Greenheck Microprocessor Controller v3.0 (469690) - Manual (Page 9)

9
Lockout dehumidific-
ation until outside
air is:10.0ºF above
cold coil set point
T
HIS SCREEN DISPLAYS THE TEMPERATURE DIFFERENCE AT WHICH THE
DEHUMIDIFICATION ON THE UNIT IS LOCKED OUT
(
FACTORY DEFAULT
= 10ºF).
This screen will only appear if cooling was provided with the unit.
This setting prevents the unit from operating in dehumidification mode when outdoor
air conditions are relatively cool. For example, if the cold coil set point is 55ºF,
dehumidification mode cannot operate until the outdoor air is at least 65ºF.
Defrost
Allow wheel defrost
mode when outside
is less than: 05.0ºF
T
HIS SCREEN DISPLAYS THE TEMPERATURE AT WHICH THE UNIT WILL BEGIN FROST
CONTROL MODE
.
This screen only appears if a frost control method was provided with the unit .
The energy wheel transfers both latent and sensible energy at relatively similar
efficiencies. Therefore, in most applications where indoor mositure levels are
below 35% RH, frost typically will not occur on the energy wheel until outdoor air
temperatures are below 5ºF. Consult the factory if you have any concerns regarding
your specific application.
Supply air low limit
alarm when supply is
less than: 35.0ºF
Alarm delay:300s
T HIS SCREEN DISPLAYS WHAT THE LOW TEMPERATURE LIMIT IS FOR THE UNIT .
If the unit supply discharge temperature falls below Supply Air Low Limit set point
(factory default 35F) for a period of time (factory default 300 sec) the unit will shut down
and an alarm will be signaled. The purpose of the Discharge Freeze Protection is to
protect the building and contents from low temperature supply air. It is NOT designed
to protect the Energy Recovery unit.
If the Energy Recovery unit does not have CW or HW coils (has only no heat, IG heat,
electric heat, no cooling, or Dx cooling) it should not need additional protection from
freezing. If the Energy Recovery unit does have CW or HW coils, please contact the
factory for more details.
End of Set Points
Economizer Lockout
Lockout econo when
outside air <:40.0ºF
Hysteresis=02.0ºF
E CONOMIZER L OCKOUT PREVENTS THE UNIT FROM GOING INTO ECONOMIZER
MODE WHEN OUTDOOR AIR CONDITIONS ARE TOO COLD
.
This screen only appears if economizer was provided with the unit.
The lockout prevents outdoor air from 1) entering the space at too cold of a
temperature or 2) entering heating and cooling coils at conditions that could freeze
the coils. Built-in hysteresis of 2ºF. The hysteresis is similar to a deadband above and
below the lockout set point.
(Example: If Lockout = 40ºF, economizer is locked out below 38ºF and enabled above
42ºF outside air temp)
SET POINTS MENU - continued
Cooling Lockout
Lockout cooling when
outside air <:55.0ºF
Hysteresis=02.0ºF
T
HIS CONTROLLER WILL LOCK THE COOLING SECTION OFF WHEN THE OUTDOOR AIR
TEMPERATURE IS BELOW THE
C
OOLING
L
OCKOUT SET POINT
(
FACTORY DEFAULT
= 55ºF).
This screen will only appear if Cooling was provided with the unit.
There is a built in hysteresis of 2ºF which prevents the compressors from short cycling.
The hysteresis is similar to a deadband above and below the lockout set point.
(Example: If Lockout = 55ºF, cooling is locked out below 53ºF and end enabled above
57ºF outside air temp).