Avaya S8700 Maintenance Manual page 1106

Maintenance-Object Repair Procedures
Variable-Speed Fans
A variable-speed fan is identified by the following features:
A fan and air filter assembly with product code ED-67077-30, Group 4 or
greater, labeled on the front of the carrier
A 5-pin white connector mounted next to each fan on the fan assembly
cover plate for speed control and alarm circuitry
A 2-pin black -48 V power connector to each fan
A power filter (ED-1E554-30, G1 or G2) located in a metal box mounted
behind the fans on the right-hand cable trough as you face the rear of the
cabinet
The AHD1 circuit pack and the two S4 sensors used with older fan
assemblies are absent.
Alarm leads from each fan are tied together into a single lead that registers a
minor alarm against CABINET whenever a fan's speed drops below a preset limit
or fails altogether.
NOTE:
The front fans may run at a different speed than the rear fans since they are
controlled by different sensors.
Replacing Variable-Speed Fans
This procedure applies to replacement of a variable-speed fan (KS-23912, L3) in
a new type fan assembly (ED-67707-30, G4 or greater). Do not use a
constant-speed fan in this assembly.
1. If replacing a fan in the front of the cabinet, remove the white plastic fan
assembly cover by pulling it outward. There is no cover on the rear fans;
they are accessible simply by opening the rear cabinet doors.
2. Connect the grounding wrist strap to yourself and the cabinet. The fan
alarm circuit can be damaged by ESD.
3. Disconnect the white 5-pin connector on the fan assembly.
4. Loosen and remove the retaining screw nearest the power connector on
the defective fan.
5. Disconnect the 2-pin black power plug on the fan.
6. Loosen and remove the other retaining screw on the fan.
7. Remove the fan from the fan assembly.
8. Position the new fan and insert the screw that is opposite the power
connector.
9. Connect the 2-pin black power plug on the fan.
8-384 Issue 1 May 2002 555-233-143