Controller for operation of evaporator on
water chiller
EKD 316
Manual
Contents
Introduction........................................................................................................ 2
Operation............................................................................................................. 3
Survey of functions........................................................................................... 4
Operation............................................................................................................. 7
Menu survey........................................................................................................ 7
Data........................................................................................................................ 9
Connections........................................................................................................ 9
Ordering............................................................................................................... 9
Start of controller............................................................................................10
If the superheating fluctuates....................................................................12
Check that the ETS valve closes when the supply voltage to the
controller is interrupted................................................................................12
Introduction
Application
The controller and valve can be used where there are requirements to accurate control of superheat and temperature in connection with refrigeration.
E.g.:
• Processing plant (water chillers)
• Cold store (air coolers)
• A/C plant
Advantages
• The evaporator is charged optimally – even when there are great
variations of load and suction pressure.
• Energy savings – the adaptive regulation of the refrigerant injection ensures optimum utilisation of the evaporator and hence a
high suction pressure.
• The superheating is regulated to the lowest possible value.
Regulation
Independent superheat regulation
The superheat in the evaporator is controlled by one pressure
transmitter P and one temperature sensor S2.
The expansion valve is with step motor of the type ETS.
Fitting the "S4" temperature sensor is optional, but the regulation is improved by an "inner loop control" when the sensor is
fitted.
Functions
• Regulation of superheat
• Temperature control
• MOP function
• ON/OFF input for start/stop of regulation
• Relay output to alarm
Valve driver (alternative use)
This is where the controller receives signals from another controller, after which it controls the valve’s opening degree.
The signal can either be a current signal or a voltage signal.
The valve can either be an ETS type or KVS type.
o61 = 2
o61 = 1
Function
• Valve driver
Battery
For safety reasons the liquid flow to the evaporator must be cut
off if there is power failure for the controller. As the ETS valve is
provided with step motor, it will remain open in such a situation.
When mounting the battery backup, the valve will close in the
event of a power cut.
Small capacities
If the controller is used for plants with smaller capacities than an
ETS 12½, a ETS 6 or Saginomiya valve type SKV, VKV or PKV can be
connected.
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EKD 316
Operation
Superheat function
You may choose between two kinds of superheat, either:
• Adaptive superheat or
• Load-defined superheat
MOP
The MOP function limits the valve’s opening degree as long as the
evaporating pressure is higher than the set MOP value.
External start/stop of regulation
The controller can be started and stopped externally via a contact
function connected to input terminals 20 and 21. Regulation is
stopped when the connection is interrupted. The function must
be used when the compressor is stopped. The controller then
closes the ETS valve so that the evaporator is not charged with
refrigerant.
Relays
The relay for the alarm function is an alternating relay.
It is the link between terminals 24 and 25 in alarm situations and
when the controller is dead.
Operation
You cannot operate the controller directly, but it is fixed with data
communication that can be used in one of the following two
ways:
• To connect an external display.
You can then operate it using the display’s control buttons
• To connect a system unit with MODBUS communication.
It can then be operated from a PC which has AK-ST software
loaded.
The controller cannot be operated via AKM type system software.
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3
Survey of functions
Function
Para- Parameter by operation via
meter data communication
Normal display
Normally the superheat is shown
The opening degree is displayed during manual operation or if the valve is under
analogue control.
Reference
Unit
Here you select whether the controller is to indicate the temperature values in °C or
in °F.
And pressure values in bar or psig.
If indication in °F is selected, other temperature settings will also change over to
Fahrenheit, either as absolute values or as delta values
The combination of temperature unit and pressure unit is depicted to the right.
Correction of signal from S2
(Compensation possibility through long sensor cable).
Correction of signal from S4
(Compensation possibility through long sensor cable).
Start/stop of refrigeration
With this setting refrigeration can be started and stopped. Start/stop of refrigeration
can also be accomplished with the external switch function. See also appendix 1.
SH / OD% r05
Miscellaneous
Units (Menu = Misc.)
0: °C + bar
1: °F + psig
r09
Adjust S2
r10
Adjust S4
r12
Main Switch
Alarm
Alarm setting
If there is an alarm, the LEDs on the front of the external display will flash if it is connected. The alarm relay in the controller is closed.
Battery alarm
Here it is defined whether the controller is to monitor the voltage from the battery
backup. If there is low voltage or no voltage alarm will be given.
Control parameters
Valve definition
0: ETS 12.5, ETS 25
1: ETS 50
2: ETS 100
3: ETS 250
4: ETS 400
5: User defined (n37 and n38 must be set)
6: ETS 6/ Saginomiya UKV, SKV, VKV, PKV
P: Amplification factor Kp
If the Kp value is reduced the regulation becomes slower.
I: Integration time Tn
If the Tn value is increased the regulation becomes slower.
D: Differentiation time Td
The D-setting can be cancelled by setting the value to min. (0).
Max. value for the superheat reference
Min. value for the superheat reference
Warning! Due to the risk of liquid flow the setting should not be lower than approx.
2-4 K.
MOP
If no MOP function is required, select pos. Off.
Start-up time for safety signal
If the controller does not obtain a reliable signal within this period of time the controller will in other ways try to establish a stable signal. (A too high value may result in
a flooded evaporator).
The value should only be changed by specially trained staff.
Signal safety during start-up
The control function uses the value as start value for the valve’s opening degree at
each thermostat cutin. By adaptive control the controller continuously calculates a
new value.
The value should only be changed by specially trained staff.
Stability factor for regulation of superheat
With a higher value the control function will allow a greater fluctuation of the superheat before the reference is changed. The value should only be changed by specially
trained staff.
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A34
Batt. alarm
n03
Injection control
Valve type
n04
Kp factor
n05
Tn sec.
n06
Td sec.
n09
Max SH
n10
Min SH
n11
n15
MOP (bar)
(A value of 20 corresponds to Off )
StartUp time
n17
Start OD%
n18
Stability
EKD 316
Damping of amplification near reference value
This setting damps the normal amplification Kp, but only just around the reference
value. A setting of 0.5 will reduce the KP value by half.
The value should only be changed by specially trained staff.
Amplification factor for the superheat
This setting determines the valve’s opening degree as a function of the change in
evaporating pressure. An increase of the evaporating pressure will result in a reduced
opening degree. When there is a drop-out on the low-pressure thermostat during
start-up the value must be raised a bit. If there is pendling during start-up the value
must be reduced a little.
The value should only be changed by specially trained staff.
Definition of superheat regulation (Ref. appendix 2)
1: Lowest permissible superheat (MSS). Adaptive regulation.
2: Load-defined superheat. The reference is established based on the line formed by
the three points: n09, n10 and n22.
Value of min. superheat reference for loads under 10%
(The value must be smaller than ”n10”).
Max. opening degree
The valve’s opening degree can be limited. The value is set in %
n19
Kp Min
n20
Kp T0
n21
SH mode
n22
SH Close
n32
ETS OD% Max
Number of steps from 0% to 100% open (User defined valve, n03 =5)
(Automatic setting when valve is selected in n03)
Spindle stroke speed (number of steps per second)
(Automatic setting when valve is selected in n03)
Integration time for the inner loop gain
Used only when o56 = 2
The value should only be changed by specially trained staff.
n37
Max. steps (100 to 6000 step)
n38
Steps / sec (5 to 300step/sec)
n44
TnT0 sec
Miscellaneous
Miscellaneous
Address/data communication
The controller must always have an address. The factory-set address is 240.
When an external display is connected, the display itself will find the address of the
controller so that communication can take place.
A display and a system unit must not be connected at the same time. The display
will not be able to communicate in this situation.
The controller can be operated via the
system unit and AK service tool.
It cannot be operated via AKM type
system software.
If the controller is to be part of a network with other controllers and a system unit, the
controller's address must be within the range 1 to 200.
This address must EITHER be set via a display before it is connected to the data communication and a scan of the network is performed
OR the network is connected and a scan is performed. The address is then set afterwards. A new scan is performed so that the new address is known.
Requirements for the installation and data communication cable are discussed in the
separate document no. "RC8AC".
o03
Application mode
1: The controller receives signals from another controller and must control the valve’s
opening degree.
2: Superheat regulation
Input signal for external control of the valve's opening degree
Only used if o61 is set to 1.
Definition of the signal's range.
0: No signal
1: 0-20 mA
2: 4-20 mA
3: 0-10 V
4: 1-5 V
(At the lower value the valve will be closed. At the upper value the value will be fully
open. There is a linear relationship between the signal and the opening degree. The
height of the valve is not taken into account.)
Manual control of outputs
For service purposes the ETS-output and alarm relay outputs can be forced
However only when regulation has been stopped.
OFF: No override
1: Manual control via o45 is enabled
2: The alarm relay releases so that there is a connection between 24 and 25 (= alarm)
3: The alarm relay picks up so that there is a connection between 25 and 26 (= no alarm)
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Manual RS8EH802 © Danfoss 11-2011
o61
Unit addr.
The address is set between 0 and 200.
(When the address is set the system
unit’s scan function should be activated.)
Appl. mode
o10
AI type
o18
Manual ctrl
5
Manual control of the ETS valve
The valve’s opening degree can be set manually.
However, it does require "o18" to be set to "1", "2" or "3".
This function must only be used for manual operation. It must not be used for external control.
Working range for pressure transmitter
Depending on the application a pressure transmitter with a given working range
is used. This working range (say, -1 to 12 bar) must be set in the controller. The min.
value is set.
o45
Manual ETS OD%
o20
MinTransPres.
The max. value is set
Selection of control algorithm
Depending on the application control can be carried out based on different parameters.
The two possibilities are shown in appendix 3.
1=normal control
2=with inner loop regulation and S4 temperature less T0
o21
o56
MaxTransPres.
Reg. type *
Refrigerant setting
Before refrigeration can be started, the refrigerant must be defined. You can select the
following refrigerants:
1=R12. 2=R22. 3=R134a. 4=R502. 5=R717. 6=R13. 7=R13b1. 8=R23. 9=R500. 10=R503. 11=R114. 12=R142b. 13=User defined. 14=R32. 15=R227. 16=R401A. 17=R507. 18=R402A. 19=R404A. 20=R407C. 21=R407A. 22=R407B. 23=R410A. 24=R170. 25=R290. 26=R600. 27=R600a. 28=R744. 29=R1270. 30=R417A. 31=R422A
(Warning: Wrong selection of refrigerant may cause damage to the compressor).
Service
A number of controller values can be printed for use in a service situation
Read value of external current signal / voltage signal (Ext.Ref.)
Read status of input DI (start/stop input)
o30
Refrigerant
u06
u10
Analog input
DI
Read the temperature at the S2 sensor
Read superheat
Read the control’s actual superheat reference
Read the valve’s opening degree
Read evaporating pressure
Read evaporating temperature
Read the temperature at the S4 sensor
u20
u21
u22
u24
u25
u26
u27
S2 temp.
SH
SH ref.
OD%
Evap. pres. Pe
Evap.Press.Te
S4 temp.
Service
-Operating status
The controller’s operating status can be called forth by a brief (1s) activation of the
upper button. If a status code exists it will be shown. (Status codes have lower priority
than alarm codes. This means that status codes cannot be seen if there is an active
alarm code.
The individual status codes have the following meanings:
S10: Refrigeration stopped by the internal or external start/ stop.
DO1 Alarm
Read status of alarm relay
EKC State
(0 = regulation)
10
* After o56 is changed, the controller must be switched off and powered up again.
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EKD 316
Operation
Via data communication
If you operate the controller via data communication, you must
use the descriptions detailed on previous pages. Here the function
is referred to in the column to the right.
Via external display
If you use an external display to operate the controller this must
be done as follows:
The values will be shown with three digits, and with a setting you
can determine whether the temperature are to be shown in °C or
in °F. (Pressure in bar or psig.)
The buttons
When you want to change a setting, the upper and lower buttons
will give you a higher or lower value depending on the button
you are pushing. But before you change the value, you must have
access to the menu. You obtain this by pushing the upper button
for a couple of seconds - you will then enter the column with
parameter codes. Find the parameter code you want to change
and push the middle button until the value for the parameter is
shown. When you have changed the value, save the new value by
once more pushing the middle button.
Example
Set a menu
1. Push the upper button until a parameter is shown
2. Push the upper or the lower button and find the parameter you
want to change
3. Push the middle button and the value is shown
4. Push the upper or the lower button and select the new value
5. Push the middle button again to conclude the setting
By pushing the middle button you go directly to setting Kp (n04
value).
Menu survey
Parameter
Function
Min.
Fac.
setting
Max.
The menus from either column 1 or column 2 are shown
SW =2.2x
Application
choise
menu = o61
1
2
Normal display
During regulation the actual level of superheating is displayed.
(If you would like to see the expansion valve’s actual opening degree, press the bottom button for about a second.)
During control with an analogue signal the opening degree is displayed.
-
K
-
-
%
-
Reference
Units (0=°C+bar /1=°F+psig)
r05
0
1
0
Correction of signal from S2
r09
-10.0 K
10.0 K
0.0
Correction of signal from S4
r10
-10.0 K
10.0 K
0.0
Start / stop of refrigeration
r12
Off / 0
On / 1
Off / 0
Battery monitoring
A34
Off / 0
On / 1
Off / 0
Regulating parameters
Valve definition:
0=ETS 12½ & ETS 25, 1=ETS 50, 2=ETS 100, 3=ETS 250, 4=ETS 400, 5=User defined, 6=ETS 6, Saginomiya type UKV/
SKV/VKV/PKV
P: Amplification factor Kp
n03
0
6
1
n04
0.5
20
3.0/0.7
I: Integration time T
n05
30 s
600 s
120
Alarm
D: Differentiation time Td (0 = off )
n06
0s
90 s
0
Max. value of superheat reference
n09
2K
15 K
10
Min. value of superheat reference
n10
1K
12 K
6
MOP (max = off )
n11
0.0 bar
20 bar
20
Signal reliability during start-up. Safety time period.
Should only be changed by trained staff
n15
0 sec.
90 sec
0
Signal reliability during start-up – Opening degree’s start value. Should only be changed by trained staff.
n17
0%
100%
0
Stability factor for superheat control.
Changes should only be made by trained staff
n18
0
10
5
Damping of amplification around reference value
Changes should only be made by trained staff
n19
0.0
1.0
0.3
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Amplification factor for superheat
Changes should only be made by trained staff
n20
0.0
10.0
0.4/3.0
Definition of superheat control
1=MSS, 2=LOADAP
n21
1
2
1
Value of min. superheat reference for loads under 10%
n22
1K
15 K
4
n32
0%
100 %
100
n37
10
600
262
(100 stp) (6000 stp)
Number of steps per second
n38
5 stp/s
300 stp/s 300
Integration time for inner loop (TnT0)
n44
10 s
120 s
30
o03
0
240
240
o10
0
4
0
o18
off / 0
3
Off /0
Max. opening degree
Changes should only be made by trained staff
Number of steps from 0-100% opening degree (only if n03 =5 (user defined))
The display can only show 3 digits, but the setting value is 4 digits. Only the 3 most important are shown, i.e. a reading of e.g. 250 means a setting of 2500. (Automatic setting when valve is selected in n03)
Miscellaneous
Controller’s address
If the valve’s opening degree should be controlled with an external signal, the signal is defined as:
0: no signal,
1: 0-20 mA
2: 4-20 mA
3: 0-10 V
4: 1-5 V
Manual control of outputs:
OFF: no manual control
1: Manual control with "o45" enabled
2: The alarm relay is activated (the coil picks up)
3: The alarm relay is activated (the coil releases)
Working range for pressure transmitter – min. value
o20
-1 bar
0 bar
-1.0
Working range for pressure transmitter – max. value
o21
1 bar
60 bar
12.0
0
31
0
o45
0%
100 %
0
o56
1
2
1
o61
1
2
2
Refrigerant setting
1=R12. 2=R22. 3=R134a. 4=R502. 5=R717. 6=R13. 7=R13b1. 8=R23. 9=R500. 10=R503. 11=R114. 12=R142b.
o30
13=User defined. 14=R32. 15=R227. 16=R401A. 17=R507. 18=R402A. 19=R404A. 20=R407C. 21=R407A. 22=R407B. 23=R410A. 24=R170. 25=R290. 26=R600. 27=R600a. 28=R744. 29=R1270. 30=R417A. 31=R422A.
Manual control of the valve’s opening degree. The function can only be operated if ”o18” has been set to "1".
This function is only for manual operation. It must not be used for a regulation function.
Selection of control mode:
1=Normal 2 = With inner loop (S media temperature less T0)
Application mode. Menus blanked out so only the shaded menus are seen. See the two columns to the right.
1: Controlling a valve with an analogue signal
2: Superheat regulation
Service
1
Analog input (21-22)
u06
mA (V)
Read status of input DI (20-21)
u10
on/off
Temperature at S2 sensor
u20
°C
Superheat
u21
K
Superheat reference
u22
K
Read valve’s opening degree
u24
%
Read evaporating pressure
u25
bar
Read evaporating temperature
u26
°C
Temperature at S4 sensor
u27
°C
Configuration settings (n03, n37, n38, o03, o30, o56 and o61) available only when
regulation is stopped. (r12=off ).
The controller can give the following messages:
E1
Fault in controller
E24
E25
E19
S2 Sensor error
error
message
n03
8
n38
A11
Valve type
n37
0
ETS 12½ and 25
262
A44
1
ETS 50
262
S5
2
ETS 100
353
3
ETS 250
381
4
ETS 400
381
5
-
6
UKV, SKV, VKV, PKV
A43
S9
300
S10
non
S4 Sensor error
The input signal on terminals 21-22 is outside the
range.
The input signal on terminals 17-19 is outside the
range (P0 signal)
E20
Valve overview
2
Alarm
message
No refrigerant has been selected
Check the supply voltage to the step motor
Battery alarm (no voltage or too low voltage)
MOP
Status codes
Error
Refrigeration stopped r12=off
Regulation
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Manual RS8EH802 © Danfoss 11-2011
EKD 316
Data
Enclosure
24 V a.c. /d.c. +/-15% 50/60 Hz, 10 VA
(the supply voltage is not galvanically separated from the input and output signals)
Controller
5 VA
ETS step motor
1.3 VA
Current signal *
4-20 mA or 0-20 mA
Voltage signal *
0-10 V or 1-5 V
Pressure transmitter AKS 32R
Digital input from external contact function
2 pcs. Pt 1000 ohm
AC-1: 4 A (ohmic)
1 pcs. SPDT
AC-15: 3 A (inductive)
Pulsating 30 - 300 mA
Mounted with MODBUS data communication
0 to +55°C, during operations
-40 to +70°C, during transport
20 - 80% Rh, not condensed
No shock influence / vibrations
IP 20
Weight
300 g
Montage
DIN rail
External display type EKA 164A or AK-ST via
data communication and system unit
EU Low Voltage Directive and EMC demands re
CE-marking complied with.
LVD-tested acc. to EN 60730-1 and EN 60730-2-9
EMC-tested acc. to EN50081-1 and EN 50082-2
If battery backup is used the requirements to
the battery is: 18-24 V d.c. See also page 12.
Supply voltage
Power consumption
Input signal
*)Ri: mA: 400 ohm
V: 50 kohm
Sensor input
Alarm relay
Step motor output
Data communication
Environments
Operation
Approvals
Battery backup
Ordering
Type
Function
Code no.
EKD 316
Superheat controller
(with terminals)
084B8040
EKA 164A
Display
(with MODBUS communication)
084B8563
Temperature sensor Pt 1000 ohm / Pressure transmitter type AKS 32R:
Kindly refer to catalogue RK0YG
ETS valves: Kindly refer to data sheet DKRCC.PD-VD1.A1.--
Max. distance between
50 m
controller and valve
Connections
Necessary connections
Terminals:
1-2
Supply voltage 24 V a.c./d.c.
3-4
Battery (the voltage will close the ETS valve if the controller
loses its supply voltage. The battery voltage must be kept
disconnected from terminals 1 and 2.
5-8
Supply to step motor
9-13 Operation via data communication
EITHER EKA 164A OR System unit + software
It is important that the installation of the data communication cable be done correctly. Cf. separate literature No.
RC8AC...
20-21 Switch function for start/stop of regulation. If a switch is not
connected, terminals 20 and 21 must be short circuited.
ETS 6/ Saginomiya
UKV, SKV, VKV, PKV
Data
communication
Class II
Application dependent connections
14-15
15-16
17-19
Superheat control
Pt 1000 sensor at evaporator outlet (S2)
Pt 1000 sensor for measuring air temperature (S4)
Pressure transmitter type AKS 32R (the signal can not be
shared with other controllers)
Control of the valves opening degree with analog signal
21-22 Current signal or voltage signal from other regulation (Ext.
Ref.)
24-26 Alarm relay
There is connection between 24 and 26 in alarm situa­tions.
EKD 316
Manual RS8EH802 © Danfoss 11-2011
max. 24 V,
1 A resistive
Class II
1,2 3,4 21,22

Connection to earth will destroy the controller
9
Connection of display
If the controller is to be operated from an external display, type
EKA 164A, the connection must be as below:
Max. distance between controller and display is 1000 m.
The supply voltage to the display must be maintained
at 12 V +/- 15%.
See also the requirements for data communication.
Connecting to networks – operation via PC
If the controller is to be operated from the AK-ST software programme, the connection must be as below:
See also the requirements for data communication.
System unit
Connection to MODBUS
Communication direct to MODBUS RTU protocol.
Start of controller
When the electric wires have been connected to the controller,
the following points have to be attended to before the regulation
starts:
1. Switch off the external ON/OFF switch that starts and stops the
regulation.
2. Follow the menu survey on page 7, and set the various parameters to the required values.
3. Switch on the external switch, and regulation will start.
4. Follow the actual superheat on the display.
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EKD 316
Appendix 1
Interaction between internal and external start/stop functions and
active functions.
Internal Start/stop
External start/stop (DI)
Off
Off
Regulation
=>
Off
Sensor
monitoring
Configuration
settings
No
Yes
Off
On
=>
Off
No
Yes
On
Off
=>
Off
Yes
No
On
On
=>
Yes
Yes
No
Appendix 2
The two types of regulation for superheat are, as follows:
Adaptive superheat (n21 = 1)
Load-defined superheat (n21 = 2)
Regulation is here based on the evaporator’s load by means of
MSS search (MSS = lowest permissible superheat).
(The superheat reference is lowered to the exact point where
instability sets in).
The superheat is limited by the settings for min.and max.superheat.
The reference follows a defined curve. This curve is defined by
three values: the closing value, the min. value and the max.
value. These three values must be selected in such a way that
the curve is situated between the MSS curve and the curve for
average temperature difference ∆Tm (temperature difference
between media temperature and evaporating temperature.
Setting example = n22=4, n10=6 and n09=10 K).
Appendix 3
Regulation algorithms for the superheat.
There are several algorithms to choose between.
Reg.type = 1 (o56=1)
This regulation algorithm is used for the classical method
and is recommended for known applications – e.g. for earlier
installations with a Danfoss controller. For a start the values for
Kp, Tn and Td can be set to values corresponding to the earlier
ones.
EKD 316
Reg.type = 2 (o56=2)
We recommend this setting if the superheating is to be regulated with precision. Here the S4 and T0 temperature is part of an
inner loop control.
The regulation algorithms require that a temperature sensor be
fitted in the chilled medium.
The temperature sensor is connected to input ”S4” and mounted
in the chilled medium after the evaporator. (Danfoss calls
a sensor S4 when it is mounted in the refrigerant after the
evaporator).
Manual RS8EH802 © Danfoss 11-2011
11
If the superheating fluctuates
When the refrigerating system has been made to work steadily,
the controller’s factory-set control parameters should in most
cases provide a stable and relatively fast regulating system.
If the system however fluctuates this may be due to the fact that
too low superheat parameters have been selected:
If adaptive superheat has been selected (n21 = 1):
Adjust: n09, n10 and n18.
If load-defined superheat has been selected (n21 = 2):
Adjust: n09, n10 and n22.
Alternatively it may be due to the fact that the set regulation
parameters are not optimal.
If the time of oscillation is longer than the integration time:
(Tp > Tn , (Tn is, say, 240 seconds))
1. Increase Tn to 1.2 times Tp
2. Wait until the system is in balance again
3. If there is still oscillation, reduce Kp by, say, 20%
4. Wait until the system is in balance
5. If it continues to oscillate, repeat 3 and 4
If the time of oscillation is shorter than the integration time:
(Tp < Tn , (Tn is, say, 240 seconds))
1. Reduce Kp by, say, 20% of the scale reading
2. Wait until the system is in balance
3. If it continues to oscillate, repeat 1 and 2.
Check that the ETS valve closes when
the supply voltage to the controller is
interrupted
This control is performed if the controller is connected to battery
backup.
The battery will make the step motor move to the end stop and
thus close the valve.
Battery information
The battery voltage must be 18-24 V DC and the capacity can be determined from the following information:
• During standard operation the battery uses approx. 17 µA
• With power supply and closed valve the battery uses approx. 17 µA
• Power supply fails and the valve closes: 120 mA for up to 7 seconds.
Installation considerations
Accidental damage, poor installation, or site conditions, can give
rise to malfunctions of the control system, and ultimately lead to a
plant breakdown.
Every possible safeguard is incorporated into our products to
prevent this. However, a wrong installation, for example, could still
present problems. Electronic controls are no substitute for normal,
good engineering practice.
Danfoss will not be responsible for any goods, or plant components, damaged as a result of the above defects. It is the installer's
responsibility to check the installation thoroughly, and to fit the
necessary safety devices.
Particular attention is drawn to the need for a “force closing” signal
to controllers in the event of compressor stoppage, and to the
requirement for suction line accumulators.
Your local Danfoss agent will be pleased to assist with further
advice, etc.
Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products
already on order provided that such alternations can be made without subsequential changes being necessary in specifications already agreed.
All trademarks in this material are property of the respecitve companies. Danfoss and Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.
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Manual RS8EH802 © Danfoss 11-2011
FC-SPMC
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EKD 316