Danfoss AK-PC 420 User Manual

Also see for AK-PC 420: Instructions

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Danfoss AK-PC 420 User Manual Manual pdf 8 page image

8 Manual RS8EL402 © Danfoss 03-2010 AK-PC 420Survey of functionsFunction Para-meterParameter by operation viadata communicationNormal displayIf the two displays are mounted:The regulation temperature is displayed on EKA 164 (the one with buttons) (Pc or S7or S8)Pc will be shown on EKA 163. Both readouts will be in temperatureS7 °CPc °CS8 °CReference Condenser controlUnitHere you can select whether the display is to indicate temperatures in °C or °F0: Will give °C / bar1: Will give °F / psigr05 Unit(In AKM only °C is used, whatever thesetting)Start/stop of refrigerationStart/stop of refrigeration may also be performed with an external contact functionconnected to the input named “ON input”. (The input must be wired).r12 Main SwitchSet pointWhen “r33 ctrl.mode” is set at 1 or 3, it is regulated according to the set value + a pos-sible displacement from a 0-10 V signal.See also page 18.r28 Set Point °CReference variation. See also page 18.Regulation with setting 1 (or 2 if the reference is to vary with the outdoor tempera-ture) will give the best regulation if the system is in balance. But if a lot of fans areconnected, it may be necessary to select setting 3 instead (or 4, if there is regulationwith the outdoor temperature). (Settings 3 and 4 will generally be preferable if a off-set can be accepted between the reference and the actual regulation temperature)1: No change of the reference. Regulation based on set setpoint + displacement witha 0-10 V signal.If there is a heat recovery signal, the reference will switch to the preset set point in"r64".2: Outdoor temperature forms part of the reference. The outdoor temperature ismeasured with Sc3 sensor and the reference will always have a fixed value “r56 Mintm K” over the measured outdoor temperature.If there is a heat recovery signal, the reference will switch to the preset set point in"r64".Setting 1 and 2 operate with a PI regulation, but if the system is unstable and the PIregulation not satisfactory the I element may be left out, so that the controller will bewith P regulation only.3: As 1, but with P regulation (xp-band)4: As 2, but with P regulation (xp-band)5: As for 1, but with a minimum reference limit in accordance with outdoor tempera-ture Sc36: As for 3, but with a minimum reference limit in accordance with outdoor tempera-ture Sc3r33 Ctrl. modeReferenceThe regulation reference is shown here.r29 Ref. °CSet point limitationWith these settings the setpoint can only be set between the two values.(This also applies to regulations where the Xp band lies above the reference).Max. permissible setpoint value. (Is set as an absolute value) r30 RefMax °CMin. permissible setpoint value. (Is set as an absolute value when "r33" = 1-4) r31 RefMin °CCorrection of pressure measurement PcAn offset adjustment of the registered pressure can be made.r32 AdjustPcDimensioning temperature Min tmThe mean temperature difference across the condenser at low capacity (tm differ-ence at max. load). This is the temperature difference between the air and condensingtemperature.When “r33 Ctrl. Mode” is set at 2 or 4, regulation takes place according to a referencethat is “Min tm” over the measured outdoor temperature.r56 Min tm KReading of regulation temperatureThis is where you can see the actual temperature being measured by the sensor cho-sen for capacity regulation. The value is displayed in °C.r58 Ctrl tempSet point value for heat recoveryWhen a heat recovery signal is received, regulation takes place according to the valueset here + any displacement via 0-10 V signal.r64 Heat SP°CAverage value for reference changesA switch in the reference will be ramped up or down over this period of time. Set inKelvin/minute.r65 RefRamp