FläktGroup Multi-DENCO, Operation Manual, Page: 87 / 120

Multi -DENCO Commissioning
FläktGroup DC-2013-0101-GB • Subject to modifications • R4-05/2018 87
Oil level check
Before the system can be left as fully charged, the oil level within the system must be
checked a final time. There are 2 different procedures depending upon your size of
unit:
Size 010 - 065 For these sized units there is no oil level sight glass available, therefore the tempera-
ture of the oil reservoir within the compressor must be taken.
With stable running conditions, the reservoir temperature must be 10 K more than the
running evaporating temperature for example:
If evaporating temperature equals 10 °C then the oil reservoir temperature must be
greater than 20 °C.
Size 092 - 130 In these units, an oil balance sight glass is fitted, allowing for visual inspection of the
system. There are also sight glasses on each compressor which should be reviewed.
The below table describes what should be observed in the sight glass when at optimum
conditions:
* For this scenario, this must be observed in the sight glass for the fixed speed compressor.
If either scenario requires additional 'top-up' of oil, ensure this is conducted whilst the
unit is off and deactivated.
Function Test of Safety Device(s)
Multi -DENCO units are fitted with High Pressure (HP) switch(s) to mechanically protect
the refrigeration circuit. After charging, these MUST BE TESTED . For details of the
procedure, please refer to the controls manual.
Unit stopped Both compressors operating
Size 092 ½ to ¾ full ¼ to ½ full
Size 130 0 to ¼ full ½ full *
Tab. 8-2
This test requires system pressure to be continually increased to check safety
devices of the system. If the devices fail the test and appropriate actions are not
taken to stop further pressure increases, there is danger of pipework ruptures and
catastrophic failures. Failure to follow recommendations may lead to death or
serious injury.
•
Do not allow the system pressures to rise above the Maximum Operating
Pressure (MOP) stated on the unit's nameplate.
•
If the High Pressure (HP) switch fails to deactivate the compressors and the
pressure continues to rise; DEACTIVATE THE UNIT IMMEDIATELY (for
example, isolate the power supply).
Before re-enabling the unit;
•
Mechanically measure the pressure within the system
•
Wait until the pressures have reduced to normal standby conditions
•
Ensure the condenser fan MCB(s) have been re-enabled.