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Using Extension Cords in the Data Center - FAQ

Issue

Frequently Asked Questions (FAQ) are explained regarding using extension cords in data center environments

Product Line

Any product lines installed in your data center

Environment

Data Center Applications
Cord lengthening questions

Cause

Due to National Electrical Code (NEC) and UL, there are certain precautions and information that a user should take under advisement when using extension cords in a data center application.

Resolution

Please review the list of FAQ listed below.

Can extension cords be used in ITE rooms?

NEC 400.8(1) says "...flexible cords and cables shall not be used... as a substitute for the fixed wiring of a structure. This has generally been interpreted to prohibit the use of extension cords in data centers.

Are cord sets and interconnect cables considered "fixed wiring"?

NEC 645.9(F) says:
Power cables, communications cables, connecting cables; interconnecting cables; and associated boxes, connectors, plugs, and receptacles that are listed as part of, or for, information technology equipment shall not be required to be secured in place.

Power supply cord sets on listed equipment are permitted in data centers up to 15 feet (4.5 m) per 645.5(B)

Can extension cords be used for "temporary" wiring in a data center?

Most AHJ's would argue that ITE equipment is not temporary; i.e., it can reasonably be expected to be in place for longer than 90 days.

See 590.3. An AHJ may be persuaded to allow a conditional use permit if convinced that
1) the installation could be considered "construction" and
2) the extension cords would be replaced by permanent wiring methods when they become available. Typically anything longer than 90 days is not considered temporary, although 590.3 does allow some leeway on the "period of construction" for construction or remodeling of buildings.
It might be a stretch to win such an argument.

Can cord sets be replaced in the field with cords of different lengths?

Some cord sets are designed and listed as replaceable, thereby allowing a rack PDU to swap out various cords depending upon what voltage is available or to accommodate different cord lengths. Most Schneider rack PDUs do not have that feature. Cord sets cannot be removed or replaced with a different length without voiding the UL listing on the product.

Please Note:Modified equipment may still meet UL requirements, but may need evaluation.