Problems
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Reasons
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Self-checking
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At the beginning, it refrigerates well, but after a while using refrigerating effect decline; the high and low pressure data is lower.
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Driving reefer trucks on the bumpy roads, because of the shocking frequently, resulting in wire contacts loose, and refrigerant leakage.
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Using leakage meter check out where the leaking place is, screw down loose contacts and fill in refrigerant.
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The truck reefer unit not refrigerating; blowing hot air from blower outlet; expansion valve outlet and inlet blowing air same temperature; low presser controller shows lower number reading.
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Using improperly.
Expansion value temperature wrap damages, valve bore closed, and resulting in refrigerant leakage.
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Change expansion value, refill in refrigerant.
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Outlet air not cooling and compressor temperature increasing; the pointer in low pressure controller downs quickly nearly to “0 “and high pressure reading more increasing.
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Expansion value filter screen is blocked by mess, and it frosts in expansion value or the expansion value “sweats”.
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If the blocking is not serious, start off freezing system at intervals can clear the mess.
Or take away the expansion value, use alcohol cleaning it, empty refrigerant and refill refrigerant again.
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Refrigerating not enough,foresting in evaporator; both high and low pressure reading are lower.
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Expansion value orifice has no effect.
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Empty refrigerant, change expansion value and refill refrigerant.
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After few days working of the units, refrigerating is declining gradually, high pressure controller reading higher and low pressure controller reading lower.
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Drying agent in reservoir is saturate; expansion throttle is blocked by ice.
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Empty refrigerant, change expansion value and refill refrigerant.
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Start off the freezing system, only has air flowing but cold air, and high and low pressure controller no reading.
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TDS poor contact or compressor electromagnetic clutch wire damages.
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Use the multi-meter check out the TDS whether damage or not; change the compressor electromagnetic clutch.
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