Instruction Manual

PN# 500-21900
Page 2 Rev. F, 06/11
3.4 BATTERY CHARGING CAPABILITY
The power supply incorporates a battery charging circuit appropriate for standby rated sealed
lead acid or gel cell batteries. Dry cell or NICAD batteries must not be used. Batteries are
an option. The power supply can be used with or without them. The battery pack of the
appropriate voltage, matching the 12V/24V Selector Switch
, is merely connected to the red
and black battery leads following correct polarity. The batteries will be kept charged at all times
by the power supply acting in concert with the components on the board. In the event of a line
voltage power failure, the batteries will automatically drive the load. If the emergency release
terminals are opened, battery power will, however, be cut off just as normal power from the
power supply would be.
Figure 1: BATTERY PACK SELECTION
Chart to determine the size of the battery pack
CURRENT
DRAW 1HR 2HR 4HR
UL
STD 8HR 16HR 24HR 48HR 72HR
150mA 5AH 5AH 5AH 5AH 5AH 5AH 8AH 8AH 12AH
300mA 5AH 5AH 5AH 5AH 5AH 8AH 12AH 16AH NA
500mA 5AH 5AH 5AH 5AH 8AH 12AH 16AH NA NA
750mA 5AH 5AH 8AH 12AH 12AH 16AH 20AH NA NA
900mA 5AH 5AH 8AH 12AH 12AH NA NA NA NA
BATTERIES MUST BE SEALED LEAD ACID TYPES.
THIS CHART IS VALID IF BATTERIES ARE OPERATED AT ROOM TEMPERATURE.
BATTERIES SHOULD BE REPLACED AFTER 5 YEARS OF USE.
The components utilized on the unit for battery charging function for battery packs up to 20 Amp
hours in capacity whether 12 or 24 volts. Note that certain long backup times are not
achievable with the maximum size of the battery packs (“N/A” appears in the chart). Consult
the battery pack chart to calculate the correct battery pack based on desired backup time and
the current drawn by the load. Note that batteries must be replaced at least every 5
years as that is their maximum operating life.
3.5 CIRCUIT POLYSWITCHES AND FUSING
A 1 Amp AC fuse is on the board together with 2 each 2.5 Amp DC Polyswitch. The AC fuse
is on the hot 120 VAC input and protects against a transformer internal short. A short in the DC
load will not blow the AC fuse as the power supply is short-circuit protected. If more than its
rated output is attempted to be drawn, it will shut off.
A DC short, therefore, cannot damage the power supply but still will cause problems as the load
will be shut off. To protect against a short circuit when batteries are being employed, a 2.5
Amp DC Polyswitch breaker is provided. The Polyswitch functions as an automatic circuit
LED DIAGNOSTIC TABLE
RED (DC) GREEN (AC) DESCRIPTION
on board on board
ON ON Normal Operation
ON OFF No AC, Battery backup is powering output
OFF ON No DC output, Polyswitch may be tripped
OFF OFF No AC, no battery or Polyswitch may be tripped
The front cover RED (DC) LED is lit when DC voltage is sensed before the Polyswitches. The
RED LED (DC) on the control board is lit when DC voltage is sensed after the output
Polyswitch at the DC+ Output. If the front cover RED (DC) LED is lit and the RED (DC) LED on
the control board is not lit, the output Polyswitch may be tripped.