Sears N9MP2100F14B1, 9MPD100J14B1 Heating and Continuous BlowerSpeed Same, Temperature Rise Check

Main Burner

Face

If it is necessary to change speeds, refer to steps below.

Refer to Furnace WMng Diagramfor location of the heating and cooling speed taps located on the electronic fan control as well as location of unused blower motor speed leads. Use the chart (Table 12) to determine the blower motor speed settings.

10-10-78

Temperature Rise Check

The blower speed MUST be set to give the correct air temperature rise through the furnace as marked on the rating plate. Tempera- ture rise is the difference between supply and return air tempera- tures.

To check temperature rise,use the following procedure:

1.Place thermometers in supply and return air registers as close to furnace as possible, avoiding direct radiant heat from heat exchangers.

2.Operate furnace continuously for 15 minutes with all regis- ters and duct dampers open.

3.Take reading and compare with range specified on rating plate.

4.If the correct amount of temperature rise is NOT obtained, it may be necessary to change blower speed. A higher blower

speed will lower the temperature rise. A lower blower speed

will increase the temperature rise.

Changing Blower Speed

Blower	Speed Chart
Wire Color	Motor Speed
Black	High
Orange*	Med-High
Blue	Medium
Red	Low

* Med-High speed may not be provided on all models.

Change the heat or cool blower motor speed by removing the motor lead from the "Heat" or "Cool" terminal and re-

place it with the desired motor speed lead from the "Un-

used Motor Lead" location. Connect the wire previously removed from the "Heat" or "coor' terminal to the vacated

"Unused Motor Lead" terminal.

If the same speed must be used for both heating and cool-

ing, remove the undesired motor speed lead from the "Heat" or "Cool" terminal and connect that lead to the open terminal at "Unused Motor Lead" location. Attach a jumper between the "Heat" and "Cool" terminals and the remaining motor speed lead.

Note: For motors with (4) speed leads, it will be necessaryto tape off the terminal of the motor speed lead removed from the "Heat" or "coor' terminal with electrical tape since an

open terminal will not be available at the "Unused Motor Lead" location.

ELECTRICAL SHOCK HAZARD

Failure to do so could result in death and/or

personal injury.

Turn OFF power to furnace before changing

speed taps.

NOTE: The speed taps that the manufacturer sets from the factory for this product are based on a nominal 400 CFM per ton cooling and the basic mid range on the temperature rise for heating.

Since the manufacturer cannot establish the static pressure that will be applied to the unit, it is the responsibility of the in-

staller dealer/contractor to select the proper speed taps for the application when the unit is installed.

REDUCED FURNACE LIFE HAZARD

Failure to properly set the air temperature rise may result in reduced furnace life.

Use ONLY the following blower motor speed taps for

setting	air temperature	rise.
Blower	Motor Speed	Taps	Model Sizes
Hi (BLK)			All
Med-Hi	(O)		All except	050F/J14
Med Lo (BL			All except	075B/F12

	and 100F/J14
Lo (RED)	050B/F12,100J20,
	and 125J/L20

Continuous Fan Operation

A terminal is provided on the electronic fan control located in the

circulating blower compartment for operation of the continuous fan option. This connection is intended for the low speed motor tap, and has a lower contact rating (8 amps) than the heat and cool taps. When the low speed blower lead is connected to this termi- nal, this will provide low speed blower operation whenever the oth- er two speeds (Heat or Cool) are not energized.

Thoroughly check the system after modification to ensure the proper operation of the circulating air blower in all modes of opera- tion.

Separate speed selections for Heat, Cool, and Continuous Fan

Connect low speed lead from circulating motor to the "Cont." ter- minal at the electronic fan control. The appropriate motor leads should already be connected to the "Heat" and "coor' terminals.

Heating and Continuous BlowerSpeed the

Same

If it is necessary to operate the heating speed and continuous blower speed using the same blower speed, connect a jumper be- tween the "Heat" and "Cont." terminals on the electronic fan con- trol.

Note: There should be only ONE motor lead going to the "Heat" and "Cont." terminals.

44001 102004 E_