ECR International A Series Installation, Operation And Maintenance Manual page 22

Table C-1: 1158-120 Electronic Fan Timer Board (EFT) Detailed Sequence Of Operati
Mode
Thermostat calls for heat. ("W"
terminal is energized).
Thermostat ends call for heat.
("W" terminal is de-energized).
HEAT
Burner fails to light.
Established flame fails.
Thermostat begins call for
cool. (G and Y terminals are
energized).
COOL
Thermostat ends call for cool.
(G and Y terminals are de-
energized).
Thermostat begins call for fan.
(G terminal is energized).
FAN
Thermostat ends call for fan.
(G terminal is de-energized).
Limit switch string opens.
LIMIT
Limit switch string closes (with
existing call for heat).
Limit switch string closes
(without existing call for heat).
Continuous circulating fan is
FAN
connected.
Electronic Air Cleaner is
EAC
connected.
HUM Humidity control is connected.
APPENDIX C - SEQUENCE OF OPERATION AND TROUBLESHOOTING
Action
EFT closes the oil primary control T - T connections.
Ignition system and the oil primary control start the furnace. Oil flows as long as the oil
primary control senses flame.
Burner motor is energized and heat "fan on" delay timing begins. When timing is complete,
the circulator fan is energized at heat speed.
The oil primary control is de-energized, terminating the burner cycle.
Heat "fan off" delay timing begins. Length of delay depends on EFT dipswitch settings.
When timing is complete, the circulator fan is de-energized.
EFT returns to standby mode, (Oil primary control and circulator fan are off, unless
continuous fan operation is selected at the thermostat).
Oil primary control locks out within lockout timing, (15 seconds).
Burner motor is de-energized. (Even though thermostat is still calling for heat).
If circulator fan has started, it continues through the selected heat "fan off" delay period.
Burner motor is de-energized and oil primary control goes into recycle mode.
If the selected heat "fan off" delay timing is longer than the recycle delay timing, the
circulator fan continues to run through the next trial for ignition.
Cooling contactor is energized immediately.
Circulator fan is energized at cool speed.
Cooling contactor is de-energized immediately.
Circulator fan turns off immediately.
Circulator fan is energized immediately at cooling speed.
Circulator fan is de-energized immediately.
Oil primary control shuts off burner.
Circulator fan is energized immediately at heat speed.
EFT opens the oil primary control T - T connections. Circulating fan runs as long as limit
string stays open.
If there is a call for cooling or fan, the circulating fan switches from heating to cooling
speed.
EFT begins heat "fan off" delay sequence.
Circulating fan turns off after the selected heat "fan off" timing.
EFT re-closes the oil primary control T - T connections.
Oil primary control is energized, initiating burner light off.
Circulator fan turns off when heat "fan off" delay time is complete.
Normal operation resumes; EFT control is in standby mode awaiting next thermostat
command.
Circulating fan is energized when there is no call for heat, cool, or fan.
If fan operation is required by a call for heat, cool, or fan, the EFT switches off the
continuous fan speed tap before energizing the other fan speed.
Electronic air cleaner (EAC) connections are energized when the heat or cool speed of
the circulator fan is energized. EAC connections are not energized when the optional
continuous fan terminal is energized.
Humidifier connections are energized when the oil burner motor is energized.
System Response
22
on (UMLA)
PN 240010964 Rev. L [10/01/2021]