Cavitation Protection (With Hydraulic Option); Water Flow Rate Detection; Frost Protection - Carrier AQUASNAP 30RBM Series Installation, Operation And Maintenance Instructions

8.3 - Cavitation protection (with hydraulic option)

To ensure the durability of pumps fitted on the integrated
hydraulic modules, the control algorithm of units in the range
includes protection against cavitation.
It is therefore necessary to ensure a minimum pressure of 60
kPa (0.6 bar) at the pump inlet both when shut down and during
operation.
A pressure below 60 kPa will prevent unit start-up, or will
cause an alarm and shut-down.
A pressure below 100 kPa will trigger an alert on the user
interface.
To obtain an adequate pressure, it is recommended:
• To pressurise the hydraulic circuit between 100 kPa (1 bar)
and 400 kPa (4 bar) maximum at the pump inlet;
• To clean the hydraulic circuit during water filling or after
any modifications are made;
• To regularly clean the screen filter.

8.4 - Water flow rate detection

Standard machine
All units are equipped as standard with a factory-set flow
switch. It cannot be adjusted on site.
The heat-transfer fluid pump must be servo-controlled by the
assembly if the unit is not equipped with the hydraulic module
option. Dedicated terminals are provided for installing the
heat-transfer fluid pump servo control (auxiliary operation
switch of the pump to be wired on site).
Machine with hydraulic module (option)
The "flow rate detection" functionality is handled by the
option via the pressure sensors.

8.5 - Frost protection

Damage caused by frost is not covered by the warranty.
The plate heat exchanger, the pipes and the hydraulic module
pump(s) can be damaged by frost. The components of the unit
(heat exchanger, pipes, hydraulic module) are protected by
following the recommendations below. Protection of the
remainder of the system is the responsibility of the installer.
The plate heat exchanger and all the components of the water
circuit can be protected against freezing by draining the entire
machine completely, checking that there are no retention
points.
If this is not possible, the plate heat exchanger and all the
components of the water circuit can be protected against
freezing:
• Down to -20°C by heaters and heat trace cables (fitted as
an option on the exchanger and internal pipe system)
supplied automatically (for units without the hydraulic
module)
• Down to -20°C by heaters and heat trace cables (fitted as
an option on the water type heat exchanger and internal
pipe system) supplied automatically and pump on/off
activation (for units with hydraulic module)
Never power off the heaters for the water exchanger and the
water circuit or pump, as they will no longer be providing frost
protection.
To ensure they continue to receive power, the main switch for
the unit or the customer's circuit and the auxiliary circuit
breaker for the heaters must be left closed (see the wiring
diagram for the location of these components).
To protect units with a hydraulic module from freezing, water
must be circulated in the water circuit by the pump, which is
activated at regular intervals.
Combination of options for the periods when the unit is
in standby mode.
Ambient unit
temperature range
without option 116
> 0°C to 48°C
-20°C to 0°C
Suitable antifreeze solution
(glycol, for example)
(1) Allow the pumps to circulate. If there is a valve, install a bypass (see diagram for winter position).
If the system is isolated by a valve, it is imperative to install a
bypass as indicated below.
Winter position
Unit
30RBM/30RBP 160-520
with option 116
-
Option 41 Option 42A(1)
or or
Suitable antifreeze solution
(glycol, for example)
Closed
Water network
Open
Closed
-
(1)
33