About Maintenance - Midea Aqua Tempto Power Series Manual

Aqua tempo power series tropical air-cooled scroll chiller 50Hz

1. About maintenance

1.1 Maintenance for main components：
1) Close attention should be paid to the discharge
and suction pressure during the running process.
Find out reasons and eliminate the failure if
abnormality is found.
2) Control and protect the equipment. See to it that
no random adjustment be made on the set points on
site.
3) Regularly check whether the electric connection
is loose, and whether there is bad contact at the
contact point caused by oxidation and debris etc.,
and take timely measures if necessary. Frequently
check the work voltage, current and phase balance.
4) Check the reliability of the electric elements in
time. Ineffective and unreliable elements should be
replaced in time.
1.2 Water quality inspection and dirt remove
According to the local water quality, please inspect
the water regularly. We recommended you to
respect it a half year a time and change the circulate
water two years a time.
After long-time operation, calcium oxide or other
minerals will be settled in the heat transfer surface
of the water-side heat exchanger. These substances
will affect the heat transfer performance when there
is too much scale in the heat transfer surface and
sequentially cause that electricity consumption
increases and the discharge pressure is too high (or
suction pressure too low). Organic acids such as
formic acid, citric acid and acetic acid may be used
to clean the scale. But in no way should cleaning
agent containing chlorine acid or fluoride should be
used as the water-side heat exchange is made from
stainless steel and is easy to be eroded to cause
refrigerant leakage. Pay attention to the following
aspects during the cleaning and scale-removing
process:
● Water-side heat exchanger should be done be
professionals.
● Clean the pipe and heat exchanger with clean
water after cleaning agent is used. Conduct water
treatment to prevent water system from being
eroded or re-absorption of scale.
● In case of using cleaning agent, adjust the density
of the agent, cleaning time and temp. according to
the scale settlement condition.
● After pickling is
treatment needs to be done on the waste liquid.
186
completed, neutralization
Contact relevant company for treating the treated
waste liquid.
● Protection equipment (such as goggles, gloves,
mask and shoes) must be used during the cleaning
process to avoid breathing in or contacting the agent
as the cleaning agent and neutralization agent is
corrosive to eyes, skins and nasal mucosa.
1.3 Winter shutdown
For shutdown in winter, the surface of the unit
outside and inside should be cleaned and dried.
Cover the unit to prevent dust. Open discharge
water valve to discharge the stored water in the
clean water system to prevent freezing accident (it is
preferable to inject antifreeze in the pipe).
1.4 Replacing parts
Parts to be replaced should be the ones provided by
our company. Never replace any part with different
part.
First startup after shutdown
The following preparations should be made for
re-startup of unit after long-time shutdown:
1) Thoroughly check and clean the unit.
2) Clean water pipe system.
3) Check pump, control valve and other equipment
of water pipe system.
4) Fix connections of all wires.
5) It is a must to electrify the machine before startup.
1.5 Refrigeration system
Determine whether refrigerant is needed by
checking the value of suction and discharge
pressure and check whether there is a leakage. Air
tight test must be made if there is a leakage or parts
of refrigerating system is to be replaced. Take
different measures in the following two different
conditions from refrigerant injection.
1) Total leakage of refrigerant. In case of such
situation, leakage detection must be made on the
pressurized nitrogen used for the system. If repair
welding is needed, welding cannot be made until all
the gas in the system is discharged. Before injecting
refrigerant, the whole refrigeration system must be
completely dry and of vacuum pumping.
● Connect vacuum pumping pipe at the fluoride
nozzle at low-pressure side.
MCAC-ATSM-2014-09