Page 525 - Handbook of Electrical Engineering
P. 525

516    HANDBOOK OF ELECTRICAL ENGINEERING


              W
              W or P               Active power, watts.
              wor ω                Frequency in radians per second.
              wdg.                 Winding of a machine or transformer.
              WHRU                 Waste heat recovery unit.

              X

              X or x               Electrical reactance.
              XLPA                 Cross-linked polyalkene.
              XLPE                 Cross-linked polyethylene.
              Y

              Y or y               Electrical admittance.
              y                    Year.

              Z
              Z or z               Electrical impedance.
              ZH                   Zero halogen, as used for cables.

              Numerical

              1P or SP             Single phase.
              3P                   Three-phase supply.
              3P-N                 Three-phase and neutral supply.
              3P-N-E               Three-phase neutral and earth supply.
              2W                   Two-wire supply.
              3W                   Three-wire supply.
              4W                   Four-wire supply.
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