Controls - aurora base control cont, Operation description – WaterFurnace Versatec Ultra User Manual

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VERSATEC ULTRA SERIES INSTALLATION MANUAL

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.

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.