Dell PowerEdge R720 and R720xd Owner's Manual

Wiring Instructions For A DC Power Supply

Your system supports up to two –(48–60) V DC power supplies (when available).

WARNING: For equipment using –(48–60) V DC power supplies, a qualified electrician must perform all connections to DC power and to safety grounds. Do not attempt connecting to DC power or installing grounds yourself. All electrical wiring must comply with applicable local or national codes and practices. Damage due to servicing that is not authorized by Dell is not covered by your warranty. Read and follow all safety instructions that came with the product.

CAUTION: Wire the unit with copper only, unless otherwise specified, use only 10 American Wire Gauge (AWG) wire rated minimum 90 ºC for source and return. Protect the –(48–60) V DC (1 wire) with a branch circuit over-current protection rated 50 A for DC with a high interrupt current rating.

CAUTION: Connect the equipment to a –(48–60) V DC supply source that is electrically isolated from the AC source (reliably grounded –(48–60) V DC SELV source). Ensure that the –(48–60) V DC source is efficiently secured to earth (ground).

NOTE: A readily accessible disconnect device that is suitably approved and rated shall be incorporated in the field wiring.

Wire-stripper pliers capable of removing insulation from size 10 AWG solid or stranded, insulated copper wire

One UL 10 AWG, 2 m maximum (stranded) black wire [–(48–60) V DC]
One UL 10 AWG, 2 m maximum (stranded) red wire (V DC return)
One UL 10 AWG, 2 m maximum green/yellow, green with a yellow stripe, stranded wire (safety ground)