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Over/Under Voltage Shutdown -
An over/under voltage condition
exists when the control voltage is outside the range of 18 VAC to
30 VAC. If the over/under voltage shutdown lasts for 15 minutes,
the lockout and alarm relay will be energized. Over/under voltage
shutdown is self-resetting in that if the voltage comes back within
range of 18 VAC to 30 VAC for at least 0.5 seconds, then normal
operation is restored.
Operation Description
Power Up -
The unit will not operate until all the inputs and safety
controls are checked for normal conditions. The unit has a 5 to 80
second random start delay at power up. Then the compressor has
a 4 minute anti-short cycle delay after the random start delay.
Standby In standby mode, Y1, Y2, W, DH, and G are not active.
Input O may be active. The blower and compressor will be off.
Heating Operation
Heating, 1st Stage (Y1) -
The blower is started on “G” speed
immediately and the compressor is energized 10 seconds after
the Y1 input is received. The ECM blower motor is switched to low
speed 15 seconds after the Y1 input.
Heating, 2nd Stage (Y1, Y2) -
The compressor will be staged to
full capacity 20 seconds after Y2 input is received. The ECM blower
will shift to high speed 15 seconds after the Y2 input is received.
Heating, 3rd Stage (Y1, Y2, W) -
The hot water pump is de-
energized and the first stage of electric heat is energized 10
seconds after the W command is received. If the demand
continues the second stage of electric heat will be energized after
5 minutes.
Emergency Heat (W) -
The blower will be started on “G” speed,
10 seconds later the first stage of electric heat will be turned on. 5
seconds after the first stage of electric heat is energized the blower
will shift to Aux speed. If the emergency heat demand is not satisfied
after 2 minutes the second electric heat stage will be energized.
Blower (G) -
The blower will start immediately upon receiving
a thermostat G command. If there are no other commands
from the thermostat the ECM will run on “G” speed until the G
command is removed. Regardless of blower input (G) from the
thermostat, the blower will remain on for 30 seconds at the end
of each heating cycle.
Cooling Operation
In all cooling operations, the reversing valve directly tracks the O
input. Thus, anytime the O input is present, the reversing valve will
be energized.
Cooling, 1st Stage (Y1, O) -
The blower is started on “G” speed
immediately and the compressor is energized 10 seconds after the Y1
input is received. The ECM blower motor is switched to low speed 15
seconds after the Y1 input.
Cooling, 2nd Stage (Y1, Y2, O) -
The compressor will be staged to
full capacity 20 seconds after Y2 input is received. The ECM blower
will shift to high speed 15 seconds after the Y2 input is received.
Blower (G) -
The blower will start immediately upon receiving a
thermostat G command. If there are no other commands from the
thermostat the ECM will run on “G” speed until the G command is
removed. Regardless of blower input (G) from the thermostat, the
blower will remain on for 30 seconds at the end of each heating,
cooling, and emergency heat cycle.
Dehumidification (Y1, O, DH or Y1, Y2, O, DH) -
When a DH
command is received from the thermostat during a compressor
call for cooling the ECM blower speed will be reduced by 15% to
increase dehumidification.
Emergency Shutdown -
Four (4) seconds after a valid ES input,
P2-7 is present, all control outputs will be turned off and remain
off until the emergency shutdown input is no longer present. The
first time that the compressor is started after the control exits
the emergency shutdown mode, there will be an anti-short cycle
delay followed by a random start delay. Input must be tied to
common to activate.
Continuous Blower Operation -
The blower output will be
energized any time the control has a G input present, unless the
control has an emergency shutdown input present. The blower
output will be turned off when G input is removed.
Load Shed -
The LS input disables all outputs with the exception
of the blower output. When the LS input has been cleared, the anti-
short cycle timer and random start timer will be initiated. Input must
be tied to common to activate.
Controls - Aurora Base Control cont.
LX ULTRA SERIES INSTALLATION MANUAL
