wheelock TPA-20, TPA-35 INSTALLATION INSTRUCTIONS

273 Branchport Avenue
Long Branch, N.J. 07740
[phone]

INSTALLATION INSTRUCTIONS

MODEL TPA-20/TPA-35

PAGING AMPLIFIER

GENERAL DESCRIPTION:

WARNING: ANY MATERIAL EXTRAPOLATED FROM THIS DOCUMENT OR FROM WHEELOCK MANUALS OR OTHER DOCUMENTS DESCRIBING THE
PRODUCT FOR USE IN PROMOTIONAL OR ADVERTISING CLAIMS, OR FOR ANY OTHER USE, INCLUDING DESCRIPTION OF THE PRODUCT'S APPLICATION,
OPERATION, INSTALLATION AND TESTING IS USED AT THE SOLE RISK OF THE USER AND WHEELOCK WILL NOT HAVE ANY LIABILITY FOR SUCH USE.

Wheelock's models TPA-20 and TPA-35 paging amplifiers are rated at 20 watts and 35 watts, respectively.

These amplifiers can accommodate three different inputs: a low-impedance microphone input (both balanced or unbalanced), a transformer isolated 600
ohm telephone input and a high-impedance music input. The background music will automatically be muted whenever a page is generated.

The amplifiers feature individual tamper resistant volume controls, tone control, a low-cut horn-protect switch and two LED's: power on and peak level
indicators.

Both models operate from 120V, 60Hz and have a power consumption of 59 watts (TPA-20) and 112 watts (TPA-35). A circuit breaker, enclosed in the
power transformer, protects the unit against excessive AC current which could cause damage to internal components. The circuit breaker is self­resettable, however, in the event it does not reset, have the trouble investigated by an authorized service technician or return unit to the factory.

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK.DO NOT EXPOSE THIS UNIT TO RAIN OR MOISTURE.

INSTALLATION:

Unpacking
The amplifier was carefully checked before leaving the factory. Inspect shipping container and unit carefully for indication of improper handling. If the
unit has been damaged, make an immediate claim to the carrier.
Mounting
The amplifiers are designed for either shelf or wall mounting. For surface wall mounting, use the 2 keyhole slots in the chassis base, and the mounting
template on page 5.
Power Grounding
The 120 VAC line cord has a three-prong plug which should be plugged into a three wire grounded electric outlet. It is very important to maintain the
amplifier grounded for safe and trouble-free operation. If there is no grounded electric outlet, connect a wire from the GND terminal of the unit to a water
or steam pipe.

POWER CORD:

CAUTION

: To prevent electric shock do not use this (polarized) plug with an extension cord, receptacle or other outlet unless the blades can be fully

inserted to prevent blade exposure/Attention: pour prevenir les chocs electriques ne pas utiliser cette fiche polarisee avec un prolongateur, une prise de
courant ou une autre sortie de courant, sauf si les lames peuvent etre inserees a fond sans en laisser aucune partie a decouvert.

TECHNICAL SPECIFICATION:

# Parameters TPA-20 TPA-35

Power Output @ 1 KHz

1.
Total Harmonic Distortion

2.
Outputs

3.

20 Watts Rms

Less Than 2% THD

20W @ 8 Ohms 12.5V 25V & 70V

-------­35W @ 8 Ohms 12.5V 25V & 70V

35 Watts Rms

Less Than 2% THD

Inputs Telephone Mic Music

Impedance

4.
Sensitivity

5.

6.

Frequency Response

7.

Signal To Noise Ratio

8.

Type Of Input

9.

Controls

10.

Indicators
Protection

11.
Tone Control Operation

12.
Lo-Cut Switch Operation

13.
Automatic Limiter/Paging

14.

Automatic Mute Operation

15.
Regulation

16.

600 Ohms

-20dBM
Shaped For Maximum

61dB
XFRMR Isolated/Bal.

Page Output Volume, Music, MIC And Tel Input Level, Tone, Lo-Cut Switch

Green LED - Power On, Red LED - Peak Level *

AC Automatic Resettable Therm. Breaker & Therm. Overload Protection On Output

± 1dB Output Level Maintained Without Clipping, Even While Exceeding Rated Input Level Up To 40dB Minimum.

No Load To Full Load Output Less Than 2dB.

LO-Z
1mV
Intelligibility
55dB
Balanced Or Unbal.

-9dB @ 12KHz

-6dB @ 250 Hz

40dB Muting At any Output Level

HI-Z
220mV
90Hz-14kHz
75dB
Unbalanced

17. Additional Features Ability To Double Output Power Into A 25V Line, RFI Protection And Shelf Mount Or Wall Mount.
Consumption

18.
Size

19.
Weight

20.

* If TPA-35 is subjected to a continuous tone signal input for more than four minutes at full rated output, then the current limiting circuit may be activated. In that case,

the unit will shut off and then automatically reset.

Copyright 1989, 1990, 1991, 1993, 1994 Wheelock, Inc. All rights reserved.

0.49A, 59W

11-1/2"W X 4-3/8"H X 7 1/4"D

(29.2 X 11.1 X 18.4 cm)

6lbs. 2 oz. (2.78kg)

--------

0.93A, 112W

11-1/2"W X 4-3/8"H X 7-1/2"D

(29.2 x 11.1 X 19.1 cm)

8lbs. 6 oz. (3.8kg)

P81782 G

Sheet 1 of 4

INPUT CONNECTIONS: (See Figure 1

.)

Telephone

Microphone

Figure 1.

: Connect telephone wires to the input screw terminals marked TIP and RING. For connection to unused CO trunk port, see

Figure 4. For connection to CO line, Centrex line, or Analog Station port, a Wheelock TPI-100 is required.

: Connect balanced low-impedance microphone wires to the input screw terminals marked LO-Z. The shield must be connected

to the GND screw terminals. An unbalanced microphone may be connected to either one of the LO-Z screw terminals and GND.

CAUTION:

To avoid possible interference, the microphone input cable must be a shielded cable with the shield connected to GND.

To connect an FM tuner, CD player or cassette to the MUSIC/HI-Z input jack, use a single conductor shielded cable terminated

Music:

in a standard RCA type phono plug.

OUTPUT CONNECTIONS: (See Figure 2.)

Figure 2.

Connect output wires to the COM screw terminal and the selected mode for constant voltage distribution, i.e. 25V or 70V. The constant voltage
distribution method facilitates the use of multiple speakers in parallel with a single amplifier. Note that each speaker must have its own line-matching
transformer. The tap on the line matching transformer is selected to give the power desired for each speaker.

It is recommended for long distances to use a wire as heavy as possible in order to minimize a consequent power loss on the distribution line.

To allow for future expansion. It is recommended that the total system wattage requirement should not exceed 85% of the amplifiers rated output

NOTE:

(i.e. 17 watts for the TPA-20 and 30 watts for the TPA-35) the total system wattage requirement is the summation of the wattage tap selections of all
system speakers and horns.

A single 8 ohm speaker may be connected to the COM and 8 ohm screw terminals. Be sure that the wattage rating of the speaker exceeds that of the
amplifier, i.e. 25 watts or higher for the TPA-20 and 40 watts or higher for the TPA-35.

CONNECTING AMPLIFIERS IN SERIES: (See Figure 3.)

In some instances where an expansion of the listening area would necessitate a number of speakers that would exceed the maximum recommended
quantity, two amplifiers may be connected in series. This hook-up will in effect double the output power (i.e. 40 watts for two TPA-20 and 70 watts for
two TPA-35) for a 25V constant voltage system.
The input wires must be arranged to parallel the inputs of the two amplifiers, and the volume and tone controls of both amplifiers must be at the same
setting to assure that each amplifier will share the load equally.

Figure 3.

P81782 G

Sheet 2 of 4

PLUGGING IN UNIT TO 120 VAC:

The TPA amplifiers have no power on/off switch. Before plugging in the AC cord to 120 VAC, make sure that all connections are proper and that the
front panel controls marked PAGE and MUSIC are turned to minimum (counterclockwise).

UNUSED CO TRUNK PORT CONNECTIONS: (See Figure 4.)