akc121Bb.pdf

(733 KB) Pobierz
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
Controllers for controlling
of refrigeration appliances
and cold rooms
AKC 121A and AKC 121B
Function description
REFRIGERATION AND
AIR CONDITIONING
865479775.106.png 865479775.117.png 865479775.128.png 865479775.139.png
Contents
Introduction ..........................................................................................................................................3
Thermostat function ............................................................................................................................4
1. ON/OFF - thermostat .................................................................................................................................................. 4
2. Modulating thermostat ............................................................................................................................................. 4
Night operation................................................................................................................................................................. 5
Settings ......................................................................................................................................................................... 5
Signal from gateway override function ............................................................................................................ 5
Defi nition of thermostat sensor locations ....................................................................................................... 5
Start and stop of control ......................................................................................................................7
Function switch ................................................................................................................................................................. 7
Forced closing.................................................................................................................................................................... 7
Day/night operation.............................................................................................................................8
Defrosting function ..............................................................................................................................9
Start of defrost ................................................................................................................................................................... 9
Defrost stop ..................................................................................................................................................................... 10
Start after defrost........................................................................................................................................................... 11
Gas defrost ....................................................................................................................................................................... 11
Defrost with warm brine ............................................................................................................................................. 11
Sensors ................................................................................................................................................12
Relay output DO1 ...............................................................................................................................12
Door function......................................................................................................................................12
Temperature alarms ...........................................................................................................................13
Alarm limits ..................................................................................................................................................................... 13
Time delay ........................................................................................................................................................................ 13
Language ............................................................................................................................................14
Clock function .....................................................................................................................................14
Supporting text ..................................................................................................................................14
Access codes........................................................................................................................................15
Display signal......................................................................................................................................15
Emergency refrigeration....................................................................................................................15
Sensor correction ...............................................................................................................................15
Alarms and messages.........................................................................................................................16
Service .................................................................................................................................................19
Measurements ................................................................................................................................................................ 19
Forced control of outputs ........................................................................................................................................... 19
Plant measurement/data ...................................................................................................................20
Operation of AKA 21..................................................................................................................................................... 20
PC operation.................................................................................................................................................................... 20
Installation considerations ................................................................................................................20
List of literature ..................................................................................................................................20
Validity
This function description was worked out in March 2004, and applies to AKA 121A with software
version 2.3x and AKC 121B software version 1.5x.
2
Function description RC.1M.D5.02
©
Danfoss
05/2004
AKC 121A / AKC 121B
865479775.001.png
Introduction
Together with valve and sensors, AKC 121A and AKC 121B constitutes a complete refrigerated surface
control for refrigeration appliances and small coldrooms.
The controller can be used in installations where injection of refrigerant is carried out by a thermo-
static expansion valve, or in installations where brine is the refrigerant.
The controllers functions replace all other automatic controls, containing, day and night thermostats,
defrost, fan control, rail heat control, alarm functions, etc. The controller is equipped with DANBUSS
data communication and is operated by means of control panel type AKA 21 and/or a PC.
The controller's main function is to control the
temperature via a signal from a temperature
sensor -SAir.
A solenoid valve is used as actuator.
Two refrigeration sections can be controlled. The
sections are marked A and B.
The temperatures are controlled individually in
the two sections, whereas the other functions,
like defrost start, night operation, rail heat etc.
are common functions.
• AKC 121A is used for controlling refrigeration
appliances
• AKC 121B is used for controlling cold rooms
Setting of the various functions takes place via a menu system. The menu system is based on several
levels according to the following principle.
Menu structure
Shown in the following section is the menu selection to be made to set the functions. The settings are
indicated the way they appear in the control panel type AKA 21, e.g.
Level 1
Level 2
Level 3
(Level 4)
Defrost Control
Scheduel Def.1 Start Times
No. Per Day ___
(Number of defrosts is set)
Def1 Sc1
Def1 Sc1 Hour ___
(Hour value is set)
The toal menu is contained in the document "Menu operation via AKA 21".
AKC 121A / AKC 121B
Function description RC.1M.D5.02
©
Danfoss
05/2004
3
865479775.012.png
Thermostat function
The controller is able to control the temperature in two sections.
In AKC 121A one or two sensors are placed in each section.
In AKC 121B only one sensor is placed in each section.
In each of the two sections the thermostat function must be defi ned. You may choose between:
1. ON/OFF - thermostat
The controller compares the measured air temperature in the section with the set temperature, and
when the air temperature drops to the cutout value, refrigeration is stopped (the relevant solenoid
valve closes).
Fan operation (AKC 121B only)
With a setting you select whether the fan is to operate or be stopped during the thermostat’s
cutout period.
2. Modulating thermostat
The control is in principle the same as the above mentioned one, but the control is now handled by
a PI function. This results in smaller fl uctuations of the regulating air temperature when loads are
stable, whereby a higher and more constant air humidity is obtained.
The function ensures constant temperature control with a temperature value placed halfway
between the thermostat’s cutin and cutout values.
The PI controller’s operating parameters are optimized automatic-ally via the set cutin and cutout
values and the valve’s opening degree.The diff erential will infl uence the controller’s amplifi cation,
and consequently it cannot be set lower than at 2K on account of the regulating stability.
4
Function description RC.1M.D5.02
©
Danfoss
05/2004
AKC 121A / AKC 121B
865479775.023.png 865479775.034.png 865479775.045.png 865479775.056.png 865479775.062.png 865479775.063.png 865479775.064.png 865479775.065.png 865479775.066.png 865479775.067.png 865479775.068.png 865479775.069.png 865479775.070.png 865479775.071.png 865479775.072.png 865479775.073.png 865479775.074.png 865479775.075.png 865479775.076.png 865479775.077.png 865479775.078.png 865479775.079.png 865479775.080.png 865479775.081.png 865479775.082.png 865479775.083.png 865479775.084.png 865479775.085.png 865479775.086.png 865479775.087.png 865479775.088.png 865479775.089.png 865479775.090.png 865479775.091.png 865479775.092.png 865479775.093.png 865479775.094.png 865479775.095.png 865479775.096.png 865479775.097.png 865479775.098.png 865479775.099.png 865479775.100.png 865479775.101.png 865479775.102.png 865479775.103.png 865479775.104.png 865479775.105.png 865479775.107.png 865479775.108.png 865479775.109.png 865479775.110.png 865479775.111.png 865479775.112.png 865479775.113.png 865479775.114.png 865479775.115.png 865479775.116.png 865479775.118.png 865479775.119.png 865479775.120.png 865479775.121.png 865479775.122.png 865479775.123.png 865479775.124.png 865479775.125.png 865479775.126.png 865479775.127.png 865479775.129.png 865479775.130.png 865479775.131.png 865479775.132.png 865479775.133.png 865479775.134.png 865479775.135.png 865479775.136.png 865479775.137.png 865479775.138.png 865479775.140.png 865479775.141.png 865479775.142.png 865479775.143.png 865479775.144.png 865479775.145.png 865479775.146.png 865479775.147.png 865479775.148.png 865479775.149.png 865479775.002.png 865479775.003.png 865479775.004.png 865479775.005.png 865479775.006.png 865479775.007.png 865479775.008.png 865479775.009.png 865479775.010.png 865479775.011.png 865479775.013.png 865479775.014.png 865479775.015.png 865479775.016.png 865479775.017.png 865479775.018.png 865479775.019.png 865479775.020.png 865479775.021.png 865479775.022.png 865479775.024.png 865479775.025.png 865479775.026.png 865479775.027.png 865479775.028.png 865479775.029.png 865479775.030.png 865479775.031.png 865479775.032.png 865479775.033.png 865479775.035.png 865479775.036.png 865479775.037.png 865479775.038.png 865479775.039.png 865479775.040.png 865479775.041.png 865479775.042.png 865479775.043.png 865479775.044.png 865479775.046.png 865479775.047.png 865479775.048.png 865479775.049.png 865479775.050.png 865479775.051.png 865479775.052.png
Melting function
(only for control of refrigeration where the temperature range is from -5 to +10°C). The function will
see to it that the refrigerated surface is not frosted over.
This function becomes operative whenever the valve’s accumulated ON time passes one hour. The
frost on the refrigerated surface will now be melted to water (or to ice, if there is a lot of frost). In
this way a better air fl ow is created at the refrigerated surface at the same time as the insulating
eff ect of the frost disappears.
Night operation
If night setback is required, you defi ne it by setting any value, except 0 (zero). A positive value will give
night setback, and a negative value will lower the temperatures.
The defi nition of night operation is described in the section named Day/night operation.
Settings
Select the thermostat function for the two sections by selecting number 1 or 2:
(1, if ON/OFF, 2, if modulating).
If a modulating thermostat is selected, the reference temperature will be the “set cutout temperature
plus half the diff erential”.
Confi guration Settings
Thermostat
TherMode A___
TherMode B___
Controller A
Thermostat Ctrl. Settings
CutOut °C A ___
Diff . K A ___
Dt Night A ___
Controller B......
..
Signal from gateway override function
Signals can be received from an override function via DANBUSS. When the off set signal is received, the
thermostat reference will change.
Defi nition of thermostat sensor locations
AKC 121B: The sensor can be placed in the air before or after the evaporator.
AKC 121A: There are three possible locations (1, 2 and 3), where the sensors are placed in the air right
in the evaporator inlet, in the evaporator outlet, or both before and after the evaporator:
1) Sensor is placed in the return air to the evaporator.
AKC 121A / AKC 121B
Function description RC.1M.D5.02
©
Danfoss
05/2004
5
865479775.053.png 865479775.054.png 865479775.055.png 865479775.057.png 865479775.058.png 865479775.059.png 865479775.060.png 865479775.061.png
 

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin