Danfoss AK-PC 420 User guide

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User Guide

Capacity controller for dry cooler

AK-PC 420

ADAP-KOOL® Refrigeration control systems

Introduction

Application

The controller is used for capacity regulation of a dry cooler including fans, three-way valve and pumps.

Advantages

• Complete dry cooler control

• Several combination options for sensor selection

• Heat recovery acc. to external voltage signal.

Regulation

Capacity regulation can include fans combined with a three-way valve or just fans. The following sensor signals can be used in regulation:

• Condensing pressure Pc

• Brine temperature S7, located immediately after the three-way valve outlet

• Brine temperature S8, located by the outlet from the dry cooler

• Outdoor temperature sensor Sc3, located by the air inlet to the dry cooler.

• Either S7, Pc or S8 can be used as a regulation sensor.

Functions

• Three-way valve control

• Speed regulation or step-by-step coupling of up to six fans

• Safety monitoring of fans

• Overriding of reference acc. to external voltage signal or outdoor temperature

• Separate reference for heat recovery

• Control and monitoring of twin pumps

• Monitoring of ow switch

• Contact inputs to alarms

• External start/stop of regulation

• Data communication via extra module

Operation

All operation takes place either via data communication or via connection of a display type EKA 164 .

Contents

Introduction ....................................................................................................... 2

Function ............................................................................................................... 3

Survey of functions .......................................................................................... 8

Operation .......................................................................................................... 13

Menu survey .....................................................................................................14

Connections ..................................................................................................... 16

Data ..................................................................................................................... 17

Ordering ............................................................................................................17

Montage ............................................................................................................ 17

Appendix - Reference and regulation .....................................................18

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Function

Application

Regulation sensor and system type are selected via one single setting. The setting will dene both the regulation sensor, if a threeway valve is being used, and how the fans are to be controlled. The fans are controlled either in steps or together with a speed control. If steps are used, up to six fans can be controlled.

Application 1-4

The capacity here is controlled via the fans combined with a threeway valve.

Applications 1 and 2 use brine return temperature S7 at the three-way valve outlet as regulation sensor and the fan capacity is controlled either in steps or via speed control. The S8 sensor, which is tted to the dry cooler’s outlet should be used in the control if there is a large distance between the dry cooler and the three-way valve. Use of the S8 sensor will provide more robust regulation, which takes long pipe lengths into account. The S8 sensor must be tted close to the dry cooler’s outlet.

Regulation (o61)

1 S7 S8 (P + PI) x Step

2 S7 S8 (P + PI) x Speed

3 Pc S7 / S7+S8 (PI) x Step

4 Pc S7 / S7+S8 (PI) x Speed

5 S8 Step

6 S8 Speed

Regulation sensor

Optional sensor

3-way valve

Fan control

Applications 3 and 4 use brine condensation pressure Pc as regulation sensor and the fan capacity is controlled either in steps or via speed control. For PI control the use of the S7 and S8 sensors is optional but they should be tted if there is a large distance between the dry cooler and the three-way valve. Use of the sensors will provide more robust regulation, which takes long pipe lengths into account. The S8 sensor must be tted close to the dry cooler’s outlet. For P control the S7 and S8 sensors are not used in the regulation, but they can be tted to ensure that the emergency control functions in the even of the Pc signal failing.

Applications 5-6

Here the capacity is controlled via step-by-step coupling or speed control on the basis of the dry cooler’s discharge temperature S8. This application is used in particular when another controller takes care of the regulation of the three-way valve, e.g. to cool several parallel-coupled condensers.

NB. The sensors Pc and S7 must not be located in positions other than those specied, as they are used for emergency regulation if the primary regulation sensor develops a fault.

The S8 sensor can be located in a dierent position than the one indicated if it is not used in the control. If the S8 sensor is required in the control, the setting "o96, S8 optional" must be selected as ON. If the S8 sensor is not used in the regulation, it can be located anywhere.

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Capacity regulation

Three-way valve + step-by-step coupling of fans (applications 1 and 3)

Capacity regulation takes place via a P or PI regulation, which controls the three-way valve and subsequent step-by-step coupling of the fans. First of all regulation takes place on the three-way valve via the analogue output. The output can be set at 0-10 V or 10-0 V, depending on which valve function is desired. Only when the three-way valve is fully open do the fans start up. The capacity of the three-way valve is 50% of the total capacity. The P/PI controller has separate regulation settings (proportional band and integration time) for the three-way valve and the fans respectively.

Capacity overlap – start of fans

As mentioned above, the three-way valve comprises a xed 50% of the total capacity. In some systems it may be necessary to start the fans slightly before (or slightly after) the three-way valve has been fully opened. An overlap is created here between the three-way valve and the start of the fans. This is done by changing the setting “FanCap OFF%” from 50% to, for example, 40% (the setting denes the capacity at which the last fan stops). In this case the fans are started before the three-way valve is fully open.

Three-way valve + speed control of fans (applications 2 and 4)

Capacity regulation takes place via a P or PI regulator, which controls the three-way valve and subsequent speed control of the fans. Here the analogue output signal is divided between the three-way valve and the frequency converter (50% of the analogue output signal is always used for the three-way valve), i.e. if the analogue output signal is set at 0-10V, 0-5 V is used for the three-way valve. The frequency converter/fans are controlled via the relay output for fan 1 on the basis of the setting “FanCapOFF%”. In the event of falling capacity, the relay output for fan 1 will be disabled when the actual capacity has fallen to “FanCap OFF%”. To achieve hysteresis when starting/stopping the frequency converter, the relay output for fan 1 will, when capacity is increasing, be enabled when the desired capacity is “FanCap OFF%” + “10% fan capacity”. If “FanCapOFF%” is set at above or below 50%, the frequency converter can be started after or before the three-way valve is fully opened. The P/PI controller has separate regulation settings (proportional band and integration time) for the three-way valve and the fans respectively.

Fan control only (applications 5 and 6)

Capacity regulation takes place via a P or PI regulator, which controls the fans either with step-by-step coupling or speed control. The analogue output and a frequency converter are used for speed control. The relay output for fan 1 is used to start/stop the frequency converter. In the event of falling capacity, the relay output for fan 1 will be disabled when the actual capacity has fallen to “FanCap OFF%”. To achieve hysteresis when starting/stopping the frequency converter, the relay will become enabled when the desired capacity is the fan capacity above “FanCap OFF%” ( The 10% fan capacity will correspond to hysteresis of 1 V in the analogue output signal, when the signal is 0-10 V.) The P/PI controller only uses regulation settings (proportional band and integration time) for the fans.

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Linear/non-linear capacity curve for fans

The rst fan step provides relatively more capacity than the subsequent capacity steps. The increase in capacity that an extra step/ speed will generate falls gradually, as more and more steps are connected/the speed is increased. The fan regulation therefore has a crooked capacity curve, which provides optimal reinforcement at both high and low capacities. However, for some systems a straight curve is required for capacity regulation, e.g. if the analogue signal is used for more than controlling fans. In this instance the capacity curve can be set at linear. (The capacity curve for the three-way valve will always be straight.)

Step-by-step coupling of fans

The fans can either be connected in the sequence dened for them (sequentially) or they can be connected in rotation (sequentially with alternating start). In sequential operation all fans are enabled at least once every 24 hours, so no fan rusts up due to being inactive for a longer period of time. In rotation the various fans take turns in being rst.

Monitoring fans

The controller must receive a signal of the status of each dened condenser step’s safety circuit. The signal is taken directly from the safety circuit and connected to a “DI” input. If the safety circuit is broken, the controller will lose the signal and emit an alarm. The associated relay output will not be disconnected. The reason is that fans are often connected in pairs, but with one single safety circuit. If there is a fault in one fan, the other will continue to operate. If no monitoring is desired, the input must be permanently wired at 24 V.

Reference

Regulation reference

The regulation reference can be dened in one of the following two ways:

• Fixed setting The set point for the regulation sensor is set in °C. If displacement is required, the reference can be displaced with a 0-10 V signal. During setup you dene how great the displacement is to be at the signal’s max. and min. value.

• Floating reference according to outdoor temperature This function allows the reference to vary according to the outdoor temperature within a dened range. The outdoor temperature is measured with the Sc3 sensor, and the reference will always fall within a xed value (min. tm) above the measured outdoor temperature.

Heat recovery

When heat recovery is enabled via the digital input, the reference will switch to another set point “Heat SP”, although this too can be overridden via the external 0-10 V signal. At the same time the relay for heat recovery is enabled, which then transmits a signal to either a pump or a valve. The reference's max. value (r30) is overriden from the set value to 99.9° C. If heat recovery is in progress and the temperature by the regulation sensor is lower than the reference’s set minimum value, the following happens (see also the following section on limiting the reference):

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The heat recovery relay is disconnected and can only be re-enabled once the temperature by the regulation sensor has reached 2 K above the reference’s minimum setting.

Ramp function

To avoid overswing and underswing of the reference, a ramp function has been included to guarantee that the reference cannot change more quickly than the preset ramp in Kelvin/minute.

Limitation of reference

To protect against regulation reference that is too high or too low, a limit must be set for the reference. The limit is valid under normal regulation, but is increased during heat recovery to 99.9° C. The upper limit is always an absolute value. The lower limit can either be an absolute value or it can vary in accordance with the outside temperature Sc3 whereby the limit has a xed value ("r56, Min tm") above the outside temperature. This means that a reference below the minimum value, making all fans run continuously, can be avoided.

Ref. Max.

Ref. Min.

Ref. Max.

P or PI regulation with oating or xed reference

See appendix.

Safety functions

Monitoring of condensation pressure

The controller has a safety function that provides protection against the condensation pressure being too high. The function can be enabled in two ways.

• Digital input - HP safety When the digital input is connected, full capacity is cut in to both fans and three-way valve. An alarm is emitted at the same time. The capacity remains cut in until the digital input is interrupted, at which point the alarm is also cancelled. The digital input can possibly be connected to an external safety pressure control.

• Measuring the Pc/S7 temperature This function always uses condensation pressure Pc if the pressure signal is connected. If Pc is not tted, brine return temperature S7 is used instead. The function cuts in all condenser steps and emits an alarm if the measured temperature is higher than 3 K below the set limit “S7/Pc max ”. Normal capacity regulation is restored when the temperature (pressure) has once more fallen to 3 K below the limit, and a delay time of 60 seconds has passed.

Ref. Min.

Pump controL

The controller can control and monitor one or two pumps that circulates the brine. If two pumps are used and operating time equalisation is selected, the controller can also execute a switch between the two pumps if operating alarms occur.

Pump selection is performed using the following settings: 0: Both pumps are stopped 1: Pump 1 is started 2: Pump 2 is started 3: Both pumps are started 4: Automatic switch between the pumps is permitted. Start before stop 5: Automatic switch between the pumps is permitted. Stop before start

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Automatic switch between the pumps. Start before stop (only for setting = 4) This setting allows a rotation between the two pumps, enabling a kind of operating time equalisation. The period time between the pump switches can be set as “p37 PumpCycle”. When switching, the pump will be kept running for the time “p36 PumpDel” until it stops.

Automatic switch between the pumps. Stop before start (only for setting = 5) This setting allows a rotation between the two pumps, enabling a kind of operating time equalisation. The period time between the pump switches can be set as “p37 PumpCycle”. When switching, the pumps will be stopped in the time "p36 PumpDel".

Monitoring pumps The controller monitors the pumps’ operation via the safety input “Flowswitch”. The signal may, for example, originate from a pressure dierence pressure switch or a ow switch. Also set a delay time to dene how the alarm is to be activated. The delay time is the time from when the input loses the signal until the controller emits an alarm and executes a pump switch if necessary.

Special information about operating time equalisation If the pumps are operating with operating time equalisation, the controller can perform a switching of the pumps in the event of a lack of ow (however, the pump switch will only be performed when the delay time on the alarm has expired). Depending on whether the pump switch recties the alarm situation or not, the following happens:

1) The pump switch recties the alarm situation If the pump switch recties the alarm situation, the non-faulty pump, which is now in operation, will run until the normal cycle time has expired. It then switches back to the “faulty pump”, as it is assumed that this has been repaired. At the same time the alarm situation is reset (the alarm is acknowledged). If the “faulty pump” has not been repaired, another alarm will be triggered and cause one more switch to the non-faulty pump. This is repeated until the situation has been rectied.

2) The pump switch does not rectify the alarm situation If, however, the alarm is still active after the pump switch, the controller will also emit an alarm for the other pump. At the same time both pump outputs are enabled in an attempt to create sucient ow for the alarm situation to be rectied. The controller will then have both pump outputs enabled until the normal cycle time has expired. A normal pump switch is then conducted and the active alarms are reset.

Separate alarm priorities can be set for the failure of one pump and the failure of both pumps. See section entitled “Alarms and messages”.

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Survey of functions

Function Para-

meter

Normal display

If the two displays are mounted: The regulation temperature is displayed on EKA 164 (the one with buttons) (Pc or S7 or S8) Pc will be shown on EKA 163. Both readouts will be in temperature

Reference Condenser control Unit

Here you can select whether the display is to indicate temperatures in °C or °F

0: Will give °C / bar 1: Will give °F / psig

Start/stop of refrigeration

Start/stop of refrigeration may also be performed with an external contact function connected to the input named “ON input”. (The input must be wired).

Set point

When “r33 ctrl.mode” is set at 1 or 3, it is regulated according to the set value + a possible displacement from a 0-10 V signal. See also page 18.

Reference variation. See also page 18. Regulation with setting 1 (or 2 if the reference is to vary with the outdoor temperature) will give the best regulation if the system is in balance. But if a lot of fans are connected, it may be necessary to select setting 3 instead (or 4, if there is regulation with the outdoor temperature). (Settings 3 and 4 will generally be preferable if a oset can be accepted between the reference and the actual regulation temperature) 1: No change of the reference. Regulation based on set setpoint + displacement with a 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 is measured with Sc3 sensor and the reference will always have a xed value “r56 Min tm 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 PI regulation not satisfactory the I element may be left out, so that the controller will be with 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 Sc3 6: As for 3, but with a minimum reference limit in accordance with outdoor temperature Sc3

Reference

The regulation reference is shown here.

Set point limitation

With 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) Min. permissible setpoint value. (Is set as an absolute value when "r33" = 1-4)

Correction of pressure measurement Pc

An oset adjustment of the registered pressure can be made.

Dimensioning temperature Min tm

The mean temperature dierence across the condenser at low capacity (tm dierence at max. load). This is the temperature dierence between the air and condensing temperature. When “r33 Ctrl. Mode” is set at 2 or 4, regulation takes place according to a reference that is “Min tm” over the measured outdoor temperature.

Reading of regulation temperature

This is where you can see the actual temperature being measured by the sensor chosen for capacity regulation. The value is displayed in °C.

Set point value for heat recovery

When a heat recovery signal is received, regulation takes place according to the value set here + any displacement via 0-10 V signal.

Average value for reference changes

A switch in the reference will be ramped up or down over this period of time. Set in Kelvin/minute.

Parameter by operation via data communication

S7 °C Pc °C S8 °C

r05 Unit

(In AKM only °C is used, whatever the setting)

r12 Main Switch

r28 Set Point °C

r33 Ctrl. mode

r29 Ref. °C

r30 RefMax °C r31 RefMin °C r32 AdjustPc

r56 Min tm K

r58 Ctrl temp

r64 Heat SP°C

r65 RefRamp

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Reference displacement at max. signal (Ext. ref.)

Here the value is set by which the reference is to be displaced when the input signal Ext. ref. is max. (10 V).

Reference displacement at min. signal (Ext. ref.)

Here the value is set by which the reference is to be displaced when the input signal Ext. ref. is min. (0 V).

Correction of signal from S7

Compensation possibility due to long sensor cable

Correction of signal from S8

Compensation possibility due to long sensor cable

Condenser capacity Condenser cong. Denition of condenser and number of fans (may only be set if step-by-step

coupling is being run, i.e. “o61 Applic mode” is set at 1, 3 or 5).

Here you set how many fan steps are to be used for regulation (to max. 6). 1-6: All fans are connected with relays. Relay 1 is assigned fan 1, the next one number 2, etc.

7-10: Not used 11-16: Total number of fan relays (as 1-6), but here the starting sequence is altered

after each time all fans have been stopped. NB The controller must receive a signal of the status of each condenser step’s safety circuit. The signal must be connected to the associated DI input.

Denition of output voltage to valve/speed control

Output signal is 0-10 V or 10-0 V. The signal can be either linear or un-linear, so that it can be adapted to the desired characteristics. 1: 0-10 V, linear 2: 10-0 V linear (not at shunt and fan speed) 3: 0-10 V, unlinear 4: 10-0 V unlinear (not at shunt and fan speed)

Regulation parameters

r68 ExtRefMax

r69 ExtRefMin

r72 Adjust S7

r73 Adjust S8

c29 Fan mode

c34 AO type

- - - - Cond Cap % Read cut-in condenser capacity

Proportional band xp for valve regulation (P = 100/Xp)

If the Xp value is increased, the regulation becomes steadier

I: Integration time Tn for valve regulation

If the Tn value is increased, the regulation becomes steadier

Manual control of condenser capacity

This sets the capacity that is to be cut in when switching to manual control.

Manual control

Manual control of the condenser capacity is enabled here. When set to ON, the capacity that is specied in “n52” is cut in. The setting will fall back to “O” if the Main switch is set to O or if there is a power outage.

P: Proportional band xp for fan regulation (P = 100/Xp)

If the Xp value is increased, the regulation becomes steadier

I: Integration time Tn for fan regulation

If the Tn value is increased, the regulation becomes steadier

Capacity overlap between valve and fans

In valve regulation the rst 50% of the capacity is controlled by the valve. When the valve is fully open continues with fan cut-in. The fans then take over. If the fans are to start before the three-way valve is fully open, a value must be set that is lower than 50%. If the fans are only to start after the three-way valve is fully open, a value must be set that is higher than 50%.

Alarm Alarm settings

The controller can give alarm in dierent situations. When there is an alarm the lightemitting diodes (LED) will ash on the display and the alarm relay will cut in.

Pc max. (Alarm and safety function, see also page 18.) Here you set when the alarm at too high condensing pressure is to enter into eect. The value is set as an absolute value.

Alarm delay DI1 (an interrupted input will give alarm).

The time delay is set in minutes. At min. setting the alarm is cancelled.

n04 Valve Xp K

n05 Valve Tn s

n52 ConManCap%

n53 ConManCap

n60 Fan XP K

n61 Fan Tn s

n62 FanCap OFF %

A30 Max. Pc. / S7

A27 DI1AlrmDelay

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Alarm delay DI2 (an interrupted input will give alarm). The time delay is set in minutes. At min. setting the alarm is cancelled.

Alarm delay DI3 (an interrupted input will give alarm). The time delay is set in minutes. At min. setting the alarm is cancelled.

Pump alarm delay

The time delay is set in seconds. At min. setting the alarm is cancelled.

Give the top button a brief push to zeroset the alarm and to have the message shown on the display.

Miscellaneous Miscellaneous Choice of application

The regulator can be congured in various ways. The application that is required out of the six applications available is set here. 1: S7 + 3-way valve + Step of fans 2: S7 + 3-way valve + VSD (speed) of fans 3: Pc + 3-way valve + Step of fans 4: Pc + 3-way valve + VSD (speed) of fans 5: S8 + Step of fans 6: S8 + VSD (speed) of fans

Sensor type (Sc3, S7 and S8) Normally a Pt1000 sensor with great signal accuracy is used for temperature measurement. But a PTC sensor may also be used (r25 = 1000) in special situations.

0=Pt1000 1=PTC1000

Pressure transmitter’s working range

Depending on the pressure, a pressure transmitter with a given working range is used. This working range must be set in the controller (e.g.: -1 to 34 bar The values must be set in bar if display in °C has been selected. And in psig, if °F has been selected.

Pc-Min. value o47 PcMinTrsPres

A28 DI2AlrmDelay

A29 DI3AlrmDelay

A63 Pump Al. Del

Reset alarm The function zerosets all alarms when set in pos. ON.

With data communication the importance of the individual alarms can be dened. Setting is carried out in the “Alarm destinations” menu.

o61 Applic.Mode

o06 Sensor type

If the values are to be set from the AKM programme, they must be set in bar.

Pc-Max. value o48 PcMaxTrsPres

Use of DI4 input

The digital input can be connected to a contact function, and the contact can now be used for one of the following functions: Setting / function:

0: DI input not used 1: Safety signal from high-pressure pressure control. If the signal is cut o, all capacity

is cut in. There is no time delay.

Operating hours

The operating hours for the pomp relays can be read and set in the following menus. The read value is multiplied by 1000 to obtain the number of hours (fx. shows 2.1 for 2100 hours). On reaching 99.9 hours the counter stops and must now be reset to, say,

0. There will be no alarm or error message for counter overow. Value for relay number 7 (pump 1) o52 DO7 run hour

Value for relay number 8 (pump 2) o53 DO8 run hour

Refrigerant setting (only if a Pc pressure transmitter is tted)

Before refrigeration is started, the refrigeration must be dened. You may choose between the following refrigerants: 1=R12. 2=R22. 3=R134a. 4=R502. 5=R717. 6=R13. 7=R13b1. 8=R23. 9=R500. 10=R503. 11=R114. 12=R142b. 13=User dened. 14=R32. 15=R227. 16=R401A. 17=R507. 18=R402A. 19=R404A. 20=R407C. 21=R407A. 22=R407B. 23=R410A. 24=R170. 25=R290. 26=R600. 27=R600a. 28=R744. 29=R1270. 30=R417A. 31=R422A. 32=R413A. 33=R422D. 34=R427A. 35=R438A. Warning: Wrong selection of refrigerant may cause damage to the compressor. Other refrigerants: Select setting 13 here, and subsequently three factors have to be set – fac1, fac2 and fac3 – via AKM.

o22 DI4 control

(In the AKM display the hour number has not been multiplied)

o30 Refrigerant

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Manuel operation (only via display and only when regulation has stopped (r12=o))

From this menu the relays can be cut in and out manually. 0 gives no override, but a number between 1 and 10 will cut in a belonging relay. 1 will cut in relay number 1, 2 relay 2, etc. 11-18 will produce voltage on the analog output. Setting 11 will give a voltage of

1.25 V, setting 12 will give 2.5 V, etc.

Frequency

Set the net frequency.

Use of S8 sensor

If application (o61) is selected to 1, 2, 3 or 4, the S8 sensor can be used for regulation or for monitoring. The S8 sensor, which has to be located near by the outlet of the dry cooler, should be used in the regulation if the distance between the dry cooler and the 3-way-valve is long. If the S8 sensor is want to be used in the regulation set o96 to ON. Is the S8 sensor not used in the regulation it can be located optional for monitoring purpose (o96 has to be set to OFF).

Address

If the controller is built into a network with data communication, it must have an address, and the master gateway of the data communication must then know this address. These settings can only be made when a data communication module has been mounted in the controller and the installation of the data communication cable has been completed. This installation is mentioned in a separate document “RC8AC”.

The address is set between 1 and 240 (gateway determined) o03

The address is sent to the gateway when the menu is set in pos. ON o04

Access code

If the settings in the controller are to be protected by a numerical code, you can set a numerical value between 0 and 100. If not, you can cancel the function with setting OFF.

Status on relay outputs

Status on relay 1 (fan 1 or start/stop of speed control) p25 Fan 1 status Status on relay 2 (fan 2) p26 Fan 2 status Status on relay 3 (fan 3) p27 Fan 3 status Status on relay 4 (fan 4) p28 Fan 4 status Status on relay 5 (fan 5) p29 Fan 5 status Status on relay 6 (fan 6) p30 Fan 6 status Status on relay 7 (pump 1) p31 Pump 1 Status on relay 8 (pump 2) p32 Pump 2 Status on relay 9 (Heat recovery) p33 Heat recovery Status on relay 10 (alarm) p34 Alarm

Pump control

Here you dene how the pumps are to be controlled: 0: Both pumps are stopped 1: Only pump 1 is started 2: Only pump 2 is started 3: Both pump 1 and pump 2 are started 4: Automatic switch between pumps 1 and 2. Start before stop 5: Automatic switch between pumps 1 and 2. Stop before start

Pump-stop delay

During pump switching both pumps can run for a short overlap. Here you set how many seconds.

Run period in cyclic operation

This is where you set the number of hours the pump will run. You then switch over to the other pump. Repeat this.

Status on DI 1 u10 DI 1 Status Status on DI 2 u37 DI 2 Status Reading temperature at Sc3 sensor u44 Sc3 Status Status on DI 3 u87 DI 3 Status Status on DI 4 u88 HP safety Status on DI 5 u89 Heat recov. Reading temperature at S8 sensor u93 S8 temp Status on Flow switch input u94 Flow switch Read o the actual reference displacement received in the analogue input Ext. Ref. u96 Ext. Ref°C Read o the value on the analogue output to the valve/frequency converter. u97 AO Volt Reading temperature at S7 sensor u98 S7 temp

o18 - - -

o12 50 / 60 Hz

(50=0, 60=1)

o96 S8 optional

Following installation of a data communication module, the controller can be operated on a par with the other controllers in ADAP-KOOL® refrigeration controls.

o05

p35 Pump ctrl.

p36 Pump del.

p37 Pump cycle

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Operating status

The controller goes through some regulating situations where it is just waiting for the next point of the regulation. To make these “why is nothing happening” situations visible, you can

Ctrl state

(0 = regulation) see an operating status on the display. Push briey (1s) the upper button. If there is a status code, it will be shown on the display. The individual status codes have the following meanings

S10: Regulation stopped with the internal and external start/stop 10

S25: Manual regulation of outputs 25

Alarm messages Alarms "Destinations"

A11: No refrigerant has been selected (cf. o30) A11 No RFG Sel

A17: High Pc A17 Hi Pc alarm

A28, A29, A30: External alarm. Interrupted signal on input "DI1" /2/3 A28 ...... A30 DI_ Alarm

A34, A35, A36, A37, A46, A47: Fan alarm. Fan 1, 2, 3, 4, 5, 6 A34 ...... A37, A46, A47 Fan_fault

A45: Regulation stopped with setting or with external switch A45 Stand by

A77: Interrupted signal on input "Flow switch" while pump 1 was operating A77 Pump 1 fault

A78: Interrupted signal on input "Flow switch" while pump 2 was operating A78 Pump 2 fault

A79: Interrupted signal on input "Flow switch" while pump 1 and 2 were operating A79 PMP1&2 fault

E1: Error in the controller E1 Ctrl. fault

E2: Control signal outside the range (short-circuited/interrupted) E2 Out of range

Safety functions

Criterion Reference / control sensor Capacity

Pc or S7 > Pc/S7 max (A30) - 3 No change 100% capacity until the signal has fallen below the

Pc signal failure S7 is used instead and the reference is lowered 5 K. Normal regulation

S7 signal failure Pc is used instead and the reference is raised 5 K. Normal regulation

Pc and S7 signal failure No change 100% capacity

Sc3 signal failure The oating reference is removed, and regulation takes

place according to the set value for the reference – “r29”.

S8 signal failure No change When using app. 1-4, regulation continues without

limit for 60 seconds.

Normal regulation

S8 sensor. When using app. 5-6, 100% capacity is cut in.

12 Manual RS8EL402 © Danfoss 03-2010 AK-PC 420

Operation

Data communication

If the controller is extended with data communication, the operation can be performed from a system unit. The parameter names for the functions can be viewed in the right-hand column on pages 8–12.

The importance of the alarms that are sent can be dened with the setting: 1 (High), 2 (Medium), 3 (Low) or 0 (No alarm).

Operation via external display

The values will be shown with three digits, and with a setting you can determine whether the pressures are to be shown in °C or in °F (bar/psig). There are two options for the display.

EKA 164

To operate the controller and view the regulation temperature. If the lowermost key is pressed, the temperature from one of the other sensors will be shown briey in the display.

Regulation Normal display Alternative view

Regulation sensor (lowermost key)

1 and 2 S7 Pc

3 and 4 Pc S7

5 and 6 S8 S7

EKA 163

The buttons on the display When you want to change a setting, the upper and the lower buttons will give you a higher or lower value depending on the button you are pushing. But before you change the value, you must have access to the menu. You obtain this by pushing the upper button for a couple of seconds - you will then enter the column with parameter codes. Find the parameter code you want to change and push the middle button. When you have changed the value, save the new value by once more pushing the middle button.

EKA 163

If the alternative temperature is to be shown constantly, a display without operating keys can be connected.

Or short:

1. Push the upper button (long push) until a parameter is shown

2. Push one of the buttons and nd the parameter you want to change

3. Push the middle button until the setting value is shown

4. Push one of the buttons and select the new value

5. Push the middle button again to conclude the setting

( A brief pushing will show the active alarm codes. See page 15.)

AK-PC 420 Manual RS8EL402 © Danfoss 03-2010 13

Menu survey

Conguration parameters can only be set when the regulation is stopped, r12=0.

SW: 1.2x

Para-

Function

Normal display

A display of the regulated temperature can be seen in EKA 164. (display with buttons)

Shows Pc in EKA 163 - °C

Reference

Select unit (0=bar and °C, 1=Psig and °F)

Start/Stop of regulation r12 OFF ON OFF

Set regulation setpoint r28 -25°C 75°C 30°C

Shows the total reference r29 °C

Limitation: reference max. value r30 -99.9°C 99.9°C 55.0°C

Limitation: reference min. value r31 -99.9°C 99.9°C -99.9°C

Correction of signal from Pc-sensor r32 -50 K 50 K 0.0

Pc reference variation.1 and 2 are PIregulation 1: Fixed reference. “r28” is used 2: Variable reference. Outdoor temperature (Sc3) included in the reference 3: As 1, but with P-regulation (Xp-band) 4: As 2, but with P-regulation (Xp-band) 5: As 1, but with min.-reference acc. to outdoor temperature 6: As 3, but with min.-reference acc. to outdoor temperature

The mean temperature dierence across the condenser at the lowest relevant capacity (min tm K)

This is where you can see the actual temperature that is part of the regulation.

Set point settings for heat recovery r64 -25°C 75°C 35°C

Average period for reference changes. r65

Displacement of reference at external signal = 10 V

Displacement of reference at external signal = 0 V

Correction of signal from S7-sensor r72 -50 K 50 K 0.0

Correction of signal from S8-sensor r73 -50 K 50 K 0.0

Capacity

Denition of fan relay 1-6: Total number of fan relays in sequential operation.

7-10: Not used 11- 16: Total number of fan relays in

cyclic operation.

Denition of the analoge output voltage 0-10 V 1: 0-10 V, linear 2: 10-0 V, linear 3: 0-10 V, unlinear 4: 10-0 V, unlinear

Proportional band Xp for (P= 100/Xp) valve regulation

I: Integration time Tn for valve regulation

Cutin condenser capacity with manual control. See also “n53”

Min. Max. Fac.

meter

- °C

r05 0 1 0

r33 1 6 1

r56 3.0 50.0 8.0

r58 °C

0.1 K/ min.

r68 -50 K 50 K 0.0

r69 -50 K 50 K 0.0

c29 0/OFF 16 0

c34 1 4 1

n04 0.2 K 40.0 K 10.0 K

n05 30 s 600 s 120

n52 0 % 100 % 0

50 K/min.

sett.

10 K/min.

Manual control of condenser capacity (when ON, the value in “n52” will be used)

Proportional band Xp for (P= 100/Xp) fan regulation

I: Integration time Tn for fan regulation n61 30 s 600 s 240

Denition of where the rst fan is connected. Set as a % of the total refrigeration capacity. Ex. 50%, if a three-way valve is also used.

Alarm

Delay time for a DI1 alarm

Delay time for a DI2 alarm A28

Delay time for a DI3 alarm A29

Upper alarm and safety limit for Pc A30 -10 °C 200°C 60.0°C

Pump alarm delay A63 1 s 600 s 15 s

Miscellaneous

Controllers address o03* 1 990

On/o switch (service-pin message) o04* - -

Access code o05

Used sensor type for Sc3, S7 and S8 0=Pt1000, 1=PTC1000

Set supply voltage frequency o12 50 Hz 60 H 0

Manual control of outputs:

0: No override 1-10: 1 will cut in relay 1, 2 relay 2, etc. 11-18: Gives voltage signal on the

analog output. (11 gives 1.25 V, and so on in steps of 1.25 V

Use of DI4-input 0=not used. 1=Safety signal from high pressure pressostat

Setting of refrigerant 1=R12. 2=R22. 3=R134a. 4=R502. 5=R717. 6=R13. 7=R13b1. 8=R23. 9=R500. 10=R503. 11=R114. 12=R142b. 13=User dened. 14=R32. 15=R227. 16=R401A. 17=R507. 18=R402A. 19=R404A. 20=R407C. 21=R407A. 22=R407B. 23=R410A. 24=R170. 25=R290. 26=R600. 27=R600a. 28=R744. 29=R1270. 30=R417A. 31=R422A. 32=R413A. 33=R422D. 34=R427A. 35=R438A.

Pc pressure transmitter’s working range

- min. value Pc pressure transmitter’s working range

- max. value Operating hours of relay 7 (value time

1000) Operating hours of relay 8 (value time

1000)

* this setting is only possible if data communication module is mounted in the controller

n53 OFF ON OFF

n60 0.2 K 40.0 K 20.0 K

n62 0 % 70 % 50 %

0 min.

A27

(-1=OFF)

0 min. (-1=OFF)

1 (0=OFF)

o06 0 1 0

o18 0 18 0

o22 0 1 0

o30 0 35 0

o47 -1 bar 0 bar -1.0

o48 1 bar

o52 0.0 h 99.9 h 0.0

o53 0.0 h 99.9 h 0.0

999

OFF

min.

999

OFF

min.

999

OFF

min.

100 OFF

200

34.0

bar

To be continued

14 Manual RS8EL402 © Danfoss 03-2010 AK-PC 420

Selection of application Regulation sensor and output are: 1: S7 + 3-way valve + Step of fans 2: S7 + 3-way valve + VSD (speed) of fans 3: Pc + 3-way valve + Step of fans 4: Pc + 3-way valve + VSD (speed) of fans 5: S8 + Step of fans 6: S8 + VSD (speed) of fans

Use of S8 On: for regulation O: for monitoring

Service etc.

Status on relay 1 (fan 1) p25

Status on relay 2 (fan 2) p26

Status on relay 3 (fan 3) p27

Status on relay 4 (fan 4) p28

Status on relay 5 (fan 5) p29

Status on relay 6 (fan 6) p30

Status on relay 7 (pump 1) p31

Status on relay 8 (pump 2) p32

Status on relay 9 (heat recovery) p33

Status on relay 10 (alarm) p34

Pump control: 0: Both pumps stops 1: Pump 1 only 2: Pump 2 only 3: Both pump 1 and pump 2 4: 2 pumps + rotation. Start before stop 5: 2 pumps + rotation. Stop before start

Pump setting. Operating time with two pumps when switching takes place.

Pump setting. After the operating time you then switch over to the other pump.

Status on DI1 input u10

Status on DI2 input u37

Read temperature at sensor "Sc3" u44 °C

Status on DI3 input u87

Status on DI4 input u88

Status on DI5 input u89

Read temperature at sensor "S8" u93

Status on "Flow switch"-input u94

Read reference displacement from the external signal

Read the value of the analogue output in V

Read temperature at sensor "S7" u98

o61 1 6 1

o96 O/0 On/1 O/0

p35 0 5 1

p36 0 s 60 s 10 s

p37 1 h 500 h 24 h

u96

u97

The controller can give the following messages

E1 Error

message

E2 Regulation is outside the range, or the control

Alarm

A11

message

A17 High Pc

A28 DI 1 alarm. Terminal 46 interrupted

A29 DI 2 alarm. Terminal 47 interrupted

A30 DI 3 alarm. Terminal 49 interrupted

A34 Fan 1 alarm. Terminal 29 is open

A35 Fan 2 alarm. Terminal 30 is open

A36 Fan 3 alarm. Terminal 31 is open

A37

A45 Regulation stopped

A46 Fan 5 alarm. Terminal 33 is open

A47 Fan 6 alarm. Terminal 34 is open

A77 Pump 1 alarm. Terminal 36 interrupted

A78 Pump 2 alarm. Terminal 36 interrupted

A79 Pump 1 and 2 alarm. Terminal 36 interrupted

Status

S10

message

S25 Manual control of outputs

PS Info

Fault in controller

signal is defective

Refrigerant not selected

Fan 4 alarm. Terminal 32 is open

Refrigeration stopped by the internal or external start/stop function

Access code is required before you have access to the settings

Messages can be brought up on the display by briey pressing the uppermost key. If there is more than one alarm, they can be scrolled through

Factory setting If you need to return to the factory-set values, it can be done in this way:

- Cut out the supply voltage to the controller

- Keep the upper and the lower button depressed at the same time as you recon nect the supply voltage

Factory settings are indicated for standard units (see code numbers, page 1). Other code numbers have customized settings.

Connections

Pc: AKS 32R: 1 = Black = + 2 = Blue = 3 = Brown = s

All inputs are low-voltage. All relay outputs may be highvoltage.

Terminals:

1-2 Supply voltage 24 V a.c. 4- 15 Relay outputs for fan motors 16-19 Relay output to pump 1 and pump 2 20-21 Relay output to heat recovery 22-24 Alarm relay

There is connection between 22 and 24 in alarm situa tions and when the controller is dead

27-28 24 V signal to start / stop of regulation 27-29 24 V signal from the safety circuit fan 1 27-30 24 V signal from the safety circuit fan 2 27-31 24 V signal from the safety circuit fan 3 27-32 24 V signal from the safety circuit fan 4 27-33 24 V signal from the safety circuit fan 5 27-34 24 V signal from the safety circuit fan 6 27-35 (not used) 27-36 24 V signal from ow switch 37-38 Output signal 0-10 V d.c. to either 3-way valve or frequen-

cy transformer for fans

39-41 Possibility of connecting an external display type EKA 163

for display of Pc

42-44 Possibility of connecting an external display type EKA 164

for operation and temperature display 45-46 DI1 - Contact function for alarm signal 45-47 DI2 - Contact function for alarm signal 48-49 DI3 - Contact function for alarm signal 48-50 HP safety - contact function for receiving of high pressure-

safety signal

51-52 Heat recovery - Contact function for receive of signal to

start of heat recovery 51-53 S7 sensor. Sensor signal from AKS 11, AKS 12 or EKS 111 54-55 Sc3 sensor. Sensor signal from AKS 11, AKS 12 or EKS 111 54-56 S8 sensor. Sensor signal from AKS 11, AKS 12 or EKS 111 57-58 Signal for displacement of reference. 0-10 V d.c. 60-62 Condenser pressure. Voltage signal from AKS 32R.

Data communication

25-26 Mount only, if a data communication module has been

mounted. For Ethernet communication the plug connection RJ45 must be used. (LON FTT10 can also be connected in this way. It is important that the installation of the data communication cable be done correctly. Cf. separate literature No. RC8AC.

Common Pc signal

If AK-PC 420 is used together with another control for compressors, e.g.: AK-PC 530 AK-PC 730 AK-PC 840 AK-CH 650 the same AKS 32R can emit a signal to both controls. But in this case separate 24 V power supplies must be used for the two controllers. In addition to this, the safety limit for “high condensation pressure” is set at the same value in the two controllers.

Data Ordering

Danfoss

84B2330.11

Supply voltage 24 V a.c. +/-15% 50/60 Hz, 5 VA

1 pcs. pressure transmitter type AKS 32R

Input signal

Digital input from contact function.

Relay output for fans 8 pcs. SPST

Relay output for twin pump

Relay output heat recovery

Alarm relay 1 pcs. SPDT

Voltage output 0-10 V d.c.

Display outputs

Data communication

Environments

Enclosure IP 20

Weight 0.4 kg

Mounting DIN rail or on wall

Terminals max. 2.5 mm2 multicore

Approvals

3 pcs. temperature sensor input for PT 1000 ohm/0°C or PTC 1000 ohm/25°C

External reference signal: 0-10 V d.c.

1 pcs. for Start/stop of regulation

8 pcs. for monitoring of safety circuits

3 pcs. for alarm function

1 pcs. for start of heat recovery

2 pcs. SPST

1 pcs. SPST

EKA 163 Pc display

EKA 164 Operation, S7 display

Possible to connect a data communication module

0 - 55°C, during operation

-40 - 70°C, during transport

20 - 80% Rh, not condensing

No shock inuence / vibrations

EU Low voltage Directive and EMC demands re CE-marking complied with. LVD-tested acc. to EN 60730-1 and EN 60730-2-9 EMC-tested acc. to EN61000-6-2 and 3

AC-1: 3 A (ohmic) AC-15: 2 A (inductive)

AC-1: 6 A (ohmic) AC-15: 3 (inductive)

Type Function Ordering

AK-PC 420 Capacity controller for dry cooler 084B8008

EKA 163B Display unit 084B8574

EKA 164B Display unit with operation buttons 084B8575

EKA 174

EKA 178B

Montage

AK-PC 420

Cable for display unit 2 m, 1 pcs. 084B7298

Cable for display unit 6 m, 1 pcs. 084B7299

Data communication module, LON RS 485 (with galvanic separation)

Data communication module, MOD-bus (with galvanic separation)

084B7124

084B8571

Pressure transmitter / temperature sensor

Please refer to catalogue RK0YG...

Only for front mounting (IP 40) Only connection via plugs

Display type EKA 163 / EKA 164

Installation considerations

Accidental damage, poor installation, or site conditions, can give rise to malfunctions of the control system, and ultimately lead to a plant breakdown.

Every possible safeguard is incorporated into our products to prevent this. However, a wrong installation, for example, could still present problems. Electronic controls are no substitute for normal, good engineering practice.

Danfoss will not be responsible for any goods, or plant components, damaged as a result of the above defects. It is the installer's responsibility to check the installation thoroughly, and to t the necessary safety devices.

Special reference is made to the necessity of signals to the controller when the compressor is stopped and to the need of

liquid receivers before the compressors.

Your local Danfoss agent will be pleased to assist with further advice, etc.

Appendix - Reference and regulation

The regulation functions are explained in more detail below. With parameter r33 Ctrl. Mode it is possible to choose between six dierent forms of regulation.

As a starting point 1, 2 or 5 are recommended. However, if the system is unstable it might be necessary to switch to 3, 4 or 6.

r33 Ctrl.

1. PI regulation. Fixed reference i.e. constant condensing pressure.

2. PI regulation. Floating reference with outdoor temperature Sc3 i.e. variable condensing pressure.

3. As ”1”, but with P regulation. A higher condensing pressure than indicated by the reference must be accepted here.

4. As ”2”, but with P regulation. A higher condensing pressure than indicated by the reference must be accepted here.

5. and 6. As 1 and 3, but with outdoor temperature dependent min. reference.

The dierent regulation modes are as follows: (For the sake of simplicity, in the example no consideration is given to any possible overriding with external reference signal 0-10 V.)

type

1 PI r28 SP+Ext. Ref r64 SP+Ext. Ref r31 Ref Min. r30 Ref Max.

2 PI Sc3+Min.tm r64 SP+Ext. Ref r31 Ref Min. r30 Ref Max.

3 P r28 SP+Ext. Ref r64 SP+Ext. Ref r31 Ref Min. r30 Ref Max.

4 P Sc3+Min.tm r64 SP+Ext. Ref r31 Ref Min. r30 Ref Max.

5 PI r28 SP+Ext. Ref r64 SP+Ext. Ref Sc3+Min. tm K r30 Ref Max.

6 P r28 SP+Ext. Ref r64 SP+Ext. Ref Sc3+Min. tm K r30 Ref Max.

No heat recovery Heat recovery Minimum Maximum

1. PI regulation with xed reference

Reference Reference delimitation

Important setting to avoid unwanted alarms

When r33 = 1,2 or 5:

Pc Ref max. must be set at least 5 K below Pc max. (A30).

When r33 = 3, 4 or 6:

Pc Ref max. must be set at least (”n04 Valve Xp” + ”n60 Fan Xp” +5) K below Pc max. (A30).

Heat recovery = on

In PI regulation the controller will make sure that the actual regulation temperature deviates as little as possible from the actual reference. The reference at any time, on the basis of which the controller regulates, can be seen in ”r29”. During normal regulation the setting “r28 SetPoint” is used as a reference. For heat recovery the reference is changed to R64 Heat SP °C, and r30 is raised to 99.9°C

2. PI regulation with oating reference

Heat recovery = on

In PI regulation the controller will make sure that the actual regulation temperature deviates as little as possible from the actual reference. The reference is at a xed value (r56 Min tm K) above the actual measured outdoor temperature Sc3 and can be seen in “r29 Ref °C”. If the outdoor temperature falls one degree, the reference will also fall one degree. For heat recovery the reference is changed to r64 Heat SP °C, and r30 is raised to 99.9°C

Raising/lowering of the reference takes place via a ramp function dened at “r65 RefRamp”. The capacity of the three-way valve is controlled via regulation parameters “n04 Valve Xp” and “n05 valve Tn s”, and the fans are controlled via regulation parameters “n60 Fan Xp” and “n61 Fan Tn s”.

Raising/lowering of the reference takes place via a ramp function dened at “r65 RefRamp”. If there is a sensor failure on the outdoor temperature sensor, the reference will switch to the setting of “r28 SetPoint”. The capacity of the three-way valve is controlled via regulation parameters “n04 Valve Xp” and “n05 valve Tn s”, and the fans are controlled via regula-

tion parameters “n60 Fan Xp” and “n61 Fan Tn s”.

3. P regulation with xed setting

Heat recovery = on

As point 1, but with P regulation the actual regulation temperature will always deviate in relation to the actual reference. The reason is that the actual cut-in capacity is solely dependent on how far the measured regulation temperature is from the actual reference. The capacity of the three-way valve is controlled via proportional band “n04 Valve Xp” and the fans are controlled via proportional band “n60

4. P regulation with oating reference

Heat recovery = on

As point 2, but with P regulation the actual regulation temperature will always deviate in relation to the actual reference. The reason is that the actual cut-in capacity is solely dependent on how far the measured regulation temperature is from the actual reference. The capacity of the three-way valve is controlled via proportional band “n04 Valve Xp” and the fans are controlled via proportional band “n60

The cutin and cutout of fans are shown in the drawing. If the entire fan capacity is controlled by speed regulation, the capacity will be indicated on the broken line.

Fan Xp”. This means that the three-way valve will be fully open when the temperature is “n04 S7/Pc Xp” over the actual reference, and the fans will provide full capacity when the temperature is “n04 S7/Pc Xp” + “n60 S8 Xp” above the actual reference. The cutin and cutout of fans are shown in the drawing. If the fan capacity is controlled by speed regulation, the capacity will be indicated on the broken line.

5. PI regulation with xed reference and with min. reference which depends on the outdoor temperature

Heat recovery = on

For heat recovery the reference is changed to R64 Heat SP °C, and r30 is raised to 99.9°C Raising/lowering of the reference takes place via a ramp function dened at “r65 RefRamp”. The capacity of the three-way valve is controlled via regulation parameters “n04 Valve Xp” and “n05 valve Tn s”, and the fans are controlled via regulation parameters “n60 Fan Xp” and “n61 Fan Tn s”.

6. P regulation with xed setting and with min. reference which depends on the outdoor temperature

Heat recovery = on

Ref. min. = Sc3 + Min. tm K

The cutin and cutout of fans are shown in the drawing. If the entire fan capacity is controlled by speed regulation, the capacity will be indicated on the broken line.

Danfoss can accept no responsibility for possible errors in catalogues, brochures and other printed material. Danfoss reserves the right to alter its products without notice. This also applies to products already on order provided that such alternations can be made without subsequential changes being necessary in specications already agreed. All trademarks in this material are property of the respecitve companies. Danfoss and Danfoss logotype are trademarks of Danfoss A/S. All rights reserved.

FC-SPMC

Danfoss AK-PC 420 User guide

Specifications and Main Features

Frequently Asked Questions

User Manual