BA112P-Q/Z3 REX 112KVA 480/277-600/347V 3PH ISO TRANSFORMER

The 'Z3' suffix indicates a 3% impedance rating on the transformer. Impedance directly affects the available fault current on the secondary side and is a critical factor in your protective-device coordination study. A lower impedance (like 3%) means higher available fault current compared to a 5% unit of the same KVA — so your downstream breakers, fuses, and bus ratings must be selected accordingly. If you're replacing an existing transformer, confirm the impedance of the original unit to ensure your protection scheme remains valid.

Yes. Isolation transformers like the Rex BA-series are generally bidirectional — the 480/277V winding can serve as either the primary or secondary depending on how the unit is connected. However, always verify the nameplate winding designations and consult a licensed electrician or engineer before reversing the feed direction, as tap settings, grounding configurations, and CSA/UL markings must be respected for code-compliant installation.

Northern Breaker Group specializes in obsolete and hard-to-find electrical equipment, including legacy Rex BA-series transformers. Whether you need the exact BA112P-Q/Z3 or a compatible equivalent, our team can source new, surplus, or reconditioned stock. Contact us with your full nameplate details and we'll track it down — or recommend the closest modern replacement if the original is no longer manufactured.