Operating Checks; Maintenance - Profroid GFS ZF 09DZ Handbuch

OPERATING CHECKS

Shortly after start-up, the operating conditions of the equipment must be checked

Compressor
The compressor must operate within its acceptable limits
-
(see Manufacturer's advice).
Check on each compressor:
-
Voltage

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 (maxi 11 K for low temperature) and should not fall below 10 K .
-
the thermostatic expansion valve 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:
-
. R404
. R22
- 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 .
. 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.

Fans
Check the current absorbed from the motors.

MAINTENANCE

9-
RECOMMENDATIONS
If the unit is stopped for long periods of time, the fan motors should be run for at least two hours each week.
. Every month:
Carry out an operating check on:
Pressures and temperatures in the compressor
-
Voltages in compressors and fan motors
-
Safety cut-off points of HP/LP safety pressure switches.
-
Cut-in of safety pressure switches in condenser fans,
-
Oil levels
-
Moisture in the circuits (through sight-glass or by analysing oil)
-
Check for leaks in the refrigeration circuit
-
Cleanliness of coil
-
Position of rotors in ferrules ( tightness on shaft, state of blades, ...).
-
.Every year:
Carry out an analysis of the oil
-
Clean the condenser.
-
In the case of HFC type fluid ( R404A ), activated aluminium oxide dryers should be avoided, dryers with a molecular
-
filter should be chosen instead.
70°C < T° discharge < 100°C
90°C < T° discharge < 120°C
.
Therefore adjust
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