4. Balancing Availability & Efficiency
I save money if my UPS doesn't have a transformer, right?

Take TCO into account, cost isn’t usually the deciding factor! Business metrics define choice per specific appetite for risk / investment Transformer Based Enterprise space In the equipment room Affords highest system availability Full galvanic isolation (neutral iso) Full DC fault management Adaptive capacity & redundancy growth model Predictable ground fault and short circuit current management Low common mode noise/voltage Better neutral management Ease of unbalanced load & harmonic load management Rectifier/Bypass source isolation for Tier 3 & Tier 4 applications     Transformerless Small/Medium business space In the row (IT) Smaller footprint / lighter weight No isolation High DC bus / fault potential Best accommodates fuzzy growth plans (softscale & 1+N) External transformers optional for fault management Lower initial cost if kVA is low Higher neutral circulating current for harmonic & unbalanced loads Marginally higher efficiency Rectifier/Bypass must be connected to same utility source