根據 GB 29415—2013《耐火電纜槽盒》，電纜橋架耐火時間分為 4 個等級：

According to GB 29415-2013 "Fire resistant Cable Tray Boxes", the fire resistance time of cable trays is divided into four levels:

F1：大于等于 90 分鐘。

F1： Greater than or equal to 90 minutes.

F2：大于等于 60 分鐘。

F2： Greater than or equal to 60 minutes.

F3：大于等于 45 分鐘。

F3： Greater than or equal to 45 minutes.

F4：大于等于 30 分鐘。

F4： Greater than or equal to 30 minutes.

另外，也有資料將電纜橋架的耐火等級分為 NI、NII、NIII 三個等級，其中 NI 等級耐火時間大于等于 60 分鐘，NII 等級大于等于 45 分鐘，NIII 等級大于等于 30 分鐘。

In addition, there are also materials that classify the fire resistance level of cable trays into three levels: NI, NII, and NIII. Among them, the fire resistance time of NI level is greater than or equal to 60 minutes, NII level is greater than or equal to 45 minutes, and NIII level is greater than or equal to 30 minutes.

不同使用環境對防火橋架的耐火時間要求有所不同，如地下車庫等對防火有特別要求的地段，防火橋架耐火時間要求大于 1 小時。在實際應用中，應根據具體的工程需求和相關規范來選擇合適耐火時間的電纜橋架。

The fire resistance time requirements for fire-resistant cable trays vary depending on the usage environment. For example, in underground garages and other areas with special fire protection requirements, the fire resistance time of fire-resistant cable trays should be greater than 1 hour. In practical applications, cable trays with appropriate fire resistance time should be selected based on specific engineering requirements and relevant specifications.