Table 3ÐHeating System Option Vs. Type of Heater Used
HEATER TYPE USED | HEAT PUMP | TWO STAGE | DUAL FUEL | FAN ON | |
FOR COOLING ONLY | |||||
SYSTEM TOGGLE: | HEAT PUMP | SYSTEM SWITCH: | |||
IN SYSTEM | TOGGLE: | ||||
TOGGLE: | |||||
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On | Off | 0oF (off) | Off | ||
On | On | 0oF (off) | Off | ||
Heat Pump/Furnace Dual | On | Off | 10 to 60oF | Off | |
Fuel |
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On | On | 0°F | Off | ||
Furnace Dual Fuel* | |||||
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Furnace Heat Only | Off | Off | 0oF (off) | On or Off | |
Strip Heater Only | Off | Off | 0oF (off) | Off |
*Refer to
Table 4ÐAvailable Heating and Cooling Stages Vs. System Type
TYPE OF HVAC | COOLING STAGE 1 | COOLING STAGE 2 | HEAT STAGE 1 | HEAT STAGE 2 | HEAT STAGE 3 | HEAT STAGE 4 | |
EQUIPMENT USED | |||||||
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Cooling Only, any Heater Type | Y1 | Y2 | W1 | W2 | |||
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Y1 | Y1 | W1 | W2 | ||||
Y1 | Y2 | Y1 | Y2 | W1 | W2 | ||
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For cooling applications, the second stage of an air conditioner is not necessarily more expensive to operate than first stage. But additional cooling can drive down the efficiency of a
heater. The electric strip heat is much more expensive to operate when comparing cost per unit of heat. Because auxiliary stages of heating tend to be more expensive to operate, Comfort Zone attempts to keep number of stages at a minimum.
CONFIGURATION OPTIONS FOR EQUIPMENT OPERATION
Comfort Zone has several configurable options which allow it to control different types of HVAC equipment and change the manner in which the equipment is controlled. This first group must be set given the type of HVAC equipment installed. These include:
1.Heat Pump Operation (Rotary Position
2.
3.Dual Fuel trip temperature (Rotary Position
4.Auto Fan Off For Heat (Rotary Position
The second group modifies the way the HVAC equipment is controlled. These include:
1.Comfort Trend Staging (Rotary Position
2.System Mode Reselect (Rotary Position
3.High/Low Temperature Limits Enabled (Rotary Position
4.High Temperature Trip Limit (Rotary Position
5.Dx Sensor (Rotary Position
6.Smart Start (Heat Pump Strip Heat Economy Feature)
The first options which must be set are based upon the type heater or heaters used. These are shown in Table 3. The only option which appears to impact cooling operation is
Comfort Zone assumes that there are always 2 stages of cooling present. These are connected to the Comfort Zone Relay Pack on the Y1 and Y2 contacts.
RELAY PACK TO HVAC EQUIPMENT CONNECTIONS
Given system configuration, Comfort Zone can determine number of heating stages that it will actually control and which relay outputs will be used to control each stage of heat. Comfort Zone can control up to 4 stages of heat depending upon system configuration.
For cooling only applications with any type of heater, Comfort Zone will only control 2 stages of heat. If system uses a heat pump, then Comfort Zone will control 3 stages of heat. The additional stage is heat pump compressor contact. The auxiliary heat is still 2 stages. If system uses a 2 stage heat pump, then Comfort Zone will control 4 stages of heat, 2 stages for heat pump and 2 stages for auxiliary heat.
The Comfort Zone Relay Pack outputs are shown in Table 4. The Y1 and Y2 contacts are used for compressor contacts only. Comfort Zone operates heat pumps by energizing compressor contacts and controlling reversing valve through Reversing Valve (RV) relay output. The W1 and W2 contacts are always used for heat sources. These are heating only units such as furnaces, strip heaters, etc. The relay outputs for Comfort Zone 1.4 are shown in Table 4.
Under no circumstances may the W1 and Y1 contacts on the relay pack be jumpered together. This is a common practice for many heat pump installations but will cause improper operation of the Comfort Zone (1.4 or greater) system.
STARTING THE HVAC EQUIPMENT
Once Comfort Zone selects a mode, controller will use configu- ration options to modify control of HVAC equipment. The controller first selects number of stages of heating and cooling that may be applied to building load. The "available" stages are determined by Reference Zone temperature demand and are shown in Table 5.
Using Table 5, if Reference Zone has a 2.3°F demand, then Comfort Zone may use 2 stages of cooling or 2 stages of heating. The HVAC equipment may not have 3 stages of heat or even 2 stages of cooling. The table is only used to determine what equipment Comfort Zone is allowed to turn on at any given time during a heating or cooling cycle. Actual operation of stages depends on other variables as well.
Normally Comfort Zone will start equipment operation when it has a demand of 1.5°F or greater. In some cases, Comfort Zone will be facing a demand greater than 1.5°F when a mode is starting. This can occur when user changes setpoints in a zone or if a schedule
10change has reset the Comfort Setpoints.