mm 8 inches in diameter and 45 dB for speakers 200 mm 8 inches or greater.
Plus:
1. A call announcement monitor lamp that lights when there are incoming
calls.
2. A recurring momentary tone that announces incoming calls.
3. Call Switch that permits a call to the master station.
4. Privacy Switch. When in the on position, the switch prevents the
transmission of sound from the remote station to the system. When in the
off position, without further switch manipulation, response can be made to
incoming calls.
5. [A handset with hook switch, telephone type, arranged to disconnect the
speaker when the handset is lifted. The cord shall be 450 mm 18 inches
long and [permanently coiled] [metallic jacketed].]
2.2.4
All-Call Amplifier
All-call amplifier shall, as a minimum, conform to the following
specifications:
Output Power:
Minimum of 0.5 watt rms for each
station
Total Harmonic
Distortion:
Less than 5 percent at rated output
power with a load equivalent to the
quantity of stations connected to it
in all-call mode of operation
Signal-To-Noise
Ratio:
60 dB or greater at rated output
Plus or minus 2 dB from 200 Hz
to 10,000 Hz
Output Regulation:
Maintains output level within 2dB from
full to no load.
Input Sensitivity:
Compatible with master stations and central
equipment so amplifier delivers full-rated
output with sound pressure level of less
than 10 dynes/sq. cm 0.000145 psi
impinging on master
station, speaker microphone or hand set
Amplifier Protection:
Prevent damage from shorted or open circuit.
2.2.5
Power Line Surge Protection
All amplifiers shall have a device, whether internal or external, which
provides protection against voltage spikes and current surges originating
from commercial power sources per IEEE C62.41 B3, combination wave form and
NFPA 70. Fuses shall not be used for surge protection. The surge
SECTION 16721
Page 11
Previous Page
