Chromalox C4 - 8.3 Two 3-Phase Loads, Closed Delta; 8.4 Two 3-phase loads, star (wye) without neutral

30
Open Delta & Wye
Three phase heating circuits are most efficient when operated under balanced conditions. If it is necessary to oper-
ate an unbalanced load, the equations below can be used to calculate the circuit values for open three phase Delta
or Wye circuits. The terms used in the equations are identified below:
3Ø Open Delta 3Ø Open Wye (Star)
2
÷ R1)
Note:
The loss of a phase or failure of an element in a
three (3) element Delta circuit will reduce the
wattage output by 33%
Note:
The loss of a phase or failure
of an element in a
three (3) element Wye circuit will reduce the
wattage output by 50%. Heating elements are
basically in series on single phase power.