Based on the numerical calculation of 3-D potential distribution in aluminum reduction cells, current distribution in the metal pad is calculated under the following conditions: 1) pot ledge ideally formed; 2) ledge extension to below anode; 3) different metal heights; 4) AC and 5) Spike. It is found that J_y in metal pad increases first to a highest point and then decreases along anode length. At normal status, the largest J_y is about 0.4A/cm^2 and it locates at about 2/3 of anode length. With longer ledge, the maximum value of J_y decreases and its position moves center-ward. The longer the side ledge, the larger the negative current flowing center-ward at side channel. J_z in metal pad increases with anode length and it is not affected by metal height; while J_y increases with metal height. At AC, current flows toward metal under new anode. At spike, current concentrates at spike rather than evenly distributes. Normally, J_x is almost negligible in metal pad.
