Trane RTUB 207-224 manual Filter Replacement Procedure, Oil Charging Procedure, Lubrication System

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Maintenance

The evaporator is large enough to hold all the charge, for any unit, below the centerline of the shell. Therefore, no special precautions are required to restart the unit after isolating the charge in the evaporator.

Filter Replacement

Procedure

A dirty filter is indicated by a temperature gradient across the filter, corresponding to a pressure drop. If the temperature downstream of the filter is 8°F [4.4°C] lower than the upstream temperature, the filter should be replaced. A temperature drop can also indicate that the unit is undercharged. Ensure proper subcooling before taking temperature readings.

1.With the unit off, verify that the EXV is closed. Close the liquid-line isolation valve. On units with remote evaporators or oil cooling circuits, close the ball valve on the oil cooler liquid line.

2.Attach the vacuum hose to the service port on the liquid-line filter flange.

3.Evacuate the refrigerant from the liquid-line and store.

4.Remove the vacuum hose.

5.Depress the Schrader valve to equalize pressure in the liquid line with atmospheric pressure.

6.Remove the bolts that retain the filter flange.

7.Remove the old filter element.

8.Inspect the replacement filter element and lubricate the o-ring withTrane OIL00048.

￿CAUTION

Do not use mineral oil. It will contaminate the system.

9.Install the new filter element in the filter housing.

10.Inspect the flange gasket and replace it with a new one if damaged.

11.Install the flange and torque the bolts to 14-16 lb-ft [19-22 n-m].

12.Attach the vacuum hose and evacuate the liquid line.

13.Remove the vacuum hose from the liquid line and attach the charging hose.

14.Replace the stored charge in the liquid line.

15.Remove the charging hose.

16.Open the liquid-line isolation valve. On units with remote evaporators or oil cooler circuits, open the oil cooler liquid-line ball valve.

Lubrication System

The lubrication system has been designed to keep most of the oil lines filled with oil as long as there is a proper oil level in the oil sump.The total oil charge can be removed by draining the oil system, the oil return line from the evaporator, the evaporator, and the compressor. Very small quantities of oil may be found in other components.

Oil Charging Procedure

Proper charging of the oil system is critical to the reliability of the compressor and chiller.Too little oil can cause the compressor to run hot and inefficiently. When taken to an extreme, low oil level may result in infant failure of the compressor.Too much oil will result in high oil- circulation rates, which will foul the condenser and evaporator performance.This will result in inefficient operation of the chiller. Taken to an extreme, high oil levels may result in erratic expansion-valve control or shut down of the chiller due to low evaporator-refrigerant temperature.Too much oil may contribute to long-term bearing wear. Additionally, excessive compressor wear is probable when the compressor is started with the oil lines dry. Oil system consists of the following components:

Compressor

Oil separator

Discharge line with service valve

Oil line from separator to compressor

Oil line drain (lowest point in system)

Oil cooler

Oil temperature sensor

Oil line shutoff valve with flare service connection

Oil filter (internal to compressor) with flare-fitting service connection and Schrader valve

Oil flow-control valve (internal to the compressor after the filter)

Oil return line from evaporator with shutoff valve, strainer, and solenoid control valve.The standard oil charge for each circuit size is shown inTable 1.

Measuring the oil level

1.To measure the oil level, use the oil drain valve on the oil line and a service valve on the discharge line. This measurement can only be made when the circuit is not running. Note: the bottom plate of the oil separator is approximately 1" [25 mm] thick.

2.The initial oil charge should be approximately at the level as shown inTable 6.This is the approximate oil level if all the oil is in the oil lines, filter, and oil sump, and the unit is in vacuum so that there is no refrigerant dissolved in the oil.

3.After the unit has run for a while, the oil level in the sump can vary greatly.

The field-charging procedure depends on the circumstances that resulted in the need for oil charge.

1.Some service procedures may result in loss of small quantities of oil that must be replaced (oil analysis, compressor filter replacement, re-tubing the evaporator, and so forth).

2.Additionally, some maintenance procedures may result in virtually all of the oil being removed (compressor motor burn or total removal of the charge to trouble- shoot a unit).

3.Finally, leaks may result in a loss of oil that must be replaced.

RLC-SVX03A-E4

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Contents Installation Operation Maintenance Refrigerant Contents Operation Unit Inspection Inspection ChecklistGeneral information Description of the Unit Loose Parts InventoryGeneral data Rtub General data Rtca Storage InstallationInstallation responsibilities Foundation Special Lifting and Moving InstructionsIsolation Length Width Height ClearancesWater Connections Rtub DrainageReleasing the Nitrogen Holding Charge Water Treatment Flow Switch InstallationWater Pressure Gauges Installing and connecting temperature sensors Refrigerant Safety ValvesExtension of sensor power cable Water Pressure-Relief ValvesConnecting the Rtub with a remote air-cooled condenser Electrical connections performed by the installerDetail of positions of refrigerant sensors 5R56-1 and 5R6-2 Units on the same level Rtca or other manufacturers condenser below the Rtub Equivalent pressure drops Pressure tests and leak detectionSize of the liquid line Discharge lineVacuum pump connection Vacuum pumpingOperation Installation ChecklistPre-start checkout Unit Voltage PhasingOverheating Start-up ProceduresSubcooling Shutdown proceduresSeasonal Unit Start-up System Restart After Extended ShutdownOperation Maintenance For units without discharge valve option For units with the discharge valve optionSome symptoms of a refrigerant over-charged unit Some symptoms of a refrigerant under-charged unitSome symptoms of an oil over- charged unit Checking the separator oil levelCharge Isolation in the high or low side of the system R134a Field-Charging ProcedureOil Charging Procedure Filter Replacement ProcedureLubrication System Measuring the oil levelFactory initial Oil-Charging Procedure Field Oil-Charging ProcedureMaintenance Training Safety recommendationsMaintenance contract