66250457-EN - V 3.4 - 31/08/16
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VK4K/6256 Series “6 wire Bus” videokit
VK4K/6256 Series - Installation handbook
Art. 4833
Speaker unit
BUILT-IN RELAYS – BACK EMF PROTECTION
The Art. 4833 includes selectable back EMF protection on the relays. The jumpers marked J4 (One jumper for each relay) are used to
select the protection type. When using a fail secure lock with connections C & NO the jumper should be in the NO position. When using
a fail open lock with connections C & NC the jumper should be in the NC position and when using the codelock to trigger a gate con-
troller or another third party controller the jumper should be removed completely (This disables the protection on the relay).
LOCK RELEASE BACK EMF PROTECTION
A varistor must be fi tted across the terminals on AC lock release (Fig.1A) and a diode must be fi tted across the terminals on a DC
lock release (Fig.1B) to suppress back EMF voltages. Connect the components to the lock releases as shown in fi gures.
VARISTOR (MOV)
12V AC
LOCK RELEASE
Fig. 1A
DIODE
1N4002
12V DC
LOCK RELEASE
Fig. 1B
SIGNALS
+V
Power input 16÷20Vdc
–
Power input ground
12Vout
12Vdc. 0,3A max. output to supply accessiories
1
Speech line input toward the loudspeaker and data signal (about 12V in stand-by, about 5V with a conversation in
progress)
2
Speech line output from the microphone (about 12V in stand-by, about 3V with a conversation in progress)
V1
Balanced video signal sync.–
V2
Balanced video signal sync.+
BS
Input/Output busy signal (about 12V in stand-by, about 0V with a call in progress)
SL
Active low output to enable the enslavement relay for video signal exchange (active with a call in progress)
PTE
Active low input to control directly the door open relay
C
Door open relay common contact
Max 24Vdc, 3A when used as dry contacts relay
NC
Door open relay normally closed contact
NO
Door open relay normally open contact
TECHNICAL SPECIFICATION
Power Supply:
Supplied by the BUS line, 20Vdc
Power consumption:
Stand-by: 70mA
Operating: 250mA
Working Temperature: -10 +50° C
