Isso deve ser bom, mas verifique o preenchimento com três etapas, se quiser ter certeza, e certifique-se de que ele esteja rotulado corretamente também!
O seu uso (fios extras passam através de uma caixa de desconexão para outra desconexão) se enquadra na NEC 312.8:
312.8 Switch and Overcurrent Device Enclosures with Splices, Taps, and Feed-Through Conductors. The wiring space of enclosures for switches or overcurrent devices shall be permitted for conductors feeding through, spliced, or tapping off to other enclosures, switches, or overcurrent devices where all of the following conditions are met:
(1) The total of all conductors installed at any cross section of the wiring space does not exceed 40 percent of the cross-sectional area of that space.
(2) The total area of all conductors, splices, and taps installed at any cross section of the wiring space does not exceed 75 percent of the cross-sectional area of that space.
(3) A warning label complying with 110.21(B) is applied to the enclosure that identifies the closest disconnecting means for any feed-through conductors.
As regras de preenchimento de 40% e 75% são triviais neste caso - as calhas mesmo nas menores desconexões são maiores que 3/4 "EMT para fornecer o espaço de dobra de cabos requerido pelo Código, então você Não se aproxime de nenhum dos dois, já que estes são verdadeiros condutores de feed-through , entretanto, a desconexão existente precisará de um rótulo aplicado a ele de acordo com 110.21 (B), porém:
(B) Field-Applied Hazard Markings. Where caution, warning, or danger signs or labels are required by this Code, the labels shall meet the following requirements:
1) The marking shall adequately warn of the hazard using effective words and/or colors and/or symbols.
Informational Note: ANSI Z535.4-2011, Product Safety Signs and Labels, provides guidelines for suitable font sizes, words, colors, symbols, and location requirements for labels.
(2) The label shall be permanently affixed to the equipment or wiring method and shall not be hand written.
Exception to (2): Portions of labels or markings that are variable, or that could be subject to changes, shall be permitted to be hand written and shall be legible.
(3) The label shall be of sufficient durability to withstand the environment involved.
Informational Note: ANSI Z535.4-2011, Product Safety Signs and Labels, provides guidelines for the design and durability of safety signs and labels for application to electrical equipment.
Dado tudo isso, eu simplesmente faria uma etiqueta impressa que diz: "Cuidado: Os condutores de passagem são desconectados pelo disjuntor XYZ no painel", onde XYZ é a etiqueta dada ao novo disjuntor no diretório do sistema de carga, e aplica para o interior da tampa de desconexão existente, onde é protegido de UV, água, etal.