Quick Answer
Bypassing module-level devices in solar installations can be hazardous, as it may compromise the safety features provided by these devices, such as rapid shutdown and arc fault protection.
Risks of Bypassing Module-Level Devices
Bypassing module-level devices (MLDs) can disable critical safety features in solar installations. MLDs are designed to quickly disconnect and reduce voltage to a module or a string of modules in the event of an arc fault or other fault condition. Rapid shutdown, a key feature of MLDs, reduces the risk of electrical shock and fire by quickly cutting off power to the installation. Without MLDs, an arc fault can spread quickly and result in catastrophic consequences.
Compliance and Code Requirements
Many jurisdictions have adopted International Building Code (IBC) and National Electric Code (NEC) requirements that mandate the use of MLDs in new solar installations. For example, NEC 690.12 requires that MLDs be installed in grid-tied systems with a maximum system voltage of 1,000 volts or less. Bypassing MLDs can put solar installers and homeowners at risk of non-compliance with these regulations.
Safe Alternatives
Homeowners and solar installers who are concerned about the cost or complexity of MLDs may consider alternative solutions, such as using MLDs that are specifically designed for small rooftop solar installations, or using other types of arc fault protection devices that can be installed at the inverter or electrical panel level. These alternatives can provide similar safety benefits while minimizing the cost and complexity of the installation.
Find more answers
Browse the full Q&A library by topic, or jump back to the topic this question belongs to.