Fast RCF Series, Manual

Page: 11 / 27

Heat recovery unit with cooling circuit - RCF -
0208-6180549-rev. 02
11
GB
Controls manual
The operating parameters are set in the
factory to control the unit depending on the
signals given by the temperature and pressure
probes.
There are 3 operating modes:
• Cooling
• Heating
• Stand-by
Cooling: this is the “summer” operating
mode; in this mode the unit is configu-
red to generate cold air.
Heating: this is the “winter” operating
mode; in this mode the unit is configu-
red to generate hot air.
Stand-by: in this mode the machine
does not perform temperature control
functions and all the alarms remain acti-
ve.
Setting set points
Activation or de-activation of the loads
varies dynamically according to the tempe-
rature control functions set, the temperature/
pressure values measured by the probes and
the set points.
Two set points are defined:
Cooling set point: this is the reference set
point when the unit is in Cooling mode
Heating set point: this is the reference set
point when the device is in Heating mode
Set points can be changed from the keyboard
by accessing submenu “SET” (see menu layout)
or by pressing the set button for 2 seconds.
Set points can be assigned values that fall
within a range determined by parameters Pa
H02 – Pa H01 (Heating) and Pa H04 – H03
(Cooling)
ON OFF from digital input
Digital inputs ID3, ID4, ID5 and AI4 (analogue
inputs) can be configured to give an ON-OFF
command. If this type of input is activated,
the instrument will turn off all loads and “E00”
appears on the display..
Electric heating coil (MBXxx) or water heating
coil (MBCxx) (accessories) (fig. 1)
In heating mode, the electric heaters or the
coils are activated when AI1 < (SET Heating
Functions
- Pa r14). If the heat pump is off because
the outdoor temperature is too low, the
electric heaters are directly controlled by
the heating set point.
Freecooling and freeheating (accessory
FCExx)
Freecooling and freeheating are used to
cool or heat the internal environment
using outdoor air. The external air enters
the environment through a damper that
mixes it with the recirculated air from insi-
de. Damper control is ON/OFF.
FREECOOLING
The freecooling set point is calculated by
subtracting the value equal to parameter
F26 (freecooling offset in cooling mode)
from the cooling set point. If the freecooling
set point were to coincide with the cooling
set point, the damper would close as the
same time as the compressors are switched
off and any energy saved by using colder
outdoor air would be lost.
This is valid if
• the outdoor temperature is lower than the
cooling set point
• the inside temperature is higher than the
outdoor temperature. If the inside tempera-
ture is lower than the outdoor temperature
and both are lower than the cooling set point,
the damper is completely open. The control
hysteresis is 10°C.
FREEHEATING
The freeheating set point is calculated by
adding the value equal to parameter F28
(freecooling offset in heating mode) to the
heating set point. If the freeheating set point
were to coincide with the heating set point,
the damper would close as the same time
as the compressors are switched off and any
energy saved by using warmer outdoor air
would be lost.
This is valid if
• the outdoor temperature is higher than the
heating set point
• the inside temperature is lower than the
outdoor temperature. If the inside tempera-
ture is higher than the outdoor temperature
and both are higher than the heating set
point, the damper is completely open. The
control hysteresis is 10°C.
Damper closed if temperature is low
Air that is too cold entering the environment
affects the well-being of its occupants. For
this reason, if the outdoor temperature is
lower than Pa F32 (freecooling shutdown
set point), the damper is forced to minimum
opening (Pa F31). If the outdoor temperature
is higher than Pa F32+ Pa F33, the freecoo-
ling control returns to normal.
Pa C04 Pa C04
Pa R14
ON R
ON COMP
SET POINT HEATING
OFF
R: electric heater
fig. 01