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5.
Operating Procedure
5.1 Cautions During Initial Period of Operation
Since a new machine just after installation does not have enough fitting of each part to bear severe
operation, operate the chiller-heater with a great care in the initial period according to the following
suggestions.
(1) One-day low load operation
Some corrosion inhibitor is added in lithium bromide solution and it becomes effective in some
hours after starting operation. Therefore, it is recommended to keep low load operation in the first
day of the initial start-up.
(2) Confirmation of gas supply pressure
Read the gas supply pressure at the time of start-up, stopping and operation to confirm its value
is just as per the specification. When the pressure difference is more than 20% of its specification,
it may cause insufficient burning, misfire or loss-fire. Stability of gas supply pressure shall be
mandatory.
(3) Stable operation
Stabilize the pressure and temperature of the entire system and be careful not to lower the
temperature of the chilled water excessively or not to change the fuel supply abruptly or
frequently.
(4) Ample flow rate of chilled (hot) water
When adjusting the valves in the water piping system, be careful not to reduce the flow rate or
cut water supply suddenly.
(5) Chilled water and hot water temperature
Keep the chilled water temperature somewhat higher and hot water somewhat lower. Generally,
adjustment of air conditioning system is often insufficient in the initial period. So, load may not be
stabilized and evaporation temperature is likely to change abruptly, which may cause freezing or
other troubles. However, in case load is stabilized at factory etc., there is no need for such
treatment.
(6) Water quality check
A long use of water with poor quality may deposit scales in the tubes to spoil the heat exchange
performance and also to generate electric or chemical corrosion. Therefore, it is recommended to
check the water quality in the initial period of operation for a longer machine life. If the slightest
corrosion or deposition is found one week or one month after the initial operation, the chemical
water treatment should be done. (Refer to the item, "Water Quality Control" in this manual.)
(7) Clean the tubes earlier
Since the contamination of the tubes cannot be detected in the initial period of operation, it is
necessary to check the state of corrosion and contamination after starting operation for one
month. Clean the tubes, if necessary. Thereafter, be sure to clean the tubes frequently
depending on the degree of contamination. Poor water quality and negligence of cleaning tubes
would promote corrosion, deteriorate the heat exchange performance and lower the capacity of
the chiller-heater. As dusts or scales entering the piping during installation may contaminate the
water tank or clog the valves in the piping and the evaporator tubes. Such water would become
dead water to be over-cooled or frozen, which may cause to break the tubes. Pay a special
attention to the water quality in the initial period of operation and check the piping system and
clean the water tank one week and one month after the initial operation, and replace the
circulating water.
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