Arc resistant acccessibility

[buddy91082]

Can anyone explain the differences and pros and cons of the various arc accessibilities for Type 2, 2B, 2C, and 2BC and where they should be applied?

Thanks.
b

 

[7anoter4]

Accessibility Level of equipment defines the level of arc flash protection.
Per IEEE C37.20.7-2007 "IEEE guide for testing metal-enclosed switchgear rated up to 38 kV for internal arcing":
Type 1 (Front only)
Type 2 (Front, Sides and Rear)
Type 2B (includes isolation between LV panel and power cell within a unit – coming with next revision of standard).
Type 1C or 2C Includes isolation between units/compartments/adjacent structures.
The differences between the Type 2, Type 2C, and Type 2BC arc resistant ratings are as follows:
Type 2 rated switchgear has arc resistant construction on the front, back, and sides.
Type 2C rated switchgear is Type 2 compliant but also includes arc resistant features or
designs between compartments within a section or between adjacent vertical sections, except the main bus compartment.
Type 2BC rated switchgear is 2C compliant but also has low voltage isolation.
See:

http://library.abb.com/global/scot/...f456f7f2265f618525759a00690fe2/$File/FAQs.pdf