Single-phase online UPS
Isolation UPS
An isolation UPS combines online double-conversion with a built-in isolation transformer. The transformer gives the load its own ground reference, which blocks common mode noise and breaks ground loops. Labs, imaging and AV systems use it where clean power matters as much as backup.
Compare models
TX91 family
Online double-conversion with an integrated isolation transformer. Unity power factor.
Below 3.8 kW, pair a UPS with a separate isolation transformer connected after it. See UPS with isolation transformer →
How to choose
| If you need | Start with |
|---|---|
| Isolation and backup, 3.8-10 kW | TX91 |
| The same with longer runtime | TX91L |
| Isolation below 3.8 kW | A UPS plus an isolation transformer after it |
| Isolation and voltage regulation without a battery | TXVR |
Frequently asked questions
What does an isolation transformer do?
It separates the load from the building wiring and gives it a new ground reference. That blocks common mode noise and breaks ground loops, the cause of instrument drift, AV hum and unexplained equipment lockups.
Where does the isolation transformer go?
After the UPS, as close to the load as practical. In the TX91 it is built in. With a separate transformer, the UPS feeds the transformer and the sensitive equipment plugs directly into it.
What input and output voltages does the TX91 support?
Input is 208V nominal, with 220, 230 and 240V optional. Output is 240/120V or 208/104V split-phase.
What if my load is under 3.8 kW?
Use a UPS with a separate isolation transformer connected after it, such as a J60 with a JX, or a P91 with an isolation PDU.
Is the TX91 TAA compliant?
Yes.