MCK-301
Control unit for middle- and low temperature
refrigerating machines with automatic defrost
1. ApplicationsThe MCK-301 is designed to control freezers, refrigerating counters, monoblocs and other refrigerating shop and industrial equipment.
The MCK-301 allows to monitor freezer and evaporator temperature and also, depending on a specified mode of operation, to monitor the second evaporator temperature or fan air stream temperature. The device permits to start automatic defrost at temperature difference between refrigerating chamber and fan air stream.
The MCK-301 can perform protective compressor cut-out if PTC- or NTC-type temperature sensor of compressor is connected to the MCK-301.
The MCK-301 provides safety compressor and fan stop under abnormal supply line parameters (the unit performs monitoring of RMS phase voltage and line voltage, phase imbalance, correct phase sequence and power contacts state of external magnetic starter before and after compressor cut-in) and also accomplishes a consequent automatic reset when voltage parameters regenerated after user-ser time delay has expired. 2. TECHNICAL BRIEF
2.1. Analog inputs: there are 3 inputs for NTC/PTC sensors with reinforced electric insulation for temperature monitoring and defrost control;
2.2. A digital input: can be used to connect a door alarm sensor or to control defrost (the decision is made according to "closed/open" state);
2.3. Main outputs:
- two-way break-before make relay output for the compressor control - 8A 250V at cos φ =1;
- a normally open relay output for the evaporator fan control - 8A 250V at cos φ =1;
- a normally open relay output for the electric heater control - 8A 250V at cos φ =1;
- an opto-triac output to start an alarm signalling - 60 mA 50Hz
2.4. Temperature resolution - 0.1 °C;
2.5. Trip threshold accuracy for voltage is no more than 3V;
2.6. Nominal supply voltage: one-phase voltage is 220V/50Hz or three-phase voltage is 380V/50Hz;
2.7. Operating voltage: 160V - 330V;
2.8. Power consumption is no more than 5Wt;
2.9. Enclosure: IP40;
2.10. Terminal block enclosure: IP20;
2.11. Operating temperature: -35 °C - +55 °C;
2.12. Storage temperature: -45 °C - +75 °C;
2.13. Weight is no more than 0,3kg;
2.14. Mounted on the standard 35 mm DIN-rail;
2.15. Mounting position is arbitrary;
2.16. Operating controls and the dimensions of the device are shown on fig.1.
3. PRE-SRARTING PROCEDURE
3.1. Connect compressor starter, fan, alarm bell, temperature sensors to the MCK-301 according to fig.2.
3.2. Plug-in the MCK-301.
3.3. Power ON and set required operation modes according to the table 2. NOTE. All connections must be performed on dead device.
Fig. 1. MCK-301 front panel, controls and dimensions.
Note . Button "▲" - UP in the text, button "▼" - DOWN in the text. INDICATION
3. LED COMP glows when compressor is ON;
4. LED FAN glows when fan is ON;
5. LED DEF glows when defrost conditions is ON;
6. LED SET glows when parameters setting mode is ON. Fig. 2. The MCK-301 connections to the three-phase mains supply.
Note 1. For the MCK-301 connection to single-phase mains supply the 1,2,3 terminals must be connected in parallel.
Note 2. Consumers are free to take their choice how to use three temperature sensors. For instance, the sensor inputs can be use as «two evaporators - the chamber», or «two evaporators - compressor», or just two temperature sensors etc.
4. The MCK-301 control levels
4.1. In the initial state the MCK-301 indicator displays an actual temperature of refrigerating chamber.
The MCK-301 provides three control levels.
4.2. A keyboard locking level.
Only viewing of the following parameters is available on this level:
- temperature setting, SP;
- first evaporator temperature, tS1;
- second evaporator temperature, tS2 (if parameter oO7=1) or fan air stream temperature, tEn (if parameter oO7=2);
- MCK-301 operation time, tbU;
- compressor operating time, tCO;
- compressor operating time to the MCK-301 operation time relation for the time set by user, dtt;
- A-phase voltage when U01=0 or AB-line voltage when U01=1, U_1;
- B-phase voltage when U01=0 or BC-line voltage when U01=1, U_2;
- C-phase voltage when U01=0 or CA-line voltage when U01=1, U_3;
To view parameters one needs to press simultaneously the DOWN and the UP buttons, the parameters scrolling is performed by the DOWN and the UP buttons, to access a parameter it's necessary to press the SET button.
When the keyboard is locked any button pressing (except simultaneous the UP and the DOWN buttons pressing) makes to appear the LOC label on the indicator. To unlock the keyboard the SET button is pressed. The "SET" LED lights up, and label "0" is blinking on the indicator. By the UP and DOWN buttons user enters a password digit from 1 to 9 and presses the DEF button. If the password is correct, the keyboard is unlocked. If after the keyboard unlocked no button is pressed during 16 sec and the lockage setting is not released by user, the keyboard is relocking.
4. 3 User level
This level allows:
- to start defrost or to stop defrost ahead-of-schedule and to go into the thermostat conditions by the DEF button pressing;
- to start refrigeration conditions by simultaneous the SET and DOWN buttons pressing;
- to change and to view the user level parameters;
- to view the adjuster level parameters.
To view and to change the user level parameters one needs to press the SET button, then "SET" LED will glow. Parameters scrolling is performed by the DOWN and UP buttons, to access a parameter one needs to press the SET button, parameter changing is effected by the DOWN and UP buttons, to set the parameter and go back into the MENU one needs to press the DEF button, going back to the menu without parameter setting is effected by the SET button. If no button is pressed during 16sec the MCK-301 goes into the initial state.
4. 4 Adjuster level
To access the adjuster level one needs to press and hold down SET button for 5sec. If the level is protected by a password, the label PAS appears on the indicator. Then press the SET button again. The "SET" LED lights up and the label "000" starts blinking on the indicator. Step-by-step enter three digits (from 1 to 9) of the adjuster password, pressing the DEF button on each digit entry. If the password is incorrect, the PAS label lights on (S is blinking), and the MCK-301 goes back to the initial state in 16 sec, otherwise the first parameter of the adjuster menu appears on the indicator;
Parameters scrolling is performed by the DOWN and UP buttons, to access a parameter one needs to press the SET button, parameter changing is effected by the DOWN and UP buttons, to set a parameter and go back into the menu one needs to press the DEF button, going back to the menu without parameter setting is effected by the SET button. If no button is pressed during 16 sec the MCK-301 goes into the initial state;
On the adjuster level the access to any user level parameter can be inhibited or permitted by simultaneous the SET and DOWN buttons pressing. If the access is inhibited a point indication appears on the right digital indicator when one is viewing the parameter value.
5.The MCK-301 modes of operation5.1. The MCK-301 supports the following modes of operation:
- thermostat conditions;
- refrigeration conditions;
- alarm conditions.
The MCK-301 in the thermostat conditions maintains preset temperature in the chamber, performs defrost and the condensate drip-off.
The MCK-301 in the refrigeration conditions performs refrigeration, defrost delay, defrost.
5.2. Thermostat conditions
5.2.1 When working in the thermostat conditions the MCK-301 holds the user-preset chamber temperature by the compressor and the fan operation control.
Chamber temperature change diagram and time diagrams of the MCK-301output relays operation (for producer-set parameter values by default).
c02 - compressor start delay
dit - chamber temperature maintenance
dEt - defrost
ddt - drip- off
SP - setting (temperature set by user)
DiF - differential
Compressor relay
Fan relay
Fans are ON and OFF together with the compressor (FCo=0)
Heater relay
Defrost by the electric heater (tdF=0)
Fan relay
Fans are ON and OFF together with the compressor (FCo=0)
Heater relay
Defrost by the electric heater (tdF=0) 5.2.2. Compressor operation
SP (Set Point) and dif (differential) parameters specify chamber temperature condition. If chamber temperature raised and reached value equal to SP+dif, compressor starts and it would stop only when temperature is down again reaching Set Point value.
LSE and HSE (a minimum and a maximum Set Point values) limit SP change area for user.
On the chamber sensor fault the compressor control is performed in fault condition (alarm conditions) according to the parameters that specify compressor operation time and compressor stop time. In this case the corresponding indication label appears on the indicator.
5.2.3. Fan operation.
Fan control type is selected according to FCo parameter:
FCo =0 - fans start and stop together with compressor;
FCo=1-fans operate without interruption.
If a maximum temperature value specified by FSt parameter is exceeded the fan is always off.
On the evaporator sensor fault MCK-301 initiates the label Er4 or Er5 appearance on the indicator (as well as the chamber temperature).
5.3 Defrost
5.3.1. The MCK-301 allows to specify defrost type, defrost stop type and between-defrost delay count method.
The defrost type can be specified according to tdF parameter:
tdF=0 - defrost by electric heater (compressor is off, electric heater is on);
tdF=1 - defrost by hot gas (compressor is on, electric heater is on);
tdF=2 - free defrost (compressor is on, electric heater is off);
Defrost stop type is specified according to EdF parameter:
EdF=0 - according to time (dEt parameter specifies defrost duration, min);
EdF=1 - when preset evaporator temperature is reached (dSt parameter specifies
defrost stop temperature, ° C);
EdF=2 - according to time and when preset evaporator temperature is reached (defrost stop is specified by dEt or dSt parameter depending on the parameter value which is reached first).
Between-defrost-cycles interval count method is specified by dCt parameter:
dCt=0 - according to user-set time (dit parameter specifies time interval between two defrost cycles);
dCt=1 - according to compressor operating time (DIGIFROST method, dit parameter specifies compressor operating hours between two defrost starts);
dCt=2 - compressor stop (defrost starts on every defrost stop).
Defrost start conditions is specified by d13 parameter:
d13=0 - according to time (dCt parameter is used);
d13=1 - defrost start is specified by temperature difference (d14 parameter, ° C) between refrigerating chamber and fan output stream (if the third temperature sensor either is absent/ out of order or used as the second evaporator temperature sensor, the 0 mode is effected).
5.3.2. Condensate drip-off.
On defrost stop the MCK-301 starts time delay for condensate drip-off (ddt parameter). Besides, it's specified the fan start delay after defrost (Fdt parameter, min). The compressor and the electric heater are also off. The label SLI appears on the indicator.
5.4. Refrigeration conditions.
This mode of operation is designed for a quick refrigeration of the chamber filled with a new (warm) product.
5.5. First start features.
User is free to pre-specify a performance type the unit will follow when power is ON:
The performance type can be selected as:
- an operation in the thermostat conditions immediately after power is ON (dPO =0)
during the time set by c02 parameter (this mode of operation starts with 30 sec delay after StA indication appears);
- first defrost after 30sec delay from the unit start-up moment has expired (dPO=1).
The MCK-301 operation diagram in the refrigeration conditions (for the parameter values preset by producer). 
CCt parameter specifies the refrigeration time.
dAF parameter specifies the start-of-defrost delay, i.e. the time before the start of the first defrost after the refrigeration time has expired.
When the refrigeration/ the defrost conditions is over, the MCK-301goes into the thermostat conditions automatically.
Compresso relay
6. Fault states control system.
In the thermostat conditions the unit performs the chamber temperature monitoring and detects when the temperature is outside the preset range (LAL and HAL parameters). This kind of monitoring is not performed in the refrigeration conditions and defrost conditions.
According to the preset additional temperature sensors (d10, o07) connection parameters the unit performs sensors short-circuit & disconnection monitoring.
If an open door state time exceeds user-preset time (AO7) parameter the situation considered to be a fault state.
The MCK-301performs power supply voltage parameters monitoring in all modes of operation and when the power supply parameters deviate from the set range, the MCK-301 stops the compressor, the fan, the electric heater and cuts-in the alarm signal. On return to normal operating conditions for power supply parameters the MCK-301 resets back to the conditions where voltage fault occurred after U05 reset delay has expired, if only user-set power voltage regeneration time doesn't exceed Utt parameter. If yes, the MCK-301 begins to perform the program executing from the start-up.
When U08=1 the MCK-301 performs a voltage monitoring at the compressor starter output terminals and stops the compressor, the fan, the electric heater and triggers the alarm signal if the starter contacts stick. To recover from this fault and from the fault induced by incorrect phase sequence one needs to restart the MCK-301.
When o07=3 or o07=4 (the third temperature sensor is used as the compressor temperature sensor) MCK-301 determines the compressor temperature sensor resistance and if the resistance is above (below) the resistance set by rd3 parameter, it stops the compressor. The compressor will reset when the time delay specified in td3 parameter has expired.
All fault state codes are displayed on the digital indicator according to the table 1.
| Fault signals on the indicator |
Alarm signals on the indicator |
| Fault in controller |
Er1 |
High temperature |
A1 |
| Disconnected refrigerating chamber sensor |
Er2 |
Low temperature |
A2 |
| Short-circuited refrigerating chamber sensor |
Er3 |
Open door |
A3 |
| Disconnected (evaporator) defrost sensor |
Er4 |
Compressor temperature is exceeded |
A4 |
| Short-circuited (evaporator) defrost sensor |
Er5 |
Minimum voltage |
U1 |
| Disconnected the third temperature sensor |
Er6 |
Maximum voltage |
U2 |
| Short-circuited the third temperature sensor |
Er7 |
Phase imbalance |
U3 |
|
|
Voltage failure at starter terminals |
U4 |
|
|
Incorrect phase sequence |
U5 |
|
|
Phase failure |
U6 |
7. Programmable and used parameters are given in table 2.
Refrigerator control unit modes of operation
Table 2
| Settings and read-off parameters |
Param eter codes |
Mini- mum values |
Maxi- mum values |
Facto- ry Setting |
Operation |
| Temperature control Temperature SP |
|
-60 °C |
50 °C |
3 °C |
Setting (refrigeration chamber temperature value set by user) |
| Thermostat |
In thermostat mode compressor starts if temperature reaches SP plus differential, and stops if temperature reaches SP |
| Differential |
diF |
1 °C |
20 °C |
2 °C |
Difference between the set temperature and the compressor start temperature |
| Upper temperature bound |
HSE |
0 °C |
60 °C |
50 °C |
Adjuster level
The limitation means that temperature which is higher than HSE can not be set by user |
| Lower temperature bound |
LSE |
-60 °C |
HSE |
-60 °C |
Adjuster level The limitation means that temperature which is lower than LSE can not be set by user |
| Chamber temperature sensor calibration |
CA1 |
-20°C |
+20°C |
0 °C |
CA1 scale shift from chamber temperature read by sensor |
| Evaporator temperature sensor calibration |
CA2 |
-20°C |
+20°C |
0 °C |
CA2 scale shift from evaporator temperature read by sensor |
| Fan air stream temperature sensor calibration |
CA3 |
-20°C |
+20°C |
0 °C |
CA3 scale shift from fan air stream temperature read by sensor (the second evaporator) |
| Temperature scale |
C_F |
0 |
1 |
0 |
0-Celsius degrees
1- Fahrenheit degrees
- Fahrenheit temperature scale is not used in this version |
| Alarm signaling |
|
Fault temperature setting mode
0 - absolute temperature value
1 - temperature value relative to the setting |
Att |
0 |
1 |
1 |
Interpretation HAL and LAL values
Alarm starts:
a) in "0" mode - when set HAL and LAL values are reached
b) in "1" mode - when upper temperature is SP+ diF+HAL - when lower temperature is SP-LAL |
| Positive temperature deviation |
HAL
Att=0
Att=1 |
LAL+1
1 |
50
50 |
5 |
|
| Negative temperature deviation |
LAL
Att=0
Att=1 |
-60 |
HAL-1 |
5 |
|
| Temperature alarm delay |
tAO |
0 |
90 min |
30 min |
|
| Temperature alarm delay after power is ON |
PAO |
0 |
48 hours |
2 hours |
|
| Temperature alarm delay after defrost and refrigeration mode |
dAo |
0 |
10 hours |
1 hour |
|
| Door alarm trip delay |
A07 |
0 |
90 min |
30 min |
|
| Compressor |
|
| Minimum ON-time |
c01 |
1 min |
15 min |
5 min |
Compressor protection against frequent cut-ins. |
| Minimum OFF-time |
c02 |
1 min |
15 min |
5 min |
|
| Compressor ON-time at refrigerating chamber sensor failure |
COn |
5 min |
120 min |
20 min |
Controller will use this value throughout the first three days and nights, then it will calculate the value by itself |
| Compressor OFF-time at refrigerating chamber sensor failure |
COF |
5 min |
120 min |
30 min |
Controller will use this value during the first three days and nights, then it will calculate the value by itself |
| Compressor and fan state at open door |
CFo |
0 |
3 |
0 |
0 - normal mode of operation
1 - compressor is ON, fan is OFF
2 - compressor is OFF, fan is ON
3 - compressor is OFF, fan is OFF |
| Compressor protection at thermal sensor failure |
cPP |
0 |
2 |
2 |
0- Compressor is constantly OFF
1- Compressor is constantly ON
2- COn and COF parameters are used |
| Compressor ON-time in refrigeration mode |
CCt |
1 h |
24 h |
6 h |
|
| Defrost |
|
| Defrost method (gas -1, electricity-0) |
tdF |
0 |
2 |
0 |
0 - compressor is OFF, electric heater is ON
1 - hot steam defrost - compressor is ON, electric heater is ON
2 - compressor is ON, electric heater is OFF |
| Defrost stop temperature |
DSt |
0 °C |
25°C |
6 °C |
Temperature is measured on the evaporator |
| Interval between defrost starts |
Dit |
1 h |
48 h |
6 h |
|
| Between-defrost- starts interval counting method |
DCt |
0 |
2 |
1 |
Between-defrosts counting method
1 - DIGIFROST method. Defrost start time (dit) is specified by the compressor total ON-time
0 - real time - defrost starts frequency is specified by real time elapsed; the interval between defrosts is always alike
2 - compressor stop; defrost starts with every compressor stop |
| Maximum defrost duration |
DEt |
0 min |
180 min |
30 min |
|
| First defrost start delay after the refrigeration mode is completed |
dAF |
0 min |
60 min |
0 min |
|
| Condensate drip-off time |
ddt |
0 min |
90 min |
3 min |
|
| Fan start delay after defrost |
Fdt |
0 min |
20 min |
1 min |
|
| Fan cut-in during defrost |
dFd |
0 |
1 |
0 |
0 - OFF
1 - ON |
| Defrost sensor |
d10 |
0 |
1 |
1 |
0 - no
1 - yes |
| Indicator readings during defrost |
ddL |
0 |
3 |
0 |
0- real temperature
1- defrost start temperature
2- Setting value (SP)
3- Label dEF |
| Defrost after start-up |
dPO |
0 |
1 |
0 |
0 - no
1 - yes |
| Defrost start mode |
d13 |
0 |
1 |
0 |
0 - according to time
1 - according to temperature difference between refrigerating chamber temperature and fan output stream temperature.
If the third temperature sensor is absent or used as the second evaporator temperature sensor the "0" mode is performed |
| Temperature difference in the 1 defrost start mode of operation (d13=1) |
d14 |
1 °C |
30 °C |
3 °C |
|
| Defrost stop type |
EdF |
0 |
2 |
0 |
EdF=0 - according to time (parameter dEt)
EdF=1 - when preset evaporator temperature is reached (parameter dSt)
EdF=2 - according to time and temperature (depending on which of the parameter value is reached first). |
| FAN |
|
| Fan cut-out at compressor stop |
Fco |
0 |
1 |
1 |
0 - yes
1 - no |
| Fans cut-out temperature |
FSt |
-20 °C |
30 °C |
2 °C |
When this temperature is exceeded, the fan always stops. -- measured on the evaporator |
| VARIA |
|
| Digital input signals |
o01 |
0 |
2 |
1 |
0 - not used
1 - door alarm
2 - defrost
Door alarm: if single-pole N.C. contact is broken down, door alarm starts
Defrost: if single-pole contact is broken down, defrost starts |
| MCK-301 ON time (1 unit == twenty four hours) |
tbU |
0 u. |
999 u. |
0 u. |
|
| Compressor ON time (1 unit == twenty four hours) |
tCO |
0 u. |
999 u. |
0 u. |
|
| Time (1 unit == twenty four hours) |
ttt |
1 u. |
15 u. |
1 u. |
The time for calculation of the dtt relation |
| User access code |
LOC |
0 |
9 |
0 |
0 - keyboard is unlocked
1-9 - user password |
| Adjuster access code |
PAS |
000 |
999 |
123 |
000 - access to the adjuster level is permitted
000-999 - adjuster password |
| Temperature sensors type |
tPd |
0 |
1 |
1 |
0 - NTC,
1 - PTC (in this version NTC type sensors are not used) |
| Third temperature sensor |
o07 |
0 |
2 |
0 |
0 - OFF
1 - used as the second evaporator temperature sensor
2 - used as output air stream fan temperature sensor
3 - used as compressor temperature PTC-sensor
4 - used as compressor temperature NTC- sensor |
| Reset delay |
td3 |
10 min |
300 min |
30 min |
Compressor reset delay after temperature failure |
| Third temperature sensor critical resistance |
rd3 |
0.45
kOm |
1.3 kOm |
1.0 kOm |
When the third temperature sensor resistance is exceeded (o07=3), compressor stops. If o07=4, compressor stops when the resistance is lower than the set one. |
| VOLTAGES |
|
| Measured voltage |
U01 |
0 |
1 |
0 |
0 - phase voltage
1 - line voltage |
| Minimum voltage |
U02 |
160-
270 V |
280-
475 V |
185-
315 V |
U01=0
U01=1 |
| Maximum voltage |
U03 |
160-
270 V |
280-
475 V |
245-
415 V |
U01=0
U01=1 |
| Phase imbalance |
U04 |
5 V
5 V |
50
85 V |
20
35 V |
U01=0
U01=1 |
| Reset delay |
U05 |
5 s |
300 s |
10 s |
|
| Minimum voltage cutout delay |
U06 |
5 s |
30 s |
10 s |
|
| All failure types delay |
U07 |
0 s |
30 s |
1 s |
|
| Starter terminals voltage monitoring |
U08 |
0 |
1 |
0 |
1 - cut-in
0 - cut-out |
| Time, if exceeded MCK-301 initiates a program performance from the start-up after voltage failure |
Utt |
0 min
|
180 min |
10 min |
|
| Device version |
rEL |
|
|
|
| |
