Rev. A.2, 10/03 Page-3
3.1 POWER SELECTION
The DK-26 operates on 12 to 24 volts AC or DC. Nearly all electric locks operate on voltage
within this range, so the power supply you would normally utilize to operate the electric lock will
also operate the DK-26. Power consumption of the DK-26 depends on voltage and is shown on
the following chart:
DK-26 POWER CONSUMPTION: 12 VOLTS 24 VOLTS
REST STATE (MIN) 7 mA 20 mA
RELAYS, LED’S, + BEEPER ON (MAX) 160 mA 190 mA
Be sure that your power source is of adequate capacity to operate both the lock and DK-
26. If the installation is "under-powered", the voltage of the supply will drop rapidly when the
lock is energized and this can crash the microprocessor.
3.2 CONNECTING THE KEYPAD CABLE TO THE CPU BOARD
There are 12 color coded wires in the keypad cable. Refer to Figure 2 and connect each wire to
the indicated terminal on the CPU Board. No other connections may be made to these
terminals (except if two keypads are used with one CPU board).
3.3 POWER AND ELECTRIC LOCK WIRING
The wiring scheme for electric lock control varies depending on the type of lock and the desired
control. The following sections provide drawings and explanations for different types. One
general point is that the DK-26’s lock control relay has 5 Amp contacts. Most electric locks draw
much less. If, however, you are using a specialty lock which draws more than 5 Amps or
has a higher in-rush current, purchase a high current relay and use the DK-26’s contacts to
switch this relay while using its high capacity contacts to switch the lock. Note finally that the
DK-26 includes additional options which are covered in Sections 6 and 7. To determine the
complete wiring for your installation, begin with the drawings shown in Section 3 and then check
Sections 6 and 7 to see if you will require any of the additional features.
3.3.1 AC LOCK WITH AC POWER
This is the simplest installation possible with the DK-26. A fail secure lock operating on AC is
used. This is generally an electric strike. “Fail secure” means that the lock is secure when it is
not powered. Power is applied to release the lock. Referring to figure 3, select a transformer of
the same output voltage as the lock (12 or 24 VAC). Make sure the capacity of the transformer
is large enough to operate both the DK-26 and the lock and that the transformer is UL listed
under the UL 294 standard (to maintain the DK-26 UL listed status). The two transformer
secondary wires connect to the “AC input” terminals as shown (there is no polarity with AC).
Power from one terminal then goes to the common of relay #1. The NO contact of relay #1 will
power the lock (releasing the door) when a correct code is entered. Note that AC locks are
normally all fail secure. If you come across a fail safe AC lock (secure when powered) you
would merely make the connection to the lock from the NC1 rather than NO1 terminal.