York B1CH180 Heat Anticipator Setpoints, Heat Anticipator Setting, Checking Supply AIR CFM

511.06-N3Y

HEAT ANTICIPATOR SETPOINTS

It is important that the anticipator setpoint be correct. Too high of a setting will result in longer heat cycles and a greater temperature swing in the conditioned space. Reducing the value below the correct setpoint will give shorter “ON” cycles and may result in the lowering of the temperture within the conditioned space. Refer to the Heat Anticipator Setting Table for the required heat anticipator setting.

TABLE 13 - HEAT ANTICIPATOR SETTING

HEATER	VOLTAGE	SETTING, AMPS
KW		TH1	TH2
18		0.29	-
36	208/230-3-60	0.29	0.29
54		0.29	0.58
72		0.58	0.58
18		0.29	-
36	460-3-60	0.29	0.29
54		0.29	0.29
72		0.29	0.29
18		0.29	-
36	575-3-60	0.29	0.29
54		0.29	0.29
72		0.29	0.29
CHECKING SUPPLY AIR CFM				FIG.9 - BELT ADJUSTMENT

The RPM of the supply air blower will depend on the required CFM, the unit options/accessories and the static resistances of both the supply and the return air duct systems. With this information, the RPM for the supply air blower and the motor pulley adjustment (turns open) can be determined from the Blower Performance Data Tables.

High speed drive accessories (containing a smaller blower pulley and a shorter belt) are available for applications requiring the supply air blower to produce higher CFM’s and/or higher static pressures. Use Model 1LD0416 for 15 ton units and Model 1LD0417 for 20 ton units. Refer to the Blower Motor and Drive Data table.

Note the following:

1.The supply air CFM must be within the limitations shown in Unit Application Data table.

2.Pulleys can be adjusted in half turn increments.

3.The tension on the belt should be adjusted as shown in the Belt Adjustment Figure.

Start the supply air blower motor. Adjust the resistances in both the supply and the return air duct systems to balance the air distribution throughout the conditioned space. The job specifications may require that this balancing be done by someone other than the equipment installer.

To check the supply air CFM after the initial balancing has been completed:

1.Remove the two 5/16" dot plugs from the blower motor and the filter access panels shown in the Dimensions and Clearances Figure.

2.Insert at least 8" of 1/4 inch tubing into each of these holes for sufficient penetration into the air flow on both sides of the indoor coil.

NOTE: The tubes must be inserted and held in a position perpendicular to the air flow so that velocity pres- sure will not affect the static pressure readings.

3.Using an inclined manometer, determine the pressure drop across a dry indoor coil. Since the moisture on an indoor coil may vary greatly, measuring the pressure drop across a wet coil under field conditions would be inaccurate. To assure a dry coil, the compressors whould be de-activated while the test is being run.

4.Knowing the pressure drop across a dry coil, the actual CFM through the unit and clean 2" filters, can be determined from the curve in the figure below.

WARNING: Failure to properly adjust the total system air quantity can result in extensive blower damage.

After readings have been obtained, remove the tubes and reinstall the two 5/16" dot plugs that were removed in Step 1.

NOTE: DE-ENERGIZE THE COMPRESSORS BEFORE TAKING ANY TEST MEASUREMENTS TO ASSURE A DRY INDOOR COIL.

BELT DRIVE BLOWER

All units have belt drive single-speed blower motors. The variable pitch pulley on the blower motor can be adjusted to obtain the desired supply air CFM.

FIG. 10 - PRESSURE DROP ACROSS A DRY INDOOR COIL VS SUPPLY AIR CFM

16 Unitary Products Group