Total Power Budget 83W but total load maybe 100W at power-on

InternJoe wrote:

Total Power Budget 83W but total load maybe 100W at power-on

As explained before, the power budget of the GS305EPP is higher than the 83W, it's exactly 120W -> 

Netgear GS305EP, GS305EPP, GS308EP, GS308EPP, GS316EP, GS316EPP Data Sheet 

This not about electrotechnics as you heard about at school.

Each powered device (PD) has does request the power required from the power source (PSE). The PD does request a certain PoE class (by pulsing and/or LLDP signalling) , the PSE does place a reservation accordingly. 

• Type 1 PSE (single-event classification) according to 802.3af: Sends a single voltage pulse and measures the current draw of the PD to determine if it is Class 0, Class 1, Class 2, or Class 3.
• Type 2 PSE (two-event classification) according to 802.3at: Sends a second voltage pulse if the current draw of the PD indicates that it is Class 4 to verify the need for higher power.
• Type 3 and Type 4 PSE (five-event or LLDP classification) according to 802.3bt : Sends out three additional pulses to determine if the device is Class 5, Class 6, Class 7, or Class 8.

Larger PSE might indeed do some stagger, to work around certain power peaks to work around the very worst case.  

It's up to the device resp. the power controller implementation, if this does not power-up some lower priority PD ports, or if it will fail PoE powering a group, or all PD.