GE Security EST3 User Manual

System calculations
EST3 Installation and Service Manual B.13
Worksheet method
Use this worksheet to determine the maximum cable length of a
notification appliance circuit for a given number of appliances.
Use this worksheet only if all the appliances are regulated. That
is, they must have a minimum operating voltage of 16 V.
Worksheet 1: NAC cable length
NAC1 NAC2 NAC3 NAC4
Total operating current [1]
A
Load factor
×
0.37 0.37 0.37 0.37 V/A
Load voltage drop
=
V
Rated voltage
20.4 20.4 20.4 20.4 V
Load voltage drop
−
V
Minimum voltage
=
V
Regulated appliance voltage
−
16.0 16.0 16.0 16.0 V
Voltage drop [2]
=
V
Total operating current
÷
A
Maximum resistance
=
Ω
Wire resistance (Ω/ft) [3]
÷
Maximum wire length
=
ft
÷
2 2 2 2
Maximum cable length
=
ft
[1] Total of the maximum operating currents for all appliances as specified for DC power. See
the appliance installation sheets for operating currents.
[2] This voltage drop is valid for regulated notification appliances only. For unregulated
appliances, see “Equation method,” later in this topic.
[3] Use the manufacturer’s published wire resistance expressed in ohms per foot. For typical
values, see Table 4, later in this topic.

GE Security EST3 Specifications

General

Brand	GE Security
Model	EST3
Category	Security Sensors
Language	English