Lucent Technologies Lineage
®
2000 400A, 60Hz Ferroresonant Rectifier J85503C-3
Issue 10 July 2000
Engineering and Ordering 3 - 1
3
Engineering and Ordering
Rectifier
Sizing
This section discusses how to determine the minimum number of
rectifiers required in a battery plant. Rectifiers of different output
current capacities can be paralleled in a plant; therefore, size mixing is
also discussed.
Sizing
Considerations
Any time the plant load exceeds the combined capacity of the rectifiers,
the batteries, which are in parallel, must discharge in order to supply the
additional current demand. Momentary discharges are handled easily by
the batteries; in fact, this capability precludes the need for the rectifiers
to handle infrequent, momentary peak current conditions. However, the
total rectifier capacity of the plant must be designed to meet prolonged
periods of current drain during “busy” demand times. In a
telecommunications environment, this is known as the “average busy
hour” (abh) current drain. It is defined as the average busy hour of busy
season current drain drawn at normal plant operating voltage.
Other parameters which the customer must decide are the maximum
length of time the batteries are allowed to discharge (reserve time), and
the amount of time allowed for recharge of the batteries (recharge time).
These two times are used in determining the “recharge factor” from
battery data similar to that shown in Figure 3-1. The recharge factor
determines the amount of current required, over and above the load
demand, to recharge the batteries concurrently with supplying the abh
load demand.
