DoorKing 1812 Plus - Manual (Page 15)

1812-161-L-12-11 13
Proper Grounding and the use of surge suppressors can significantly reduce the chance of component failure because of static
charges or surges. To be effective, ground connections should be made with a minimum 12 AWG wire to a ground point within
10 feet of the device being protected. The ground point can be at an electrical panel, a metallic cold water pipe that runs in the
earth or a grounding rod driven at least 10 feet into the soil. A gooseneck mounting post anchored in concrete does NOT make
a good ground.
Telephone Line Surge Suppressor
It is highly recommended that telephone line surge
suppressor (DoorKing P/N 1877-010) be installed
to help protect the system from phone line power
surges. Surge suppressor must be positioned 3 ft
or less from the ground source, 12 AWG min.
Low Voltage Surge Suppressor
It is highly recommended that a low voltage surge
suppressor (DoorKing P/N 1878-010) be installed to
help protect the telephone entry system from power
surges. Surge suppressor must be positioned 3 ft or
less from the ground source, 12 AWG min.
1.4 16.5 VAC Power Wiring ONLY!
The 1812 Plus operates ONLY on 16.5 VAC. DO NOT power the 1812 with 24 volt AC power. Use the supplied power trans-
former, 16 VAC, 20 VA (or U.L. listed equivalent) to power the telephone entry system. DO NOT power any other devices
(electric strikes, magnetic locks, etc.) from the 1812’s power transformer. See table below for wire run distances.
Power Interruption Note: The Time
and Date calendar chip (Section 2,
2.6.1) in the 1812 Plus will keep time
for approximately 48 hours if power
to the system is lost or removed. If
power is off longer than this, the
Time and Date will need to be
reprogrammed into the system. All
other specific programming that has
been done will remain intact after
power has been restored.
DoorKing offers a 12 volt .8 amp
hour gel cell battery that can
connect to the main terminals 9 and
10 to provide back-up power during
power interruptions.
(DoorKing P/N 1801-008)
Wire Size Max Distance
18 AWG
16 AWG
100 ft
200 ft
Power Transformer Wire Run Table
1.5 Grounding and Surge Suppression
Power Transformer Wires
(Not supplied)
Supplied Transformer
Polarity does
not matter.
Output
16.5 V
AC
20 V
A
CAUTION
DO NOT power the 1812 from a 24-Volt
source (Such as a gate operator).
Damage will occur to the 1812 that is
NOT covered under DoorKing’s warranty.
Some Acceptable Ground Sources
Ground to metallic cold water pipe.
Ground
Wire
Ground
Wire
Phone Company
Transformer
1812
Ground to existing electrical system.
Electrical
Panel
Grounding rod 10 feet in soil.
77 8 9
4 5 6
0
1812
7 8 9
4 5 6
0
IMPORTANT: Ground wire shown without
safety protection for clarity. Make sure
ground wire is protected from being
touched or electrical shock could occur!
Surge suppressor within
3 ft of ground source.
PHONE LINE 1877-010
Surge suppressor
within 10 ft of 1812.
Surge suppressor within
3 ft of ground source.
POWER LINE 1878-010
Surge suppressor
within 10 ft of 1812.
Over Voltage Power Note: LED located on
bottom left corner of board will light up if
too much power is applied to circuit board.
OV