Carrier 48HE003---006, 48HJ004---007 48HE,HJ, Cooling, MainBurners, AltitudeCompensation, Heating

48HE,HJ

2.Turn off power to the unit and tag disconnect.

3.Reverse any two of the unit power leads.

4.Turn on power to the unit and energize the compressor.

The suction and discharge pressure levels should now move to their normal start-up levels.

NOTE: When the compressor is rotating in the wrong direction, the unit makes more noise and does not provide cooling.

Step 10 —Cooling

Set the space thermostat to the OFF position. Set the system selector switch at COOL position and the fan switch at AUTO position. Adjust the thermostat to a setting below room temperature. The compressor starts when contactor closes.

Check the unit charge. Refer to Refrigerant Charge section.

Reset the thermostat at a position above room temperature. The compressor will shut off. Evaporator fan will shut off after a 30-second delay.

To Shut Off Unit - Set the system selector switch at OFF position. Resetting the thermostat at a position above room temperature shuts off the unit temporarily until the space temperature exceeds the thermostat setting. Units are equipped with a Cycle-LOC™protection device. The unit shuts down on any safety trip and remains off; an indicator light on the thermostat comes on. Check the reason for the safety trip.

Step 11 —Main Burners

Main burners are factory set and should require no adjustment.

TO CHECK ignition of main burners and heating controls, move thermostat set point above room temperature and verify that the burners light and evaporator fan is energized. Check heating effect, then lower the thermostat setting below the room temperature and verify that the burners and evaporator fan turn off.

Refer to Tables 37 and 38 for the correct orifice to use at high altitudes.

Table 37—Altitude Compensation*

48HJ004-007, 48HE003-006 Standard Units

	72,000 AND		150,000 BTUH
	115,000 BTUH
			NOMINAL INPUT
ELEVATION	NOMINAL INPUT
(ft)	Natural	Liquid	Natural	Liquid
	Gas	Propane	Gas	Propane
	Orifice	Orifice	Orifice	Orifice
	Size†	Size†	Size†	Size†
0-2,000	33	43	30	37
2,000	36	44	31	39
3,000	36	45	31	40
4,000	37	45	32	41
5,000	38	46	32	42
6,000	40	47	34	43
7,000	41	48	35	43
8,000	42	49	36	44
9,000	43	50	37	45
10,000	44	50	39	46
11,000	45	51	41	47
12,000	46	52	42	48
13,000	47	52	43	49
14,000	48	53	44	50

*As the height above sea level increases, there is less oxygen per cubic foot of air. Therefore, heat input rate should be reduced at higher alti- tudes.

†Orifices available through your Carrier distributor.

Table 38—Altitude Compensation* —

48HJ004-006, 48HE003-006 Low NOx Units

	60,000 AND		120,000 BTUH
	90,000 BTUH
			NOMINAL INPUT
	NOMINAL INPUT
ELEVATION
(ft)	Natural	Liquid	Natural	Liquid
	Gas	Propane	Gas	Propane
	Orifice	Orifice	Orifice	Orifice
	Size†	Size†	Size	Size†
0-2,000	38	45	32	42
2,000	40	47	33	43
3,000	41	48	35	43
4,000	42	49	36	44
5,000	43	49	37	45
6,000	43	50	38	45
7,000	44	50	39	46
8,000	45	51	41	47
9,000	46	52	42	48
10,000	47	52	43	49
11,000	48	53	44	50
12,000	49	53	44	51
13,000	50	54	46	52
14,000	51	54	47	52

*As the height above sea level increases, there is less oxygen per cubic foot of air. Therefore, the input rate should be reduced at higher alti- tudes.

†Orifices are available through your local Carrier distributor.

Step 12 —Heating

1.Purge gas supply line of air by opening union ahead of the gas valve. If gas odor is detected, tighten union and wait 5 minutes before proceeding.

2.Turn on electrical supply and manual gas valve.

3.Set system switch selector at HEAT position and fan switch at AUTO or ON position. Set heating temperature lever above room temperature.

4.The induced-draft motor will start.

5.After a call for heating, the main burners should light within 5 seconds. If the burner does not light, then there is a 22-second delay before another 5-second try. If the burner still does not light, the time delay is repeated. If the burner does not light within 15 minutes, there is a lockout. To reset the control, break the 24 v power to W1.

6.The evaporator-fan motor will turn on 45 seconds after burner ignition.

7.The evaporator-fan motor will turn off in 45 seconds after the thermostat temperature is satisfied.

8.Adjust airflow to obtain a temperature rise within the range specified on the unit nameplate.

NOTE: The default value for the evaporator-fan motor on/off delay is 45 seconds. The Integrated Gas Unit Controller (IGC) modifies this value when abnormal limit switch cycles occur. Based upon unit operating conditions, the on delay can be reduced to 0 seconds and the off delay can be extended to 180 seconds. When one flash of the LED (light-emitting diode) is observed, the evaporator-fan on/off delay has been modified.

If the limit switch trips at the start of the heating cycle during the evaporator on delay, the time period of the on delay for the next cycle will be 5 seconds less than the time at which the switch tripped. (Example: If the limit switch trips at 30 seconds, the evaporator-fan on delay for the next cycle will occur at 25 seconds.) To prevent short-cycling, a 5-second reduction will only occur if a minimum of 10 minutes has elapsed since the last call for heating.

The evaporator-fan off delay can also be modified. Once the call for heating has ended, there is a 10-minute period during which the modification can occur. If the limit switch trips during this period, the evaporator-fan off delay will increase by 15 seconds.

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