maintenance
Maintenance procedures
CAUTION
Motor Winding Damage!
Do not use a megohm meter or apply greater than 50 VDC to a compressor motor winding while it is under a deep vacuum. Voltage sparkover may cause damage to the motor windings.
WARNING
Hazardous Pressures!
If a heat source is required to raise the tank pressure during removal of refrigerant from cylinders, use only warm water or heat blankets to raise the tank temperature. Do not exceed a temperature of 150°F. Do not, under any circumstances, apply direct flame to any portion of the cylinder. Failure to follow these safety precautions could result in a violent explosion, which could result in death or serious injury.
Charging the Refrigerant System
To completely charge the system, charge gaseous refrigerant into the suction line shrader valve with the unit running. However, make sure that some refrigerant is present in each circuit before starting the compressors.
CAUTION
Compressor Damage!
Do not allow liquid refrigerant to enter the suction line. Excessive liquid accumulation in the liquid lines may result in compressor damage.
CAUTION
Compressor Damage!
Never manually or automatically pump down below 7 psig. This may cause the compressor to operate in a vacuum and result in compresor damage.
Table
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| high pressure |
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| 280 to 430 psig |
| 320 to 570 psig | |
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| low pressure |
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| 100 to 160 psig | ||
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| superheat |
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| 4 to 9°F | ||
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| subcooling |
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| 5 to 10°F | ||
Table |
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| control | disarming | rearming |
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| high pressure control | 624±17.5 psig | 464±29 psig | unit (ton / voltage) | ||||
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| high pressure control | 450±10 psig | 348±14.5 psig |
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| low pressure contol | 51±7 psig | 94±7 psig |
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| 266±5F | 194±5 |
| 3 / | ||
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| 275±5F | 198 |
| 5 / | ||
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| 266±5F | 198 |
| 5 / 575 | ||
| motor windings thermostat, standard motor only | 194±5F | 135 |
| 7.5 - 10 / | |||
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| 248±5F | 156 |
| 7.5 - 10 / 575 | ||
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| 194±5F | 135 |
| 12 - 15 / | ||
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| 221±5F | 142 |
| 12 - 15 / 575 | ||
28 |