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

TO REMOVE COVER
LOOSEN SCREW,
THE N ACTI VATE L ATCH

PLASTIC
COVER

WIREWAY OPENING
TO WALL PLATE AND
JUNCTION BOX

CIRCUIT BOARD
HOUSING ASSEMBLY

SNAP LATCH

OPERATION

Figure 3 shows a V-9924C simplified schematic.
When the V-9924C is idle, 1T IN is shorted to 1T
OUT, 1R IN is shorted to 1R OUT, 2T IN is
shorted to 2T OUT, 2R IN is shorted to 2R OUT,
3T IN is shorted to 3T OUT, and 3R IN is
shorted to 3R OUT.
A signal appearing at the T IN, R IN terminals
will also appear at the T OUT, R OUT terminals
for each zone.

Signaling

When ringing or buzzer voltage appears at the
signaling input leads of the V-9924C, or UNA
closure pins are connected, relays are
energized and the 1T OUT, 1R OUT, 2T OUT,
2R OUT, 3T OUT, and 3R OUT leads are
switched to the outputs of three 5 Watt
amplifiers (One for each zone). At the same
time, the electronic warble tone is connected to
the input of each of the amplifiers and the warble
signal (Which follows the interrupted ringing
pattern) is broadcast to all of the speakers.
Each zone has its own volume control so the
volume can be set to a comfortable level.

BRACKET
LOCKING
SCREW

FIGURE 1A

WIRE TIE LOOP
WIRE TIE USED TO BUNDLE WIRES
ENTERING AND LEAVING TERMINAL AREA

METAL WALL
MOUNTING
PLATE

.155 DIA. HOLES FOR MOUNTING TO
SINGL E OR DO UBLE GA NG JU NCTION B OX
HOLE PATTERN MATCHES BOTH EURO
AND US JUNCTION BOXES

1.5 x 2 WIRE ACCESS OPENING
TO JU NCTIO N BOX

Pitch Control

Dipswitches have been provided to vary the
pitch of the warble ring tone should a different
pitch be desired. Generally, this control does
not require adjustment (See Figure 2B). If
adjustment is necessary, see chart to select
desired pitch (See Figure 2A).

SNAP LATCH
FOR COVER

3

TECHNICAL ASSISTANCE

When trouble is reported, verify power is being
supplied to the unit, buzzer, ringing voltage or
contact closure appears at the unit and that
there are no broken connections at the
punchdown block. To effectively test the unit, a
VOM and a lineman's test set will be required.
Use the VOM to check for voltage from the
power supply and to verify that buzzer or ringing
is coming from the telephone system. The
lineman's test set can be used to check for the
warble tones on the T OUT and R OUT leads to
the speaker. If a spare unit is available,
continue to troubleshoot by substituting a spare
unit for the suspected unit.
Assistance in troubleshooting is available from
the factory. When calling, you should have a
VOM, a telephone test set available and call

from the job site. Call [phone] and press
1 for Technical Support, or visit our website at

http://www.valcom.com.

The V-9924C is not field repairable. Valcom
equipment contains no user serviceable
parts inside. Valcom, Inc. maintains service

facilities in Roanoke, VA. Should repairs be
necessary, attach a tag to the unit clearly stating
your company name, address, phone number,
contact person and the nature of the problem.
Send the unit to:

Valcom, Inc.

Repair and Return Dept.

5614 Hollins Road

Roanoke, VA 24019-5056

ZONE 1

ZONE 2

LOW

MED

H I

*DEFAULT

BIT 1

OFF

OFF

ON

ON

FIGURE 2A

BIT 2

OFF

ON

OFF

ON

PITCH
CONTROL

1

2

-24 VDC

105 VAC SIGNAL

GROUND

15

30

2829 2627

-24 VDC
GROUND

SIGNAL COMMON

18 VAC SIGNAL

121314 11 10

90 VAC SIGNAL

18 VAC SIGNAL

AUX 2 N.O.

25

SIGNAL COMMON

UNA CLOSURE

AUX 2 COMMON

AUX 2 N.C.

789 56

2324 2122

AUX 1 N.C.

AUX 1 N.O.

AUX 1 COMMON

FIGURE 2B

UNA CLOSURE

ZONE 3

ZONE 3 OUT

ZONE 2 OUT

ZONE 1 OUT

234 1

20

1819 17 16

ZONE 2 IN

ZONE 3 IN

ZONE 1 IN

4

FIGURE 3 – SIMPLIED SCHEMATIC

VALCOM LIMITED WARRANTY

Valcom, Inc. warrants its products to be free from defects in materials and workmanship under conditions of normal use and service
for a period of one year from the date of shipment. The obligation under this warranty shall be limited to the replacement, repair or
refund of any such defective device within the warranty period, provided that:

1. inspection by Valcom, Inc. indicates the validity of the claim;

2. the defect is not the result of damage, misuse, or negligence after the original shipment;

3. the product has not been altered in any way or repaired by others and that factory sealed units are unopened (a service

4. freight charges for the return of products to Valcom are prepaid;

5. all units ‘out of warranty’ are subject to a service charge. The service charge will cover minor repairs (major repairs will

This warranty is in lieu of and excludes all other warranties, expressed or implied and in no event shall Valcom, Inc. be
liable for any anticipated profits, consequential damages, loss of time or other losses incurred by the buyer in connection
with the purchase, operation, or use of the product.

This warranty specifically excludes damage incurred in shipment. In the event a product is received in damaged condition, the
carrier should be notified immediately. Claims for such damage should be filed with the carrier involved in accordance with the
F.O.B. point.

Headquarters: In Canada
Valcom, Inc. CMX Corporation
5614 Hollins Road 35 Van Kirk Drive #11 and 12
Roanoke, VA 24019-5056 Brampton, Ontario L7A 1A5
Phone: [phone] Phone: [phone]
FAX: [phone] FAX: [phone]

charge plus parts and labor will be applied to units defaced or physically damaged);

be subject to additional charges for parts and labor).

5