Danfoss EKE 1A User Manual page 79

Superheat controller, Type EKE 1A, 1B, 1C, 1D
ID Symptom
16 Flash gas
17 Steppe valves open/ close
too slow
18 Opening degree of valve at
maximum OD for longer
time period
19 Hunting or fluctuation valve
position
20 Unstable OD on driving the
valve in Valve driver mode
21 Internal Leakage in the valve Wrong selection of the valve.
© Danfoss | Climate Solutions | 2022.06
Possible cause/Reaction
Loud refrigerant or undercharged refrigerant.
Flash gas can lead to high SH or low suction pressure
Pressure drops across filter.
Incorrect selection of valve type.
Incorrect valve installation.
MOPD is higher than valve specification.
Check valve speed setting.
Lack of cooling capacity.
The condenser pressure is too low.
The filter drier is blocked by dirt
Flash gas in liquid line due to loss of refrigerant or under-
charge of refrigerant.
Wrong valve setting.
Pressure transmitter is wrongly defined.
Wrong refrigerant selected
Too high gain (Kp and KpTe) or too low integration time
(Tn).
S2 thermal contact.
Fluctuating Al signal for SH reference.
Fluctuating pressure signal.
Fluctuating Superheat.
Fluctuating Al signal.
Step loss in stepper motor valve.
Solution
• Charge the system with appropriate refrigerant capaci-
ty.
• Check for leakage is the system.
• If the valve is placed much higher than condenser
tweet check pressure difference.
• Use the right valve size.
• Also refer to section "High Superheat" and "Suction
pressure too low"
• Check and replace the Stet.
• Dane the correct valve type.
• Check the physical vale and cable and intake in light
way.
• Check the valve spec and choose the correct vane.
• Drive the stepper valve with the recommended Speed.
• Too high or too low speed could result in loss step in
the valve.
• For the user defined valves, check the other valve set-
tings such as current, duty cycle, holding current and
other relevant parameter.
• Check the cooling capacity in the system Also check
section, expansion valve too small
• Check the ambient temperature.
• Adjust the condenser controller.
• Replacement Filter drier.
• Check section flash gas.
• Check valor setting matching installed valve.
• Oita pressure range and correct pressure transmitter
type.
• Choose the correct refrigerant in the controller.
• Decrease Kp by factor of 1.5%
• Increase Tn 25% of the set value.
• Perform 1 and 2 in loop if needed.
• Check mounting of S2 sensor, Check the installation
guide section temperature sensor mounting.
• Check Al signal quality.
• Check section Fluctuating pressure signal.
• Check section Fluctuating Superheat.
• Check the Al signal quality.
• Use the Valve neutral zone feature.
• Check the valve type and its setting.
• Power cycle the controller.
• Enable the step loss feature i.e. overdriving. choose the
recommended overdrive value with respect to the in-
stalled valve.
• Drive the stepper valve with the recommended speed.
• Too high or too low speed could result in loss step in
the valve.
• Longer cables mounted than specified for the control-
ler.
• Separate Valve cable from other high-power cables and
do not bundle the cables.
• Blockage in the valve or high friction in the valve.
• MOM, exceeded than specified in the valve specifica-
tion.
BC398828796060en-000101 | 79