When a power Cable is connected to a power consumer, it may cause the Port at the other end of the Cable to become overloaded, or any further upstream Ports or Equipment objects to become overloaded. Similarly, if a power Cable is connected to a power supplier (PDU, power strip, breaker, etc.), the Equipment at the other end of the Cable may draw enough power to overload the Port, the Equipment, or something upstream. Also, if a power-consuming device is plugged into a Slot, the equipment containing the Slot or any upstream power supplier may become overloaded. The user is warned by IRM about these potential power overloads via a dialog that pops up.
More specifically, whenever a Cable connection is made that involves a Power Flow In Port, or an object is plugged into a Slot, all of the following are checked and the user is warned appropriately:
If the capacity of any upstream Port would be exceeded. That is, if Equipment's Nominal total watts divided by Selected Input Voltage is greater than Port Definition's Amps value for the Port at the other end of the Cable supplying power to that Equipment.
If either of the Power Capacity constraints would be exceeded for any upstream Equipment. That is, the Equipment's Nominal total watts assuming the extra load and see if it exceeds Equipment's Max power (W) can supply (if set) or Equipment Type's Power Capacity (if set).
If the Rack's Power Capacity would be exceeded for the Rack that the Equipment is contained in, or any upstream Rack.
When a Cable connection is made that involves a Power Flow Out Port, similar checks are made, the only difference is that the capacity of the Port being connected is being checked, and the Equipment at the other end of the Cable is what indicates what the additional load is.
The warnings given are very specific, which is essential for the user to be able to understand exactly which power/voltage/current limitations are being exceeded as, more than one constraint may be violated by a single connection, the violation results are displayed in a table with the following columns:
Equipment (name of Equipment with the issue)
Port (name of Port, if applicable)
Constraint Violated (Port capacity, Supply Watts, or Power Capacity)
Amount (how much beyond the constraint the user would go if making the connection)
Use case scenarios in which the application is checking for power overloads:
when a card/module is plugged into a Slot
when an Equipment is added to a Rack
when an Equipment is replaced
Below is an example of an Power Overload warning dialog, which displays violation result details for two Equipment objects that have a port capacity overload:
