Section 3 - Installing the Control
3-37
3. In Table 3, enter devices connected to the Alarm
Output. Calculate alarm currents, then add to get
the Alarm Output current subtotal.
Table 3: Alarm Output Current Load
Total Current
Device
Model #
Device Current X
# of Units
Standby
Alarm
XXXXXX
XXXXXX
XXXXXX
XXXXXX
XXXXXX
XXXXXX
XXXXXX
Alarm Output Subtotal
(terminals 4 & 5 – 1.7A max.)
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-128BP/VISTA-250BP Current
Load
Total Current
Standby
Alarm
Polling Loop Subtotal (see Table 1)
Aux. Power Subtotal (see Table 2)
Alarm Output Subtotal (see Table
3)
VISTA-128BP/VISTA-250BP PCB
Current (Includes 2-wire smoke
detector loading on zone 1)
250mA 330mA
Total Current Load
Determining the Size of the Standby Battery
The cabinet supplied with the control panel can house
batteries of up to 12V, 14AH (two 12V, 7AH batteries
wired in parallel). The VISTA-ULKT kit provides a
cabinet that can house batteries of up to 12V, 17.2AH
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 to 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
providing 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 5 to determine the required backup battery
capacity and use Table 6 to determine the battery
model number.
A dual battery harness is supplied
that allows two batteries to be wired in parallel for
increased capacity.
5. Using the total calculated from Table 4, calculate
the battery capacity required for the installation.
Table 5: Battery Capacity Calculation Table
Capacity
Formula
Calculated
Value
Standby
Capacity
For 4-hour standby time:
Total
standby current
X 4 hours
X 1.4 contingency factor.
For 24-hour standby time:
Total
standby current
X 24 hours
X 1.1 contingency factor.
Alarm
Capacity
For 4-, 5-, or 15-minute alarm
time:
Total
alarm curr.
X 0.067 (4 min)
0.250 (15 min)
Total
Capacity
Add standby and alarm
capacities
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