Understanding Power Supplies

Purpose

Inspect the power supplies to ensure that they distribute power to the other router components according to their voltage requirements.

What Is a Power Supply

The power supplies are internally connected to the midplane, which delivers the power input from the circuit breaker box and distributes the different output voltages produced by the power supplies to the router's components, depending on their voltage requirements.

Table 54 lists some router characteristics for each router type.

Table 54: Router Power Supply Characteristics

Power Supply Characteristic	M5/ M10	M7i/ M10i	M20	M40	M40e	M160	M320	T320	T640
Watts per AC/DC power supply	434 W	293 W	750 W	1500 W	AC 2900 W DC 3000 W	DC original 2600 W DC enhanced 3200 W	1750 W	3200 W	6500 W
Supports both AC and DC power supplies	Yes	Yes	Yes	Yes	Yes	No; original or enhanced DC only	Yes	No; DC only	No; DC only
Turn off power supply before removing	X	X	X	X
Turn off circuit breaker before removing power supply					X	X	X	X	X

Power supplies in the router must be of the same type: either two AC or two DC power supplies. You cannot mix power supply types. The M160 router supports DC power supplies only.

The following sections describe each routing platform power supply location and type:

• M5/M10 Router Power Supplies
• M7i Router Power Supplies
• M10i Router Power Supplies
• M20 Router Power Supplies
• M40 Router Power Supplies
• M40e Router Power Supplies
• M160 Router Power Supplies
• M320 Router Power Supplies
• T320 Router Power Supplies
• T640 Routing Node Power Supplies