This page contains the answers to some commonly asked questions about AC Solar. If you have a question that is not answered here, please email us at info@acsolarwarehouse.com and we’ll do our best to answer it for you.

• 1. Do AC Solar systems disconnect from the electricity network when the grid fails or is turned off?

  Microinverters are designed and tested to meet the same electrical and safety standards as conventional inverters and operate in a similar way. AC Solar modules turn off if the grid supply is lost or falls outside of preset limits, and reconnect several minutes after supply is restored.

• 2. Are AC Solar Systems as safe as conventional solar systems?

  The inverters in AC Solar systems are required to meet the same electrical and safety standards as larger conventional inverters. In normal solar installations, DC voltages of up to 600 volts are common in the cables joining the individual modules and connecting the modules to the centralised inverter. During the day, these voltages exist even when the system is switched off at the main switchboard and can pose serious fire and personal safety hazards.

  Under fault conditions, a DC (Direct Current) arc can be difficult to extinguish. Special DC circuit breakers are required to be used and even these do not eliminate the risk of fire caused by a fault within the DC wiring.

  AC Solar systems do not pose the same risk because there are no significant DC voltages present within the system.

  AC Solar systems are connected to the main switchboard via a conventional circuit breaker and their wiring poses no more risk than normal household electrical wiring. Furthermore, the cables connecting the panels to the main switchboard are de-energised instantly when the mains fail or the isolating switch on the main switchboard is operated thus removing any risk of shock to residents or emergency services personnel.

• 3. Do microinverters and AC modules need to be earthed?

  Yes, microinverters and AC modules need to be earthed in accordance with AS3000 and AS5033. This is, however, usually a simple process. An earth conductor is typically run from the main switchboard (or sub board) along with active and neutral conductors and carried through to each AC module via the module connection plug. From the connection plug, the earth is connected to both the microinverter input and the module frame, ensuring the entire array is securely earthed.

  Where the microinverter is mounted separately to the module (i.e. on the rail beneath the module), an earthing washer should be used between the microinverter and the rail to ensure that the earthed frame of the microinverter provides an acceptable earth connection to the rail. Earth washers are also required between the modules and the rails. You should always refer to the technical specifications and installation instructions provided by the manufacturer of the equipment you are installing to make sure appropriate earthing is achieved in accordance with the required standards.

  We are happy to answer any questions you may have regarding the correct installation of any equipment purchased from the AC Solar Warehouse.

• 4. What length warranties do AC Module and microinverter manufacturers offer?

  Solar module warranties are generally unaffected by their use as an AC module. You should seek confirmation of this from your solar module supplier.

  Microinverters warranties vary from 10 to 25 years depending on the manufacturer.

• 5. How does the data logging / system monitoring work?

  Most AC solar module and microinverter manufacturers incorporate comprehensive data logging features in their products. Data is normally transmitted either wirelessly or via a power line carrier (PLC) signal from each individual module to an Internet Gateway device mounted in a convenient location within the home or business. This device is connected to the customer’s broadband connection – either via LAN cable or wirelessly. If the homeowner accesses the internet via a USB dongle, an inexpensive wireless router may be required to be installed in order for the Internet Gateway to be connected into the system. The Internet Gateway aggregates the data from the individual solar modules and sends it to a data warehouse on the internet.

  The installer and the customer can access the data via a password protected website 24/7 to monitor the performance of the system. Some equipment manufacturers have the facility to send the installer and/or customer an email if the operation of the system falls outside of preset parameters. This makes new shading or solar module failures quick and easy to identify and troubleshoot.

• 6. Can AC Solar systems be installed at sites where there is no internet connection available?

  If no internet connection is available close by the site of the installation, then the remote monitoring functionality will obviously not be able to be implemented.

  It is still possible to install a microinverter system without an internet connection – only the remote monitoring function will be affected.

  Some microinverter Internet Gateways provide a local indication of the status of the AC Solar system which can be useful if the remote monitoring function is not going to be implemented. For further information about the best products to use in these situations contact the team at at the AC Solar Warehouse.

• 7. How much do AC Solar systems cost, compared to conventional DC systems?

  The total equipment cost of AC Solar systems is currently around 10% – 25% more than that of a similar quality DC system. This additional cost is offset by savings in the installation of the system, particularly savings from not having to install DC cables, isolators and circuit breakers and not having to run the DC cables in heavy duty conduit in the roof space. Because of the increased energy yield over the full life of the system the overall return on investment for AC Solar systems can be substantially more attractive than for DC systems.