Voltage Sensor Errors

One of my servers, a PE 1850, generated two voltage sensor errors last week.  One was from the 2.6V sensor, the other from the 1.5V sensor.  Both sensors returned to normal within about a second.  This server shares a large UPS with several other servers, none of which reported a voltage error.  The last time this happened on an older PE 2400 I replaced the power supply but still receive an occasional voltage error.

 

My question is: are these voltage errors something to be concerned about?  Or is this time of micro-second fluctuations something to be expected?

 

Thanks!

Joe