Danfoss EKE 1A User Manual page 53

Superheat controller, Type EKE 1A, 1B, 1C, 1D
• Fail safe operation
• Superheat close
• LOP (Low operating pressure)
• MOP (Maximum operating pressure)
• HCTP (High condensing temperature protection)
• Min. S4 (Minimum S4 temperature)
Figure 77: Protection features (limiters)
HCTP
MOP
LOP
Fail Safe Operation
In the case of sensor error, the EEV controller will go into an emergency mode ("safe mode"). where the valve
opening degree is defined by desired OD scheme as described below
User can read the failure status via [U118 Operation status].
EKE 1x implements two Failsafe mode:
• SH control Failsafe mode
• Thermostat Failsafe mode
Table 37: SH control Failsafe mode
SH control Failsafe mode:
SH control needs Pe and S2 signal. so, if one of these
signal fails, SH control based on the actual superheat
is not possible.
Table 38: SH control Failsafe mode parameters
Parameter
N143
N145 [only if N143= 1]
N138 [only if N144= 2]
© Danfoss | Climate Solutions | 2022.06
Superheat
close
Superheat
reference
Enthalpy (H)
Description
User can via parameter [N143] SH control sensor error action, under control advanced. configure the relevant
option
Stop valve forced closed and SH control (default)
Fixed OD valve at fixed position (Fail safe OD), this keeps the refrigeration unit running
Use average OD (calculated as an average of the last hour) to set a reduced OD which will be fixed dur-
ing error period. This keeps the refrigeration unit running
Function
SH control sensor error
Fixed OD during
emergency cooling
Average OD
Description
0 = Stop | 1 = Fixed OD | 2 = Average OD
define fixed OD % during Emergency cooling
Calculated When superheat control/ Temperature control is active and stored in
EEPROM. Its value is updated every 3 hours. Reset to factory will not delete the
calculated average values. Used in average OD
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