ERU50-001 Emergency Relay Unit
SM83 Installation and Operation Manual
Installation and Operation Manual
Issue 1.01
Page 1-1
CONFIDENTIAL AND PROPRIETARY TO COBHAM
Section 1 Description
1.1
Introduction
Information in this section consists of product description, design features and specifications for the
ERU50-001 Emergency Relay Unit. All derivative product information shall be contained in the applicable
manual supplement, which may be obtained from Cobham as required.
Review all notes, warnings and cautions.
1.2
Product Description
The ERU50 is an Emergency Relay Unit for use with the Cobham Digital Audio Communication System
(DACS).
1.3
Design Features
The DACS is a management system that distributes and controls all of the transceiver, receiver and
warning source audio in an aircraft. It enables the transmission of microphone audio to a selected
Transceiver and distributes all Inter-Communication System (ICS) audio.
The ERU50 allows continued communications between a crew member and cabin crew member when
the DACS is either in Backup or Emergency mode of operation. The ERU50 is a bulkhead mounted unit.
The ERU50 is powered from the corresponding cabin Audio Control Panel (ACP) power output which
comes from the AMU50 Audio Management Unit (AMU). The ERU50 is controlled either by the
corresponding cabin ACP NORM Mode output or by the corresponding AMU ACP power output.
The ERU STATUS DISCRETE functionality is intended for activating an alert on the AMU.
1.4
Specifications
1.4.1
Electrical Specifications
Power Supply
Input Current:
500 mA maximum @ 28.0 Vdc
Normal Operating Conditions:
Nominal:
+28.0 Vdc
Maximum:
+30.3 Vdc
Minimum:
+22.0 Vdc
Emergency:
+18.0 Vdc
Abnormal Operating Conditions:
Maximum:
+32.2 Vdc
Minimum:
+20.5 Vdc
