Evaporator Fan Control; Condenser Fan Control; Auxiliary Regulators; Analogue Outputs - Emerson DIXELL XWi70K Installing And Operating Instructions

NOTE:
All configured fans must have a valid Modbus address
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The internal logic controls the available fans in parallel mode: all (configured) fans will receive
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the same speed command.
Set S00=0 to disable condenser fans controlled via Modbus
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6

EVAPORATOR FAN CONTROL

The evaporator 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 also during defrost.
The par. FAP is used to select which temperature probe will be used from the evaporator fan regulator.
A specific setpoint (par. FSt) provides the temperature value, detected by the evaporator probe, above
which the fans are always OFF. This is used to make sure circulation of air only if his temperature is
lower than set in FSt-HYF.
6.1 FORCED ACTIVATION FOR EVAPORATOR FANS
This function, managed by the FCt parameter, is designed to avoid short cycles of fans, that could
happen when the controller is switched on or after a defrost, when the room air warms the evaporator.
If the difference between the evaporator temperature and the room temperature is higher than the FCt
value, the controller will activate the fans. This function is disabled if FCt=0.
6.2 CYCLIC ACTIVATION OF THE FANS WHEN THE COMPRESSOR IS OFF
When FnC=C-n or C-Y (fans in parallel to the compressor), the fans will be able to carry out on and off
cycles even if the compressor is switched off. The on and off interval of time follow the Fon and FoF
parameters. When the compressor is stopped, the fans will go on working for the Fon time. On the other
side, with Fon=0 the fans will stay always off when the compressor is off.
7

CONDENSER FAN CONTROL

The condenser fan control mode is selected by means of the FCC parameter:
FCC = C_n: fans will switch ON and OFF with the compressor and not run during defrost;
FCC = o_n: fans will run even if the compressor is off, and not run during defrost;
FCC = C_Y: fans will switch ON and OFF with the compressor and run during defrost;
FCC = o_Y: fans will run continuously also during defrost.
The par. FAC is used to select which temperature probe will be used from the condenser fan regulator.
This regulator uses a specific setpoint (par. St2) and differential (par. HY2) to activate and deactivate
the condenser fans:
If T>St2+HY2 the condenser fans are activated
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If T<St2 the condenser fans are deactivated.
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The par. FCo can be used to keep the ventilators active for a period after compressor OFF.
7.1 MODBUS CONFIGURATION
In case of fan controlled via Modbus, the following parameters need to be properly configured:
CMi: minimum speed in percentage
CMA: maximum speed in percentage
CSS: safety speed in case of any communication od regulation error
8

AUXILIARY REGULATORS

Up to 2 auxiliary regulators can be used. Both can be linked:
To a digital output (relay) for ONOFF regulation
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To an analogue output for proportional regulation
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The parameters used to configure the auxiliary regulators are the following:
ACH Type of action for auxiliary regulator
SAA Set point for auxiliary regulator
SHY Differential for auxiliary regulator
ArP Probe selection for auxiliary regulator
Sdd Auxiliary regulator disabled during any defrost
A2C Type of action for auxiliary regulator 2
SA2 Set point for auxiliary regulator 2
SH2 Differential for auxiliary regulator 2
Ar2 Probe selection for auxiliary regulator 2
Sd2 Auxiliary regulator 2 disabled during any defrost
9

ANALOGUE OUTPUTS

The controller is equipped with 2 configurable analogue outputs, type 4-20mA or 0-10Vdc (both
selectable). It is possible to use them for proportional regulation of:
Evaporator fan speed
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Condenser fan speed
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Or as proportional output linked to the:
Auxiliary regulator 1 (linked only to analogue output 1)
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Auxiliary regulator 2 (linked only to analogue output 2)
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The parameters used to configure the analogue outputs are the following:
1An Type of analogue output 1 (4,20mA or 0-10Vdc)
1oL Minimum value for analogue output 1 (in percentage)
1oH Maximum value for analogue output 1 (in percentage)
1At Start-up time with analogue output 1 at 100%
2An Type of analogue 2 output (4,20mA or 0-10Vdc)
2oL Minimum value for analogue output 2 (in percentage)
2oH Maximum value for analogue output 2 (in percentage)
2At Start-up time with analogue output 2 at 100%
1592026601 XWi70K STD FULL EN r1.6 2022.07.29.docx

10 VARIABLE SPEED DRIVE CONTROL

10.1 FREQUENCY MODE
The controller can drive variable speed drives with frequency control input. The frequency output port
can issue a frequency signal from 0 to 200Hz, duty cycle=50%. A special cable must be used to connect
the frequency output of the controller to the frequency input of the specific inverter.
CAB/EMB2: cable DD900002 20 for Embraco models
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CAB/SE1: cable DD900002 21 for SECOP NLV models
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NOTE:
An inverter compressor is totally controlled from the frequency output.
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Due to maximum current value of the frequency driver, only one compressor can be connected
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when frequency mode is used.
10.1.1 CABLES FOR FREQUENCY MODE CONTROL
10.2 SERIAL MODE CONTROL
The controller can drive variable speed compressors with serial control input. The speed command will
use RPM's (from 0 to 4500rpm) instead of values in Hertz. A special cable must be used to connect the
serial port of the controller to the serial port of the relative inverter.
CAB/EMB 1.5MT: cable DD190001 51 for Embraco models
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CAB/SE2 1.5MT: cable DD190001 52 for SECOP NLV models
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10.2.1 CABLES FOR SERIAL MODE CONTROL
10.3 PARAMETERS
The regulation band is from SET to SET+HY+HY1. When the regulation is running, the compressor
speed is continuously calculated and updated by the PI regulator.
I case of regulation probe error, the compressor speed will be set to the value of par. SPi.
It is possible to enable a cyclic or a continuous mode operation both during normal mode and energy
saving mode:
CMn, CME = Y: after reaching the SETPOINT the VSC will keep on running
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CMn, CME = n: after reaching the SETPOINT the VSC will be stopped
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10.4 HOT GAS DEFROST
If hot-gas defrost is selected, it will be possible to set the compressor speed by using par. Aod.
10.5 PULL DOWN
An automatic function named PULL DOWN is implemented. This function forces the controller to work
at FMA until reaching a specific SETPOINT (par. CCS) for a maximum interval of time (par. CCt). The
PULL DOWN function is activated:
At start-up if the temperature measured from the regulation probe is higher than the
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SET+HY+HY1
After any defrost
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If the temperature measured from regulation probe go over the SET+HY+HY1+oHt value.
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If one of the above conditions happens, the controller will maintain the maximum compressor speed
(FMA) until reaching the CCS setpoint. The maximum interval of time for any PULL DOWN is defined
from par. CCt. At the end of any PULL DOWN it is possible to set an interval of time (par. t1F) with
predefined compressor speed (FMi).
10.6 OIL MIGRATION CONTROL (VALID ONLY FOR VSD)
To avoid oil migration during variable speed compressor operation, a lubrication control is implemented.
If the compressor works with a speed lower than the MnP threshold for tMi time, then the compressor
speed will be increased to FMA for tMA time.
NOTES:
MnP= FMi to FMA, nu, OFF
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If MnP=nu, then this function is disabled
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XWi70K
GRAY → GND (-)
PINK → FREQ (+)
R- → GND
R+ → FREQ
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