Pioneer DR Air Handler WTM-X Series Electric Heater Installation Instructions

General Information

This electric heater series is engineered, designed, and approved for installation in Pioneer DR series air handlers. Before proceeding, check the heater label for the correct voltage and KW requirements.

Installation and servicing of this equipment should only be performed by trained and qualified personnel and is not accessible to the general public. Before proceeding with the heater installation, inspect thoroughly for shipping damage. Notify the shipper immediately if any damage is found. Check all porcelain insulators for breakage and inspect heater element wire to see that none have been deformed. Clean all dirt, dust, and moisture from equipment. Check for proper clearances of live parts, between phases, and to ground. Make sure that all required barriers are in place. Check conductors run in multiple to ensure that they are properly wired. Refer to base installation instructions for complete unit installation details. Verify that all elements are properly secure in their ceramic holders.

⚠️ Safety Warning

This appliance is not intended for use by persons (including children) with reduced physical, sensory, or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety. Children should be supervised to ensure that they do not play with the appliance.

Note: Appliance not for use exceeding 2000 m.

Heater Installation

1. Refer to the base unit installation instructions as required. Affix Warren Heater installer label to the equipment access panel.
2. Remove blower access panel of the air handler unit.
3. Remove cover plate from the back panel of the air handler control and wiring compartment.
4. Before inserting the heater into the blower section, bend the heater alignment tabs 90 degrees out. These tabs are located on the endcap section of the heater and will slide into the upper alignment holes in the back of the air handler box.
5. Position and slide heater assembly into blower section through the access opening (mounting position is important, check the label "AIR FLOW" on the heater for correct position). Secure heater into place with screws removed from the cover plate.
6. Carefully separate wires from the bottom section of the breaker bracket. Secure the bracket to the cabinet mounting rail with screws provided. Use wire ties to fasten loose wires around the bracket area. All excess wire needs to be routed away from sharp edges.
7. Remove the conduit knockout in the unit cabinet for electrical connections. Install the appropriate size conduit connector.
8. Remove circuit breaker knockout(s) in the unit access panel as required and cut insulation from the breaker knockout area.
9. Apply wiring diagram to the cabinet for future reference.

Diagram Descriptions:

Fig. 1 - Alignment tabs: Illustrates the 90-degree bent tabs on the heater's endcap.

Fig. 2 - Alignment tab insertion: Shows the bent tabs sliding into the upper alignment holes of the air handler box.

Fig. 3 - Heater insertion: Depicts the heater assembly being positioned and slid into the blower section.

Important Warnings

⚠️ Warning

Before performing service or maintenance operations on the system, turn off all main power switches. There may be more than one disconnect. Turn off accessory heater power switch if applicable. Electrical shock can cause personal injury. TAG DISCONNECT SWITCH(ES) WITH A SUITABLE WARNING LABEL. When installed in a garage, heater elements should have a clearance of 18 inches from the floor. Insure that the area is ventilated.

Electrical Connections

All electrical connections, wire sizes, type, and conduit sizes shall meet the National Electric Code, State, and Local Codes. Main power supply, minimum wire sizes, circuits, fusing, etc., are shown on schematic wiring diagrams. Use copper wire only.

Power may be brought into the unit through the top when the unit is in a vertical position or through the left or right side panel. Refer to base unit instructions for recommended wiring procedures.

For electric heat installations, connect the supply power to the circuit breaker supplied with the heater. Connect the 4-pin plug to the control circuit board of the air handler (see Fig. 4). Use wire nuts provided to connect the Black and Red wire leads from the adaptor harness to the AHU incoming power leads.

Separate all wires from incoming power leads. Be sure that all electrical terminal connections, clamps, screws, etc., are tight before proceeding. Verify that there are no possible shorts to ground. Check wiring diagram supplied with the heater for specific connections and information. Check operation as described in the start-up section.

Diagram Description:

Fig. 4 - Installed 4-pin plug: Shows the 4-pin plug connected to the air handler's control circuit board.

Start-Up and Check-Out

⚠️ Caution

Before proceeding, verify that all wiring is correct per the factory-approved schematic. Notify the factory immediately of any discrepancies.

1. Refer to base unit installation instructions as required.
2. Check for loose terminal connections.
3. Check that all fuse and circuit breaker short circuit interrupting ratings are adequate.
4. Turn on unit and heater power.
5. Set thermostat to call for heat.
6. Check operation of heater.
7. Check that air flow across the heater is at or above the minimum recommended fan speed. Refer to base instructions for Air Flow Data Tables and adjustment of fan motor speed.

Over-temperature Limit Note

The electric heater in this system contains a manually resettable over-temperature safety limit. In the event of a "NO HEAT" limit trip, check for possible issues with dirty filters, blocked outlets, or possible fan failure prior to resetting. To reset the limit circuit, simply turn the system off at the thermostat (or at the unit power circuit breaker) and then immediately turn the system back on. If a limit reset is required more than 2 times in a short period, consult a service technician before reenergizing the system.

Air Flow Considerations

When commissioning any AHU with electric heat, always check to see if the heater is cycling on its automatic reset high-temperature limit when the system is producing the highest temperature leaving the AHU coil. If the heater is cycling, increase the air flow by increasing the fan speed or lowering the ductwork static pressure.

Heater Kit Contents

• Heater assembly
• Installation Instructions
• Installer label
• Wiring diagram
• (1) wire tie

User Caution

The use of improperly selected air filters and/or operation with dirty filters may result in insufficient airflow, which may result in abnormal operation of electric heaters and tripping of temperature safety limits. Also, insufficient airflow will degrade the efficiency of the system (SEER rating) and excessive wear and premature failure of the system compressor may result. Other conditions, such as undersized or obstructed ductwork, may also cause insufficient airflow. It is recommended that a qualified technician be consulted to ensure proper airflow and air filtration selection and application. See www.lowairflow.com for more information.