LAVATORY CALL LIGHTS AND MASTER CALL LIGHT MODULES -FUNCTIONAL DESCRIPTION
EFFECTIVITY BEJ ALL  33-25-00  
Page 9  
D633W101-BEJ  Jan 05/2002 
777 AIRCRAFT MAINTENANCE MANUAL
THIS PAGE IS INTENTIONALLY LEFT BLANK
33-26-00
Page 1 D633W101-BEJ Jan 05/2002
LAVATORY LIGHTS AND SIGNS -LIGHTS -INTRODUCTION
Purpose 
The lavatory lights supply light in the lavatories. 
Location 
The lavatory lights are in the ceiling and on the sidewall of the lavatories. 
The mirror light is above the mirror. 
The dome light is in the passenger service unit (PSU). 
Physical Description 
The light above the mirror is fluorescent. It has a ballast and an electrical connector. 
The light in the lavatory PSU is incandescent. 
Training Information Point 
You compress the mirror light lens to remove it. You can get access to the lamp and the ballast when you remove the lens. 
You lower the PSU and lift up on the cover to get access to the lamp. 
EFFECTIVITY BEJ ALL  33-26-00  
Page 2  
D633W101-BEJ  Sep 05/2002 
LAVATORY LIGHTS AND SIGNS -LIGHTS -INTRODUCTION
EFFECTIVITY BEJ ALL  33-26-00  
Page 3  
D633W101-BEJ  Jan 05/2002 
LAVATORY LIGHTS AND SIGNS -SIGNS -INTRODUCTION
Purpose 
Signs tell when all the lavatories in an area are in use and when to lock the lavatory door. 
Location 
The lavatory occupied signs are below the PSUs at the front or rear of a zone. They are above the passenger seats and below the PSUs. Also there is a lavatory occupied sign in the flight deck. 
Training Information Point 
There is a lock door sign in the lavatory. 
You can use the configuration database in the cabin services system to program which lavatories make up an area. 
EFFECTIVITY BEJ ALL  33-26-00  
Page 4  
D633W101-BEJ  Sep 05/2002 
LAVATORY LIGHTS AND SIGNS -SIGNS -INTRODUCTION
EFFECTIVITY BEJ ALL  33-26-00  
Page 5  
D633W101-BEJ  Jan 05/2002 
LAVATORY LIGHTS AND SIGNS -LAVATORY LIGHTS -FUNCTIONAL DESCRIPTION
General 
The cabin services system (CSS) controls the lavatory lights through the zone management unit (ZMU) and the overhead electronics unit (OEU). 
Functional Description 
When the airplane is on the ground, the cabin system management unit (CSMU) sends a signal to the ZMU. The ZMU sends a signal to the OEU. The OEU sends a signal to the lavatory module and the fluorescent lights come on in the bright mode. 
When the door is latched a signal goes to OEU. The OEU sends the discrete signal to the ZMU. The ZMU changes the format of the signal and sends it to the OEU. The OEU sends the signal to the lavatory module and the lights come on in the bright mode and the lock door sign light goes off. 
When the door is not latched and the airplane is in the air, the fluorescent lights go off and the lock door sign light comes on. 
The dome light comes on when the OEU has power. 
See the cabin management system section for more information about the OEU (SECTION 23-39). 
Power 
Power for the fluorescent lights and the dome light comes from the transfer buses. 
See the passenger service system section for more information about the power for the OEU (SECTION 23-33). 
Training Information Point 
You can use the CSS configuration database to make the fluorescent light come on in the dim mode when the door is open. 
EFFECTIVITY BEJ ALL  33-26-00  
Page 6  
D633W101-BEJ  Sep 05/2002 
LAVATORY LIGHTS AND SIGNS -LAVATORY LIGHTS -FUNCTIONAL DESCRIPTION
EFFECTIVITY BEJ ALL  33-26-00  
Page 7  
D633W101-BEJ  Jan 05/2002 
LAVATORY LIGHTS AND SIGNS -PASSENGER AREA SIGNS -FUNCTIONAL DESCRIPTION
Functional Description 
When you close and latch the lavatory door, the lavatory module sends a signal to an OEU. The OEU gives a signal to the ZMU. 
The ZMU gets data about the lavatories from other OEUs. The lavatory side of the lights come on when the ZMU has power. When all the lavatory doors in an area are closed and latched, a signal goes to an OEU. The OEU closes a switch that makes the applicable occupied side of the lights come on. The occupied side of the lights in a zone will also come on when the waste tanks related to that zone are full. 
 
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址:777 AMM 飞机维护手册 灯 Lights(24)