Why are Geist cord-connected units listed with a de-rated Amperage?

Geist’s cord-connected PDUs carry a nameplate current rating that is 80 percent of the branch circuit rating listed in the catalog specification. The nameplate current rating has been lowered in order to comply with UL®/NEC requirements. Geist PDUs are UL® Listed as Information Technology Equipment to the UL® 60950 Standard. UL® 60950 requires that the attachment plug of Listed Information Technology Equipment shall be rated not less than 125 percent of the Rated Current of the equipment at the nominal system voltage range as defined by the configuration of the plug. This clause in UL® 60950-1 is based on the requirements of the National Electrical Code (NFPA-70), which state that branch circuit conductors and overcurrent protection devices shall be sized to carry 125 percent of the continuous load and 100 percent of the non-continuous load on the circuit breaker. Due to this UL®/NEC requirement, the nameplate current rating of a Geist PDU is 80 percent of the maximum current rating of the branch circuit used to power the PDU. Most of Geist’s customers base their PDU input current specifications on the branch circuit ratings; consequently, the catalog lists the ratings of the branch circuit that the PDU is intended to be connected to. In addition to the branch circuit rating, it is important to consider the nameplate PDU rating which includes the 80 percent de-rating factor required by UL®/NEC when calculating PDU requirements.