Installation guide

Auxiliary Power Unit (Model 820 only)

The Auxiliary Power Unit connects to the Model 820 control unit to provide the extra power

necessary in systems with many accessories or 34-button deluxe voice terminals. Follow

these steps to see if the system requires an Auxiliary Power Unit.

Count how many voice terminals are connected to the control unit. Do not count 34-

button deluxe voice terminals or voice terminals that have a Voice Terminal Power

supply.

Count how many accessories (such as Hands-Free Units) and 34-button deluxe voice

terminals are connected to the control unit and add the two numbers together. Do not

count voice terminals that have a Voice Terminal Power Supply.

Add numbers from steps 1 and 2. If the total exceeds 28, an Auxiliary Power Unit is

recommended. If the problem occurs only at 34-button deluxe voice terminals, adding

Voice Terminal Power Supplies at those voice terminals instead of an Auxiliary Power

Unit is recommended.

Aux Power light: Goes on when the

Auxiliary Power Unit is connected to

the Power Module of the control unit.

Aux Power jack: Connects via dc cord

(supplied) to the Auxiliary Power jack on

the Power Module of the control unit.

AC Output jack: Connects the ac power

cord from the control unit.

AC Input connector: Connects power

cord to an ac outlet.