44
3P362438-5N English
16 . Operation of the unit
Once the units are installed and test operation of outdoor units,
Branch Selector units and indoor units are finished, the operation of
the system can start.
For operating the indoor units, the user interface of the indoor units
should be switched ON. Refer to the indoor unit operation manual for
more details.
17 . Maintenance and service
17 .1 . Maintenance introduction
In order to ensure optimal operation of the unit, a number of checks
and inspections should be carried out on the unit at regular intervals,
preferably yearly.
This maintenance shall be carried out by the installer or service agent.
17 .2 . Service precautions
DANGER: DO NOT TOUCH PIPING AND INTERNAl PARTS
See Safety considerations on page i.
CAUTION
When performing service to inverter equipment:
1
Do not open the control box cover for 10 minutes after the power
supply is turned off.
2
Measure the voltage between terminals on the terminal block for
power supply with a tester and confirm that the power supply is
turn off. In addition, measure points as shown in the figure below,
with a tester and confirm that the voltage of the capacitor in the
main circuit is less than 50 V DC.
1
2
3
REYQ72T
REYQ96-168T
2
2
3
3
1
+ -
+
-
+
-
1 Terminal block for power supply
2 Tester
3 White connector
3
To prevent damaging the printed circuit board, touch a noncoated
metal part to eliminate static electricity before pulling out or plug-
ging in connectors.
4
Pull out junction connectors X1A, X2A (X3A, X4A) for the fan
motors in the outdoor unit before starting service operation on the
inverter equipment. Be careful not to touch the live parts.
(If a fan rotates due to strong wind, it may store electricity in the
capacitor or in the main circuit and cause electric shock.)
5
After the service is finished, plug the junction connector back in.
Otherwise the malfunction code E7 will be displayed on the user
interface or on the outdoor unit segment display and normal opera-
tion will not be performed.
For details refer to the wiring diagram labelled on the back of the
control box cover.
Pay attention to the fan. It is dangerous to inspect the unit while the
fan is running. Make sure to turn off the main switch and to remove the
fuses from the control circuit located in the outdoor unit.
NOTE
Play it safe. For protection of the printed circuit board, touch the con-
trol box casing by hand in order to eliminate static electricity from your
body before performing service.
17 .3 . Service mode operation
Refrigerant recovery operation/vacuuming operation is possible by
applying setting [2-21]. Refer to 13.2. Operating the push buttons and
DIP switches on the printed circuit board on page 25 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.
17 .3 .1 . Vacuuming method
1
When the unit is at standstill, set the unit in [2-21]=1.
2
When confirmed, the indoor units, the Branch Selector units and
outdoor unit expansion valves will fully open. At that moment
the segment display indication=
01
and the user interface of
all indoor units indicate “Test Operation” and
CENTRAL
CONTROL
and the
operation will be prohibited.
3
Evacuate the system with a vacuum pump.
4
Press BS3 to stop vacuuming mode.
17 .3 .2 . Refrigerant recovery operation method
This should be done by a refrigerant reclaimer. Follow the same proce-
dure as for vacuuming method.
18 . Caution for refrigerant leaks
18 .1 . Introduction
The installer and system specialist shall secure safety against
leakage according to local regulations or standards . The following
standards may be applicable if local regulations are not available .
The VRV System, like other air conditioning systems, uses R410A as
refrigerant. R410A itself is an entirely safe non-toxic, non-combustible
refrigerant. Nevertheless care must be taken to ensure that air con-
ditioning facilities are installed in a room that is sufficiently large. This
assures that the maximum concentration level of refrigerant gas is not
exceeded, in the unlikely event of major leak in the system and this in
accordance to the local applicable regulations and standards.
Maximum concentration level
The maximum charge of refrigerant and the calculation of the maxi
-
mum concentration of refrigerant is directly related to the humanly
occupied space in to which it could leak.
The unit of measurement of the concentration is lbs./ft.
3
(kg/m
3
) (the
weight in lbs. (kg) of the refrigerant gas in 1 ft.
3
(1 m
3
) volume of the
occupied space).
Compliance to the local applicable regulations and standards for the
maximum allowable concentration level is required.
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