Carrier 52S manual Removing Heater Screws

3.Remove the unit from the sleeve as detailed in the GENERAL DISASSEMBLY section.

4.Remove the discharge air grille and the discharge air deck as detailed in the GENERAL DISASSEMBLY section. Save screws.

5.Once the air discharge deck is removed, the heater assembly is exposed. After noting positions of wires and labelling them, use a pair of needle nose pliers to carefully remove the wires connected to the heater assembly.

6.Remove the two 1¤4-in. screws mounting the heater assembly to the inside of the partition. Save the screws. See Figure 42.

7.Remove the heater assembly (Figure 43).

Examine the heater as follows to determine if it is operational:

Perform a visual inspection. The heater coil should be free of breaks. If there are any breaks in the coil, replace- ment of the heater assembly is necessary.

Coil resistance must also be checked to verify the heater is operating correctly. The resistance of the heater coils must meet approximate levels for the heater to per- form at its optimum efficiency. See Figure 44 for approxi- mate resistance for heaters at 75 F. Before checking the heater coil resistance, be sure all power to unit is off.

To check resistance, set the volt-ohmmeter selector switch to the lowest ohms value. Next connect the volt- ohmmeter leads to each side of the heater coil at the studs that hold the limit switches in place. Incorrect readings can be obtained if the wires are not removed from the limit switches on the heater assembly. If the resistive reading is in®nite or zero, the heater is failed and replacement is necessary. Reinstall the heater assembly by reversing steps 1 - 7.

SCREWS (2)

FIGURE 42 Ð REMOVING HEATER SCREWS

FIGURE 43 Ð HEATER REMOVED

HEATER SIZE	WATTS	VOLTS	ACCEPTABLE RESISTANCE
			(Ohms)
2.3 kW	2300	230	20 - 23
	2300	265	28 - 31
3.4 kW	3400	230	13 - 16
	3400	265	19 - 21
5.0 kW	5000	230	9 - 11
	5000	265	13 - 15

FIGURE 44 Ð ACCEPTABLE HEATER

RESISTANCE VALUES

23