Power Supply Backup (Ups) - Avaya 4600 Series Installation Manual

IP Office Installation
P ower Supply Backup (UPS)
2 4 B
The use of an Uninterrupted Power Supply (UPS) with any telephone system is recommended. Even at
sites that rarely lose electrical power, that power may occasionally have to be switched off for
maintenance of other equipment. In addition, most UPS's also provide an element of power conditioning,
reducing spikes and surges.
The capacity of UPS systems and the total equipment load the UPS is expected to support are usually
quoted in VA. Where equipment load is quoted in Watts, multiply by 1.4 to get the VA load.
The calculation of how much UPS capacity is required depends on several choices.
•
What equipment to place on the UPS?
Remember to include server PC's such as the voicemail and Feature Key Server PC's. It is
recommended that the total load on a new UPS is never greater than 75% capacity, thus allowing
for future equipment.
•
How many minutes of UPS support is required?
Actual UPS runtime is variable, it depends on what percentage of the UPS's capacity the total
equipment load represents. For example, a 1000VA capacity UPS may only support a 1000VA
(100%) load for 5 minutes. This relationship is not linear, the same UPS would support a 500VA
(50%) load for 16 minutes. Therefore the lower the percentage of capacity used, the increasingly
longer the UPS runtime, typically up to 8 hours maximum. Remember also that for most UPS's
the ratio of discharge to full recharge time is 1:10.
•
How many output sockets does the UPS provide?
Multiple UPS units may be required to ensure that every item of supported equipment has its own
supply socket.
Installation Manual
IP Office 3.2 15-601042 Issue 14b (13th November 2007)
Page 24