Emerson Liebert Remote Monitoring Panel User Manual download pdf (Page 32)

Operating Instructions

4.5 Current Plus Monitoring

The Liebert RDC has a Current Plus Monitoring (CPM) feature that monitors the current and voltage

of the panelboard main circuit breaker. The CPM includes a monochrome Liquid Crystal Display

(LCD) with oval bezel that includes power and alarm LEDs, audible alarm and silence push button.

The CPM displays the power parameters and alarms listed below for each panelboard main. The dis-

play is mounted on the front and rear doors. The display and switches are accessible without opening

the door.

The CPM displays circuit identification, the status of each breaker and the following parameters:

• Voltage - Line-to-Line

• Voltage - Line-to-Neutral

• Neutral Current

• Ground Current

• kVA

• Power Factor

• Voltage Total Harmonic Distortion (THD)

• Current Total Harmonic Distortion (THD)

• Crest Factor

The CPM annunciates alarm messages for the following conditions. Alarm thresholds for monitored

parameters are adjustable through the service port to match site requirements. The alarms and their

factory setpoints for the alarms are:

Summary Alarm - detects and annunciates upon occurrence of any alarm.

Summary Alarm Contacts - The CPM has two Form C (1 NO and 1 NC) summary alarm contacts

for remote alarm status—one contact per panelboard. The contacts are rated at 24VAC @ 1A. The con-

tacts change state when any alarm or warning occurs and reset when the alarm is cleared.

To facilitate troubleshooting, all alarms are stored in non-volatile memory to protect against erasure

by a power outage. Alarms must be manually reset after alarm conditions are corrected. Alarms may

be reset through Modbus.

An event log saves details of up to 128 alarms using a first-in, first-out (FIFO) storage method.

Communication - A two-wire multidrop RS485 Modbus port is available for connections to a

Building Management System (BMS) or Liebert SiteScan Monitoring Interface. See Figure 23 for

connection details.

Alarm Default Setpoint

• Overvoltage A line-to-line voltage exceeds +6% of nominal

• Undervoltage A line-to-line or line-to-neutral voltage falls below -13% of nominal

• Neutral Overcurrent Current exceeds 95% of breaker amps

• Ground Overcurrent Current exceeds 5 amps

• Phase Overcurrent Warning Current exceeds 75% of breaker amps

• Phase Overcurrent Current exceeds 80% of breaker amps

• Summary Alarm

1 2 ... 27 28 29 30 31 32 33 34 35 36

No comments

Emerson Liebert Remote Monitoring Panel User Manual Page 32