14
OPERATION
On a system operated with refrigerant R-407C, during the evaporation phase at constant pressure the temperature increases;
and during the condensation phase at constant pressure the temperature decreases a certain value. Consequently, the terms
“evaporation temperature” and “condensation temperature” should be redefined.
The refrigerant R-407C is a mixture of other three refrigerants that behave as pure compounds. This fact makes that the
operations of installation, service and maintenance must be special, for the next operations:
COMPRESSOR OIL
With HFC refrigerants as R-407C, the compressors incorporate ester oil instead of mineral oil used for R22 (HCFC).
LEAKS
If a leak takes place in the system that has produced an important evacuation of the refrigerant charge, instead of recharging
the system, it is convenient to eliminate the whole charge completely, the system must be evacuated and charged again or to
introduce the charge according to an specified value.
REFRIGERANT CHARGING
To maintain the mixture composition, the refrigerant must be charged always in liquid phase. For what it is necessary to have
special caution when it is little quantity of refrigerant in the bottle.
VACUUM OF THE SYSTEM (When the unit has loosed refrigerant charge).
Vacuum must be done until 0.225 mm Hg, since the compressor oil high hygroscopic degree can cause corrosion in some
metallic materials.
This unit can only work with R-407C Refrigerant.
Do not use another type of refrigerant.
SERVICE AND MAINTENANCE
PROTECTIONS ADJUSTMENT (FWCK / FWHK)
DESCRIPTION EFFECT
STD high pressure switch. (HP)
UNITS
FWHK FWCK
RATED
OFF ON
X X 28,7 kg/cm
2
24 kg/cm
2
Unit stops
RESET
Manual (electric)
High pressure switch (HP) with
presostatic valve as option.
N/A X 24 kg/cm
2
19 kg/cm
2
Unit stops Manual (electric)
Low pressure switch (LP). X X (*) 1,8 kg/cm
2
2,7 kg/cm
2
Unit stops Manual (electric)
Thermostat anti-freeze (BT). X N/A + 5ºC +7,3ºC
Unit stops Manual (electric)
Differential water switch (DFS). X N/A Without regulation Unit stops Manual (electric)
Flow switch (FS) option. X X
Nominal water flow
(see capacity tables)
Unit stops Manual (electric)
Heat overload sensor (ID). X N/A + 63ºC +46ºC
FWHK unit stops
on heating mode
1º automatic reset.
2º Press ON/OFF button
in the controller
Coil anti-freeze sensor (ID). X X + 0ºC (**) +12ºC
Cooling only units
or heat pump units
on cooling mode
stop.
Automatic
N/A: Not available.
(*) Not available for 04-06-07 models.
(**) With 0ºC during 1 min. and the compressor working during 10 min.
Manual (electric) reset means electrical reset for the unit turning the power off / on after the cause which produced the cut has
been repaired.
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