Emerson 318-6030, Инструкция по установке и эксплуатации

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2 • XR75CX I&O Manual 026-1210 Rev 0 09-FEB-2011
3 Controlling Loads
3.1. Compressor
The regulation is performed according to the tem-
perature measured by the thermostat probe with a pos-
itive differential from the setpoint: if the temperature
increases and reaches setpoint plus the differential,
the compressor is started and then turned OFF when
the temperature reaches the setpoint value again. In
case of a fault in the thermostat probe, the start and
stop of the compressor are timed through parameters
Con and CoF .
3.2. Defrost
Two defrost modes are available through the tdF
parameter: defrost through electrical heater ( tdF = EL )
and hot gas defrost ( tdF = in ).
The defrost interval depends on the presence of the
RTC (optional). If the RTC is present, it is controlled
by means of parameter EdF :
• with EdF = in the defrost is made every IdF time (the
standard method for the controller without RTC)
• with EdF = rtC , the defrost is made in real time de-
pending on the hours set in the parameters.
Ld1..Ld6 on workdays and in Sd1…Sd6 in holi-
days
Other parameters are used to control defrost cy-
cles: its maximum duration ( MdF ) and two defrost
modes: timed or controlled by the evaporator’s probe
( P2P ).
At the end of defrost dripping time is started, its
duration is set in the Fdt parameter. With Fdt = 0 , the
dripping time is disabled.
3.3. Control of Evaporator
Fans
The fan control mode is selected by means of the
Fnc parameter:
• Fnc = C_n : fans will switch ON and OFF with the
compressor and not run during defrost.
• Fnc = O_n : fans will run even if the compressor is
OFF, and not run during defrost; after defrost, there
is a timed fan delay allowing for drip time, set by
means of the
Fnd parameter.
• Fnc = C_y : fans will switch ON and OFF with the
compressor and run during defrost.
• Fnc = O_y : fans will run continuously during de-
frost also.
An additional parameter called FSt provides the
setting of temperature, detected by the evaporator
probe, above which the fans are always OFF. This is
used to make sure of air circulation only if this tem-
perature is lower than set in FSt .
3.3.1. Forced Activation of Fans
Managed by the FCt parameter, this function is
designed to avoid short cycles of fans that could occur
when the controller is switched ON or after a defrost,
when the room air warms the evaporator. Function-
ing: if the difference of temperature between the
evaporator and the room probes is more than the value
of the FCt parameter, the fans are switched ON.
When FCt = 0 , the function is disabled.
3.3.2. Cyclical Activation of the Fans
With Compressor Off
When Fnc = C-n or C-y (fans in parallel to the
compessor), by means of the Fon and FoF parameters
the fans can carry out ON and OFF cycles even if the
compressor is switched OFF. When the compressor is
stopped the fans continue working for the Fon time.
When Fon = 0 , the fans always remain OFF when the
compressor is OFF.
Figure 3-1 - Compressor Temperature Regulation