Panel Earth Ground Connections; Determining The Control's Power Supply Load - Honeywell VISTA-128BPT Installation And Setup Manual

VISTA-128BPT/VISTA-250BPT Installation and Setup Guide

Panel Earth Ground Connections

In order for the lightning transient protective devices in this product to be effective, the designated earth ground
terminal (terminal 30) must be terminated in a good earth ground. Recommended wire gauge for the ground connection
is #16 AWG, run no farther than 30 feet. The following are examples of good earth grounds available at most
installations:
•
Metal Cold Water Pipe: Use a noncorrosive metal strap (copper is recommended) firmly secured to the pipe to
which the ground lead is electrically connected and secured.
•
•
AC Power Outlet Ground: Available from 3-prong, 120VAC, power outlets only. To test the integrity of the ground
terminal, use a three-wire circuit tester with neon lamp indicators, such as the UL-Listed Ideal Model 61-035, or
equivalent, available at most electrical supply stores.
The panel requires the earth ground connection for its lightning transient protection devices.

Determining the Control's Power Supply Load

Use the tables that follow to calculate the total current for the Auxiliary Power, the Alarm Output, and the Polling Loop.
In each table, multiply each device's standby and/or alarm current by the number of units used.
1. In Table 1, enter devices used on the polling loop. Calculate total current draw on the polling loop.
Table 1: Total Polling Loop Current Draw
Polling Loop Device
Polling Loop Subtotal
(terminals 24 & 25 – 128mA)
*The total current cannot exceed 128mA. If total load exceeds 128mA, then a 4297 Loop Extender Module can be used. Note that the
total number of points connected to the panel cannot exceed 119.
3-26
Current # of Units Total
*