Recommendations for how I should create my table based on data given?
Can an equipment be part of multiple set's? ( assume: yes)
Can an item(one piece with one serial) be part of multiple equipments? (assume : no)
I would break the equip in parts at the serial level as smallest item.

Equip:
eqid
ssn
description
currentQty
totalQty

Item:
item_id
eqid
serial
location

Set:
setid
description?

Equip_to_set:
setid
equipid


With this model you have the location per unique serial item.
You have equip with multiple set assignments.
SSN and serial are optional.