Instruction manual
The 4400-Series Telephone Family
3-15
4400-Series Telephones
Auxiliary Power Supply Unit 3
An Auxiliary Power Supply Unit is required and automatically shipped with each 
4424LD+ telephone. Only one Auxiliary Power Supply Unit is required when 
you connect one or two DSS 4450s to a 4424LD+ telephone. 
The Auxiliary Power Supply Unit is not automatically shipped and must be 
ordered (PEC 4499-PWR, comcode 108596412) if you connect one or two 
DSS 4450s to a 4424D+ telephone. 
CAUTION:
Do not use a different type of power supply from any other piece of 
equipment. Using another power supply can severely damage the DSS 
4450, the 4424D+ telephone, or the 4424LD+ telephone.
Connecting Cords when An Auxiliary 
Power Supply Unit is Needed. 
3
Follow these instructions and refer to Figure 3-5 to connect the Auxiliary Power 
Supply Unit to the 4424LD+ or to any 4400-Series telephone when auxiliary 
power is needed (for example, when connecting one or two DSS 4450s to a 
4424D+):
1. Connect one end of the satin-silver D4BU line cord (packaged with the 
4424LD+ telephone) to the LINE jack of the telephone. 
2. Connect the other end of the satin-silver D4BU line cord to the TEL jack of 
the Auxiliary Power Supply Unit.
3. Connect one end of the clear D2R line cord (packaged with the 4400-
Series telephones) to the LINE jack of the Auxiliary Power Supply Unit. 
4. Connect the other end of the clear D2R line cord to the communications 
system wall jack.










