Installation manual

POWER DISTRIBUTION AND SHORT CIRCUIT PROTECTION

A Main Station or Power Supply is the heart of an intercom system. It has special features which are

not found in traditional designs. It must supply low-noise 30 Volt DC current to multiple intercom lines.

It must continue to operate in adverse conditions such as low AC line voltage, momentary shorts on the

DC power lines to the stations, and excessive peak loads during power-on conditions.

Use the chart on this page to determine how many Speaker Stations and Beltpacks can be powered in

varying combinations by a Main Station or Power Supply. Additional power supplies can be connected

for additional power capability if required by the application. The current requirements of Clear-Com

Remote Stations and Beltpacks vary with model and use. A station which is simply '"on" and not being

used may draw only a small amount of current. Contact your dealer or Clear-Com if you require further

assistance in determining the overall current requirements of your system.

For example, a 2 ampere Main Station will power 60 Beltpacks or 20 Speaker Stations. The total cur-

rent capability of a Main Station or Power Supply is split between its channels. Short circuits and over-

loads on either channel will not damage a Main Station or Power Supply. It will simply cut power off to

each channel which exceeds its maximum current or which causes the system maximum to be ex-

ceeded. A channel which is within its maximum current rating will not be affected by another channel

being automatically cut.

Within 15 seconds of automatically cutting power to an overloaded channel, the Main Station or Power

Supply will attempt to turn power on again. This allows momentary short or overload conditions to

clear automatically. Red Short LEDs corresponding to each channel light if power is cut, indicating

which channel is affected. This indication will assist in locating the shorted or overloaded channel.

Shorts are generally caused by miswiring or damaged cables. Overloads are generally caused by con-

necting too many beltpacks and stations to a channel.

Overload

Acceptable

for

1 Amp Supplies

Number of Beltpacks

Number of

Speaker

Stations

5 1015202530354045505560

Acceptable

for

2 Amp Supplies

Clear-Com System Installation Manual