Any-Grid Hybrid Inverter in Split-Phase Environments

A guide to using the Any-Grid PSW-H in split-phase (2-phase) environments

The Any-Grid PSW-H series of hybrid inverter/chargers with MPPT allow working in grid-connected or off-grid environments, and interfacing with multi-phase electrical sources and loads. The following outlines several ways to interface with split-phase systems in order to take advantage of the Any-Grid PSW-H series’ versatility and provide power to your AC loads under various conditions. Split-phase electrical grids are common throughout the Americas. The following scenarios work with or without a connected battery bank and only focus on the AC side. No PV or battery connections are shown as well as RCDs, SPDs or other safety equipment that may be legally required in your area. Every Any-Grid PSW-H must be installed by a trained professional while respecting the local electric code and other regulations.

Single Any-Grid PSW-H Unit

1. Use of a 230 Vac PSW-H with 220 ~ 240 Vac AC loads
In this scenario an isolating transformer is needed to satisfy the requirement for a neutral at the AC input. This is because any PSW-H, if connected to an AC source, must be connected to a live (L) and neutral (N). It may never be connected to two live phases. This transformer converts the 120 Vac split-phase signal to a 240 Vac single-phase signal referenced to neutral. From this point a normal 230 Vac PSW-H can be used to supply 220 ~ 240 Vac loads and utilise the AC source as needed:

2. Use of a 120 Vac PSW-H with 120 Vac loads
In this case a single leg of the split-phase AC source is used (neutral and 120 Vac live wires). A 120 Vac PSW-H is fed with this AC source and supplies 120 Vac loads.

Multiple Any-Grid PSW-H Units

Use of two or more 120 Vac PSW-H units
Either of the single-unit examples above can be applied with multiple Any-Grid PSW-H mounted in parallel to increase output power. The further examples below show how to interface with two phases.

180° Split-Phase
Phase 1 and neutral of the split-phase AC source is fed into the AC input of one or more 120 Vac PSW-H. Phase 2 and neutral goes to one or more other PSW-H unit(s). The split-phase distribution is upheld and at the AC output of the PSW-H cluster single-phase 120 Vac loads can be powered either from phase 1 or 2, just like when connecting loads directly to a split-phase utility grid. 240 Vac loads can be powered by connecting to phase 1 and phase 2 at the AC output of the Any-Grid PSW-H cluster (no neutral).
Each Any-Grid on phase 1 is set to “2P1” in settings menu 28. So phase 1 of a split-phase / 2-phase system. Every unit on phase 2 is set to “180 2P2” in menu 28, showing it is on phase 2 of a 180° split-phase system.

120° Split-Phase
Here too phase 1 and neutral of the AC source are connected to the AC input of one or more 120 Vac Any-Grid PSW-H unit(s). Phase 2 of the AC source and neutral go to one or more PSW-H unit(s) in a separate group. Just like in 180° split phase above, single-phase 120 Vac loads can be powered either off the PSW-H unit(s) on phase 1 or on phase 2, always being connected to neutral and either one of the two phases for 120 Vac. Where this system differs from the 180° split-phase is in the total voltage between phases. This is not 240 Vac as in the 180° system, but rather 208 Vac. So 208 Vac loads can be powered between phase 1 and phase 2 of the PSW-H AC outputs.
Each Any-Grid on phase 1 is set to “2P1” in settings menu 28. Each unit on phase 2 is set to “120 2P2” in menu 28, showing it is on phase 2 of a 120° split-phase system.

Learn more about the Phocos Hybrid Inverter Series.