Carrier WeatherMaker® Two-Zone Installation and Start-Up Instructions

Safety Considerations

Improper installation, adjustment, alteration, service, maintenance, or use can cause fire, electrical shock, or other conditions which may cause personal injury or property damage. Consult a qualified installer, service agency, or your distributor or branch for information or assistance. The qualified installer or agency must use factory-authorized kits or accessories when modifying this product. Refer to the individual instructions packaged with the kits or accessories when installing.

Follow all safety codes and wear safety glasses. Have fire extinguisher available. Read these instructions thoroughly and follow all warnings or cautions attached to the unit. Consult local and state building codes and Sheet Metal and Air Conditioning National Association (SMACNA) for special installation requirements.

Recognize safety information. This is the safety-alert symbol ⚠️. When you see this symbol on the unit or in instructions and manuals, be alert to the potential for personal injury.

Understand the signal words DANGER, WARNING, or CAUTION. These words are used with the safety-alert symbol. DANGER identifies the most serious hazards which will result in severe personal injury or death. WARNING signifies hazards which could result in personal injury or death. CAUTION is used to identify unsafe practices which would result in minor personal injury or product and property damage.

Installation Considerations

1. Install in non-condensing area with ambients between 32°F and 150°F.
2. Use vibration isolators (flex connectors) on zone dampers and ductwork to minimize noise.
3. Place dampers away from areas that may be noise sensitive.
4. TXV is required in air conditioning and heat pump applications.
5. Use separate isolated transformer to supply power to WeatherMaker Two-Zone Center. (40va minimum, class 2, transformer, field supplied)
6. Load calculations must be performed to determine equipment size. Equipment selection is matched to block load. It is imperative equipment is not over sized.
7. Ductwork must be designed based off the sum of peak plus 25 percent oversize. It is imperative ductwork is not under sized.

Introduction

The WeatherMaker Two-Zone System allows the air conditioning and heating equipment to control temperatures in 2 distinct spaces or zones within a building. Each zone has independent temperature settings controlled by a thermostat. Thermostats are purchased separately.

The comfort temperature settings can change automatically through the use of schedules if programmable thermostats are selected. This allows WeatherMaker Two-Zone to change the temperature settings in zones to reflect occupancy or usage. The WeatherMaker Two-Zone System uses motorized air volume control dampers (also called zone dampers) to regulate the flow of conditioned air into the zones.

Installation

Step 1-Check Equipment and Jobsite

INSPECT EQUIPMENT — File claim with shipping company, prior to installation, if shipment is damaged or incomplete.

Step 2-Wiring

WARNING: To prevent personal injury or possible equipment damage, disconnect the power supply before routing wire.

All wiring must comply with local, state, and national codes.

NOTE: Use No. 18 AWG color-coded, insulated (35°C min) wire. If thermostats are to be located more than 100 ft from the WeatherMaker Two-Zone Center as measured along the control voltage wires, use 16 AWG colored-coded wires to avoid excessive voltage drop. All wiring is run back to the WeatherMaker Two-Zone Center.

Step 3-Install WeatherMaker Two-Zone

NOTE: WeatherMaker Two-Zone is approved for indoor use only and should never be installed with any of its components exposed to the elements. Do not mount WeatherMaker Two-Zone Center where it will be accessible to children. Do not locate the center in areas of the home that are noise sensitive since relays are energized and de-energized during operation and may be an annoyance. Install WeatherMaker Two-Zone in an area with a temperature range between 32°F and 150°F.

Install WeatherMaker Two-Zone center in a vertical position. Locate in an area that is easily accessible in case servicing should be required.

CAUTION: To prevent possible damage to the WeatherMaker Two-Zone Center, do not mount on plenum, ductwork, or flush against furnace.

Step 4-Install Zone Dampers

IMPORTANT: If conditions exist for possible condensing, the motor must be positioned for adequate draining. (See Fig. 2.)

NOTE: If a multi-damper enabler is used to link dampers together, then add 5va per damper to the transformer power supply rating. Reference multi-damper enabler Installation Instructions.

Zone dampers may be installed in any direction.

Install dampers so the actuator is visible for inspection and accessible in the event it would ever need service. The black mark on the end of the damper shaft represents the position of the damper blade.

NOTE: Insulate damper using 1-1/2 in. insulation (check local codes). In areas where excessive condensing may occur, carefully insulate over the actuator assembly. Make sure insulation does not interfere with operation of actuator.

Before insulating the ductwork, check for proper damper operation. Apply 24vac between COM and OPN to open the damper and COM and CLS to close the damper. (See Fig. 3.) The damper will modulate counter-clockwise to open and clockwise to close.

If in an emergency it becomes necessary to force a damper open manually, press in red quick blade release button with 1 hand and turn mounting hub to reposition the damper shaft. Release button to hold damper shaft in the new position.

To avoid noise and vibration, do not hard mount dampers to any solid structure such as joists.

Round Metal Ductwork

IMPORTANT: If application exists with all metal ductwork without insulation, flex connectors should be used on each end of the zone dampers to avoid noise and vibration.

1. Crimp end of branch duct.
2. Slip end of flex connector over zone damper and use self-tapping sheet metal screw to secure. (See Fig. 4.)

1. Properly seal joint using duct tape, mastic, or other approved method. Do not allow mastic to come in contact with actuator.
2. Insulate damper using 1-1/2-in. to 2-in. insulation. (Check your local codes.) (See Fig. 5.)

NOTE: All zone dampers and ductwork must be properly supported according to local codes or SMACNA standards.

Rectangular Metal Ductwork

1. Make connections using S-lock and drives. (See Fig. 6.)

1. Properly seal joint using duct tape, mastic, or other approved method. Do not allow mastic to come in contact with actuator.
2. Insulate damper using 1-1/2-in. to 2-in. insulation. (Check your local codes.) (See Fig. 7.)

NOTE: All zone dampers and ductwork must be properly supported according to local codes or SMACNA standards.

NOTE: There should be a minimum of 4 ft between the zone damper and the first branch duct if more than 1 branch duct is downstream of the zone damper.

Round Flexible Ductwork

1. Slip 1 end of flexible ductwork over 1 end of zone damper. (See Fig. 8.)
2. Secure the flexible duct to zone damper using SMACNA or other approved method.
3. Properly seal joint using duct tape, mastic, or other approved method. Do not allow mastic to come in contact with actuator.
4. Insulate damper using 1-1/2-in. to 2-in. insulation. (Check your local codes.) (See Fig. 9.)

Rectangular Fibrous Glass Ductwork

1. Insert 1 end of zone damper into 1 end of fibrous glass ductwork approximately 2 to 3 in. (See Fig. 10.)

1. Screw field-supplied screws and tabs into zone damper.
2. Properly seal joint using duct tape, mastic, or other approved method. Do not allow mastic to come in contact with actuators
3. Insulate damper using 1-1/2-in. to 2-in. insulation. (Check your local codes.) (See Fig. 11.)

Sequence of Operation

Step 1-Sequence of Events for a Normal Heating or Cooling Cycle

The thermostats will determine if active heating or cooling is required. If so, the WeatherMaker Two-Zone System will perform the following:

• Make sure all zone dampers are fully open.
• Energize HVAC equipment fan.
• Energize heating or cooling equipment. The equipment may be a compressor, furnace, strip heater, etc.
• Set zone damper to the open or closed position based upon individual zone demand.
• Energize additional stages of heating or cooling if the thermostat demand warrants.
• Turn off heating or cooling equipment when all zones are satisfied.
• Open all zone dampers when equipment is turned off (after 90 sec delay).

This is the basic sequence of operation for the WeatherMaker Two-Zone System. The actual control of the dampers, HVAC equipment, and system fan will change with the configuration of the system. Depending upon the configuration, WeatherMaker Two-Zone can control heat pumps, furnaces, and dual fuel applications (dual fuel will require a third party relay interface).

Step 2-Selection of a System Mode

The first step in any heating or cooling cycle requires WeatherMaker Two-Zone to receive an input from any thermostat located in a zone. WeatherMaker Two-Zone will then prepare to operate the heating or cooling equipment as requested by the thermostat. (See Fig. 12.)

Step 3-Pre-Positioning Dampers and Starting System Fan

In order to minimize noise and enhance system operation, WeatherMaker Two-Zone maintains fully open zone dampers prior to starting the system fan or the heating/cooling equipment. The intent is to provide the HVAC equipment with unrestricted ductwork and to reduce pressure surges. WeatherMaker Two-Zone also fully opens the dampers whenever a heating or cooling cycle is completed (this is done after a 90 sec delay). All zone dampers will remain fully open until the next heating or cooling cycle.

The other reason for opening the dampers is to provide unrestricted ductwork to other equipment which is not directly controlled by WeatherMaker Two-Zone. One example may be a Heat Recovery Ventilator. If WeatherMaker Two-Zone is not actively controlling the HVAC system, then it must not impose any control influences (such as closed zone dampers) on the system and prevent proper operation of other devices.

Only the zone 1 thermostat controls continuous fan operation. When the zone 1 thermostat has the fan selector switch in the AUTO position, the fan will operate only when the heating and cooling equipment is operating. When the zone 1 thermostat has the fan selector switch in the ON position, the fan will operate continuously. Zone 2 will not control this.

Step 4- HVAC Equipment Connections

The WeatherMaker Two-Zone relay outputs are shown in Table 1. The Y1 and Y2 contacts are used for the compressor contactor only. WeatherMaker Two-Zone operates the heat pump by energizing the compressor contactor and controlling the reversing valve through the O 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 WeatherMaker Two-Zone are shown in Table 1.

Duct Temperature Optimizer (DTO)

As the WeatherMaker Two-Zone System operates through a heating or cooling cycle, the zone demands will change. This changes the actual load that is applied to the HVAC equipment. If the zone airflow decreases, the cooling equipment will tend to lower supply-air temperatures which could tend to exceed the LAT trip limits. Conversely, the heating equipment will tend to raise the supply-air temperatures which could exceed high trip limits. In cooling, when the LAT reaches the non-adjustable low temperature trip limit (50°F) the LAT algorithm begins operating, closed dampers are initially opened 3 positions, then 1 position every 20 sec there after until full open. WeatherMaker Two-Zone will not shut down second-stage cooling (if used); however, if temperature continues to drop to 45°F, the zoning system will turn off both stages of cooling. If the temperature improves, the system will stay in the duct temperature optimizer mode until the LAT reaches 55°F or higher. At 55°F the LAT algorithm will reset and return dampers to their original position. In the heating mode, WeatherMaker Two-Zone will perform the same duct temperature optimization. The trip limits will be determined by the jumper setting. (See Fig. 12.) This will continue until the LAT problem is corrected.

This control helps WeatherMaker Two-Zone System cope with installations where the air conditioning system may suffer from poor ductwork, improperly sized heating or cooling equipment, and/or improper settings of the barometric bypass damper. This control is especially useful in retrofit applications where the size and routing of the ductwork may not be entirely known or satisfactory.

The duct temperature optimizer works by controlling how cold or hot the air inside the supply-air duct gets by monitoring the temperature of the air inside the supply-air system.

Whenever WeatherMaker Two-Zone is providing heating or cooling, the zone within the home that is asking for conditioned air will always have its damper fully open. The other zone in the system may or may not have an open damper depending upon its particular needs. If the ductwork is too small (or the air conditioner/heater is too large), then the zone requiring conditioned air may not be able to take enough air to allow your equipment to operate properly. WeatherMaker Two-Zone will detect this, and open up the closed damper allowing the equipment to continue to operate.

CAUTION: The duct temperature optimizer may be disabled on the control center. A 10k resistor can be installed in place of the duct sensor at the terminal block. By disabling the duct temperature optimizer, the LAT safety algorithm is removed from the system.

It is highly recommended that you use this control option. The heating LAT is adjustable for the duct sensor. In this Installation Instruction, you will find the section showing an adjustment for the heating LAT. (See Fig. 12.) It is very important that this temperature is properly set. For gas or oil furnaces, the temperature limit will be in the higher temperature range. For heat pumps the temperature setting should always be in the lower temperature range.

If you encounter a situation where 1 zone seems to have poor ductwork, then the WeatherMaker Two-Zone system is capable of reverting back to a fully open, constant-volume system. If this condition persists, it should always be looked upon as an indication of a HVAC problem, not a WeatherMaker Two-Zone problem.

Electronic Thermostat Connection with WeatherMaker Two-Zone Control

Carrier electronic non-programmable and programmable thermostats can be connected to the WeatherMaker Two-Zone. See pre-sale literature for thermostat part numbers.

NOTE: The zone control board is only capable of 2-stage heat and 2-stage cool operation. Fig. 13 and 14 will reflect these applications only. Review and understand the following items before installing.

Thermostat Setup

1. Thermostat will not operate unless both R and C are connected to zone module input.
2. If selected thermostat is a heat pump (HP) or 2-speed (2S) model, convert thermostat to air conditioning operation. This will assure that Y signals are generated for cooling, and W signals are generated for heating from thermostat to zone module input. The thermostat O/W2 output will now be the second-stage heat call. If installation is a heat pump system, the zone control board will provide proper output signal to heat pump.
3. Select "Zoning" option on thermostat. This will disable the Timeguard and 4-cycle per hr (cph) protection built into thermostat. Let zone control board perform the Timeguard and cycle protection. Refer to thermostat Installation Instructions under Zoning for more detail.
4. The zone 1 thermostat is the only thermostat that can control continuous fan operation with zoning. Connect G between zone 1 thermostat and zone 1 input on zone control module.
5. Follow all safety and installation considerations outlined in the thermostat Installation Instructions.

Zone Control Board Setup

1. Configure zone control board jumper for Tstat (thermostat) Fnc option only. Do not use Tstat HP option. When Tstat Fnc is selected this will setup control inputs to recognize Y1 and Y2 for first- and second-stage cooling, and W1 and W2 for first- and second-stage heating.
2. Configure zone control board for either Equipmt (equipment), HP, or Fnc. When a heat pump system is used, Equipmt HP mode should be selected. The zone control board will provide the proper output signal to the heat pump. When a gas/electric furnace is used, Equipmt Fnc mode should be selected for proper output signal.
3. Configure zone control board for either Fnc Ht, w/f (with fan), or w/of (without fan). With Fan mode should be selected when a heat pump is installed and fan is needed to come on immediately with demand. Without Fan mode should be selected when fan is controlled by gas/electric furnace.
4. Configure zone control board for either DTO On or Off. When DTO On is selected (Factory default) and if a LAT trip occurs, closed dampers will begin opening to try and keep equipment running by maintaining proper air temperatures. However, if LAT temperatures exceed their limits, equipment will start staging down. When DTO Off is selected, equipment will stage down. Closed dampers will not open on initial trip, however if LAT temperatures exceed their limits, control will lockout and damper will open.

NOTE: An HP temperature sensor must be used with a heat pump application using electric strip heat. This is necessary in case the DTO is set to the Off position.

Timeguard

The WeatherMaker Two-Zone provides equipment protection with an internal 5-minute timeguard delay. This delay is present upon initial power up. There is also a 5-minute timeguard delay for all cooling (Y1) and heat pump modes. The time guard can be cleared by using the comprotec override feature. Second-stage (Y2) and (W2) will have a 5-minute delay between stages and also can be cleared using the comprotec override feature.

Maximum Cycle Rate

The WeatherMaker Two-Zone will allow a maximum of 4 equipment cycles per hr or 1 every 15 minutes when a heating or cooling mode is activated. When a demand exists, and internal timer will start counting down 15, 14, 13...0 minutes. Once the timer expires the control will allow a new mode to restart the equipment. The internal time, as well as the cooling 5-minute timeguard can be cleared by using the comprotec override feature.

Troubleshooting

This section contains information to assist you in troubleshooting problems and errors associated with the WeatherMaker Two-Zone system. See Table 2.

Step 1-System Diagram, Jumpers, and Switches

NOTE: For correct control board operation, it must have either a sensor attached or a 10k resistor in place at the duct and HP inputs.

Wiring Diagrams

Table 3 shows a temperature/ohm/voltage relationship to help aid in troubleshooting the WeatherMaker Two-Zone System. This table will evaluate both the Duct/HP temperature sensor operation. Use a digital multimeter to perform the following:

To verify a sensor is good, disconnect both leads from the I/O board and measure the resistance through the sensor. Match ohm reading to table and compare temperature reading on table to ambient temperature surrounding sensor (Accuracy should be ± 5-10 percent). Example: if 10.92k ohms are measured, this equals approximately 73°F.

To verify if I/O board is normal, reattach sensor to I/O board, set meter to 5vdc, and measure voltage across terminal connections. Match voltage reading to temperature reading in chart. The ambient temperature surrounding sensor should be ± 5-10 percent. Example: 2.61vdc is approximately 73°F.

[Diagrams for various wiring configurations as referenced in Table 4, including single-stage and two-stage furnaces, and typical and FK4C fan coils, with single-speed and two-speed air conditioners and heat pumps.]