are jumpered to complete the holding
cooling air through the ducts between the
ground circuit to power supply relay K180
inner and outer walls of the case. The
(fig. 25). The rt unit case blower plug
blower is driven by a single-phase ac in-
P1401 must be properly connected to jack
duction motor that operates on 115 volts
J1407, otherwise the rt unit will not re-
ac, 60 cps. Input power is supplied through
main on after POWER control S701 is re-
terminals D and E of plug P1401. Capacitor
leased (fig. 25).
C1401 provides starting torque for the
motor. Terminals F and H of plug P1401
Figure 31. Centrifugal Fan HD-390/U, schematic diagram.