Jumper Cords, Y-Splitters and PC Power Adapters

Reading the ends of an IEC jumper cord

Jumper cords link equipment to a power distribution unit or UPS. The two ends differ: the male C14 end plugs into a C13 outlet, and the female C13 end plugs into the device's C14 inlet. Larger C19 and C20 pairs carry more current. A Y-splitter, such as C14 to two C13, divides one outlet between two devices, so add up their loads and stay within the cord's amp rating. Gauge matters: 14 AWG carries more current than 18 AWG.

Adapter leads inside the PC need care

Internal power adapters are riskier than they look. A PCIe 6-pin connector is rated for far less power than an 8-pin, so a 6-to-8-pin adapter only helps when the supply can deliver the extra current on that line. Never split a graphics card power lead to run more devices than the cable is rated for. Barrel-plug leads from a PCIe plug supply 12 V DC and need the right plug size, such as 5.5 by 2.5 mm, and polarity. Check wire gauge, since thin leads heat up under load.

Questions about Jumper Cords, Y-Splitters and PC Power Adapters

What is a jumper power cord?

A jumper cord is a short power cable, often with a C14 plug on one end and a C13 socket on the other, used to connect servers and network gear to a rack power strip or UPS. Short lengths keep the rack tidy.

Can I power two devices from one C14 to dual C13 splitter?

Yes, if the combined current of both devices stays below the cord's amp rating and the outlet's capacity. Add the amps printed on each device's label. Splitters suit low-power items, not two heavy servers sharing a single circuit.

How does an external PC power button cable connect?

It connects to the two front-panel power-switch pins on the motherboard, usually marked PWR_SW, either beside or in place of the case button. Pressing it briefly joins those pins to start the PC. Check the motherboard manual for the pin location.