PN# 500-16900
Page 4
Rev. D, 12/11
FIG. 3: OVERVIEW OF CPU BOARD
SRC
REX UCD HCD NCX
CX
NOX NC2
C2
NO2
NC1
C1
NO1
GRN
YEL
RE
D
BL
U
WHT
BL
K
GRY
BR
N
BGE
OR
G
PNK
VIO
A
C
IN
F
DC I
N
/O
UT
+
PRGM
HARD
CODE
CODE
MICROPROCESSOR
AUX.
SOCKET
DPDT RELAY
SPDT
RELAY
12/24 AC POWER
FREE TERMINAL
12/24 DC POWER +
12/24 DC NEGATIVE
DC TERMINALS MAY
ALSO BE USED AS
OUTPUT TO POWER
DC LOCK, IF AC
POWER IS SUPPLIED
B
E
E
PER
COM
M
ON
RE
D
L
E
D
GRN
LE
D
Y
E
L LE
D
KE
Y
S
KE
Y
S
KE
Y
S
KE
Y
S
KE
Y
S
KE
Y
S
KE
Y
S
VI
O
L
ET
PI
N
K
ORA
N
G
E
BEI
G
E
BR
O
W
N
GRA
Y
BL
AC
K
WH
IT
E
BL
U
E
RED
Y
E
LLOW
G
R
EEN
PU
SH
T
O
SET
PR
O
G
R
A
M M
O
D
E
P
U
S
H
T
O
P
R
O
G
RAM
HA
RD
C
O
DE
CO
M.
F
O
R R
E
X
, UC
D,
HC
D
T
E
RMS
R
E
X
IN
PU
T
(R
E
M
O
T
E
R
E
L
E
ASE
)
D
IS
ABL
E
AL
L
U
S
E
R
C
O
D
E
S
DI
S
A
B
L
E H
A
RD
CO
D
E
LOCK CONTROL
RELAY CONTACTS
PROGRAM
RELAY
CONTACTS
KEYPAD CABLE
PS1
PS2
PS3
3.3.2 DC LOCK WITH AC POWER
For convenience and economy, most DC electric locks can be operated from an AC transformer
when the DK-26 is used. Select a transformer of the same voltage as the lock (12 or 24). The
CPU board converts the input AC to DC to operate the lock. 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. The lock must accept full wave rectified DC
power. This is true of most DC locks (including Securitron’s Magnalocks) but some specialty
units require regulated DC power. You must operate those as described in the next Section.
Note finally that many DC lock installations call for battery backup. To achieve this, you must
employ a DC battery backup power supply and also follow the wiring description in Section
3.3.3.
DC locks come in “fail secure” and “fail safe” versions. A fail secure lock is secure when not
powered and a fail safe lock is secure when powered. All magnetic locks are fail safe. Figure
4 shows AC power being input to the AC terminals. The DC terminals furnish output power for
RELAY CONTACTS
RATED AT 5 AMPS
Summary of Contents for Securitron DK-26
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