限制使用　

1. End-product constructional details and test performance are not covered under this category; such investigations are found in the end-product standards under which the products are examined and tested.

使用符合UL1446絕緣系統認證的馬達、或變壓器之最終成品，必須送UL執行成品UL認證確認使用是否適用此馬達、或變壓器。

例如：馬達申請符合Electric Motor UL1004 時，14.4節

規定絕緣等級E以上者必須符合UL1446絕緣等級系統，必須經UL認證確認符合該標準規定。

2. Special chemical environments, such as refrigerants, oils, soaps, x-rays, ultraviolet light, etc., are not covered under this category.

本類別不含蓋：特殊化學環境，如refrigerants, oils, soaps, x-rays, ultraviolet light, etc.,

3. The acceptability of construction features of the transformer, motor or coil assemblies produced with these insulation systems, such as spacings, insulation thicknesses (greater than those specified under " Construction Details " in the individual Reports for the insulation systems), thickness and voltage rating of lead insulation (if applicable), etc., shall be determined in the end-use application.

馬達、或變壓器之間隙，絕緣厚度、及出口線之電壓絕緣，於最終產品認證時規定之。

例如:

絕緣系統UL1446並無規範規定馬達、或變壓器之間隙，絕緣厚度、及出口線之電壓絕緣，該項規定於馬達 Electric Motor UL1004 或  變壓器 Standard for Class 2 and Class 3 Transformers UL1558, Transformer-Specialty UL 506 中規定之。

例如:

申請電動跑步機，使用Standard for Motor-Operated Massage and Exercise Machines UL1647標準中3.1.1規定馬達必須符合Electric Motor UL1004

又於18.2.2 節規定，使用之馬達過載保護必須符合UL 2111，除非符合Exception No. 1, 2, 或 3

所以，通常申請UL1647跑步機之馬達必須申請符合UL 1004 及，如溫昇超出B級以上時，也必須再申請符合UL1446絕緣系統，甚至馬達過載保護必須符合UL 2111，除非符合Exception No. 1, 2, 或 3