Vertiv™ | Liebert® LDMF™ Distribution Monitoring User Manual | 20
5.1 Alarms
The Liebert LDMF constantly monitors electrical data for each breaker and subfeed. When the
unit detects an alarm condition, it annunciates and displays alarm messages via the Monitor
program (see 5.4 - Using the Monitor Tool (Used Only for Startup and Diagnostics)) as well as
showing the alarm on the local display (if installed).
Alarms must be manually reset after the alarm condition has been corrected and may be reset
through Modbus or by pressing the alarm Silence/Reset button on the front display assembly.
To facilitate troubleshooting:
• All alarms are stored in non-volatile memory to protect against erasure by a power outage.
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 7 shows the types of alarms for the various types of breakers, along with a description,
factory default setpoints and allowable range for each.
Table 7 Alarm conditions and factory setpoints
Alarm Description Default setting Range Comments
Branch Breakers
• Overcurrent Warning Current exceeds 75% of breaker amps 15A
0-
200%
0% Disables
• Overcurrent Alarm Current exceeds 80% of breaker amps 16A
0-
200%
—
• Low Current Alarm Minimum current level of a branch breaker
0% (disables
the alarm)
0-70% —
Panelboard Main Breaker and SqD I-Line Panelboard
• Phase Overcurrent Warning Current exceeds 75% of breaker amps 170A
0-
200%
0% Disables
• Phase Overcurrent Alarm Current exceeds 80% of breaker amps 180A
0-
200%
—
• Neutral Overcurrent Alarm Current exceeds 95% of breaker amps 214A
0-
200%
—
• Ground Overcurrent Alarm
Current exceeds 5 amps (15-125kVA) 5A 1-100A —
Current exceeds 10 amps (150-225kVA) 10A 1-100A —
Current exceeds 15 amps (300kVA) 15A 1-100A —
Current exceeds 20 amps (450kVA) 20A 1-100A —
Current exceeds 25 amps (800kVA) 25A 1-100A —
• Overvoltage Alarm
At least one of the line-to-line voltages
exceeds +6% of nominal
—0-50%
100% to
Disable
• Undervoltage Alarm
At least one of the line-to-line or line-to-
neutral voltages falls below -13% of nominal
—0-50%
100% to
Disable
Subfeed Breakers and I-Line Output Breakers
• Phase Overcurrent Warning Current exceeds 75% of breaker amps 170A
0-
200%
0% Disables
• Phase Overcurrent Alarm Current exceeds 80% of breaker amps 180A
0-
200%
—
• Low Current Warning Minimum current level of a branch breaker
0% (disables
the alarm)
0-70% —
• Ground Overcurrent Alarm Current exceeds 5 amps 5A 1-100A —
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