DURASTAR DRF2TA2421ASTNJB1 (01) PDF Document

The DURASTAR DRF2TA2421ASTNJB1 air handler includes the following features and benefits:

• Front or Bottom Return with aluminum tube and fin coil

• TXV for cooling or heat pump operation

• Wall-hanging brackets

• Built in Filter Rack

• Molex Plug Connections for field installed heater kits

• Dual Voltage Direct Drive Blower with multi-speed motor

• Thermoplastic Drain Pan with bottom primary and secondary connections

• Optional Decorative Grill for front return applications

• Optional Factory Installed Condensate Float Switch which shuts off the outdoor unit in the event the condensate pan becomes clogged

• Cabinet air leakage less than 2% at 1 inch H2O when tested in accordance with ASHRAE Standard 193

• Can be field wired for single or two stage applications

The model number provides specific details about the unit’s configuration. Here is a breakdown:

[] Designates Metric Conversions

The standard equipment for the DURASTAR DRF2TA2421ASTNJB1 includes:

• Exclusive Incoloy sheath type electric heating elements

• Field convertible air supply

• Durable framed cleanable air filter

• Indoor coil design provides low air side pressure drop, high performance and compact size

• PVC condensate elbow is standard on all coils

• All indoor coils have aluminum tubing and aluminum fins

• Molded polymer corrosion resistant condensate drain pan

• Supply and return duct flanges

• High and low voltage connection points inside cabinet

• Concentric knockouts provided for power connection with hole size up to 2 inches [51 mm] for 1 1/2 inch [38mm] conduit

• Internal checked TX valves for quiet refrigerant metering

• Front refrigerant and drain connection

The return air opening dimensions for the DURASTAR DRF2TA2421ASTNJB1, which has a 21-inch cabinet size, are as follows:

The dimensions, weights, and specifications for the DURASTAR DRF2TA2421ASTNJB1 are detailed below.

For optimum blower performance, operate the unit in the .3 [8 mm] to .7 inches [18 mm] W.C. external static range. Units with coils should be applied with a minimum of .1 inch [3 mm] W.C. external static range. The operating limits for the DURASTAR DRF2TA2421ASTNJB1, which has a 21-inch cabinet, are as follows:

The airflow performance data for the DURASTAR DRF2TA2421ASTNJB1 (2 Ton model) at various external static pressures is detailed in the table below. This data is for dry delivery with filter and heaters installed.

The DURASTAR DRF2TA2421ASTNJB1 air handler has a 5-speed constant torque motor. The speed taps are configured for different applications:

• Speed tap 1 is for continuous fan.

• Speed tap 2 (low static) and speed tap 3 (high static) are for lower tonnage models (1.5 or 2.5 tons).

• Speed tap 4 (low static) and speed tap 5 (high static) are for higher tonnage models (2.0 or 3.0 tons).

The air handler is always shipped from the factory set to speed tap 5.

To adjust the speed, move the blue wire to the appropriate speed tap on the motor terminal block based on your application’s needs:

• Use the low static speed tap (2 or 4) for external static pressures below 0.5″ WC.

• Use the high static speed tap (3 or 5) for external static pressures exceeding 0.5″ WC.

The airflow for the continuous fan (speed tap 1) is always set at 50% of the speed tap 4 airflow.

The electrical data for the blower motor only (no electric heat) for the DURASTAR DRF2TA2421ASTNJB1 is as follows:

*Blower motors are all single phase motors.

When installing a U.L. Listed original equipment manufacturer provided heater kit, refer to the following electrical data. The heater kits compatible with the DURASTAR DRF2TA2421ASTNJB1 (21-inch cabinet) are prefixed with RXHJ-21B.

• Electric heater BTUH = (heater watts + motor watts) x 3.414.

• Supply circuit protective devices may be fused or “HACR” type circuit breakers.

• If a non-standard fuse size is specified, use the next size larger standard fuse size.

• Largest motor load is included in single circuit or circuit 1 of multiple circuits.

Follow these guidelines for electrical power wiring and grounding:

• Field wiring must comply with the National Electrical Code (C.E.C. in Canada) and any applicable local ordinances.

• This product must be sufficiently grounded in accordance with the National Electrical Code (C.E.C. in Canada) and any applicable local ordinances.

• Supply wiring must be 75°C minimum copper conductors only.

• See electrical data tables for the product’s Ampacity rating and Circuit Protector requirement.

• A grounding lug is provided.

The Drain Pan Over Flow Switch Kit RXHK-A01 is an accessory used to detect a condensate drain blockage. If a blockage is detected, the switch will shut down the outdoor unit to prevent structural damage to the surrounding areas of the air handler.

The Bottom Return Conversion Kit (RXHK-series) is used to divert the return air from the factory standard front return to a bottom return configuration. For the DURASTAR DRF2TA2421ASTNJB1, you should use the kit corresponding to the DRF2TA-FR24 indoor unit model.

The Louvered Cabinet Grill Kit (RXHK-series) is a decorative grill that covers the return air opening of the front return air handler. For the DURASTAR DRF2TA2421ASTNJB1, you should use the kit corresponding to the DRF2TA-FR24 indoor unit model.

The Decorative Wall Grill accessory, model RXHK-D01 or RXHK-D02, is used in applications where the DURASTAR DRF2TA2421ASTNJB1 air handler is installed in a closet or interior wall. This grill allows for adequate return air to flow back to the unit through the wall.