Start on the equipment I installed (6)
I believe the answer is:
origin
'start' is the definition.
(I've seen this in another clue)
'on the equipment i installed' is the wordplay.
'the equipment' becomes 'rig' (rig is a kind of equipment).
'installed' means one lot of letters goes inside another.
'rig'+'i'='rigi'
'on' enclosing 'rigi' is 'ORIGIN'.
(Other definitions for origin that I've seen before include "Beginning (of species?)" , "Where axes cut" , "Source, derivation" , "Where X meets Y" , "spring" .)