Update power documentation

docs/core-functionality/power.md

@@ -5,34 +5,4 @@
 
 # Example Power Topology
 
-Below is a simple diagram demonstrating how power is modeled in NetBox.
-
-!!! note
-    The power feeds are connected to the same power panel for illustrative purposes; usually, you would have such feeds diversely connected to panels to avoid the single point of failure.
-
-```
-          +---------------+
-          | Power panel 1 |
-          +---------------+
-            |           |
-            |           |
-+--------------+     +--------------+
-| Power feed 1 |     | Power feed 2 |
-+--------------+     +--------------+
-       |                     |
-       |                     |
-       |                     |    <-- Power ports
-     +---------+     +---------+
-     |  PDU 1  |     |  PDU 2  |
-     +---------+     +---------+
-       |       \     /       |    <-- Power outlets
-       |        \   /        |
-       |         \ /         |
-       |          X          |
-       |         / \         |
-       |        /   \        |
-       |       /     \       |    <-- Power ports
-      +--------+     +--------+
-      | Server |     | Router |
-      +--------+     +--------+
-```
+![Power distribution model](../../media/power_distribution.png)

docs/models/dcim/powerfeed.md

@@ -1,8 +1,21 @@
 # Power Feed
 
-A power feed identifies the power outlet/drop that goes to a rack and is terminated to a power panel. Power feeds have a supply type (AC/DC), voltage, amperage, and phase type (single/three).
+A power feed represents the distribution of power from a power panel to a particular device, typically a power distribution unit (PDU). The power pot (inlet) on a device can be connected via a cable to a power feed. A power feed may optionally be assigned to a rack to allow more easily tracking the distribution of power among racks.
 
-Power feeds are optionally assigned to a rack. In addition, a power port – and only one – can connect to a power feed; in the context of a PDU, the power feed is analogous to the power outlet that a PDU's power port/inlet connects to.
+Each power feed is assigned an operational type (primary or redundant) and one of the following statuses:
+
+* Offline
+* Active
+* Planned
+* Failed
+
+Each power feed also defines the electrical characteristics of the circuit which it represents. These include the following:
+
+* Supply type (AC or DC)
+* Phase (single or three-phase)
+* Voltage
+* Amperage
+* Maximum utilization (percentage)
 
 !!! info
-    The power usage of a rack is calculated when a power feed (or multiple) is assigned to that rack and connected to a power port.
+    The power utilization of a rack is calculated when one or more power feeds are assigned to the rack and connected to devices that draw power.

docs/models/dcim/powerpanel.md

@@ -1,3 +1,8 @@
 # Power Panel
 
-A power panel represents the distribution board where power circuits – and their circuit breakers – terminate on. If you have multiple power panels in your data center, you should model them as such in NetBox to assist you in determining the redundancy of your power allocation.
+A power panel represents the origin point in NetBox for electrical power being disseminated by one or more power feeds. In a data center environment, one power panel often serves a group of racks, with an individual power feed extending to each rack, though this is not always the case. It is common to have two sets of panels and feeds arranged in parallel to provide redundant power to each rack.
+
+Each power panel must be assigned to a site, and may optionally be assigned to a particular rack group.
+
+!!! note
+    NetBox does not model the mechanism by which power is delivered to a power panel. Power panels define the root level of the power distribution hierarchy in NetBox.