Through out our years we have seen several installations with no protection on the AC line side. Most of the systems that are integrated with an automatic generator or have the utility (AEE, PREPA) as back up should have the AC surge arrestor integrated on the inverter side. Lighting Strike is not the only threat to the system. Yes, the systems have breakers for protection, but those breakers protect for current spikes, however you need a AC surge protector to prevent damages to your equipment due to spikes on the generator voltage or spikes on the AEE side coming through the house on the inverter AC input. In addition all system shall be mechanically grounded to prevent additional damage. Here we want to share an extract from an article from Norther Arizona Wind and Sun.
“Surge Arrestors, or Surge Protectors, act like “clamps” in most cases. They go across the live wires with another wire going to the ground. Normally they just sit there, but if the voltage goes above a certain level, they start to conduct, shorting the higher voltage to the ground. In lighting prone areas you should also install a surge capacitor – this is not really an arrestor, but acts extremely fast, and will catch those high voltage spikes on the AC line that are too fast for a surge arrestor. For most systems to get the best protection, you should have a DC surge arrestor on the INPUT to the charge controller. It should be as near the charge controller as possible. On the AC side (and this applies to BOTH the inverter AC input and AC output (for generator and/or grid tie systems) you should have both an AC surge arrestor and a surge capacitor.
Most inverter damage is caused by surges on the AC side coming in through house or generator wiring. In many systems with a backup generator, the generator is located outside, quite some distance from the inverter, and is a common hit point for lightning strikes.”
At Caribe Solar Engineering we are always protecting the customers investement, we install all the safeties and protections required by the NEC and local codes. As an option to protect your system we currently have in Stock the Midnite Solar MNSPD300-AC Solar Protection Device. For more info Click on the following link: https://www.solar-electric.com/lib/wind-sun/MN-SPD-specs.pdf
Call us at 787-672-9104 or 787-395-5614 or write us at firstname.lastname@example.org.