I made my own. The genset is in the worshop building where it has to pass through a Heinmann magnetic breaker switch to get to the underground cabling to the house. In the house there is a 100 amp 3 pole contactor which will not connect the genset line (phase-phase-neutral) to the 60 amp branch circuit (used to input genny power into the main breaker box) unless there is AC power alive on the generator feed. A further condition must also be met before the contactor can close. A microswitch physically senses that the main breaker to the street is in the OFF position before the coil on the contactor can close. No way to engage the generator feed unless `A` it is live, and `B` the main breaker is OFF. Furthermore, shud I wish to disconnect the genset from the house breaker box in some sort of emergency like maybe the genset is having a load related heart attack, I merely open the 60 amp twin breaker on my breaker box labelled `Genset`, or from the genset location with the Heinmann breaker switch.
One final touch. A pair of 25 watt incandescent light bulbs, one per phase, are attached to the incoming genset line prior to the contactor. Each lamp has a line fuse. These lamps confirm existence and at a glance display the quality of the power coming from the genset while working under no house connection or varying states of house load.
In the shop I bring the 120-0-120 volt output from each of my generator plants to a common electrical board on the wall and they are then each wired to two 50 amp rated Welding receptacles. The house line to the Heinmann 30A, 2-pole breaker is a male welding plug. Presently I can decide to run the house off either two of the 3-phases of the 10 kW VW diesel plant (about 7 kW) or the Petter 5 kW diesel plant. I may similarly select which genset to put the shop on, but the shop isn`t yet hardwired for genset. I presently use extension cords on the floor (like 100 foot run of 6/3 cabtyre to the machine shop) as needed to get to the generator room from whatever machinery or heaters I want to power on genset.
As I add gensets I will simply add welding receptacles on this panel. One day when I have the money for materials I hope to make a sound silencing cinder block room within the shop building for all the generators to be set up together.
Heinmann breakers are the best circuit breakers I have had any experience with. They are beautifully made and open reliably when the circuit is overloaded by just a few percent. Personally I do not trust commercially offered, code approved thermal circuit breakers found in most home panels. They are crap compared to a Heinmann. The Heinmann breakers I use are found in surplus electrical cabinets and switchgear from industry of 50 years ago. They have a heavy black bakelite enclosure and may be surface mounted to a plywood panel with woodscrews. They have heavy duty plated, machined copper block setscrew wire terminals. They can be used without an electrical box or in one. My Petter has one on the output control box on the plant itself (DIY genset). I will use Heinmanns everywhere in my off-grid power setup as I proceed. They provide very good overcurrent protection but are convenient to use as on-off switches.
