve tracers, power analyzers and thermal imaging cameras are not mandatory but may be regarded as useful to carry out certain diagnostic testing or to assess different performance parameters of the solar PV system.
It is therefore largely up to the installer to decide whether he wishes to purchase individual items of equipment or select one or possibly two instruments which provide a combination of tests to enable measurements to be taken in a fast, safe and efficient fashion.
There are many instruments available on the market that are sold under the title of Solar Testing so it is vital to ensure that the instruments selected are capable of performing all of the tests required by the IEC 62446 standard. The nature of PV testing is such that it can expose the installer to high voltages, so the selection of an instrument, which is capable of automatically, and safely performing tests greatly improves efficiency and safeguards the installer.
The availability of new multi-purpose solar PV test instrumentation also means that the functions of a number of individual test instruments can be combined in a single tool – with consequent savings in cost and improved practical considerations.
The electrical output will vary significantly with changes in the level of in-plane irradiance.
Solar PV panel manufacturers quote the electrical output at standard test conditions (STC) with an irradiance level of 1000W/m2.)
Therefore, when commissioning a PV system, it is necessary to measure the level of irradiance at the same time as testing its electrical output, to know whether it is working to its potential under the existing irradiance levels. If the electrical output is different from the manufacturers’ quoted values, it must be determined whether this is due to a fault in the PV installation, or simply because irradiance was different from STC.
Simultaneous measurement and recording of irradiance, open circuit voltage (Voc) and short circuit current (Isc) is required for the PV Array Test Report for IEC 62446
Solar irradiance meters that assess PV modules must have a spectral response close to that of a PV module in order to measure ‘true irradiance’ as a PV system would.
There are two irradiance measurement methods defined and accepted by international standards covering the performance measurement of PV systems:
1. Pyranometer High precision, high-cost instruments using thermal sensors in a glass dome.
2. PV Reference Cell effectively a small-scale version of a PV module, having the same response to solar energy.
Temperature compensation ensures accuracy is not affected by heat. Devices such as light meters, lux meters or devices using photo diode sensors do not have the same spectral response as a PV module, they do not compensate for temperature and are likely to introduce significant measurement errors if used for solar PV applications.
They are not suitable for use on PV systems.