In the center, PEF-301, contactors. This facility has 2 independent single-phase inputs and one consumer. The generator starts only after the voltage disappears on both inputs, with priority on phase “A”. Simple-cheap-effective).

PEF-301 has protection against contact sticking. If the load does not exceed 16 A, contactors may be completely avoided.

Another interesting application of PEF-301 from a regular customer:

The very first automatic phase switch PEF-301 I installed for a customer (we installed a network quality analyzer OMIX and delved into ORTEA stabilizers), who so thoroughly investigated the local energy providers that they ended up pulling the contacts at the local substation together. Thanks to this, the energy providers turned a blind eye to his request to install a phase switch in his apartment.

Now I am, of course, surprised how such a thing could be built, but it remains on his conscience and seems to have stopped being a secret over the years. It is important for me to showcase this solution because the PEF-301 has been reliably switching 63A inputs and periodically clicking contactors without any issues for 4 years. During this time, no problems have arisen, and everything works as expected.

Here is an enlarged section of the cottage panel from the TwinLine series, where everything is visible. Note the trick: on the circuit breaker protecting the phase switch, the phases are not arranged as L1-L2-L3 (White-Red-Black for my panels), but as L3-L2-L1. This is done so that the inverter phase (for which this switch is installed) is the third by default. If something happens to it, the switch will select another phase.

Here is a nice but brain-draining office panel in the CITY (the panel is good, but the customer has been a headache for me for six months, and I am ready to throw it out the window, even without payment, as with audiophiles). Everything here is very responsible, so I installed the phase switch PEF-319 to be able to see what is connected to it and what it shows, but I attached contactors for reliability. All of this is protected by a single circuit breaker and powers the server room, DALI automation, and various small components inside the panel.

Over the years, the phase switch has become a standard feature in my panels for powering boiler rooms or critical loads. If the panel is serious, I include it even without asking.