3 power wiring, 4 surge suppression and grounding – DoorKing 1838 Telephone Access Plus User Manual
Page 11

1.3 Power
Wiring
POWER WIRING
WIRE SIZE
MAX DISTANCE IN FEET
18 AWG
100
16 AWG
200
1838-066-D-1-12
Page
11
The 1838 Access Plus operates on 16.5 VAC. Do not power this device with 24 volt AC power.
If the OV LED is ON, the input voltage is too high. Check the transformer to be sure it is rated
at 16 VAC. Use the supplied power transformer, 16 VAC, 20 VA (or U.L. listed equivalent) to power
the access controller. Do not power any other devices (electric strikes, magnetic locks, etc.) from this
power transformer. For wire runs up to 100 feet, use 18 AWG wire. For wire runs up to 200 feet, use
16 AWG wire.
Do not run telephone lines or data cables and high voltage lines in the same conduit. Separate high
voltage and telephone line / data cable conduits by at least six (6) inches.
1.4
Surge Suppression and Grounding
Proper grounding and the use of surge suppressers 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 must 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.
It is highly recommended that a low voltage surge suppresser (DoorKing p/n 1878-010) be installed to
help protect the access controller from power surges.
It is highly recommended that telephone line surge suppresser (DoorKing p/n 1877-010) be installed
to help protect the system from phone line power surges (if using a telephone line to program the
1838 via modem).
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
Mic
Vol
1 2 3 4 5 6 7 8 9 1011
Speaker
Vol
Keypad
OV
Over Voltage
LED
ON
SW1
MODEM / TCP ENB
1
2
3
4
5
6
7
8
SW2
ON
TERMINATION
OFF
RS-485 RX
BAD DNS
LAN DOWN
Phone Line
In Use
LA
N
Co
n
n
ec
ti
o
n
Da
ta
Tr
a
n
s
m
it