Valcom V-9924C Service Manual

Issue 0

V-9924C

COMMON AUDIBLE RINGING UNIT

GENERAL

The Common Audible Ringing Unit provides an
audible signal over the paging system when
there is an incoming call. It is used between a
telephone system and the public address
system.

SPECIFICATIONS

Activation

• 1A2 Bell/Buzzer ICM

• PABX Station Port

• Electronic Key System Station Port

• Contact Closure

Features

• Activates via ringing voltage, buzzer voltage
or contact closure

• Capable of switching signal to three zones
simultaneously

• Uses standard 1A2 key system voltages

• Each zone is equipped with a 5 Watt

amplifier and volume control

• Contains a punchdown block as part of the
unit

• Compact size, can be mounted on wall or in
cabinet

• Automatically switches paging speakers
from paging system to audible signal of the
V-9924C during the ring interval of the
incoming call

• Variable pitch control

• Two auxiliary contact closures

Other Materials Required

• -24VDC power supply

• Cat 3 or 5 twisted pair telephone cable

• Mounting screws and hardware

1 947023

Dimensions/Weight

• 8.20" H x 4.55" W x 2.30" D
(20.83cm H x 11.56cm W x 5.84cm D)

• 1.3 lbs. (.59kg)

Power Requirements

The V-9924C requires a -24VDC "B" battery
and draws 50mA idle and 300mA maximum
operating.

Signal Requirements

The V-9924C requires interrupted ringing or
buzzer voltage or dry contact closure to operate.
The output of the V-9924C will follow the
interruptions of the input. The ringing voltage
should be approximately 90VAC and the current
requirement would be 8mA. The buzzer voltage
should be approximately 18VAC and the current
requirement would be 10mA. The V-9924C
pulls approximately 3mA through a dry contact
closure for activation. Ringing and buzzer
voltages cannot be applied simultaneously. Use
only one method of activation.

To Key

System

Common

Audible

o UNA or Ring

Dry Closure

Power

Supply

AUX Relay

Contacts

AUX Relay

Contacts

SIGNAL COMMON

18 VAC SIGNAL

90 VAC SIGNAL

UNA CLOSURE

UNA CLOSURE

GROUND

-24 VDC

AUX 1 N.O.

AUX 1 COMMON

AUX 1 N.C.

AUX 2 N.O.

AUX 2 COMMON

AUX 2 N.C.

FIGURE 1 - SIMPLIFIED BLOCK DIAGRAM

11

12

13

7

22

14

15

25

23

24

10

8

9

INSTALLATION
Precautions

Failure to observe the following precautions
could result in damage to the V-9924C and
other equipment.
a. Unplug the power supply when connecting

the power leads and signal leads to the unit.
These leads are brought in on adjacent
terminals. Accidental bridging of these two
terminals could damage the equipment.

b. Use pared crossconnect wire for all voice

connections and voltages.

c. Set all volume controls to their minimum

(Counter clockwise) level.

Mounting

Remove the metal mounting plate from the rear
of the V-9924C enclosure. Using two #6 ¾"
wood screws, mount the plate in a vacant space
on the backboard with the telephone system
common equipment. Both mounting holes

must be utilized to insure secure mounting
of the unit. See Figure 1A.

Open the V-9924C enclosure to access
connections and option switches. Slide the rear
of the unit (Contains the board) onto the
mounting plate and lock in place with screw
provided. Make connections.

Signaling Connections

The V-9924C can be activated via ringing
voltage, buzzer voltage or a dry contact closure.
When used with buzzer voltage, apply one side
of the pair to SIG COMMON (Pin 11 or 26) and
the other side of the pair to 18VAC SIG (Pin 12
or 27). For ringing voltage connections, put one
side of the pair on SIGCOMMON (Pin 11 or 26)
and the other side of the pair to 90VAC SIG (Pin
13 or 28).

ZONE 1 IN - RING

17

ZONE 1 OUT - TIP

1

ZONE 1 OUT -RING

2

ZONE 2 IN - TIP

18

ZONE 2 IN - RING

19

ZONE 2 OUT - TIP

3

ZONE 2 OUT - RING

4

ZONE 3 IN - TIP

20

ZONE 3 IN - RING

21

ZONE 3 OUT - TIP

5

ZONE 3 OUT - RING

6

From Page Unit

Speakers for Zone

From Page Unit

Speakers for Zone

From Page Unit

Speakers for Zone

ZONE 1 IN - TIP

16

The V-9924C can also be activated by
connecting one side of a dry contact closure to
pin 7 and the other side of the dry closure to pin

22.

Speaker Connections

The V-9924C Common Audible Ringing Unit is
capable of switching up to three zones of
speakers to the audible signal generated by the
unit. The device is intended to be placed in
series with the speakers. Zone 1 IN (Pins 16
and 17) are connected to the speaker/zone
output leads of the page control. Zone 1 OUT
(Pins 1 and 2) are connected to the speakers.
Zones 2 and 3 hook up in a similar fashion.
Refer to Figure 2B for pin numbers.

Power Connections

Connect -24VDC from the power supply to pin
15 or 30 on the crossconnect block and ground
to pin 14 or 29.

Contact Closure

Two form C auxiliary contact closures are
provided on the V-9924C. These contacts
follow the input cadence and may be used for
special applications. The contact ratings are 1
Amp at 24VDC.

Set Up

After all connections are complete and double
checked, apply voltage to the unit. Place a call
to the telephone system and while ringing or
buzzer is being applied to the unit or when the
dry contact closure closes, adjust the volume of
each zone by turning the volume control
clockwise for each zone. Replace cover when
all connections and adjustments are complete
and lock in place using the #6 ½" screws
provided.

2