Instruction manual

POWER AND GROUNDING
Standby Power—Single-Carrier Cabinet System
The following provides Battery Reserve, Uninterruptible Power Supply, and Battery Backup infor-
mation for single-cabinet systems.
Battery Reserve (Single-Carrier System)
During commercial power failure, the power supply provides a 250-millisecond power holdover to
allow the system to remain in service. If power is restored within 250 milliseconds, there is no
interruption of service.
A battery reserve is automatically activated if commercial AC power fails. These batteries allow
the power supply to provide a 2-minute battery reserve holdover to the control circuit packs and
fans during power failure beyond 250 milliseconds. All port circuit packs are out of service during
this time. When commercial power is restored within 2 minutes, the system reinitializes from the
memory stored in the Memory circuit pack. All port circuit packs continue to remain out of ser-
vice during the approximately 25 seconds required to restore the system.
When commercial power is restored after 2 minutes, the system reinitializes from the system
tape. Reinitialization takes approximately 10 minutes and the port circuit packs remain out of ser-
vice during this time.
The Emergency Transfer feature becomes active if commercial power failure exceeds 250 mil-
liseconds. Selected voice terminals are automatically connected to trunks in the central office.
If additional holdover power is required, an alternate, independent source of on-premises power
is required to maintain the system for a limited time. An external, commercial Uninterruptible
Power Supply (UPS) or a battery backup arrangement are used as an alternate source of power
during a commercial power failure.
Uninterruptible Power Supply (Single-Carrier System)
If long-term holdover power is required, an external Uninterruptible Power Supply (UPS) can be
provided as an alternate source of power during a commercial power failure. Any UPS that
meets the requirements given in Table T can be used with the system.
TABLE T. UPS Power Requirements
Maximum
No. of Volt-Ampere Frequency Power Cut-In Time
Cabinets Rating Hertz Factor (milliseconds)
1 1200 60 ± 5% 0.6 200
2 2400 60 ± 5% 0.6 200
3 3600 60 ± 5% 0.6 200
4 4800 60 ± 5% 0.6 200
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