United Technologies Edwards 3-ZA20A, Installation Sheet

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© 2019 United Technologies Corporation 1 / 4 P/N 387463- EN • REV 005 • ISS 18MAR19
3- ZA20A, 3 - ZA20B, 3 - ZA40A,
3- ZA40B Zoned Audio
Amplifiers Installation Sheet
Description
The 20 and 40 watt zoned audio amplifier modules are key
components in emergency communication systems that consist of
audible and visible notification appliances. Models are available in
Class A and Class B versions. See Table 1 for a list of model numbers.
The amplifiers provide the following:
• 20 or 40 w atts of power
• Standard output line levels of 25 VRMS or 70 VRMS
• A 1 kHz temporal (3 -3- 3) tone to use as an evacuation signal and
a 20 SPM tone to use as an alert signal in the event of a failure of
audio distribution
Each amplifier is also provided wit h an independently controlled
supervised, power limited 24 VDC NAC circuit. This facilitates the
addition of visual notification appliances to audio notification circuits.
Each zoned audio amplifier requires one space on the rail chassis
assembly.
Table 1: Models
Model
Description
3- ZA20A 20 watt zoned amplifier
Class A or Class B audio
Class A or Class B 24 VDC outputs
3- ZA20B 20 watt zoned amplifier
Class B audio
Class B 24 VDC outputs
3- ZA40A
40 watt zoned amplifier
Class A or Class B audio
Class A or Class B 24 VDC outputs
3- ZA40B
40 watt zoned amplifier
Class B audio
Class B 24 VDC outputs
Installation
Install and wire this device in accordance with applicable national and
local codes, ordinances, and regulations.
Caution: Operating the amplifier at an output greater than that
required by the speaker may overdrive the speaker circuit and result in
damage to the equipment.
To install the amplifier:
1 . Remove all power from the panel.
2 . Set jumpers JP1 and JP2 on the audio power module for 25 or
70 VRMS, depending on the input required by the audio circuit
speakers. See Figure 1 .
JP1 JP2
25 VRMS 2 to 3 2 to 3
70 VRMS 1 to 2 1 to 2
3 . Set the jumper on the audio amp transformer for 25 or 70 VRMS,
depending on the input required by the audio circuit speakers. See
Figure 1 .
4 . Slide the module into the required rail/slot position.
5. Gently push the module into the connectors to ensure good
contact.
6 . Secure the module to the rail by pushing in the top and bottom
snap rivet fasteners.
7 . Connect the field wiring. See Figure 2 through Figure 5.
Note: The gain control pot (Figure 1) should be adjusted to the desired
output levels using a 1 k Hz signal after installation. Fully counter
clockwise is maximum gain and fully clockwise is minimum gain.
Figure 1: Jumper and gain control settings
( 1) Front view
( 2) Rear view
(3) Audio power module
(4) Audio amp transformer
(5) Configuration jumper
(6) Output gain control adjust
(7) Configuration jumpers