IS 16221

IS 16221 is the Indian Standard that solar inverter manufacturers, EPC procurement teams and permit designers check for inverter safety. This entry explains what IS 16221 Parts 1 and 2 cover, how they map to IEC 62109, and which companion standards a grid-connected inverter needs for BIS registration in India.

Key Takeaways

• IS 16221 = Indian inverter safety standard.
• Equivalent to IEC 62109.
• Grid-tied inverters also need IS 16169 (anti-islanding) and IS 17980 (efficiency).
• Required for BIS Compulsory Registration of solar inverters.
• Inverters are not on ALMM; BIS registration is the approval route.

What is IS 16221?

IS 16221 is a safety standard, not a performance one, it addresses how an inverter protects installers, technicians, and building occupants from electric shock, fire, and overheating rather than how efficiently the inverter converts DC to AC. That distinction matters when reading a datasheet: an inverter’s IS 16221 mark speaks to enclosure protection, insulation resistance, and fault-clearing behavior, while efficiency is tested separately under IS 17980 and anti-islanding under IS 16169.

All three sit under the same BIS registration, so a manufacturer usually tests a model against them in one certification cycle.

Where IS 16221 Fits in the Compliance Chain

For a project team, IS 16221 rarely appears as a standalone checkpoint, it surfaces indirectly, through the equipment list. A DISCOM or CEIG reviewer checking a net metering or interconnection application generally confirms that the specified inverter model carries a valid BIS registration covering IS 16221 (Part 2). Unlike modules, inverters are not on the ALMM list, so BIS registration is the main equipment check.

Specifying an inverter that hasn’t completed IS 16221 certification, common with newer models entering the Indian market, is one of the more avoidable reasons a permit package gets sent back for equipment substitution late in the review cycle.

Related Reading

Since IS 16221 sits inside the broader BIS certification framework for solar equipment, our glossary entry on BIS Solar walks through how IS 16221 relates to the other IS standards (modules, cables, earthing) that make up a complete compliance package. For the state-by-state view of how equipment certification gaps affect approval timelines in practice, see Solar Permits India: State-Wise Processing Times 2026.

On the manufacturer side, Qbits Energy’s breakdown of solar inverter regulatory compliance in India and its IEC 62109 glossary entry go deeper into the international standard that IS 16221 is modeled on.

Disclosure: Qbits Energy is a Heaven Designs group company.