Danfoss EKE 1A, EKE 1B, EKE 1C, EKE 1D Data sheet

Data Sheet

Superheat controller
Type EKE 1A, 1B, 1C, 1D (PV04)

For commercial air conditioning and refrigeration applications

The exible pre-programmed EKE superheat
controller from Danfoss provides ultimate
software control, allowing you to tailor the
performance of your system to your exact
requirements. EKE is ideal for controlling a wide
range of commercial air conditioning and
refrigeration applications, such control helps
you to achieve the highest eciency in the
system reducing the operational cost by up to
20% with minimal eort. EKE is generally used
where there is a requirement for accurate
control of superheat or temperature control in
connection with air conditioning and
refrigeration. The superheat is regulated to the
lowest possible value within a short period of
time. It regulates the superheat of the
evaporator by charging optimally even when
there are great variations of load resulting in
reduction of energy consumption and
operational cost

Typical Applications:

• Chillers

• Processing plant / Cabinet cooling

• Cold store (air coolers)

• A/C plant / Air conditioning

• Heat pumps. Residential Heat Pump

• Transport cooling

• Stepper Motor Driver

AI197986442906en-000501

Features

EKE 1A

EKE 1B

EKE 1C

EKE 1D

Power supply:

Power Supply Type

24 V AC / DC ± 20%••••

Battery Backup input

18-24 V DC••••

Class of insulation

Class II

Data communication

MODBus

RS 485 RTU••

Wired CANbus

(4 wires)

(3 wires)

CANbus RJ 12

Danfoss MMI service port

•••

•

Inputs::

Number of temperature
sensors

123

2

Temperature sensor types

PT1000

•

NTC 10K, type EKS••••

NTC 10K, type ACCPBT

•••

•

NTC 10K, type Sensata

•••

•

Number of Pressure sen­sor

112*

1

Pressure Transmitter
types

Ratiometric 0.5 - 4.5 V

•••

•

Voltage signal 0 – 10 V

•••

•

Current signal 0 – 20 mA

•

Share Pressure Signal

Hardware (Up to 5 devi­ces)

•••

Via wired CANbus (not
possible to share ratio­metric sensor)

•

•

Via MODbus••

Number of external refer­ences

111

1

External reference

0-20mA

•

User dened current

•

0-10V

•••

•

0- 5V

•••

•

User dened voltage( max
10V)

•••

•

Digital input Dry contact

3

2

Outputs

Digital output

1

Relay

Normally Open

3A General purpose, 250V ac, 100k

Normally closed

2A General purpose, 250V ac, 100k

Relay Function

Alarm relay or LLSV (Liquid Line Solenoid Valve)

User interfaces

Koolprog Software tool

•••

•

MMIGRS2 screen••••

Master controller••

•

Superheat controller, Type EKE 1A, 1B, 1C, 1D

Portfolio overview

Table 1: Portfolio overview

*The 2nd pressure sensor is mounted on AI4

© Danfoss | Climate Solutions | 2022.02 AI197986442906en-000501 | 2

Red constant

Green constant

Flashing red

Flashing green

Flashing red and green

Hardware functions

Digital inputs

Used to interact with the EKE for systems where the EKE is not connected to a system controller via data communica­tion.
The available digital inputs DI can be used for the following functions:
a. Injection control ON/OFF(DI1). b. Defrost sequence (DI2). c. Heating and cooling selection mode (DI2) d. Preset OD
(DI2)

Digital Output (Relay)

• The relay for the liquid line solenoid valve will operate when refrigeration is required

• The contact of the relay is closed in alarm situations and when the controller is de-energized.

• The digital output DO1 O013 can be congured for solenoid valve, max capacity or for alarm function.

NC1+C1

Power On

NO

Power On +Alarm

NC

Power Off

NC

NO1+C1

Power On

NC

Power On +Alarm

NO

Power Off

NO

Handling power failure

For safety reasons the liquid ow to the evaporator must be cut o in case of power failure. The valve’s stepper Motor
will remain open in power failure situation
There are two ways of coping with this situation
One of the following two solutions can be applied in the system

• Mounting of a solenoid valve in front of EEV (using LLSV relay signal from EKE)

• Mounting of a battery backup for EEV valve (Use Danfoss EKE 2U)

Analog Inputs

External Reference Signal:
Used for:

• Driving the stepper motor valve to a desired opening degree (Driver Mode)

• Displacing temperature reference, superheat reference or max OD

The voltage signal e.g., 0 – 10 V can be used in all EKE controllers whereas current signal e.g 0 – 20 mA signal is only
available in EKE 1C

Communication: RS485 Modbus / CANbus

The controller can be provided with data communication for connecting to other devices in the systems.
In this case, monitoring and data collection can be performed from one device i.e., PLC – which will be benecial for
the diagnostic or during the installation processes.
For example, it is possible to substitute the physical sensors of the EKE controller by writing sensor values via Bus. The
frequency of update should be according to the Modbus maximum update interval G004 (Refer to parameter list)

Light-emitting diodes (LEDs)

Two sets of light-emitting diodes make it possible to follow the operation status of the valve and the controller. They
indicate the following

• Power/data transmission and Alarm/Error indication

• Stepper valve operational status

LED status:

valve is closed

valve is fully open

valve is moving in close direction

valve is moving in open direction

Error

Superheat controller, Type EKE 1A, 1B, 1C, 1D

Functions

The EKE 1x products supports a wide range of functionalities illustrated in table 3 and 4. Check the user guide for
more detail about congurations and other detailed options.

Table 2: Hardware functions

© Danfoss | Climate Solutions | 2022.02 AI197986442906en-000501 | 3

Valve Driver

The EKE controls the opening degree of the valve, the control signal can be an analog signal or a value via communica­tion bus

Superheat Reference Calculation

• Fixed Superheat The controller keep the superheat at a xed reference value determined by the user. SH xed setpoint
can be varied according to the need of application.

• Minimum Stable Superheat (MSS): The superheat control algorithm will attempt to regulate the superheat down to
the lowest stable value between the minimum superheat setting, “Min SH” and the maximum superheat setting, “Max.
SH”.

• LoadAP Superheat LoadAP is a kind of preprogrammed MSS curve. In Load ap application, SH reference follows a
dened curve as shown in the diagram. This two-point curve is dened by SH max and SH min, this method will give a
robust SH reference and can in many cases be the best t for systems.

• Delta temp. superheat SH reference is calculated as a ratio between the media temperature and evaporator tempera­ture. This reference mode is only possible if media temperature (S3) sensor is available and if the system uses n and tube
evaporator.

Temperature Control *

EKE has a feature to regulate the temperature control. This can be done with either

• Thermostat cut in/cut out function: if temperature is above the set point + dierential, cooling is started with maxi­mum cooling capacity. In maximum capacity superheat is controlled to be on superheat set point. Cooling is active until
the temperature is below set point.

• Modulating Thermostat (MTR): When temperature is getting close to the MTR reference the cooling capacity gradually
reduce so that the temperature can be stable on the MTR reference and the superheat will be oating.

Protection Functions

• Failsafe operation: During operation if sensors error occurs, the valve position can be set to full close, xed

opening degree or average calculated OD as required.

• Superheat close: When the superheat is below a set minimum value, the valve will close faster to protect the compres­sor from the risk of getting liquid in the suction line and bring the superheat back to superheat reference.

• Maximum Operating Pressure (MOP): To reduce the strain on the compressor, a maximum operating pressure is set. If
the pressure comes above this limit the controller will control the valve to provide a lower pressure instead of a low su­perheat.

• Low Operating Pressure (LOP): known as Cold start feature, it allows applications such as heat pumps to operate at
lower ambient conditions to prevent compressor from stopping due to low suction pressure in the startup phase.

• High Condensing temperature protection (HCTP)**: High condensing temperature protection will make sure that
the load on the condenser is reduced in case a too high condensing temperature is reached. This is done by limiting the
valve opening degree.

• Minimum S4/leaving media (freeze protection) *: Lowers the ow in the expansion valve if temperature of leaving
media out of the evaporator is below a minimum value set by the user.

Other Functions

• Fast Start up: Quickly open an EEV valve when compressor turns ON to prevent too low suction pressure as well as for
faster stabilization of superheat or temperature set point. This can be ensured by setting either P-control, Start opening
degree with protection or Fixed opening degree without protection. This start up condition is kept until the start time
expire or superheat reaches at setpoint.

• Defrost sequence: The controller does not itself handle defrost of the evaporator. It is however possible to enter a spe­cial defrost sequence which will overrule the normal control of the valve.

• Manual control: The valve can be controlled manually by setting the desired opening degree via Analog signal or com­munication bus used for commissioning purpose. A special service mode is also available for service and testing purpose.

• Service mode: Service mode is designed to provide a very simple way of operating the valve for diagnostic and service
purpose. There is neither application nor protection in this mode. The user can open and close the valve using simple
button presses on MMIGRS2.

Superheat controller, Type EKE 1A, 1B, 1C, 1D

Table 3: Control Functions

*Not available in EKE 1A

**Only Available EKE 1C

© Danfoss | Climate Solutions | 2022.02 AI197986442906en-000501 | 4

Danfoss

80G8221.01

EEV

TT

Pe

S2

Battery

Optional connection

Alarm indication

Normal close

Mandatory connection

ON/OFF signal

Modbus or Analog signal

Power 24 V AC / 24 V DC

EKE controller (in driver mode)

MASTER controller

Superheat controller, Type EKE 1A, 1B, 1C, 1D

Applications

EKE series devices are used where precise control of superheat in air conditioning system is needed. It helps
achieving high energy eciency and reliable operation

EKE serves 2 main applications:

• Driver Mode

• Controller Mode

1.

Superheat controller

2.

Temperature controller

Driver mode

Driver Mode:A master is commanding the valve open degree to the EKE controller. The control signal can be fed for

example by:

• Analog signal e.g., 0 – 10 V, a 4 – 20 mA

• Bus communication via RS485 (Modbus RTU).

Figure 1: EKE as Driver Mode

 NOTE:

'Normal closed' valve in front of EEV is optional alternative to a battery backup solution which closes the EEV in case
of power fail. The Digital output can also be used as alarm indication to the master controller. The Master can send a
start signal to EKE DI terminals

Controller Mode

Controller Mode:

Superheat Control: EKE can serve as a PI controller that controls the superheat of the evaporator based on a

pressure Pe and temperature (S2) sensors. In superheat mode the controller will control the superheat to be stable
and close to the superheat reference. If superheat is too low the ow in the expansion is decreased and superheat
will be higher

© Danfoss | Climate Solutions | 2022.02 AI197986442906en-000501 | 5

Danfoss

80G8222.01

TT
S2

EEV

EKE 1X

Pe

Danfoss

80G8223.01

EEV

EKE controller

Preset OD

Defrost
Heat / cool mode

Battery
Power 24 V AC / 24 V DC

External reference

Optional connection

Mandatory connection

Temperature control

Alarm indication

Normal close

External main switch

TT

S4

Pe

TT
S2

TT

S3

Superheat controller, Type EKE 1A, 1B, 1C, 1D

Figure 2: Superheat control application

Temperature controller The temperature control is an ON/OFF thermostat that opens/closes the stepper valve or
modulating thermostat that regulates temperature more smoothly following a temperature reference point. The
temperature control can be accomplished via a signal from temperature sensor S3 placed in the air ow before the
evaporator or S4 placed in the air ow after the evaporator.

EKE has 2 methods of controlling temperature:

• ON/OFF thermostat

• Modulating thermostat (MTR)

The need for cooling can either be dened by the incoming media (S3) or the outgoing media (S4) temperature

Figure 3: Temperature control application

 NOTE:

EKE1A can only work in the driver mode or superheat control mode as it supports only one temperature sensor
input

© Danfoss | Climate Solutions | 2022.02 AI197986442906en-000501 | 6

Feature

Description

Power supply

Galvanic isolation by switch mode power supply
Input voltage rating (AC): 24 V AC ± 20 % (min.19.2 V AC - max. 28.8 V AC
Input frequency (AC): 50 / 60 Hz
Input voltage rating (DC): 24 V DC (min. 20 - max. 40 V DC)
Provides 5 W at 5 V and 15 V outputs isolated from the 24 V input
Insulation between power supply and the extra-low voltage.
Class of insulation Class II

Power Consumption

Total Power consumption with following valve in operation and MMIGRS2 con­nected to the controller:
CCMT 16 - CCMT 42: 15VA/10W
ETS 6: 11 VA / 7.5W
ETS 12C - ETS 100C: 20VA / 14W
KVS C: 20VA / 14W
ETS 12.5 - ETS 400 7 VA / 5W
CCMT 2 - CCMT 8 7 VA / 5W
CTR 20: 7 VA / 5W

Plastic Housing

• DIN rail mounting complying with EN 50022

• Self-extinguishing V0 according to IEC 60695-11-10 and glowing / hot wire
test at 960 °C according to IEC 60695-2-12

• Material used for Enclosure are UL94-V0 and RoHS compliant

• Ball test: 125 °C according to IEC 60730-1

• Leakage current: ≥ 250 V according to IEC 60112

Connectors

• Plug able Screw connector Pitch 3.5 mm, relay and power connector Pitch 5
mm, CAN MMI: Modular Jack 6P4C

• Material used for connectors are RoHS and UL approved

Feature

Type

Description

Protection

Short circuit

Motor driver: dissipative over current protection

Over voltage

Analog input: current limit and internal clamp diode
Digital input: current limit and internal clamp diode
Communication: transceiver IC

Over Temperature

Motor driver: thermal shutdown at 150 °C

Unstable Digital Input

Continuous variation of the digital input state

I/O

Type

Specications

Analog inputs

• Max. 15 V input voltage

• Open circuit HW diagnostics available for voltage input on: AI3, AI4
(EKE 1C) AI4 (EKE 1A and EKE 1B).



WARNING:

Do not connect voltage sources without current limitation (overall 80
mA) to analog inputs while unit is not powered.

0 – 5 V

EKE 1C (AI3, AI4) and EKE1A/1B/1D AI3 | Accuracy ± 40 mV, resolution 1.2
mV.

0 – 10 V

EKE 1C (AI3, AI4) and EKE1A/1B/1D AI3 | Accuracy ± 50 mV, resolution 2.5
mV.

0 – 20 mA (EKE 1C only)

Accuracy ± 100 μA, resolution 10 μA.
Input resistance: <100 Ω

NTC Sensor

NTC temperature probes: 10 kΩ at 25 °C range: 300 kΩ to 100 Ω
Accuracy: 50 – 120 °C: 1.5 K, -40 – 50 °C: 0.4 K, 0 °C: 0.2 K
Resolution: ≤ 0.1 K, ≤ 0.3 K (EKC 1C, AI5)

Pt1000 sensor

Range: 723 Ω to 1684 Ω
Accuracy: ≤ 0.5 K
Resolution: ≤ 0.1K

Pressure Sensor

Type: Ratiometric

• Accuracy: 1.6 %

• Range: 0.5 – 4.5 V

• Resolution: 1.2 mV

• Supply voltage: 5 V DC / 15 mA, overload protection approximately
150 mA

Superheat controller, Type EKE 1A, 1B, 1C, 1D

Product specication

Technical data

Table 4: General specication

Table 5: Electrical specication

Table 6: Input/Output

© Danfoss | Climate Solutions | 2022.02 AI197986442906en-000501 | 7

I/O

Type

Specications

Digital Input DI

Voltage free contacts

Steady current of 1 mA (EKE 1C only). A cut-in input will activate a func­tion.
Cleaning current of 100 mA at 15 V DC.
On: RIL <= 300 Ω . O: RIH >= 3.5kΩ.
No destructive if Vbat + is connected to DI (only for DI on bottom pcb).
Min. pulse time 64 ms.

Digital output (D01)

Relay

Normally Open: 3 A General purpose, 250 V AC, 100 k cycle
Normally Open: 3 A Inductive (AC-15), 250 V AC, 100 k cycle
Normally Closed: 2 A General purpose, 250 V AC, 100 k cycle

Stepper motor

Bipolar and unipolar stepper Mo­tor Output

Danfoss ETS / KVS / ETS C / KVS C / CCMT 2 – CCMT 42 / CTR / CCMTL
Valves (green, red, black, white)

ETS 6 / CCMT 0 / CCMT 1 (black, red, yellow, orange)
Other Valves:

• speed 10 - 400 pps

• drive mode full step, half step, 1/8 microstep

•

max. peak phase current: 1.2 A (848 mA RMS)

• max. output power 12 W

Battery backup

VBATT: 18 – 24 V DC:
Leakage: <15 μA @30 V DC
Optional: critical low alarm below 12V
Optional: low alarm at 17 V, high voltage alarm at 27 V
The valve will not close at power fail if voltage is higher than 27 V
Required power to do 1 closing of stepper valve:
ETS 6: 110 J / 30 VmAh
ETS 12.5 - ETS 400: 60 J / 17 VmAh
KVS 15 / KVS 42: 60 J / 17 VmAh
ETS 12C - ETS 100C: 55 J / 15 VmAh
KVS 2C / KVS 5C: 55 J / 15 VmAh
CCMT 2 - CCMT 8: 60 J / 17 VmAh
CCMT 16 - CCMT 42: 175 J / 49 VmAh
CTR 20: 60 J / 17 VmAh



NOTE:

Danfoss recommends using EKE 2U as a battery backup

Communication

RS-485 RTU (only for EKE 1B and
1C)

Galvanic isolation. No Built-in termination.
Supported commands with max. of 50 ms response time: 0 x 03, 0 x 04, 0
x 06
Supported commands without dened max response time : 0x08, 0x10,
0x14, 0x15,0x2b

CAN

• EKE 1A/1B: CANOpen over RJ12 connector.

• EKE 1C: CANOpen over CAN 4pin terminal and RJ12 connector.

• EKE 1D: CANOpen over CAN 3pin terminal and RJ12 connector.



NOTE:

• For EKE EKE 1A/1B, RJ12 connector is used directly connect and sup­ply a user interface MMI

• Refer to the user guide for information about type of connection ca­bles

Feature

Description

Operating conditions

-20 – 60 °C, 90% RH non-condensing

Storage / Transport conditions

-30 – 80 °C, 90% RH non-condensing

Vibration and shock

According to IEC 60068-2-27 Ea

Integration

In Class I and / or II appliances

Index of protection

IP40 only on the front cover (General IP20 )

PCB protection

None (no conformal coating)

Period of electric stress across insulating parts

Long

Superheat controller, Type EKE 1A, 1B, 1C, 1D

Environmental conditions:

Table 7: Environmental conditions

© Danfoss | Climate Solutions | 2022.02 AI197986442906en-000501 | 8