According to tooltip description the node should add cold and lightning melee damage if you have enough physical damage on weapon.
As demonstrated in video below, this node actually seems to decrease Basic Attack DPS when Enchant Weapon is active.
Without Frozen Sparks: Echant Weapon active effect increases DPS 593->1690
With Frozen Sparks: Echant Weapon active effect increases DPS 593->1386
Nothing in node description explains why DPS is decreased when this node is taken, regardless of how much physical damage I have on my weapon.