Hello, if I understand your question, you have a three-phase group and the distributor gives you a monophysite connection. if so, you must identify the neutral of your generator and connect it to the neutral of your network at the outlet of the thermomagnetic key. Then one of the phases of the generator at the thermo-magnetic output of your installation, would be the free terminal of that key. It is important that you identify phase and neutral well at both points. In case of cutting of the distributor side, you start the equipment and it will work perfectly. Needless to say, you must install between another generator and the main thermomagnetic of your installation another key whose nominal current is equal to or less than the generator E S VERY IMPORTANT THAT BEFORE LIGHTING YOUR GENERATOR THAT YOU CUT THE MAIN THERMOMAGNETIC WRENCH IN ORDER TO AVOID A RETURN TO THE DISTRIBUTOR NETWORK AND CAUSE ACCIDENTS THAT CAN BE FATAL TO THE OPERATORS OF THE COMPANY THE TWO KEYS MUST NEVER BE CONNECTED AT THE SAME TIME