UFC 3 -520-01
June 10, 2002
The conductors will have smaller voltage drop, which will often be necessary to meet
other design criteria. For example, IEEE 1100 recommends a maximum voltage
drop of 1 percent for electronic installations.
Greater flexibility will be available in the existing system to accommodate future load
The system can better accommodate the adverse effects of nonlinear loads.
In many cases, no changes to the raceway system will be necessary to
accommodate a larger cable. In these cases, the payback period for energy savings is
often less than 2 years. Even if a larger condui t is required, a reasonable payback
period is often achievable. Appendix B provides example calculations.
To ensure that energy savings can actually be obtained without other hidden
costs, ensure that the larger conductor is compatible with the upstream breaker or fuse,
as well as the downstream load, in terms of physical size and termination ability.
CONVENIENCE OUTLETS AND RECEPTACLES .
Receptacles for installation on 15 ampere and 20 ampere branch circuits
should be of the grounding type with the grounding contacts effectively grounded.
Ensure these receptacles conform to UL 498, Attachment Plugs and Receptacles, and
NEMA WD 1, General Requirements for Wiring Devices.
Incorporate the grounding pole into the body of a polarized receptacle for the
Three phase outlets.
Outlets supplied with voltages in excess of 150 volts between conductors.
All voltages installed in hazardous locations.
Use a separate conductor (green wire or bare copper) to ground all grounding
type outlets and receptacles.
Provide a separate single -branch circuit for each three-phase receptacle.
Branch circuits should be three-phase, five -wire, each protected by a three-pole thermal
magnetic molded case circuit breaker. Regulation of the circuit should be limited to not
more than 5 percent below normal.
Install computer-related circuits and receptacles separate from motor load
circuits. If required by the manufacturer to minimize noise, provide a separate
grounding conductor back to the branch circuit breaker for each circuit, consistent with
NEC grounding criteria.