An assembly that is replaced in its entirety when any one of its components fails. In some cases a field replaceable unit may contain other field replaceable units; for example, a brush and a brush block that can be replaced individually or as a single unit.; 一種組合部件,當(dāng)其中任一組成元件失效時(shí)可以作為一個整體更換。在某些情況下,一個 現(xiàn)場可更換部件可能包含另一些現(xiàn)場可更換部件,例如電刷和電刷組,可以個別地更換電刷, 也可以將電刷組作為一個單一部件更換。