VIKING TECHNICAL SUPPORT 1.800.908.0884
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Relays In General
NOTE:
Viking Access Systems does not provided the external safety devices and access
controls. These items can be purchases from your dealer or distributor.
APPENDIX (A)
In General
In regards to the Viking control board,
all external safety devices and access
controls contain, and are, simple relays
that provide an input to the Viking
control board when the device is
activated.
When these devices are activated,
their internal relays create a contact
,or short, between the “C” and “N.O.”
terminals This contact is what provides
the command to the Viking control
board.
!
TECHNICAL TIP:
Viking uses the
Normally Open “N.O.” contact from the
device, excluding “fail-safe” type photo
beams. In such instances, the Normally
Closed “N.C.” will be used instead.
Glossary of Terms
1. Terminal:
Wire Connections.
2. Input Terminal:
On the Viking
control board, the terminal which is
labeled for a specific command (Re-
Open, Exit, Radio, etc.). The N.O.
contact from the access control
device is to be connected to the Input
Terminal.
3. Terminal Block:
On the Viking
control board, a removable block
containing multiple terminals.
4. Relay:
The component of an access
control or safety device that provides
an input or command to the Viking
control board.
5. “C” Relay Common Terminal:
This
is the relay terminal that make contact
(a short) to the N.O. terminal when the
device is activated.
Always wire this
relay terminal to any “GND” terminal at
the control board.
6. “N.O.” Relay Normally Open
Terminal:
The relay terminal that has
an open contact to “C” while the relay
is not activated, and a closed contact
when the relay is activated.
Almost
always wire this relay terminal to any
“GND” terminal at the control board,
7. “N.C.” Relay Normally Closed
Terminal:
The relay terminal that has
an open contact to “C” while the relay
is not activated, and a closed contact
when the relay is activated.
This
terminal is rarely used.
8. Relay Coil:
Contains the terminals
that provide power at the relay.
9. “
+
” Relay Positive Terminal:
The
positive power pole for the relay coil.
Always wire this relay terminal to any
“+28v” terminal at the control board.
10. “
–
” Relay Negative Terminal:
The
negative power pole for the relay coil.
Always wire this relay terminal to any
“GND” terminal at the control board.
+
—
COM
N.O.
N.C.
EXIT
Not
Used
+28V
GND
GND
