Installing Solar Electric Since 1983


Project: Air Pollution Control District System Upgrade
Description: The County of San Luis Obispo Air Pollution Control District installed a grid-tied solar-electric system in 2002. The work was done by a competing contractor and there were some defects in the design and implementation. Specifically: The high voltage wiring was haphazard and poorly supported. The inverters were roof mounted, making it difficult to replace.
Rewire: In 2014 we reworked the wiring and replaced and relocated the inverters. All high-voltage DC wiring was placed in conduit and the corroded bonding was replaced. The old inverters were removed and upgraded inverters were installed at ground level in a location that is easy to service and that is visible to the public. This enhances the project as a public demonstration for the District.
Below are before and after photographs of this project.
Heavy on roof Hohg voltage loose
Before: These inverters weigh 32 kg and roof access is solely by ladder. Bad idea. The high voltage string wiring was supported by plastic cable ties which predictably failed years ago.
High voltaeg wires in the rain Loose wires
Here are the PV leads laying in a puddle in the rain. Voltage and currents are in the fatal range in these leads. The leads are laying on the abrasive roof deck. These were all placed in metal conduit.
New location Lifting device
The new inverters now at ground level, in public view in an existing shade structure. The new inverters weigh 53 kg. They have no provisions for safe lifting. We jury rigged lifting points and included provisions for an A-frame. SMA, please include threaded insert for a lifting eye.