10ft IEC320 C20 to C21 Heavy Duty Power Extension Cord, 12 AWG, 20A/250V, SJT, Black

The CableLeader PW151-1210 is a 10-foot IEC 60320 C20 to C21 heavy-duty server power cord designed to deliver up to 20 amps at 250 volts from a standard C20-output power distribution unit, uninterruptible power supply, or rack-mount power panel to equipment fitted with a high-temperature C21 inlet. One end carries a three-pin C20 male plug (33.8 × 29.0 mm face, "20A 250V" stamped on the plug face); the opposite end exposes a C21 female receptacle (32 × 24 mm body), the high-temperature variant of the more common C19. Between the two connectors runs 12 AWG SJT flexible cord wired L-to-L, N-to-N, and E-to-E for direct one-to-one passthrough.

The C20 male plug is the heaviest IEC 60320 receptacle pair, rated for 20 amps continuous at 250 volts on dedicated 250V circuits typical of data center power distribution. The plug face is molded with the certification stamp (cULus E210037) and the polarized L/N/E pin configuration that prevents reverse insertion. C20 inlets appear as the upstream feed on virtually every 20A rack PDU output strip, on UPS battery output panels, and on rack-mount power conditioners; this cord plugs directly into any of those without adapters and preserves continuous ground through the dedicated circuit.

The C21 female receptacle is the high-temperature counterpart to the standard C19. While C19 bodies are rated for 70°C ambient, C21 receptacles carry a 155°C body rating and are specified for equipment that runs hot — blade chassis, high-density compute nodes, certain lab ovens and environmental chambers, and rack equipment whose chassis enclosure exceeds C19's thermal envelope. C21 receptacles look almost identical to C19 from the outside but carry a different keying notch position, so a C21 end will only mate with C20 plugs and is mechanically prevented from accepting C18 or unrelated variants.

Safety certifications cover both the cordage and the molded ends. UL Listing file E204978 applies to the SJT 12 AWG conductor; UL file E210037 covers both the C20 plug and the C21 receptacle assemblies, including cUL recognition for Canadian installation codes. RoHS directive compliance ensures the cord contains no restricted lead, mercury, cadmium, hexavalent chromium, PBB, PBDE, or the four added phthalates. The SJT jacket carries VW-1 flame-rated marking, 105°C continuous service rating, and 300V dielectric. Each ground path is continuous from the C20 ground pin through the green conductor to the C21 ground socket, preserving protective earth for downstream equipment.

Typical deployments center on dense rack environments where high-output equipment shares space with high-output power distribution. Data center technicians install this cord as a jumper between the C20 output of a 20A metered or switched rack PDU and a blade chassis whose C21 inlets demand the high-temperature variant. Lab managers use it between a benchtop power conditioner with C20 output and an environmental chamber, oven, or instrument with C21 inlets. AV and broadcast integrators reach for it when high-current rack-mount equipment needs C20-to-C21 routing inside hot equipment cabinets where airflow is restricted.

The black jacket provides a professional appearance and suits standard data center and enterprise rack deployments.

Compatibility & Ordering Information — PW151-12XX is compatible with every standards-compliant IEC 60320 C20 outlet found on high-density rack PDUs and 20A UPS output panels from all major manufacturers, and mates with any device fitted with a C21 inlet — high-temperature blade chassis and enterprise compute enclosures, plus lab instruments that specify C21. The cord is available in 1 ft / 2 ft / 3 ft / 5 ft / 6 ft / 10ft / 8 ft / 10 ft / 15 ft lengths to fit in-rack drops, rack-to-rack jumpers, and cross-room deployments. Custom lengths, bulk packaging, and OEM kitting are available — contact CableLeader for quotations, imprinted labels, or rack-kitting programs.

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Product Comparison: C20 to C21 vs C20 to C19 Heavy Duty Power Cord

Buyers shopping for a C20-output power cord frequently cross-compare the C21 high-temperature variant against the more common C19 cord, since both start from the same 20A C20 outlet on a rack PDU or UPS. The table below summarizes the decision:

Select PW151-12XX (C20 to C21) when the equipment manufacturer's spec sheet explicitly calls for a C21 inlet, or when the equipment runs hot enough that a 70°C C19 receptacle is not safe. Common cases: high-temperature blade chassis, enterprise compute enclosures, lab ovens, and environmental chambers.
Select the C20 to C19 cord when the equipment has a standard C20 inlet (most rack-mount servers, 20A UPS battery cabinets, large network switches). The C19 cord is the more common choice — verify your equipment's inlet keying before ordering.

If you are unsure whether your equipment requires C21 or C19, check the inlet keying: C21 inlets have the keying notch on the side, while C19 inlets have it at the top. Or refer to the equipment's installation manual — both connector types are explicitly named in any IEC 60320-compliant spec sheet.

FAQ

What is the difference between a C20 to C21 cord and a C20 to C19 cord?

A C20 to C21 cord (this product) uses a high-temperature C21 receptacle rated to 155°C, while a C20 to C19 cord uses the standard C19 receptacle rated to 70°C. Electrically the two are identical — both 20A / 250V — but the C21 is required by equipment specifying high-temperature operation, such as blade servers and certain lab instruments. C19 and C21 inlets are keyed differently, so each cord only mates with its specified inlet type. Always match the receptacle to the equipment manufacturer's spec sheet.

Is this 10ft C20 to C21 cord compatible with rack PDUs and UPS units from all major manufacturers?

Yes. Any rack PDU, UPS, or power panel that provides a standards-compliant IEC 60320 C20 output accepts this cord's C20 plug. That includes 20A basic, metered, and switched rack PDU models from every manufacturer that follows the IEC 60320 standard. The C21 end mates with any device fitted with a C21 high-temperature inlet, including high-temperature blade chassis and enterprise compute enclosures.

Why does this cord use 12 AWG instead of 14 AWG, and can I use a 14 AWG cord at 20A?

12 AWG is the minimum conductor gauge required to safely carry 20 amps continuously per UL and NEC standards; 14 AWG cords are limited to 15 amps and cannot substitute on a 20A circuit. The C20 / C21 interface is rated 20A and the cord rating must match the connector rating, which forces 12 AWG SJT or heavier. If you only need 15A on standard C19 equipment, a 14 AWG C20-to-C19 cord works — but C21 inlets typically pair with 20A loads.

Which end of the C20 to C21 cord plugs into the PDU?

The C20 male plug — the rectangular end with three flat blade pins and "20A 250V" stamped on the plug face — inserts into the PDU's C20 outlet. The C21 female receptacle — the end with three rectangular slots in a curved housing — receives the equipment's C21 inlet. The cord is polarized and keyed, so each end only fits its correct counterpart and reverse insertion is mechanically prevented.

Which length C20 to C21 power cord should I choose for my server rack?

Match the cord length to the physical distance between the PDU outlet and the equipment's C21 inlet, plus a 6-inch service loop for cable management. For in-rack drops where the equipment sits within 1U–2U of the PDU, choose 1 ft to 3 ft. For rack-to-rack jumpers within the same row, choose 5 ft to 10ft. For cross-row routing or mobile equipment carts, choose 8 ft to 15 ft. Never stuff slack cord behind a hot rack — restricted airflow accelerates jacket aging.