Installation manual

31
ENVISION RESIDENTIAL INSTALLATION MANUAL
Microprocessor Control cont.
ECM blower changes from medium to high speed 15
seconds after the “Y2” input.
The Comfort Alert will delay the second stage compressor
until 5 seconds after it receives a “Y2” from the board.
Heat, 3rd Stage (Y1,Y2,W) Single-Speed Units
The first stage of resistance heat is energized 10 seconds
after “W” input, and with continuous 3rd stage demand, the
additional stages of resistance heat engage sequentially
every 5 minutes.
Heat, 3rd Stage (Y1,Y2,W) Dual Capacity Units
The hot water pump is de-energized which directs all heat
to satisfy the thermostat. The 1st stage of resistance heat is
energized 10 seconds after “W” input, and with continuous
3rd stage demand, the additional stages of resistance heat
engage sequentially every 5 minutes.
Emergency Heat (W only)
The fan is started on high speed, and the first stage of
resistance heat is energized 10 seconds after the "W" input.
Continuing demand will engage the additional stages of
resistance heat sequentially every 2 minutes.
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.
Cool, 1st Stage (Y1,O)
The blower motor and hot water pump are started
immediately, the loop pump(s) is energized 5 seconds after
the “Y1” input is received. The compressor will be energized
(on low capacity for Dual Capacity units) 10 seconds
after the “Y1” input. The ECM blower will shift from low
to medium speed 15 seconds after the “Y1” input (85% of
medium speed if in dehumidification mode).
Cool, 2nd Stage (Y1, Y2, O) Single Speed Units
The fan changes to high speed (85% of high speed if in
dehumidification mode) 15 seconds after the “Y2” input
(ECM only).
Cool, 2nd Stage (Y1, Y2, O) Dual Capacity Units
The second stage compressor will be activated 5 seconds
after receiving a “Y2” input as long as the minimum first
stage compressor run time of 1 minute has expired. The
ECM blower changes to high speed 15 seconds after the
“Y2” input (85% of high speed if in dehumidification mode).
The Comfort Alert will delay the second stage compressor
until 5 seconds after it receives a “Y2” from the board.
Fan (G only)
The fan starts on low speed (PSC ON). Regardless of fan
input “G” from thermostat, the fan will remain on low speed
for 30 seconds at the end of each heating, cooling or
emergency heat cycle.
A DIP switch on the Envision control allows field
selection of 15% reduced fan speeds for cooling in the
dehumidification mode or medium and high fan speeds for
cooling in the normal mode.
NOTE: Fan speed can change automatically only with an
ECM Motor.
ECM2 Airflow Selection DIP Switches (SW1)
A 12-position DIP switch package on the Envision control
allows the airflow levels to be set for low, medium and high
speed. (Refer to the ECM Blower table.)
Only three of the DIP switches can be in the “on” position.
The first “on” switch (the lowest position number)
determines the “low speed fan” setting. The second “on”
switch determines the “medium speed fan” setting, and the
third “on” switch determines the “high speed fan” setting.
Lockout Conditions
During lockout mode, the appropriate unit and thermostat
lockout LEDs will illuminate. The compressor, loop pump,
hot water pump, and accessory outputs are de-energized.
Unless the lockout is caused by an ECM2 low RPM fault, the
fan will continue to run on low speed. If the thermostat calls
for heating, emergency heat operation will occur.
Comfort Alert lockouts cannot be reset at the thermostat.
All other lockout modes can be reset at the thermostat
after turning the unit off, then on, which restores normal
operation but keeps the unit lockout LED illuminated.
Interruption of power to the unit will reset a lockout
without a waiting period and clear all lockout LEDs.
High Pressure
This lockout mode occurs when the normally closed safety
switch is opened momentarily (set at 600 PSI).
Low Pressure
This lockout mode occurs when the normally closed low
pressure switch is opened for 30 continuous seconds (set
at 40 PSI). A low pressure fault may also be indicated when
a Comfort Alert lockout has occurred.