O bozo que ligou esses circuitos tentando queimar sua casa?
Supondo que os fios são 10AWG (isto é, 30A), este é um grande problema, na verdade, já que os fios podem superaquecer gravemente devido ao consumo excessivo de corrente antes que o disjuntor perceba que algo está errado! Pense no que um elemento de torradeira ao vivo inserido na sua parede faria ...
Quanto ao código, seu problema viola 210.19 (A) (1):
(1) General. Branch-circuit conductors shall have an ampacity not less than the maximum load to be served. Conductors shall be sized to carry not less than the larger of 210.19(A)(1)(a) or (b).
(a) Where a branch circuit supplies continuous loads or any combination of continuous and noncontinuous loads, the minimum branch-circuit conductor size shall have an allowable ampacity not less than the noncontinuous load plus 125 percent of the continuous load.
(b) The minimum branch-circuit conductor size shall have an allowable ampacity not less than the maximum load to be served after the application of any adjustment or correction factors.
e 240,4 (as exceções em A-G não se aplicam ao seu caso):
240.4 Protection of Conductors. Conductors, other than flexible cords, flexible cables, and fixture wires, shall be protected against overcurrent in accordance with their ampacities specified in 310.15, unless otherwise permitted or required in 240.4(A) through (G).