EST3 Installation and Service Manual

Centralized audio applications power to the amplifiers has failed and the EST3 audio is active during an alarm condition.

Battery backup

To charge the batteries, you will use either the ATP’s integral battery charger or an external LaMarche model A33-10-24 battery charger.

The internal battery charger is capable of charging 40 Ah batteries.

Caution: Do not connect t he battery chargers of multiple ATPs in parallel to increase charger current.

When multiple ATPs share a common battery, or when the amplifier backup is to be supplied from a single battery source, a

LaMarche model A33-10-24 external battery charger must be used. The Amplifier Terminal Panel switches battery power to the amplifiers.

When calculating the battery size required to support the amplifiers, the alarm current must be known. Each 250 W amplifier connected to the system draws 20 amperes at 24 Vdc at full load; 125 W amplifiers draw 10 amperes at 24 Vdc at full load.

The amplifiers draw no current in the standby mode. NFPA 72 specifies that designing the system to provide 15 minutes of the evacuation alarm at full load is the equivalent of 2 hours of emergency operation. The local authority having jurisdiction or local codes can modify the amount of time for which standby power must be provided.

EST3 Installation and Service Manual 4.7