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Operation
16
5.1 Alarms
The Liebert LDM constantly monitors configured parameters for normal values. When the unit
detects an alarm condition, it annunciates and displays alarm messages via the Monitor program (see
5.4 - Using the Monitor Tool).
Alarms must be manually reset after the alarm condition has been corrected and may be reset
through Modbus.
To facilitate troubleshooting:
• All alarms are stored in non-volatile memory to protect against erasure by a power outage.
• Alarms are saved in an event log. The event log stores up to 128 events using a first-in, first-out
format (FIFO).
All alarm thresholds for monitored parameters are adjustable by using the Configuration tool to
match site requirements (see 5.5 - Using the Configuration Tool).
Table 6 shows the types of alarms for the various types of breakers, along with a description, factory
default setpoints and allowable range for each.
Table 6 Alarm conditions and factory setpoints
Alarm Description Default setting Range
Branch Breakers
• Overcurrent Warning Current exceeds 75% of breaker amps 15A 0-75%
• Overcurrent Alarm Current exceeds 80% of breaker amps 16A 10-80%
• Low Current Alarm Minimum current level of a branch breaker
0%, which
disables
the alarm
0-70%
Panelboard Main Breaker and SqD I-Line Panelboard
• Phase Overcurrent Warning Current exceeds 75% of breaker amps 170A 0-75%
• Phase Overcurrent Alarm Current exceeds 80% of breaker amps 180A 10-80%
• Neutral Overcurrent Alarm Current exceeds 95% of breaker amps 214A 10-200%
• Ground Overcurrent Alarm Current exceeds 5 amps 5A 1-50A
• Overvoltage Alarm
At least one of the line-to-line voltages exceeds +6% of
nominal
— 0-50%
• Undervoltage Alarm
At least one of the line-to-line or line-to-neutral voltages
falls below -13% of nominal
— 0-50%
Subfeed Breakers and I-Line Output Breakers
• Phase Overcurrent Warning Current exceeds 75% of breaker amps 170A 0-75%
• Phase Overcurrent Alarm Current exceeds 80% of breaker amps 180A 10-80%
• Low Current Warning Minimum current level of a branch breaker
0%, which
disables
the alarm
0-70%
• Neutral Overcurrent Alarm Current exceeds 95% of breaker amps 214A 10-200%
• Ground Overcurrent Alarm Current exceeds 5 amps 5A 1-50A
Summary Alarm Detects and annunciates upon occurrence of any alarm — —
Panelboard Summary Alarm
Detects and annunciates upon occurrence of branch or
panelboard main breaker alarm
——