SURT20KRMXLT

[UpsTech1]

My client has a 208V SURT20KRMXLT. They are reporting that the incoming power occasionally drops below the required 208V reaching a low of 204v. This causes the batteries to go in to an active state and drains the batteries. The UPS can not recharge and goes into error mode due to "mains power being out of range".  The input voltage limits on the product data sheet are 160v-280v. I do not understand why it is having an issue with 204v. This is a completely normal voltage drop. They have had a Schneider tech visit the UPS and had no input. Has anyone else had a issue with their UPS?

[Teken]

Show me the following logs from the system: Event, Data, UPS

Next show me a screen capture of the power quality, upper & lower transfer voltage settings.

If the system has the ability to define the frequency and slew show me.

Questions Ask . . . 👍

[Teken]

Well?!?

[MorneMeintjes]

Good morning,

When reviewing UPS input voltages, it is important to differentiate between the bypass (or reserve) input voltage and the rectifier input voltage.

The bypass input voltage window is the range in which the UPS will transfer to bypass if the inverter is switched off or becomes faulty. Any related alarms will typically include the word "bypass."

The rectifier's operational voltage window is wider. Its lower limit (approximately 160V) is the point at which there is just enough energy to support the load. The upper limit is the point beyond which component failure becomes a risk.

In short:

• If an alarm contains the word "bypass," the UPS can still function normally but is unable to transfer to bypass.

• If an alarm indicates "Mains out of limits," the input voltage is too high or too low, and the UPS will run on batteries.

Note that the lower voltage limit can vary based on the load. At higher load levels, 160V may not provide sufficient energy, causing this effective limit to move closer to the standard voltage.