ADEMCO VISTA-128B, Installation And Setup Gude, Page: 102 / 208

VISTA-128B Installation and Setup Guide
18-6
4. In table 4, enter the total calculated subtotals of all listed outputs from Tables 1 through
3, then add to get the combined current.
Table 4: Total VISTA-128B Current Load
Total Current
Standby Alarm
Polling Loop Subtotal (see Table 1)
Auxiliary Power Subtotal (see Table 2)
Alarm Output Subtotal (see Table 3)
VISTA-128B PCB Current (
Includes 2-wire smoke
detector loading on zones 1 & 2
)
250mA 330mA
Total Current Load
Determining the Size of the Standby Battery
The cabinet supplied with the VISTA-128B panel can house up to 12V, 14AH batteries (two
12V, 7AH batteries wired in parallel). The VISTA-ULKT kit provides a cabinet that can
house up to 12V, 17.2AH batteries and that may be used with this panel. The total standby
current drawn from the auxiliary power and polling loop outputs combined must be limited
to 270mA when 14AH batteries are used; and 390mA when 17.2AH batteries are used.
DO NOT use Gates batteries (sealed lead-acid type). These batteries require a different charging
voltage than is supplied by the panel.
UL
Household Fire or Combination Household/Fire/Burglary installations require the use of a backup
battery that is capable of proving 24 hours of standby time followed by 4 minutes of alarm time.
UL1023 Household Burglary-only installations require the use of a backup battery that is capable
of providing 4 hours of standby time followed by 4 minutes of alarm time.
Use Table 6 to determine the required backup battery capacity and use Table 7 to determine
the battery model number. A dual battery harness is supplied that allows two batteries
to be wired in parallel for increased capacity.