30RB/30RQ
GB - 11
ENGLISH
Refrigerant charge and electronic control
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 signi cant 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.
• Signi cant undercharge (large bubbles in the sight glass, signi cant
drop in suction pressure).
- Completely drain the refrigerant charge, using a refrigerant recovery
unit. After detection and repair check the charge with the unit o ,
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.
WARNING:
If brazing is to be done, the refrigerant circuit must be lled with
nitrogen.
Combustion of refrigerant produces toxic phosgene gas.
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.
Electronic control
Operation and control of all units is carried out via the electronic control.
The instructions supplied with the control include comprehensive
descriptions
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 e ciency.
It also controls the operation of the water pump.
A powerful control system
The PID control algorithm with permanent compensation for the
di erence 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 bu er 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 o er 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 mm 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 de nition 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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