The faults are described using a fault description which comprises data which have been determined using failure modes and effects analysis. The primary surface sheet is used to transfers heat from a donor fluid to a recipient fluid. Alternatively, pulse search positions are determined in such a manner that they become dense in a pitch peak position vicinity and coarse in the other portions. In another embodiment, the base region is formed as a buried layer. The switch is operable between first and second positions to control the operation of the first of said components and is operable between third and fourth positions to control operation of the second of said components. An exemplary support structure includes an improved spacer block that is configured to reduce electrical flashover, in the form of creep, between adjacent high voltage conductors, without necessarily increasing the width of the spacer block.