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