DC String Voltage

Category: infrastructure

The total accumulated voltage produced by a series of connected solar panels routed to an inverter input.

Calculated by adding up the open-circuit voltage ($V_{oc}$) of every panel in the series loop. Standard commercial systems allow string configurations up to 1,000 or 1,500 volts DC. Underwriters must calculate maximum cold-weather voltage spikes to avoid frying the inverter inputs.

Common Examples

• The engineer adjusted the string sizing downward to ensure the maximum DC string voltage didn’t breach the inverter’s safety threshold.
• High-voltage DC string lines require strict layout routing inside metal armored conduit armor to pass commercial building inspection codes.