Chapter 3 Pre-Installation
Gen 3 Site Controller System Manual
Electrical Requirements
3-12
68P80801E30-A 5/1/2002
Electrical Requirements
All electrical wiring for the site must meet the requirements of NEC and all
applicable local codes.
AC service
The DC power system operates from a 50-60 Hz AC service. Either of the
following services are required:
■
240/120 V single-phase, 3-wire
■
208/120 V three-phase, 4-wire
Equipment rooms constructed inside existing buildings that use higher
voltage systems require a step-down transformer. A main disconnect switch
located within the site is recommended.
Emergency Generator and Transfer Switch
Some sites may contain permanently installed emergency generators,
however, most telecommunications sites are equipped with connections for
portable generators. Sites with permanently installed generators usually
have an automatic transfer switch used to transfer the AC service from the
utility power to the generator after the generator has started. Sites with
connections for a portable generator require a manual transfer switch and
external connector.
Generators and transfer switches must be capable of supporting the
maximum load for the customer defined service area of the generator.
Start-up loads that include the HVAC and rectifiers must also be taken into
consideration when selecting a generator size. Motorola offers several
different generators for the site.
In a shared site with multiple emergency power switches installed, each
should be labeled with the associated system name with a weatherproof
placard attached to or mounted next to the switch.
The site contains an Environmental Alarm System (EAS/EAS2) that has
eight dry contact closure outputs and 48 customer defined inputs. The relay
closures are controlled from the Operations and Maintenance Center (OMC)
and one may be used as a remote start for permanent generators, if desired.
The customer defined inputs may be used to monitor permanent generator
operation if desired.