We use Lithium for network monitoring. For Xserves, by default it throws an alert when the PSU temperature goes above 65°C. Lately, we've been getting multiple alerts a day with the temperature briefly spiking to ~70°C. The average temp is ~55°C.
Lithium has a tendency to be very "cautious" with default trigger values. Are the temperatures I'm seeing truly an issue, or are they within an acceptable range for Xserve PSUs?