Product Overview

© Danfoss | DCS | 2019.04
Data sheet | Superheat controller type EKE 1A, EKE 1B, EKE 1C
DKRCC.PD.RS0.A4.02 | 66
ID Symptom Possible cause / Reaction Solution
1 Regulation does not
start on using control
modes i.e. MSS
DI is not connected, if dened as ON/OFF
hardware switch.
• Turn on DI switch.
Sensor / transmitter error. • Check and clear alarm.
Alarm conguration conict i.e. S2 sensor not
dened or no refrigerant selected.
• Clear and clear Alarm.
Alarm: standby mode active i.e. Parameter
R012 is OFF.
• Set R012 main switch to 1.
2 Suction pressure too low Pressure drop across evaporator too high. • Check refrigerant ahead of expansion valve.
• If valve is placed much higher than condenser outlet.
• Check pressure dierence.
Lack of sub cooling ahead of expansion valve. • Limit max opening degree of the valve setting in controller.
• Check refrigeration system capacity and compare with expansion
valve capacity.
• Use proper valve size.suitable for the system.
Evaporator superheat too high. • Check the section “ High Superheat “.
Pressure drop across the expansion valve less
than valve is sized for.
• Check pressure drop across expansion valve.
• Replace with larger valve.
Expansion valve too small. • Check refrigeration system capacity and compare with expansion
valve capacity. Replace with larger valve if necessary.
• Check selected valve type in the controller valve list.
Expansion valve block with foreign material. • Remove valve and examine the orice /piston.
Wrong selection of Refrigerant in the controller
settings.
• Choose the correct Refrigerant from the pre-dened list.
Lack of Charge in the system. • Charge the system with appropriate refrigerant capacity.
• Check for leakage in the system.
Pressure transmitter ranges or type is wrongly
dened.
• Dene the correct pressure range.
MOP set point is dened very low. • Check the MOP setting, if Modbus is used, check if the values have
been scaled as indicated in the parameter list.
Evaporator wholly or partly iced up. • De-ice evaporator.
Low chilled water ow • Check ow as per design
chilled water temp too low • Check temp set points as per design
3 Low pressure cut out
due to compressor cut
in and cut out
Missing start signal. • Check for digital input DI signal or its settings.
Startup problem. • Check section start- up problem and its solution.
4 Liquid hammer in
compressor (noisy or
unusual compressor
sound) and /or frost on
the suction line
Superheat reference set too low. • Increase the SH reference by changing the SH min. max. parameter.
Superheat is too low. • Make sure SH Close function is ON.
• Increase the values of SH close and SH min.
• Also check section “Too low superheat”.
Inaccurate SH measurement or slow response
in S2 sensor.
• Ensure that S2 sensor is secured on suction line.
• Insulate temperature sensor properly.
• Check the product installation guide section temperature sensor.
Refrigerant or pressure transmitter is not set
correctly.
• Check the related parameters.
5 Too Low superheat Min. SH parameter is too low set. • Raise the min. SH parameter.
Valve Cannot Close fully. • Reduced the Valve OD or forced opening time at Start up.
Valve OD too large at start up. • Use P-control.
• Reduce Start OD.
Inaccurate superheat. • Mounting position of Temperature sensor. Place sensor close to
evaporator.
High pressure drop in suction line. • Mounting position of the pressure transmitter. Place the
transmitter close to evaporator.
• Check the product installation guide section temperature sensor.
Valve is stuck at open. • Check valve installation.
Liquid returns to compressor. • Check section Liquid hammering.
27.0 Trouble shooting