8
Outdoor Coil Temp (OCT)
}
Outdoor Air Temp (OAT)
}
COMM STATUS
A05332
Fig. 11
---
Control Board
Time Delays
The unit time delays include:
S
Five minute time delay to start cooling or heating oper-
ation when there is a call from the thermostat or user
interface (To bypass this feature in a non--communicat-
ing system, momentarily short and release forced de-
frost pins, in a communicating system push the UI fan
and up buttons simultaneously for approximately 10
seconds)
S
Five minute compressor recycle delay on return from a
brown out condition
S
Two minute time delay to return to standby operation
from last valid communication (with Evolution only)
S
One minute time delay of outdoor fan at termination of
cooling mode when outdoor ambient is greater than or
equal to 100
_
F/37.78
_
C.
S
Fifteen second delay at termination of defrost before
the auxiliary heat (W2) is de--energized
S
Twenty second delay at termination of defrost before
the outdoor fan is energized
S
Thirty second compressor delay when Quiet Shift en-
abled
Utility Interface
With Evolution Control
The input labeled UTIL is active only when a communicating
Evolution Control is used. This input allows a power utility
device to interrupt compressor operation during peak load
periods. See Fig. 12 for wiring connections. When the utility
sends a signal to shut the system down, the User Interface will
display ”CURTAILMENT ACTIVE”.
EVOLUTION BOARD
R
UTILITY RELAY
*
UTILITY SIGNAL
OPEN RELAY
*
SUPPLIED BY UTILITY PROVIDER
UTIL
A05409
Fig. 12
---
Utility Interface
With Non--Communicating Thermostats
When the utility curtailment interface is used with a
non--communicating thermostat, the utility relay should be wired
between R and Y.
Low Ambient Cooling
When this unit is operating below 55
_
F/12.78
_
C outdoor
temperature, provisions must be made for low ambient operation.
Evolution Controlled low ambient cooling:
This unit is capable of low ambient cooling without a kit ONLY
when using the Evolution control. A low ambient kit is not
required, and the outdoor fan motor does not need to be replaced
for Evolution controlled low ambient operation. The Evolution
Control provides an automatic evaporator coil freeze protection
algorithm that eliminates the need for an evaporator freeze
thermostat. Low ambient cooling must be enabled in the User
Interface set up.
Fan may not begin to cycle until about
40
_
F/4.44
_
C OAT. Fan will cycle based on coil and outdoor air
temperature.
Evolution controlled low ambient mode operates as follows:
S
Fan is OFF when outdoor coil temp is < (outdoor air
tempe 3
_
F/--16.11
_
C) or outdoor fan has been
ON for 30 minutes. (Fan is turned off to allow refriger-
ant system to stabilize.)
S
Fan is ON when outdoor coil temp > (outdoor air temper-
ature + 25
_
F/--3.89
_
C) or outdoor coil temp >
80
_
F/26.67
_
C or if outdoor fan has been OFF for 30
minutes. (Fan is turned on to allow refrigerant system
to stabilize.)
S
Low pressure switch is ignored for first 3 minutes during
low ambient start up. After 3 minutes, if LPS trips, then
outdoor fan motor is turned off for 10 minutes, with the
compressor running. If LPS closes within 10 minutes
then cooling continues with the outdoor fan cycling per
the coil temperature routine listed above for the remainder
of the cooling cycle. If the LPS does not close within
10 minutes, then the normal LPS trip response (shut
down cooling operation and generate LPS trip error) will
occur.
264A
/265A
