Printed wiring boards, including the coatings, shall comply with C22.2 No. 0.17 and UL 796, and have a minimum HB flame rating. Those printed wiring boards providing direct support of live parts shall additionally comply with the direct-support requirements for insulating materials in C22.2 No. 0.17 and UL 746C.Exception: A printed-wiring board in an extra-low voltage, non-safety circuit is not required to comply with the bonding requirements in C22.2 No. 0.17 and UL 796 if the board is separated from parts of other circuits such that loosening of the bond between the foil conductor and the base material will not result in the foil conductors or components coming in contact with parts of other circuits of the control or of the end-use product.