Table C-1: Eft Detailed Sequence Of Operation - Nordyne O4HD-091A-12-FA Installation Instructions Manual

TABLE C-1: EFT DETAILED SEQUENCE OF OPERATION

Mode
Thermostat calls for heat.
HEAT
("W" terminal is energized).
Thermostat ends call for heat.
("W" terminal is de-
energized).
Burner fails to light.
Established flame fails.
Thermostat begins call for
COOL
cool. (G and Y terminals are
energized).
Thermostat ends call for cool.
(G and Y terminals are de-
energized).
Thermostat begins call for
FAN
fan. (G terminal is energized).
Thermostat ends call for fan.
(G terminal is de-energized).
LIMIT Limit switch string opens.
Continued on following page.
Action
a. Electronic fan timer energizes oil burner. (T – 3/T connections
b. R7184 oil primary control starts the oil burner. Oil flows as
c. Burner motor and valve is energized and heat "fan on" delay
a. R7184 oil primary control is de-energized, terminating the
b. Heat "fan off" delay timing begins. Length of delay depends on
c. Electronic fan timer returns to standby mode, (Oil primary
a. Oil primary control locks out within lockout timing, (30
b. Burner motor is de-energized. (Even though thermostat is still
c. If circulator fan has started, it continues through the selected
a. Burner motor is de-energized and oil primary control goes into
b. If the selected heat "fan off" delay timing is longer than the
a. Cooling contactor is energized immediately.
b. Circulator fan is energized at cool speed.
a. Cooling contactor is de-energized immediately.
b. Circulator fan turns off immediately.
a. Circulator fan is energized immediately at cooling speed.
a. Circulator fan is de-energized immediately.
a. Oil primary control shuts off burner.
b. Circulator fan is energized immediately at heat speed.
c. Electronic fan timer opens oil primary control. (T – 3/T
System Response
for Beckett R7184).
long as the oil primary control senses flame.
timing begins. When timing is complete, the circulator fan is
energized at heat speed.
burner cycle.
electronic fan timer dipswitch settings. When timing is
complete, the circulator fan is de-energized.
control and circulator fan are off, unless continuous fan
operation is selected at the thermostat).
seconds).
calling for heat).
heat "fan off" delay period.
recycle mode.
recycle delay timing, the circulator fan continues to run
through the next trial for ignition.
connections for Beckett R7184).
20 151B0801 R5 3/28/2006