Valcom VP-4124 Service Manual

Issue 5

VP-4124/VP-4124-E
24/48 VOLT DC SWITCHING POWER SUPPLY

INTRODUCTION

These instructions provide the specifications,
installation and maintenance information for the
VP-4124 and VP-4124-E, 24/48 Volt Power Supplies.

FCC INFORMATION

This device complies with part 15 of the FCC Rules.
Operation is subject to the following two conditions:

• This device may not cause harmful interference.

• This device must accept any interference received,

including interference that may cause undesired
operation.

NOTE: This equipment has been tested and
found to comply with the limits for a Class B
digital device, pursuant to part 15 of the FCC
Rules. These limits are designed to provide
reasonable protection against harmful
interference in a residential installation. This
equipment generates, uses and can radiate radio
frequency energy and if not installed and used in
accordance with the instructions, may cause
harmful interference to radio communications.
However, there is no guarantee that interference
will not occur in a particular installation. If this
equipment does cause harmful interference to
radio or television reception, which can be
determined by turning the equipment off and on,
the user is encouraged to try to correct the
interference by one or more of th e following
measures:

• Reorient or relocate the receiving antenna.

• Increase the separation between the

equipment and receiver.

• Connect the equipment into an outlet on a

circuit different from that to which the
receiver is connected.

• Consult the dealer or an experienced

radio/TV technician for help.

SPECIFICATIONS

The VP-4124 and VP-4124-E are fully regulated 24VDC,
4 Amp Power Supplies. The primary is protected by a 3

Amp slo-blo fuse and the 2 Amp outputs by
auto-resetting fuses. The outputs are floating

with respect to ground. The regulator will maintain 24
Volts +/- 2% over the rated range of input voltages
and output loads. A greater than 4 Amp load on
power up will cause the power supply to current limit.
Short circuit protection is provided. Overvoltage is
provided to limit the output voltage to approximately
28 Volts should a failure occur within the power
supply. Outputs may be used in a series for 48V @
2A.

Applications

The VP-4124/VP-4124-E are designed to be used with

• All Valcom page control units

• Valcom one-way amplified speaker assemblies

• Any application where 24VDC filtered talk battery

is required

Design Features

• VP-4124: 115VAC, 60Hz input

• VP-4124-E: 230VAC, 50Hz input (preset at the

factory for the specific unit)

• Hold Up Time: 350ms Power Line Ride Through

• (2) LPS outputs (24VDC @ 2A each)

• Can be used as a 24 Volt or 48 Volt power source

1 947272

• Short circuit protection

• UL Listed for US and Canada

• FCC Class B

• CE Mark

• LED operational indicator

• EMI filtering

• 94.3% efficiency green technology

• Auto recovery overload protection

• 3 second power -up delay to drive large capacitive

loads up to 40K µF

Nominal Specifications

General

Efficiency: 94.3% Min @ 1A load
90% @ 4A full load
Dimensions: 8.45"H x 4.70"W x 2.35"D
(21.46cm H x 11.94cm W x 5.97cm D)
Weight: 3.5 lbs. (1.59 kg)

INSTALLATION

Mounting

The VP-4124 and VP-4124-E are designed for wall
mounting only. The unit should be mounted within 7

feet of an AC receptacle.

Screw mounting plate to wall and position power
supply on mounting plate via the mounting slots.

See pages 5 and 6 for mounting instructions.

Connections

• Connections to Valcom page control units are

shown in Figure 1.

Input - VP-4124
Voltage: 115VAC
Frequency: 60 Hertz
Rated Power: 110 Watts
Full Load Line Current: 1.0A

Input - VP-4124-E
Voltage: 230VAC
Frequency: 50 Hertz
Rated Power: 110 Watts
Full Load Line Current: 0.5A

Output
Rated Power: 100 Watts
Voltage: 24 Volts
Current: 4 Amps, 2 - 2A outputs
Fusing: Two - 2A Auto-reset polyswitch fuses
Ripple & Noise: Less than 0.2% RMS

Environmental
Operating Temperature: 0 to +40oC
Storage Temperature: -40Co to +85oC
Cooling: Free Air Convection
Humidity: 10 to 90% (non-condensing)
Shock: 10 G

Precautionary Notes:

• When using the VP-4124 or VP-4124-E as a

-24VDC power supply with Valcom page
equipment, a strap may be added from the local
ground terminal to both of the "+" outputs to
provide an AC ground reference.

• When installing Valcom one-way amplified horns,

connect the white and black wires of the horn to
the power supply "-" and "+" terminals
respectively.

• When installing Valcom one-way speakers,

connect the "-24VDC" and "GND" terminals of
the speaker to the "-" and "+" terminals
respectively.

• Plug power supply into wall outlet.

• Power supply activates after 3 seconds delay.

NOTE: Each -24VDC screw terminal is fused by a 2
Amp polyswitch automatic. Therefore, when
connecting equipment to this power supply, the load
should be distributed between the (2) 2 Amp output
terminals (within 1.5 Amps) and each load should
not exceed 2 Amps.

TECHNICAL ASSISTANCE

When trouble is reported, verify the unit is properly
connected and there are no broken connections
leading to this unit. Assistance in troubleshooting is

CAUTION

RISK OF ELECTRIC SHOCK

DO NOT OPEN

CAUTION: To reduce the risk of electric shock,

Refer servicing to qualified service personnel.

Do not remove cover.

No user serviceable parts inside.

available from the factory. When calling, you should
have a VOM and a test set and call from the job site.
Call [phone] for Technical Support or call (540)
767-1555 for Valcom 24-hour Faxback System or visit
our website at http://www.valcom.com.

Valcom equipment is not field repairable. Valcom, Inc.

This symbol indicates that dangerous
voltage constituting a risk of electric
shock is present within this unit.

maintains service facilities in Roanoke, VA. Should
repairs be necessary, attach a tag to the unit clearly
stating company name, address, phone number,

This symbol indicates that there are
important operating and maintenance
instructions in the literature accompanying
this unit.

contact person and the nature of the problem. Send
the unit to:

Valcom, Inc.

2

Repair and Return Dept.

5614 Hollins Road

TROUBLESHOOTING CHART

Roanoke, VA 24019-5056

PROBLEMS

1. No output

2. LED pulses in reset mode

SOLUTIONS
a. Verify AC present at receptacle.

b. Remove DC load and check for 24VDC using a VOM.

a. Locate and correct short circuit in output wiring.
b. Verify total equipment power consumption does not exceed 4 Amps.

Optional

Typical Page
Control Unit

A Ground
A Battery
B Ground
B Battery

Ground
Reference
Strap

To other page units
or amplified
speaker assemblies

VP-4124/VP-4124-E
Power Supply

- + - +

Local
GND

24V Outputs

FIGURE 1

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 be

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 damage s, 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);

subject to additional charges for parts and labor).

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VP-4124/VP-4124-E

Figure 3. Mounting Bracket

CONNECTIONS FOR USE AS A 48 VOLT DC POWER SOURCE

Output at 48 Volts

Rated Power: 100 Watts
Voltage: 48 V olts
Current: 2 Amps, 1 - 2A output
Fusing: Two - 2A Auto-reset polyswitch fuses
Ripple & Noise: Less than 0.2% RMS

Optional Ground
Reference Strap

Terminals connected together
to provide a 48 Volt output

Connections (48 Volts)

To use the unit as a 48 Volt power source, strap the
center "+" and "-" terminals together (see Figure 2).

VP-4124/VP-4124-E
Power Supply

Local
GND

- + - +

48V Output

To Valcom
Page Control

(+) GND

(-) 48VDC

Green
Red

Black
White

V-1038
30 Watt
Horn

FIGURE 2

Mounting

Use Steps 1 through 3 and Figures 3 and 4 to mount the power supply on a wall or other surface capable of
supporting the weight of the supply (approximately 5 pounds). Carefully unpack the power supply and inspect for
shipping damage.
Select a location for installation of the power supply in a clean, dry, vibration-free area with moderate temperature
within six feet of an approved AC outlet.

1. Using the mounting bracket (see Figure 3) as a template, mark the two slotted holes on the surface of the wall.

2. Using mounting hardware capable of supporting approximately 5 pounds, mount the bracket to the wall ensuring
that the mounting holes are oriented as shown in Figure 3.

Top

4

Slotted
Mounting
Holes

Bottom

3. Using Figure 4 as a guide, mount the power supply onto the mounting bracket.

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