6.5 Maintenance of Water Circuit
● If clogging in the plate heat exchanger occurs seriously, this will cause insufficient cooling performance o
freezing in the heat exchanger. It is strongly recommended that the plate heat exchanger be cleaned at
the same time when the water strainer is cleaned.
● In case of removing the scale formed on the plate heat exchanger, it is recommended to use 5% diluted
solutions which contains formic acid, citric acid, oxalic acid, acetic acid or phosphoric acid.
Do not use corrosive solutions with hydrochloric acid or nitrate.
● Circulate the cleaning solution of 50~62
o
C by using a water pump for 2 to 5 hours.
Cleaning time depends on the change of the dirtiness (color) of cleaning solution.
After circulating the cleaning solution, remove the solution from the plate heat exchanger.
Then circulate the neutralization solution such as 1~2% sodium hydroxide (NaOH) or sodium bicarbonate
(NaHCO
3
) for 15~20 minutes.
● When using any cleaning detergent sold in the market, make sure that it does not cause corrosion to
stainless steel and copper. For details of cleaning method, contact the manufacturer of cleaning detergent.
● Cleaning of plate heat exchangers shall be performed by specialists. Contact your contractor or distributor.
● After cleaning has been completed, make sure that the unit can be operated normally.
When the freeze protection is activated during operation, make sure to remove the cause before restarting
the operation. In case the freezing is repeated, the heat exchanger is damaged and refrigerant leakage or
water enter the refrigerant pipe may occur.
● When the water pressure difference during operation is over the allowable range, make sure to stop the
water source unit and remove the cause.
If the water pressure difference at the water inlet and outlet sides of the plate heat exchanger is higher
compared to during Test Run, the water strainer may be clogged.
Be sure to regularly clean the water strainer according to the clogging degree and check the water flow rate (or
pressure drop).
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Summary of Contents for AVWW-114FKFW
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