LG RCWFH Series Instruction Manual page 115

Yearly inspection
- Yearly inspection
Classification Inspection items
Motor Terminal fas-
Motor
ten bolt
Chemical analysis
Condenser
Tubes condition
Chemical analysis
Evaporator
Tubes condition
Oil cooler cleaning
Ejector cleaning
Oil and lubricant
Filter cleaning
Oil tank cleaning
Oil Replacing
<Water quality analysis>
The cooling water at the open circulation type cooling tower uses the evaporation latent heat to lower down the
water temperature and also recycles it.
At this time the water evaporates and the chloride ions in the water and the acid ions will increase. This will lead to
enrichment situation and eventually deteriorate the water quality.
Also, in the cooling tower, water and air are always in contact with each other and the contaminating material(auto-
mobile exhaust gas, sulfurous acid gas, dust, gas of chemical plants such as ammonia or petroleum gas, etc.) deterio-
rates the water quality even more.
These pollutant causes can corrode the pipe, scales adhered causes the tubes to have holes and lockouts which are
leading to a decreasing effect of heat exchanger.
Therefore, it may end to replacing the tubes, increased power cost, or the chiller failure.
Thus, cooling water quality must be maintained at a certain level.
Water quality analysis should be taken place periodically and if the results are out of the standards boundary(Table
23.), it must be replaced. At the beginning of the season and at the initial starting of the machine, water quality analy-
sis is inevitable.
To prevent the cooling water enrichment, certain amount of cooling water should be drained during the circulation
and then supplying fresh cooling water. Another way of water quality analysis would be using chemical handling.
<Tubes State>
If water corroded dirt is adhered or foreign substances are mixed in the tubes, resistance is increased which makes it
hard for the chiller to have a good efficiency. It also makes it easy to cause surge.
If sandy like solid materials are mixed in the cooling water, erosion or corrosion may occur at the entrance of the
tubes, therefore when cleaning the tubes make sure that you check the inner surface of it.
Install a filter at the inlet of the cooling water pipe. Generally, a cooling tower is used for the cooling water system,
but when using the subterranean water or the riparian water it is possible for the scales to be adhered easily due to
low quality of water compared to the chilled water.
Inspection method
Check the slackness
Water quality analysis
Check it at the operation record or
by opening the waterbox.
Water quality analysis
Check it at the operation record or
by opening the waterbox.
Clean by refrigerant
Disassemble cleaning
Filter exchanging, Cleaning the
housing
Disassemble cleaning
Figure 93. Yearly inspection standard
Criteria
Check the loose
Loose terminal finishing state
Water quality standard
No pollution
Water quality standard
No pollution
No corrosion or pollution should be pres-
ent
No abnormality
No abnormality
No pollution
2000 hours or 1 year
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