User`s guide

7-4
Alarm Configuration
7.1.1. Over Temperature Alarms - Load Shedding and Auto Recovery
For Over Temperature Alarms, the Load Shedding feature is used to switch specific,
user-defined circuits On or Off whenever temperature exceeds the Alarm Set Threshold
value. This allows the RPC to automatically shut Off non-essential devices in order to
reduce the temperature generated within the rack, or automatically switch On devices
such as fans or cooling systems in order to dissipate heat. When the Auto Recovery
feature is enabled, the RPC can also automatically "undo" the effects of the Load
Shedding feature when the temperature again falls to a user-defined non-critical level.
Note: Load Shedding Configuration Menus for both the Initial and Critical
Over Temperature Alarms offer essentially the same set of parameters, but
parameters defined for each alarm are separate and unique. For example,
parameters defined for Over Temperature (Initial) Alarm Load Shedding will not
be applied to Over Temperature (Critical) Alarm Load Shedding and vice versa.
The Load Shedding Configuration menus allow you to defined the following parameters:
• UnittoConfigure: In some WTI power control products, this item is used to select
either a local unit or an auxiliary unit. In RPC series products, this option presently
has no function. (Default = Local.)
• ConfigureLoadsheddingforUnit: In the Text Interface, this item is used to
access the Load Shedding parameters listed below. In the Web Browser Interface,
Load Shedding parameters are accessed via the "Load Shedding" button in the
Temperature Alarm configuration menus.
• Enable: Enables/Disables Load Shedding for the Over Temperature Alarm.
When enabled, the RPC will switch the user specified circuits whenever the
temperature exceeds the Alarm Set Threshold value. (Default = Disable.)
• CircuitState: Determines whether the selected circuits/circuit groups will be
switched On or Off when Load Shedding is enabled and temperature exceeds
the user-defined Alarm Set Threshold. For example, if the Circuit State is set to
"Off", then the selected circuits/circuit groups will be switched Off when the Alarm
Set Threshold is exceeded. (Default = Off.)
• AutoRecovery: Enables/Disables the Auto Recovery feature for the selected
unit. When both Load Shedding and Auto Recovery are enabled, the RPC will
return circuits to their former On/Off state after the temperature falls below the
Alarm Clear Threshold value. This allows the RPC to "undo" the effects of the
Load Shedding feature after the temperature returned to an acceptable level.
(Default = Off.)
• CircuitAccess: Determines which Circuit(s) will be switched when the
temperature exceeds the Alarm Set Threshold and Load Shedding is triggered.
For example, if circuits A1, A2 and A3 are selected, these circuits will be switched
On or Off whenever the temperature exceeds the Alarm Set Threshold.
(Default = undefined.)
• CircuitGroupAccess: Determines which Circuit Group(s) will be switched
when the Load Shedding feature is triggered. (Default = undefined.)
Note: Circuit Groups must first be defined (as described in Section 5.6) before
they will be displayed in the Load Shedding menu's Circuit Group Access
submenu.