Vertiv Liebert LDMF - Branch Circuit Monitoring Sensor Module (BSM); Power Supply with EMI Filter

Vertiv™ | Liebert® LDMF™ Distribution Monitoring User Manual | 7
3.4 Branch Circuit Monitoring Sensor Module (BSM)
The Branch Circuit Monitoring Sensor Module (BSM)—more commonly referred to as the CT
Module—contain 21, 27 or 36 individual Current Transformers filled inside an epoxy enclosure.
Each load circuit is passed through one of the openings for branch circuit current monitoring. The
signals leave the CT module via a ribbon cable which is connected directly to the PM4 Monitor
Board (PMB) for attenuation and processing.
There are two BSM designs depending on the manufacturer of the panelboard installed:
• Utilize 1" spacing between circuits.
• Utilize 3/4" spacing between circuits.
For larger panelboards, the CT Module is designed to interlock to maintain alignment between
the breaker poles and the CT Modules.
3.5 Power Supply With EMI Filter
The power supply assembly converts 100-240VAC (+10%/-13% range) 50/60Hz into 12VDC to
provide logic level power for the PMB.
The Power Supply is fed from the line side of the panelboard main breaker. If during normal
operation the panelboard main breaker trips or is turned off, the PMB will still have power to
communicate alarms via the local display or remotely via Liebert IntelliSlot
®
cards.
NOTE
The diameter of each CT hole is 0.433" (11mm). Wire diameter and thickness of insulation must be
taken into account before wiring each branch circuit. Using wire that is too large may prevent the
conductor from fitting through the CT hole. Do not attempt to alter the diameter of the CT
opening.