Definition
The IEC 60320 C19 and C20 are the larger, higher-current siblings of the familiar C13/C14 pair. The C20 is the male inlet on the equipment or PDU; the C19 is the female cord connector that mates with it. This grounded three-wire coupling is rated 16A at 250V internationally and is commonly certified up to 20A at 250V in North America, again with a 70 C conductor rating.
Why it matters for ASIC miners
A modern hydro or air-cooled ASIC and its power supply can pull well beyond the ~15A ceiling of a C13/C14 jumper. The C19/C20 coupler exists precisely for this class of single-device load: high-wattage server power supplies, blade chassis, and the heavy PDUs that feed mining racks. A typical deployment runs a C19-tailed cord from a rack PDU outlet into the C20 inlet on the miner's PSU.
Reading the numbering convention
IEC 60320 follows one rule worth memorising: odd-numbered bodies (C13, C15, C19) are the female connectors on the cord, and the next even number (C14, C16, C20) is the male inlet on the equipment. So a C19 always plugs into a C20. The C19/C20 body is physically larger and rectangular, preventing accidental cross-mating with the smaller C13/C14.
Cabling and capacity
Because these cords carry real current, conductor gauge matters: 14 AWG copper is typical for a 16/20A C19-to-C20 cord. Undersized cordage on a hot-running miner is a fire risk, so match the cord rating to the breaker and the device nameplate.
For the lower-current coupler see the IEC 60320 C13 / C14 connector, and for the rack-feed cabling upstream see the busway.
Match cordage to the PSU in the ASIC PSU reference.
In Simple Terms
The IEC 60320 C19 and C20 are the larger, higher-current siblings of the familiar C13/C14 pair. The C20 is the male inlet on the equipment…