Profroid GSB Notice D'instructions page 37

Discharge pressure
Measure suction temperature
Measure discharge temperature
Measure crankcase temperature acting at the oil drain plug.
The intake superheat must not exceed 20°K and should not fall below 10°K.
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and ensure that the charge in the condensing unit is correct.
The discharge temperatures on the high pressure line must be within the following range:
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. R404A 70°C <
- The crankcase temperature must not fall below 40°/45°C
Very important:
There is no need to add oil over and above the required quantity during start-up. Wait several hours.
Excess oil generally leads to oil slugs on the condensing unit which causes damage to the compressors (broken valves or gaskets).
. If oil level is low, this could be caused by:
- Too much oil being entrained by emulsification in the crankcases resulting in an excessive amount of refrigerant fluid being
dissolved into the oil (superheat too low at suction inlet - crankcase heaters defective or not energised).
- Bad design of the LP piping on the equipment trapping the oil, particularly when running with reduced refrigerant charge.
9- MAINTENANCE
RECOMMENDATIONS
Every month:
Carry out an operating check on:
Pressures and temperatures in the compressor
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Voltages in compressors and fan motors
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Safety cut-off points of HP/LP safety pressure switches.
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Oil levels
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Moisture in the circuits (through sight-glass or by analysing oil)
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Check for leaks in the refrigeration circuit
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.Every year:
Carry out an analysis of the oil
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Clean the condenser.
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.In the case of HFC type fluid (R404A), activated aluminium oxide driers should be avoided, driers with a molecular
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filter should be chosen instead.
Instructions or recommendations appearing in the various technical advice notes and manufacturer's service manuals
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should be followed precisely ; please contact our Technical Department for any additional information.
T° discharge < 100°C
Therefore adjust the thermostatic expansion valve
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