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Table 6. Smart Hub Parameters
Parameter
(In alphabetical
order)
Description
Zoning Anticipated
Discharge Air
Temperature
Adjustment
This parameter setting compensates for a rapid change of the discharge air temperature due to fast changing conditions. It examines the change in the discharge air
temperature for the previous two minutes and extrapolates or looks forward by the number of seconds set in the parameter and uses this as the DATS value for staging.
This parameter setting helps prevent limit trip/frozen coil from occurring.
Range is 0 to 120 seconds. Default is 0 seconds. Adjustments are in increments of 5 seconds.
Zoning Gas
Heating DAT Cool
Down Target
At the end of a gas cycle, the Heat Blower Off-Delay may not be long enough to completely cool the heat exchanger. This may result in a primary limit trip then, or at the
beginning of the next heat demand. This parameter allows the blower to run after a gas heat call ends until the discharge air temperature sensor (DATS) cools to the
temperature set in the parameter. If the temperature is set too low this will cause the temperature in the room to overshoot.
Range is 80 to 90°F (26.67 - 32.22°C). Default is 90°F (32°C). Adjustments are in increments of 1°F (0.56°C).
Zoning Initial
Staging Hold Time
for Gas Heating
In zoning systems, the furnace was upstaging before the discharge air sensor reached a steady-state value and it would sometimes trip a limit due to staging up the gas
before the blower would even come on (as occurs during pressure switch calibration).
In addition and options for delaying the first staging event even further since the starting point of the modulation gas heat in zoning is picked to be appropriate for the
airflow being provided, so this parameters allows an adjustment on top of the initial delay. Range: 3.0 – 8.0 minutes, with a default: 5.0 minutes. Can be adjusted in 1
minute increments.
Zoning Minimum
Zone Run-Time
Range is 90 to 600 seconds. Default is 120 seconds. Adjustments are in increments of 30 seconds.
Zoning Supply
Air Temp Limit
for Cooling
In cooling mode, this setting sets the discharge air temperature low limit. Below this temperature, the cooling is turned off.
Range is 35 to 45°F (1.67 - 7.22°C). Default is 40°F (4.44°C). Adjustments are in increments of 1°F (0.56°C).
Zoning Supply Air
Temp Limit for Gas
/ Electric Heating
In heating mode, this setting sets the target discharge air temperature.
Range is 120 to 160°F (48.88 to 54.44°C). Default is 125°F (52°C). Adjustments are in increments of 5°F (2.78°C).
Zoning Target
Supply Air Temp
for Cooling
In cooling mode, this setting sets the target discharge air temperature.
Range is 40 to 60°F (4.44 - 15.56°C). Default is 45°F (7.22°C). Adjustments are in increments of 1°F (0.56°C).
Zoning Target
Supply Air Temp
for HP Heating
In heat pump heating mode, this setting sets the target discharge air temperature.
Range is 85 to 110°F (29.44 to 43.33°C). Adjustments are in increments of 1°F (0.56°C). Default 90°F (32°C) plus 20 degrees overshoot for both stage and modulating
systems.
Zoning Target
Supply Air Temp
for Gas/Electric
Heating
Default is 110°F. Range is 100°F to 130°F with 1 degree increment adjustable. In heating mode, this setting sets the target discharge air temperature. Default 100°F
(38°C) plus 20 degrees overshoot for both stage and modulating systems.
