1 Scope

1.1 This standard applies to the following types of transfer switches that have a maximum rating of 1000 volts for use in non-hazardous locations, in accordance with Annex A1, Item 1:

1. a) Automatic transfer switches;

2. b) Manual or non-automatic transfer switches;

3. c) Closed transition transfer switches;

4. d) Hybrid transfer switches;

5. e) Transfer switches for fire pumps;

6. f) Bypass/isolating switches;

7. g) Softload transfer switches;

8. h) Transfer switches intended for use as service equipment;

9. i) Transfer switches intended for use in mobile/portable applications such as recreational vehicles, motor homes, camping trailers, and mobile health care facilities;

10. j) Inlet assemblies for transfer switch equipment;

11. k) Arc resistant transfer switch equipment;

12. l) Cord connected transfer switch equipment;

13. m) Combination meter/transfer equipment assemblies; and

14. n) In Mexico and the United States, branch circuit emergency lighting transfer switches (BCELTS).

15. In Canada, the requirements for BCELTS do not apply.

Summary of Topics

This revision of ANSI/UL 1008 dated August 25, 2026 includes the following changes:

– Bypass/isolation switches provided as removable elements; 3.7A, 3.8A – 3.8C, 3.13, D1.4, D3.1, D3.2, Table D3.1, Section D4, Section D12A, Section D12B.

– Floor Mounted Transfer Switches; 5.2.1.38 and 6.5.32.

– Requirements for equipment grounding terminals; Table 14A, 5.2.1.39, Figure 5.1, 5.2.6.1.8, 6.13.1.10 – 6.13.1.12, 6.15.4 – 6.15.6, Section 9.19, and Table 14A.

– Transfer equipment with multiple outlets; 5.2.7.14.

– Correcting references in 6.3.2.5 and M6.2.2.5.

– Correction to references in 6.3.2.7 and M6.2.2.7.

– Closed transition automatic transfer switches; 7.1.10.

– Mechanical Interlocking Testing; 7.1.20, 7.1.22, Section 9.18, D2.2, D4.2, and G6.2.

– Restricted Access Definition and Application to 7.1.17; 3.8C

– Temperature rise requirements for polymeric materials in support of live parts; 9.8.1, 9.8.9A, 9.8.11, and Table 16.

– DC testing of equipment; 9.9.4 and M8.8.4.

– Use of separate main devices; 9.13.3.10.

– Relocation of closing test; 9.13.2 (revised and relocated)

– Integrity of Mounting of Live Parts; 9.13.3.4

– Deformed doors and covers after short-circuit testing; 9.13.3.4

– Neutral Switching; 9.13.3.33, 9.13.3.36, and Annex O

– Bypass isolation transfer switches; D1.1, D1.3 – D1.6, D2.5, D2.7 – D2.12, D3.3, D3.4, Table D3.1, D4.3, D5.1 – D5.4, D7.1 – D7.2, D9.1, D10.1, D11.1 – D11.3, D14.2A, and D14.2B.

– Transfer switches for fire pump service; E2.3, E2.18, E3.1, Section E4.5