Chapter 5 Maintenance and Inspection
UD-series Screw Compressor
5.2 Maintenance and Inspection List
5-4
Table 5-1 Daily Inspection Item (continued)
Inspection item
Inspection details
Checkpoints and actions
O
ther
s
Motor current
A Whether it is higher than the
current at test run
Compressor failure
Motor failure
Oil level of oil separator
-
Oil level
Oil loss
Replenish oil
Fluid level in the receiver
-
Fluid level
Replenish refrigerant
Check for refrigerant leak
-
Leak or not
The machine room and the load side
facilities(Cold storage etc)
■
Unless otherwise noted, the pressure unit MPa represents the gauge pressure in this manual.
■
Daily Maintenance Items
1.
Lubrication oil level
When the oil level in the oil separator reaches the lower limit, charge lubricant by referring to the
instruction manual of the compressor package.
2.
Replacing Oil Filter
When the differential pressure between oil filter inlet and outlet is higher than specified by the
manufacture, replace the oil filter element. The oil filter differential pressure may increase for a
short time during startup.
3.
Cleaning of Suction Strainer
After 500 h of operation inspect the suction strainer. Also remove the temporary filter(suction cloth
bag) if it was supplied with the package.
At the beginning of operation or just after the periodical maintenance, the differential pressure of
the suction strainer may increase in a short time. If the differential pressure increases, inspect
and clean the suction strainer..
4.
Oil Leak from Mechanical Seal
If there is a significant increase of oil leak from the mechanical seal, confirm the rate of the
leakage per hour. The table below specifies the allowable leak rate and the upper limit for
inspection. If any damage is found in the mechanical seal during inspection, replace the
mechanical seal.
Table 5-2 Reference values for Leak Rate from Mechanical Seal
Model of UD-series
125
160
200
250
320
400
Acceptable leakage amount (mL/h)
≤
3
≤
3
≤
3
≤
3
≤
6
≤
12
Inspection is required (mL/h)
≥
9
≥
9
≥
9
≥
9
≥
18
≤ 3
6
Note: The specifications above are just for reference. They are not guaranteed
values.
5.
Contamination of Condenser and Oil Cooler Tubes.
The degree of clogging and contamination of the cooling tubes is mostly affected by the cooling
water quality. If the oil temperature and discharge pressure increase gradually in an initial period
of operation, inspect and clean the cooling water side of the oil cooler and condenser even when
the inspection time has not come..
