Called head of electrical chain (5)
I believe the answer is:
range
'chain' is the definition.
(synonyms)
'called head of electrical' is the wordplay.
'called' becomes 'rang' ('ring' can be a synonym of 'call').
'head of' suggests taking the first letters.
The first letter of 'electrical' is 'e'.
'rang'+'e'='RANGE'
(Other definitions for range that I've seen before include "Span" , "Amplitude" , "area for stock" , "Variety; scope" , "Mountain chain" .)