I A Operating Characteristics - Mitsubishi Electric CLIMAVENETA BRAN2 0021M Installation, User And Maintenance Manual

OPERATING CHARACTERISTICS
Cooling set point
(factory setting) = 12°C, Hysteresis = 3°C.
The compressor starts at outlet water temperatures above
12°C+3°C (15°C).
The compressor stops at water temperatures below 12°C.
In the event of temporary power failure, when power returns,
the mode set previously will be retained in the memory.
Heating set point
(factory setting) = 40°C, Hysteresis = 3°C.
The compressor starts at water outlet temperatures below
37°C.
The compressor stops at water temperatures above 40°C.
In the event of temporary power failure, when power returns,
the mode set previously will be retained in the memory.
COMPRESSOR START-UP DELAY
Two functions prevent the compressor from starting up too
frequently.
- Minimum time since last shut-down 180 seconds.
- Minimum time since last start-up 300 seconds.
CIRCULATING PUMP
The electronic board includes a pump control output. The
pump starts when "cool" mode is activated and stops a few
seconds after "standby" mode is selected.
After the first few seconds of pump operation when the
water flow is at full speed, the water flow alarm functions are
activated (differential pressure switch and flow switch).
FAN SPEED CONTROL
To enable the unit to function correctly at different outside
temperatures, a microprocessor with pressure reading via
pressure sensor controls the fan rotation speed. This allows
the exchange of heat to be increased and/or decreased,
maintaining condensing or evaporation pressures essential-
ly constant.
The fan operates independently of the compressor.
FROST ALARM
The frost protection function is always active, so as to prevent
the water freezing and damaging the plate heat exchanger; to
do this, the microprocessor shuts down the compressor if the
temperature measured by the heat exchanger outlet tempera-
ture sensor is less than: +4°C on the system side.
The frost prevention temperature set point can be modified
by an authorised service centre only and only after verifying
that the water circuit contains antifreeze.
Tripping of this alarm shuts down the compressor but not the
pump, which remains active.
To reset normal functions, the water outlet temperature must
rise to more than: +7°C on the system side.
Reset is manual.
30 BRAT2 - BRAN2 EN
WATER FLOW ALARM
The microprocessor provides for the management of a
water flow alarm controlled by a differential pressure switch
fitted as standard on the appliance and flow switches to be
installed on the water inlet piping.
This safety device may trip after the first 60 seconds of
pump operation when the water flow is up to speed.
Tripping of this alarm shuts down the compressor but not
the pump, which remains active.
The alarm is reset automatically is it lasts less than 20 sec.
If it lasts longer, it must be reset manually.
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