10 Troubleshooting
Installation manual
46
RWEQ96~432TAYD
∗
+ RWEQ96~432TATJ
∗
VRV W T-Series water-cooled system air conditioner
3) Connect the piping for circulation of cleaning chemicals to
the inlet and outlet piping of plate-type heat exchanger. Fill
the cleaning solution of 122-144°F (50-62°C) for a while in
the plate-type heat exchanger. Then, circulate the cleaning
solution by a pump for 2-5 hours.
The time for cleaning depends on the temperature of
cleaning solution or the degree of scale accumulation.
Therefore, please watch the change of the dirtiness (color)
of cleaning solution to determine the level of removal of
scale.
4) After circulating the cleaning solution, discharge the solution
from the plate-type heat exchanger, fill the heat exchanger
with a solution of 1-2% sodium hydroxide (NaOH) or sodium
bicarbonate (NaHCO
3
). Circulate this solution for 15-20
minutes for neutralization purpose.
5) After the process of neutralization has been completed, rinse
the inner part of the plate-type heat exchanger with care
using fresh and clean water.
6) When using any cleaning agent sold in the market, check in
advance that such agent has no corrosive features against
stainless steel and copper.
7) For details of cleaning method, ask the manufacturer of
related cleaning agent.
3
After cleaning has been completed, make sure that the unit can
be operated in a normal fashion.
9 .4
About service mode operation
Refrigerant recovery operation/vacuuming operation is possible by
applying setting [2-21]. Refer to "7.2 Making field settings" on page 36
for details how to set mode 2.
When vacuuming/recovery mode is used, check very carefully what
should be vacuumed/recovered before starting. See installation
manual of the indoor unit for more information about vacuuming and
recovery.
9 .4 .1
To use vacuum mode
1
When the unit is at standstill, set the unit in [2-21]=1.
Result:
When confirmed, the indoor and outside unit expansion
valves will fully open. At that moment the 7-segment display
indication=
and the user interface of all indoor units
indicate “test operation”) and “central control” and the operation
will be prohibited.
2
Evacuate the system with a vacuum pump.
3
Press BS3 to stop vacuuming mode.
9 .4 .2
To recover refrigerant
This should be done by a refrigerant reclaimer. Follow the same
procedure as for vacuuming method.
DANGER: RISK OF EXPLOSION
Pump down – Refrigerant leakage .
If you want to pump
down the system, and there is a leakage in the refrigerant
circuit:
▪ Do NOT use the unit's automatic pump down function,
with which you can collect all refrigerant from the
system into the outside unit.
Possible consequence:
Self-combustion and explosion of the compressor
because of air going into the operating compressor.
▪ Use a separate recovery system so that the unit's
compressor does NOT have to operate.
NOTE
Make sure to NOT recover any oil while recovering
refrigerant.
Example:
By using an oil separator.
10
Troubleshooting
10 .1
Overview: Troubleshooting
This chapter describes what you have to do in case of problems.
It contains information about:
▪ Solving problems based on error codes
10 .2
Solving problems based on error
codes
In case of a displayed malfunction code, perform correcting actions
as explained in the malfunction code table.
After correcting the abnormality, press BS3 to reset the malfunction
code and retry operation.
The malfunction code which is displayed on the outside unit will
indicate a main malfunction code and a sub code. The sub code
indicates more detailed information about the malfunction code. The
malfunction code will be displayed intermittent.
Example:
Code
Example
Main code
Sub code
With an interval of 1 second, the display will switch between main
code and sub code.
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