Carrier TJF004, TJF005-007, 48TJD, 48TJE specifications Start-Up

START-UP

Unit Preparation — Make sure that unit has been in- stalled in accordance with these installation instructions and applicable codes.

Return-Air Filters — Make sure correct filters are in- stalled in filter tracks. See Table 1. Do not operate unit without return-air filters.

Compressor Mounting — Compressors are internally spring mounted. Do not loosen or remove compressor hold- down bolts.

Internal Wiring — Check all electrical connections in unit control boxes. Tighten as required. Ensure electrical wires do not come in contact with refrigerant tubing or sharp edges.

Refrigerant Service Ports — To service refrigerant service ports, remove refrigerant service port access panel. See Fig. 43. Each unit system has 4 Schrader-type service gage ports: one on the suction line, one on the liquid line, and two on the compressor discharge line. Be sure that caps on the ports are tight. When a controls upgrade package is used, one Schrader-type valve is located under both the high-pressure switch and the low-pressure switch.

High Flow Valves — Located on the compressor hot gas and suction tubes are High Flow Valves. Large black plastic caps distinguish these valves with o-rings located inside the caps. These valves can not be accessed for service in the field. Ensure the plastic caps are in place and tight or the possibility of refrigerant leakage could occur.

Fig. 43 — Service Panel Location

Compressor Rotation — On 3-phase units with scroll compressors, it is important to be certain compressor is rotating in the proper direction. To determine whether or not compres- sor is rotating in the proper direction:

1.Connect service gages to suction and discharge pressure fittings.

2.Energize the unit.

3.The suction pressure should drop and the discharge pres- sure should rise, as is normal on any start-up.

If the suction pressure does not drop and the discharge pres- sure does not rise to normal levels:

1.Note that the evaporator fan is probably also rotating in the wrong direction.

2.Turn off power to the unit and install lockout tag.

3.Reverse any two of the unit power leads.

4.Reapply power to unit and recheck pressures.

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

NOTE: When the compressor is rotating in the wrong direc- tion, the unit makes an elevated level of noise and does not provide cooling.

Cooling — Set space thermostat of OFF position. To start unit, turn on main power supply. Set system selector switch at COOL position and fan switch at AUTO. position. Adjust ther- mostat to a setting below room temperature. Compressor starts on closure of contactor.

Check unit charge. Refer to Service, Refrigerant Charge section, page 41. Allow unit to operate a minimum of 10 min- utes before checking charge.

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

TO SHUT OFF UNIT — Set system selector switch at OFF position. Resetting thermostat at a position above room tem- perature shuts unit off temporarily until space temperature ex- ceeds thermostat setting.

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. After en- suring that the unit continues to heat the building, lower the thermostat setting below room temperature and verify that the burners and evaporator fan turn off. (Fan will turn off only if fan selector switch is in the AUTO. position and after a 45-second delay has elapsed.)

Refer to Table 30 for the correct orifice to use at high altitudes.

Table 30 — Altitude Compensation*

	74,000 AND 115,000		150,000 BTUH
	BTUH NOMINAL
			NOMINAL INPUT
	INPUT
ELEVATION
(ft)	Natural	Liquid	Natural	Liquid
	Gas	Propane	Gas	Propane
	Orifice	Orifice	Orifice	Orifice
	Size†	Size†	Size†	Size†
0-2,000	33	43	30	38
2,000	34	43	30	39
3,000	35	44	31	40
4,000	36	44	32	41
5,000	36	44	33	42
6,000	37	45	34	43
7,000	37	45	35	43
8,000	38	46	36	44
9,000	39	47	37	44
10,000	41	48	38	45
11,000	43	48	39	45
12,000	44	49	40	46
13,000	44	49	41	47
14,000	45	50	42	47

*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 altitudes.

†Orifices available through your Carrier distributor.

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