Inspect building electrical system for faults in grounding, or errors in code. Check age and state of conductors and raceways. Inspect building electrical system for faults in grounding, or errors in code. Check age and state of conductors and raceways. The entire electrical system is in proper operating order.Please see attached pictures. All phasing, connections and terminations as per code. There is no need at all to replace this 100 Amp sub panel.