Earth Ground Connections; Backup Battery Calculations - ADEMCO VISTA-32FB Installation And Setup Manual

VISTA-32FB Installation and Set-Up Guide

Earth Ground Connections

The VISTA-32FB requires connection to a good earth ground in order to provide proper 120VAC
shock hazard protection, lightening transient protection, and earth ground fault detection. Refer
to the National Electrical Code for proper earth grounding methods.
When using the built-in transformer shipped with the VISTA-32FB, follow the steps below to
make connections to earth ground.
1. Run an earth ground wire into the transformer enclosure via the same knockout used for
120VAC wiring.
2. Use a wire nut (not supplied) to splice this earth ground wire to the green flying lead
located inside of, and bonded to, the transformer enclosure.
3. Connect the green flying lead that emerges from the top of the transformer enclosure to
the VISTA-32FB's earth ground terminal (Terminal 30).
4. Replace the transformer enclosure cover after wiring is complete.
When using the optional 1451 transformer, follow the steps below to make connections to
earth ground.
1. Connect the earth ground post inside the 1451 transformer to a good earth ground (use
grounding methods specified in the National Electric Code). Use a green wire nut
(supplied) to secure the wire to the ground post.
2. Run a 16AWG wire from this post to the panel's earth ground terminal (terminal 30).
Use a second green nut (supplied) to secure this wire to the ground post. This method of
connection avoids ground loops that may occur when the 1451 transformer and panel are
connected to different earth ground systems.

Backup Battery Calculations

In the event of an AC power loss, the VISTA-32FB must be supported by a 12VDC, 7AH
min/34.4 max sealed lead acid battery.
As shipped, the VISTA-32FB enclosure can house up to 14AH batteries (i.e., two 7AH batteries
wired in parallel). The optional VISTA-ULKT enclosure kit may be used to house up to 34.4 AH
batteries.
The battery's capacity must be sized to provide 4 hours (commercial burglary installations),
24 hours (local or central station commercial fire installations), or 60 hours (remote station
commercial fire installation of standby time followed by 5 minutes (commercial fire
installations or 15 minutes (commercial burglary installations) of alarm time. This can be
determined as follows:
1. If using the polling loop, fill out the Polling Loop Current Draw Worksheet (shown below)
to determine the total current.
2. Fill out the Total Control Panel Load Worksheet (shown below) to determine the total
standby and alarm load drawn from the control panel's internal 12V power supply.
3. Fill out the Battery Capacity Calculation Worksheet, following the other worksheets, to
determine the required capacity for the back-up battery. Select one of the batteries given
in the Battery Selection Table (later in this section) which has a capacity greater than or
equal to the calculated battery.
19–2