Thanks for sharing these details @Nyarp . There are many variables that can cause power fluctuation, it sounds like you have a sufficient transformer so at least thats checked off. You will want to also check the gauge (thickness) of your wiring and how long the wire run is. Please ensure there is no old, corroded, or fraying wires in circuit as this can cause resistance, and a loss of power. We recommend contacting support for hardwiring concerns as it usually requires a closer look.