Help CenterInverters
Parallel inverter operation (stacking)
Inverter3 min readUpdated: 2026-08
When required power exceeds the largest available model in a range, or when redundancy is required (critical site), several identical inverters can be paralleled to add up their power.
| Requirement | Why |
|---|---|
| Same brand and same model | Phase and frequency synchronization between different inverters is usually unsupported |
| Same firmware version | Master-slave communication protocols change between versions |
| Dedicated communication cable | Inverters synchronize in real time (phase, frequency, load sharing) |
| Respect the manufacturer's max parallel count | Varies by brand: often 6 to 16 units maximum |
Paralleling two inverters of different power ratings or brands without manufacturer validation can create circulating currents between units, damaging the power electronics.
For a site requiring high availability (hospital, telecom), stacking also provides N+1 redundancy: if one inverter fails, the others keep powering part of the load instead of a total outage.
Common mistakes
- Paralleling inverters of different models or firmware versions
- Forgetting the dedicated communication cable for master-slave synchronization
- Exceeding the manufacturer's recommended maximum parallel unit count