zero cross

Greetings everyone, Recently i have the final year project of heater load control using zero crossing method. The heater capacity is 2300 kW, and i decrease the scale into 1/3 (760 kW). The heater supply voltage is 690V. It's full capacity is divided into 5 branches and each branches are...

230v, 50Hz, two wires dimming circuit. Zero cross and phase angle are fine, but when triac is fired, due to missing neutral, and due to mains sine wave chopped by the phase control, then zero crossed is messed and the bulb goes disco blinking. If I power the circuit from separate mains source...