0440BA61122622REGULATOR11260422VOLTAGE400131318SP2IM21613SCR008685HTO LOP1801312VBATTERYSCRSMIM1SP14411POWERWINDING3322WINDINGPOWERSTATOR40560SCPage 114utility VoltaGe reStored / re-tranSFer to utilityThe “Load” is powered by the standby power supply. The circuit board continues to seek an acceptable utilitysource voltage. On restoration of utility source voltage, the following events will occur:• On restoration of utility source voltage above 75 percent of the nominal rated voltage, a “retransfer time delay”on the circuit board starts timing. The timer will run for about fifteen (15) seconds.• At the end of fifteen (15) seconds, the “retransfer time delay” will stop timing and circuit board action will openthe Wire 23 circuit to ground. The transfer relay (TR) will then de-energize.• When the transfer relay (TR) de-energizes, its normally-closed contacts close. Utility source voltage is thendelivered to the utility closing coil (C1), via Wires N1A/N2A, the closed TR contacts, Wire 126, limit switch XA1,and a bridge rectifier.Part 4 DC CONTROLsEctioN 4.2oPEratioNal aNalYsis0G9266revA.indd 114 10/15/2008 11:28:01 AM
