Johnson Controls HVWHP072B32S - Caution for Refrigerant Leakage; Maintenance Work for Water Circuit

6-2
SM-18006
FIELD WORK INSTRUCTIONS
6.1 Maintenance Work for Water Circuit
6.2 Caution for Refrigerant Leakage
Refer to Section 3 “Troubleshooting” when dealing with problems or difculties.
If you cannot solve the problem, contact your distributor or contractor.
● Special Attention Regarding Refrigerant Gas Leakage
Make sure that the entire VRF system meets ASHRAE Standard 15 or, any local codes, regarding Safety.
The ASHRAE Standard 15-2013 provides safeguards for life, limb, health, property, and prescribes safety
requirements.
The standard is recognized as the main guide for personal safety involving refrigeration systems. It strives
to ensure a safe application of refrigerant systems by limiting the maximum charge so that a complete
discharge due to a leak into a small, occupied, and enclosed room can never exceed the allowable limit.
● If clogging in the plate heat exchanger occurs seriously, this will cause insufcient cooling performance or
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 122~144
o
F (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 changes
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 ow rate (or
pressure drop).