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30RB/30RQ - 30RBY
Refrigerant charge and electronic control
30RB-RQ units are shipped with a full operating charge of refrigerant.
Refer to Table I.
If it is nevertheless necessary to add more refrigerant, run the unit for
some time in cooling mode and then slowly add liquid refrigerant into the
suction side until there are no bubbles in the sight glass.
30RB-RQ units use a R-410A refrigerant charge. For your information, we are
reproducing here some extracts from the official publication dealing with
the design, installation, operation and maintenance of air conditioning and
refrigeration systems and the training of people involved in these activities,
agreed by the air conditioning and refrigeration industry.
Refrigerant guidelines
Refrigeration installations must be inspected and maintained regularly and
rigorously by specialists. Their activities must be overseen and checked by
properly trained people.
To minimise discharge to the atmosphere, refrigerants and lubricating
oil must be transferred using methods which reduce leaks and losses to
a minimum.
If an oil draining or recovery operation becomes necessary, the fluid transfer
must be made using mobile containers.
• Leaks must be repaired immediately.
• Service valves fitted to the flow and return lines permit charge transfer
to a suitably arranged external container.
• It is indispensable to use a dedicated transfer station.
• Compressor lubricating oil contains refrigerant. Any oil drained from
a system during maintenance must therefore be handled and stored
accordingly.
• Refrigerant under pressure must never be discharged to the atmosphere.
Recharging liquid refrigerant
R-410A refrigerant operates at 50%-70% higher pressures than R-22.
Be sure that servicing equipment and replacement components are
designed to operate with R-410A.
The cylinders that contain R-410A are pink.
The cylinders that contain R-410A are provided with a dip tube that allows
fluid to escape from the cylinder both when in upright position and when
turned upside down.
Unit R-410A should be charged with liquid refrigerant. Apply a common
flow regulator available on the market to the hose pipe to vaporize the
liquid refrigerant before it enters the unit.
R-410A, like other HFCs, is only compatible with the oils selected by the
manufacturer of compressors(POE).
NOTE:
Regularly carry out leak checks and immediately repair any leak found.
Undercharge
If there is not enough refrigerant in the system, this is indicated by gas
bubbles in the moisture sight glass.
There are two possibilities:
• Small undercharge (bubbles in the sight glass, no significant change in
suction pressure).
- After detection and repair the unit can be recharged.
- The replenishment of the charge must always be done in the cooling
mode, slowly introducing liquid refrigerant at the suction side, until
there are no bubbles in the sight glass.
• Significant undercharge (large bubbles in the sight glass, significant drop
in suction pressure). In this case:
- Completely drain the refrigerant charge, using a refrigerant recovery
unit. After detection and repair check the charge with the unit off,
drain the system and recharge the full amount of liquid refrigerant
(see Table I) on the suction and discharge side.
- The refrigerant container used must contain a minimum of 10% of its
initial charge.
CAUTION:
If brazing is to be done, the refrigerant circuit must be filled with nitrogen.
Combustion of refrigerant produces toxic phosgene gas.
Change the refrigerant after an equipment failure, following a procedure
such as the one described in NF E29-795 or carry out a refrigerant analysis
in a specialist laboratory.
IMPORTANT:
Never use the compressor as a vacuum pump.
Always add refrigerant via the suction line.
Refrigerant must be added very slowly.
Do not overcharge the system with refrigerant.
If the refrigerant circuit remains open for longer than a day after an
intervention (such as a component replacement), the openings must be
plugged and the circuit must be charged with nitrogen (inertia principle).
The objective is to prevent penetration of atmospheric humidity and
the resulting corrosion on the internal walls and on non-protected steel
surfaces.
Electronic control
Operation and control of all units is carried out via the electronic control.
The instructions supplied with the control include comprehensive
descriptions.
After use, check the user interface is properly inserted into its housing
and the cover is closed by means of the screw supplied. This way, the
electronic control and the unit are protected against any impacts and
atmospheric agents.
PRO-Dialog + electronic control
PRO-DIALOG + is an advanced numeric control system that combines
complex intelligence with great operating simplicity.
PRO-DIALOG + constantly monitors all machine parameters and safety
devices, and precisely manages the operation of compressor and fans for
optimum energy efficiency.
It also controls the operation of the water pump.
A powerful control system
The PID control algorithm with permanent compensation for the difference
between entering and leaving water temperature and anticipation of load
variations regulates compressor operation for intelligent leaving water
temperature control.
To optimise power absorption, the PRO-DIALOG + automatically
re-calibrates the set point of the entering water temperature based on
the outside air temperature to one of the two pre-set values (occupied
building and of an unoccupied building for example).
PRO-DIALOG + control is auto-adaptive for full compressor protection.
The system permanently optimises compressor run times according to
the application characteristics (water loop inertia), preventing excessive
cycling. In most comfort air conditioning applications this feature makes
a buffer tank unnecessary.
Clear and easy-to-use control system
The operator interface is clear and user-friendly: two LEDs and digital
displays allow the immediate control of the device operating data.
The menus offer direct access to all machine controls, including a history
of possible faults, for rapid and complete chiller fault diagnosis.
Extended communications capabilities
PRO-DIALOG + allows remote control and monitoring of the unit through
a wired connection: 7-8 x 0.5 mm² multiple cables. The cable should be
screened of the FROH2R or BELTEN 9842 type.
The screening should be grounded only on the electric unit panel board.
Functions available are start/stop, cooling/heating mode selection (only
30RQ unit), power demand limit or dual set-point and customer safety lock.
The system permits remote signalling of any general anomaly for each
refrigerant circuit.
Three independent time schedules permit definition of: chiller start/stop,
operation at the second set-point (e.g. unoccupied mode), and operation
at low fan speed (e.g. during the night).
This option also permits cascade operation of two units and remote control
via communication bus (RS 485 serial port).
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