Carrier 50AH024-096 specifications Start-Up, Service, Condenser-FanPerformance

Table 4 — Condenser-Fan Performance

UNIT								EXTERNAL STATIC PRESSURE (in. wg)
SIZE	CFM		0.0			0.1				0.2			0.3			0.4			0.5
50AH		Rpm		Bhp	Rpm		Bhp		Rpm		Bhp	Rpm		Bhp	Rpm		Bhp	Rpm		Bhp
024	1700	247		0.07	255		0.07		262		0.08	269		0.08	277		0.08	284		0.09
036	2000	276		0.11	282		0.11		289		0.12	295		0.12	301		0.12	307		0.13
048	2500	251		0.17	305		0.18		357		0.22	408		0.27	456		0.32	501		0.37
060	3000	287		0.22	334		0.28		378		0.33	421		0.38	464		0.43	505		0.49
072	5200	367		0.68	438		0.89		464		0.98	490		1.07	516		1.16	542		1.25
096	6400	448		1.26	524		1.59		546		1.70	568		1.81	—		—	—		—

LEGEND

Bhp — Brake Horsepower

NOTES:

1.Refer to Table 1 for condenser fan motor and drive information.

2.Upgrade 1 Static Motor is required for boldface values.

3.Upgrade 2 Static Motor is required for shaded values.

START-UP

Unit Preparation — Make sure unit has been installed in accordance with installation instructions and applicable codes.

Compressor Mounting — Compressors are internally mounted on rubber-in-shear (RIS) isolators. Do not loosen or remove compressor holddown bolts.

Internal Wiring — Check all electrical connections in unit control boxes and tighten as required.

Refrigerant Service Valves — Each unit system has 2 Schrader-type service ports, one on the suction line and one on the compressor discharge line. Be sure that caps on the ports are tight.

Compressor Rotation — On 50AH036-096, 3-phase units, it is important to be certain compressor is rotating in the proper direction. To determine whether or not compressor is rotating in the proper direction:

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

2.Energize the compressor.

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 condenser and evaporator fans may also be rotating in the wrong direction.

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

3.Reverse any two of the unit power leads.

4.Reapply power to the unit; remove tag.

5.Verify correct refrigerant pressures.

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

NOTE: When the compressor is rotating in the wrong direc- tion, the unit will sound louder than normal and will not provide cooling.

Cooling — To start unit, turn on main power supply. Set system selector switch at COOL position and fan switch at AUTO. position. Adjust thermostat to a setting below room temperature. Compressor, condenser and evaporator motors start on closure of contactors.

TO SHUT OFF UNIT — Set system selector switch at OFF position or reset thermostat at a position above room temperature.

SERVICE

WARNING

Disconnect all power to the unit before performing mainte- nance or service. Electrical shock and personal injury could result.

IMPORTANT: If repairs to refrigerant cycle compo- nents (e.g., compressor, filter drier, etc.) are required, recover all refrigerant from the system by using both high and low-pressure ports. Then remove base unit from the space.

Filters — Filters are disposable and should be inspected and replaced at regular intervals monthly or as conditions require. They are located in front of the evaporator coil and may be re- moved by sliding them horizontally out to edge of unit. See Fig. 2-5. No tools are required for installation or removal of filters.

Condenser Coil — The condenser coil is accessible through the side access panel on condenser section, or through side access panel on condenser section. Use a stiff brush when cleaning coil. Be careful not to bend aluminum fins.

Evaporator Coil — The evaporator coil is accessible for cleaning through the side access panel on evaporator section. When necessary, wash coil with a commercial cleaner (Oakite

164)or dishwasher detergent using a pressurized spray canis- ter. Flush coil from return-air duct side and take care not to get water in ductwork or unit insulation.

Condensate Drain — Clean and empty drain pan at least once a year to prevent sludge build-up.

Lubrication — Lubrication of the condenser and evapora- tor motors is not necessary since both are equipped with permanently lubricated bearings. Do not oil.

Unit Condenser Motor — All 50AH units contain belt-driven adjustable-pulley fan systems. The unit fan motors are shipped with adjustable pulley at 4 turns open.

Blower Wheel Servicing — In-space servicing is rec- ommended for the evaporator and condenser blowers. Both are removed by loosening and removing the 2 screws (sizes 024-

060)or 4 screws (sizes 072 and 096) that hold them in place. In both cases, the entire assembly is then moved outside of the base unit. Once outside, the blower wheel and condenser shaft bearings and/or evaporator motor can be serviced.

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