UPS: Compensating for high input voltage

[cduncan]

Hi folks,

Recently our UPS is sending us notices that it's compensating for high input voltages.  With a Code: 0x010D.   I haven't found any threshold settings for input voltages, I see under Power Settings that there is an Output Upper Limit and Lower Limit, is this the threshold that this alert runs against?

It's set to 127.  I can see in the data log that Vmax is hitting 126 pretty consistently at different periods of times for hours and the notifications seem to match logs.

If all that adds up can you please tell me if 127 is the correct setting and what it impact to our equipment if the UPS is output hot.  When Vmax is at 126 Vout is 126 also.  Can this hurt equipment.   Can you also tell me what might cause out input/output to be so high?

[Teken]

Depending upon which specific model APC UPS. There will be 1-3 power management options available for you to adjust to meet your environmental needs.

Sensitivity: Generally speaking this setting determines the acceptable input power quality to be used. The labels can be seen as normal, low, high, etc.

The sensitivity determines when the unit will go into battery only mode. As such if the unit constantly goes into battery only mode it will always provide the cleanest inverted output voltage (power) to the connected outputs. 

The downside is the obvious reduction in battery service life. ☝️ The batteries are rated for 2-5 years of service based on (Usage, Temperature, and Environmental Factors).

The sensitivity also monitors the frequency and THD. As such this normally detects what people often call *Dirty Power* as this also monitors very brief changes in input voltage: Sag, Surge, Spike, etc.

Transfer Voltage: Adjusting the upper and lower transfer voltage determines when the unit will engage and remain in AVR mode.

The unit simply engages the different transformer taps to Boost / Trim the voltage to the output thus providing an acceptable voltage to the connected loads.

Generally speaking there is no harm to the electronics when the AVR is engaged. But you should be aware you’ll see a increase / decrease in the power consumption. Devices that are so called PFC (Power Factor Correcting) do not always behave well when the input voltage swings high / low.

Bypass: This forces the unit to receive power directly from the AC Mains. This bypasses the battery circuit / inverter depending upon model. 

NOTE: Every APC Enterprise UPS has a (Relay Weld) error code. This directly relates to the system transferring over from online vs battery only power and to a lesser extent when the AVR circuit is enabled.

Meaning repeated transfers will reduce the service life of the UPS. As each time the relay changes state it induces (contact arc) which pits, melts, the internal contacts.

Let me know if this answers your question. If so please consider marking this as a solution to help the next person asking the same. 👍