MiCOM P921/P922/P923 - Schneider - error

P92x/EN FT/H42Page 14/70Technical GuideUser GuideMiCOM P921/P922/P923To clear all alarm messages press ; to return to the display of the first alarmmessage and leave the alarms uncleared, press . There is no need to enter apassword before the alarm messages can be cleared. When the alarms have beencleared the yellow alarm LED will extinguish, as will the red trip LED if it wasilluminated following a trip.The alarm messages are classified as indicated below:• Electrical system alarms,• Relay hardware or software alarms.1.4.1 Electrical Network AlarmsAny crossing of a threshold (instantaneous or time delay) generates an "electricalnetwork alarm". The involved threshold is indicated. Regarding the phasethresholds, the phase designation (A, B or C) is also displayed.For example:V< 2/3PHASE AB BC CANOTE: Instantaneous information leads to a self-resetting alarmmessage. The alarm LED will then be switched off as soon as theinstantaneous information has disappeared.If several alarms are triggered, they are all stored in their order of appearance andpresented on the LCD in reverse order of their detection (the most recent alarm first,the oldest alarm last). Each alarm message is numbered and the total number ofalarm messages is displayed.The user can read all the alarm messages pressing .The user acknowledges and clears the alarm messages from the LCD pressing .The user can acknowledge each alarm message one by one or all by going to theend of the list to acknowledge, and clear, all the alarm messages pressing .The control of the ALARM LED (LED 2) is directly assigned to the status of thealarm messages stored in the memory.If one or several messages are NOT READ and NOT ACKNOWLEDGED, theALARM LED (LED 2) flashes.If all the messages have been READ but NOT ACKNOWLEDGED, the ALARM LED(LED 2) lights up continuously.If all the messages have been ACKNOWLEDGED, and cleared, if the cause thatgenerated the alarm disappears, the ALARM LED (LED 2) is extinguished.1.4.2 Relay Hardware or Software Warning MessagesAny software or hardware fault internal to MiCOM relay generates a"hardware/software alarm" that is stored in memory as a "Hardware Alarm". Ifseveral hardware alarms are detected, they are all stored in their order ofappearance. The warning messages are presented on the LCD in reverse order oftheir detection (the most recent first and the oldest last). Each warning message isnumbered and the total stored is shown.