351652602 Ed. 03
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Control of superheating
Superheating (SH) is the temperature difference between the temperature at the evaporator outlet and the evaporat-
ing temperature. To obtain the SH value, sensors S5 (evaporator outlet temperature) and S6 (pressure sensor) are re-
quired. The pressure is converted to temperature according to the refrigerant gas used, so that the SH is obtained as:
SH (K) = S5 temperature - S6 temperature
A low superheat allows for better evaporator efficiency, but too low a value may cause liquid to enter the compres-
sors because the liquid in the evaporator is not completely evaporated.
The AKO-16526 provides stable superheat regulation and a fast response to pressure or load fluctuations, thus
ensuring a high level of system safety.
When the EEV is regulating, the cold icon on the display performs a dimming sequence, indicating that
the expansion regulation is electronic and is therefore constantly being adjusted.
The superheat value is shown on the bottom line of the display by default. Parameter b23 defines which
value is displayed on that line.
When there is no cooling required, the superheat value is not updated, as the regulation is stopped.
When the controller does not generate coolant, the display shows the last superheat value reached
before cooling was required, for the user's information.
IMPORTANT
Install sensors S5 and S6 at the evaporator outlet.
The parameters must be set correctly in the set-up wizard to ensure correct regulation of superheating.
Incorrect configuration can lead to problems in the refrigeration system.
Manual opening of the electronic expansion valve (EEV)
By using parameter U11, a fixed opening value can be set for the EEV. The equipment performs ON/OFF cycles
according to U03 but always with the selected opening %.
This function should only be used by qualified personnel and in exceptional circumstances.
• Access parameter U11. The equipment will ask for a security code.
• Enter the code 63
• Enter the opening % and press
SET
The equipment will not readjust the opening of the valve until U11=0 is configured again
(manual opening disabled).
While there is no demand for cooling, the valve will remain closed.
Summary of Contents for AKO-16526
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