Filter
Top Products
MERLIN LEGEND Communications System Release 6.1
Installation
555-661-140
Issue 1
August 1998
Installing the Control Unit
Page 2-17
Unit Loads
Unit Loads
A unit load is a measure of power (1.9 watts) that you use to determine
the electrical load that the components listed below place on the control
unit’s power supply.
■ Telephones and adjuncts
■ 800 DID modules
Only the telephones and adjuncts that connect to the analog and digital
extension jacks (ports) on the control unit require unit load calculation.
When calculating unit load, do not include any equipment with its own
power supply.
Checking Unit Loads
In the event of maintenance or equipment changes, recalculate the unit
loads for each carrier where there is a new configuration. Use the
worksheet in Appendix B, “Unit Load Calculation Worksheet.”
As a general rule, if you can distribute the 800 DID modules and
telephone modules equally across the carriers, you prevent
unnecessary drain on any one carrier. However, the rule varies
depending on the system’s operating mode. The next two sections
provide the rules for calculating unit loads in various modes.
Unit Loads for Hybrid/PBX Mode
Older power supplies (models 391A1 or 391A2) generally support six
modules of any type in Hybrid/PBX mode, without requiring an upgrade
to a newer power supply (model 391A3 or 391C1). If the following
conditions are true, however, the unit loads on a carrier can exceed the
54-unit maximum and, therefore, require a newer power supply (model
391A3 or 391C1):
■ All six carrier slots are occupied by MLX telephone or analog
multiline telephone modules.