BEST ACCESS SYSTEMS W Series Service Manual page 218

Minimum gauge wire chart for lock circuits
The chart in Figure 38 helps you find the minimum wire gauge needed for a specific length wire run. It assumes that the lock circuit is made of two
conductor cable. The chart also factors in a 15% voltage loss at 24 volts.
Maximum 1.500
lock current
(in amps)
1.375
1.250
1.125
1.000
.875
.750
.625
.500
.375
.250
.125
0
Figure 38—Minimum gauge wire chart for lock circuits
To find the correct gauge wire:
1 Determine the maximum lock current and find that value on the left
side of the chart.
2 Determine the total footage of cable to be used in the lock circuit
and find that value at the bottom of the chart.
3 Locate the intersection of current and footage. The line above or to
the right of the intersection shows what minimum gauge wire you
need.
Example
Lock current: 0.750 amp maximum
Total wire run: 500 feet
Wire gauge needed: 16 AWG two conductor cable
Note: For 12 volt locks, double the maximum lock current, then use
that value on the left side of the chart.
T61993/Rev – 18XXXXX ER7991-19 June 2000
Example
Total footage of two conductor cable for lock circuit (in feet)
Installation hints
1 Wire gauge (or size) determines how efficiently the lock will operate.
Consider wire gauge before installation. To find the recommended
minimum wire gauge for all wire runs, see Figure 38.
2 Use wire of 20 AWG (gauge) or larger. We do not recommend using a
smaller wire gauge than 20 AWG.
3 When wiring two or more locks to a single power supply, make sure
that the power rating of the power supply is 1
the sum of the lock's power requirement.
Example
For two locks powered by one supply:
Lock 1 (30H) is rated at 24 volts, 0.75 amps—24 volts × 0.75 amps
= 18 volt-amps
Lock 2 (30H) is rated at 24 volts, 0.75 amps—24 volts × 0.75 amps
= 18 volt-amps
Choose a transformer with a rating of at least: (18 volt-amps + 18
volt-amps) × 1
BEST ACCESS SYSTEMS
Indianapolis, Indiana
Do not use this
chart for any plots
made to this
shaded area.
½
= 54 volt-amps
½
times greater than