Danfoss AK-RC 251 User guide

User Guide

Temperature controller

for walk-in coolers and freezers Type AK-RC 251

User Guide | Temperature controller for walk-in coolers and freezers, Type AK-RC 251

Contents	1.	Versions and references..............................................................................................................................................		3
	2.	Warnings.............................................................................................................................................................................		3
	3.	Maintenance......................................................................................................................................................................		3
	4.	Description.........................................................................................................................................................................		3
	5.	Installation.........................................................................................................................................................................		4
	6.	Wiring...................................................................................................................................................................................		5
	7.	Initial configuration.......................................................................................................................................................		5
	8.	Operation............................................................................................................................................................................		6
		8.1	Cold regulation........................................................................................................................................................	7
		8.2	Door management.................................................................................................................................................	9
		8.3	Defrost.......................................................................................................................................................................	10
		8.4	Defrost control.......................................................................................................................................................	10
		8.5	Fan control...............................................................................................................................................................	11
		8.6	Alarms.......................................................................................................................................................................	12
		8.7	Alerts..........................................................................................................................................................................	13
		8.8	Light control............................................................................................................................................................	13
		8.9	Password..................................................................................................................................................................	13
		8.10	Remote Stand-by mode......................................................................................................................................	13
		8.11	Operation of the auxiliary relays......................................................................................................................	13
	9.	Configuration..................................................................................................................................................................		14
	10.	Technical specifications.............................................................................................................................................		19
	11.	Ordering............................................................................................................................................................................		20

2 | BC364433930186en-000101

User Guide | Temperature controller for walk-in coolers and freezers, Type AK-RC 251

1. Versions and references

Model	Description	Power supply	Circuit Breaker Protection	Contactor
AK-RC 251	5 relay temperature controller	100 – 240 V~	No	No
AK-RC 251	5 relay temperature controller	50 – 240 Hz	No	No
		50 – 240 Hz

2. Warnings

•Using the unit without observing the manufacturer's instructions may alter the appliance's safety requirements. Only NTC probes supplied by Danfoss should be used for the unit to operate correctly.

•From -40 – +68 °F, if the NTC probe is extended to 3,280 ft with at least 20AWG cable, the maximum deviation will be 0.45 °F.

•It should be installed in a place protected from vibrations, water and corrosive gases, where the ambient temperature does not exceed the value indicated in the technical data.

•For the reading to be correct, the probe should be used in a place without heat influences apart from the temperature you want to measure or control.

•IP65 protection degree is only valid with the protection cover closed.

•IP65 protection degree is only valid if the cables enter the device using electrical conduit + gland with IP65 or above. The size of the glands should be suitable for the diameter of the conduit used.

•Do not spray the unit directly with high-pressure hoses, as this could cause damage.

Important:

•Before starting the installation, you must take the advice of local regulations in force.

•The AUXILIARY relays are programmable, and their operation depends on the configuration.

•The function of the digital inputs depends on the configuration.

•The recommended currents and powers are the maximum working currents and powers.

3.0 Maintenance

•Clean the surface of the unit with a soft cloth, water and soap.

•Do not use abrasive detergents, gasoline, alcohol or solvents, as this might damage the unit.

4.0 Description

Display

Keypad

Fixed: Stand-By Mode activated. Regulation is paused. Flashing: Controlled shutdown process for the regulation underway.

Fixed: Cold room door open.

Flashing: The door has been open for a greater time than has been defined in parameter A12.

There is an active alarm, but not an active HACCP alarm.

Fixed: HACCP alarm active.

Flashing: HACCP alarm registered and unconfirmed. Press the key to confirm an HACCP alarm.

Fixed: Evaporator fans active.

Flashing: The evaporator fans should be active but a delay is preventing this.

(Refer to the Drip time section).

Fixed: The cold solenoid is active.

Flashing: The solenoid should be active but a delay or protection is preventing this.

(Refer to the Fan start-up section).

Fixed: Compressor active.

Flashing: The compressor should be active but a delay or protection is preventing this.

(Refer to the Compressor Protection timing section).

Defrost relay active.

Continuous cycle mode active.

Cold room light active.

Alarm in progress muted.

Temperature displayed in ° Fahrenheit / ° Centigrade.

Programming mode active.

BC364433930186en-000101 | 3

User Guide | Temperature controller for walk-in coolers and freezers, Type AK-RC 251

4.1 Keypad

Pressing it for 3 seconds activates/deactivates Stand-By mode. In this mode, regulation is paused and the power icon is displayed.

In the programming menu, this exits the parameter without saving changes, returns to previous level or exits programming.

Pressing once displays the temperature of probe S2 for 10 seconds (If it is enabled).

Pressing it for 3 seconds starts/stops the defrost.

In the programming menu, this allows scrolling around the different levels, or, during the setting of a parameter, changing its value.

Pressing it for 3 seconds activates/deactivates continuous cycle mode.

In the programming menu, this allows scrolling around the different levels, or, during the setting of a parameter, changing its value.

Pressing once activates/deactivates the cold room light. Pressing it for 3 seconds accesses the condensed programming menu.

Pressing it for 6 seconds accesses the expanded programming menu.

In the programming menu, this accesses the level shown on the display or, during the setting of a parameter, accepts the new value.

Pressing once displays the current effective value of the Set Point, taking into consideration temporary modifications by other parameters (C10 or C12). When an alarm is underway, pressing once mutes the acoustic alarm. Pressing for 3 seconds accesses the Set Point setting.

STAND-BY

If the temperature regulation cannot be instantly stopped due to its configuration, a controlled stop process starts and the icon flashes. To stop the controlled stop process and force the step to Stand-by, press the Stand-by key again for 3 seconds.

5. Installation

•Remove the bezels (1) by pulling out on one side first and then the other side.

•Make a 1/4 turn of the screws (2) counter-clockwise and open the door (3).

•Install the necessary glands (4) removing the provided caps.

•Mark and make the holes in the wall with the aid of the template included.

•Fix the device to the wall. If it is a brick wall, use the screws and anchors supplied; if the wall is made of sheet metal (cold room store), use the screws provided without anchors (5).

•Remove the plastic cover (7) loosening the screw (6) and wire the device by following the recommendations indicated on p. 7.

•Once the wiring is done, reinstall the plastic cover (7), close the cover (3), tighten the screws (2) and reinstall the bezels (1)

	<![if ! IE]> <![endif]>Danfoss 80Z8117
1
	2
3
7
6
5
4	Ø Max.25 mm
	Ø Max.25 mm

4 | BC364433930186en-000101

User Guide | Temperature controller for walk-in coolers and freezers, Type AK-RC 251

6. Wiring

Always disconnect the power supply to do the wiring. The probes and their cables should NEVER be installed in a conduit together with power, control or power supply cables.

For disconnection, the power supply circuit must be equipped with a switch of at least 2 A, 230 V, located near the device. The power supply cable will be H05VV-F or NYM 1x16/3. The section to be used will depend on the local standard in force but must never be less than 14AWG.

Cables for relay or contactor outputs should have a section of 14AWG, allow working temperatures equal to or over 158 °F and be installed with as few bends as possible.

The 120/230 V~ wiring must be kept clear of any other external element.

•The specific wiring to be performed depends on the option selected in the initial configuration wizard.

•Use the appropriate diagram based on the option selected.

•Check the available options on the diagram sheet included with your device.

Important:

•Before starting the installation, you must take the advice of local regulations in force.

•The AUXILIARY relays are programmable, and their operation depends on the configuration.

•The function of the digital inputs depends on the configuration.

•The recommended currents and powers are the maximum working currents and powers.

7. Initial configuration

The first time the unit is powered up, it will enter into the Wizard mode. The display will show the message flashing with 0.

Step 1:

Select the most suitable InI option based on the type of installation to be carried out and press SET. The available options will be shown in the following table:

	Type of installation								Parameters
InI	Cold regulation	Pump	Defrost	Evaporator	Pd	o00	I00	I10	I11	I20	I21
InI

		Down		fans
		Down		fans
0	Demo Mode: it displays the temp. but does not regulate or activate relays
1	Solenoid	No	Electric	Yes
1	Solenoid	No	Electric	Yes	0	0	2	0	0	0	0
2	Solenoid + compressor	Yes	Electric	Yes	1	1	2	7	1	0	0
3	Solenoid + compressor	No	Electric	Yes	0	1	2	0	0	0	0
4	Solenoid	No	Air	Yes	0	0	1	0	0	0	0
5	Solenoid + compressor	Yes	Air	Yes	1	1	1	7	1	0	0
6	Solenoid + compressor	No	Air	Yes	0	1	1	0	0	0	0
7	Solenoid + compressor	Yes	Hot gas	Yes	1	1	2	7	1	9	1
8	Solenoid + compressor	No	Hot gas	Yes	0	1	2	0	0	9	1
9	Solenoid + compressor	Yes	Reversed	Yes	1	1	2	7	1	0	0
9	Solenoid + compressor	Yes	cycle	Yes	1	1	2	7	1	0	0
			cycle
10	Solenoid + compressor	No	Reversed	Yes	0	1	2	0	0	0	0
10	Solenoid + compressor	No	cycle	Yes	0	1	2	0	0	0	0
			cycle
11	Solenoid	No	Static	No	0	0	1	0	0	0	0
12	Solenoid + compressor	Yes	Static	No	1	1	1	7	1	0	0
13	Solenoid + compressor	No	Static	No	0	1	1	0	0	0	0

<![if ! IE]>

<![endif]>Danfoss 80Z8118

			Diagram
d1	d7	F3	to be
d1	d7	F3	used
20	0	0	A
20	0	0	B
20	0	0	B
20	1	1	A
20	1	1	B
20	1	1	B
5	2	0	C
5	2	0	C
5	3	0	D
5	3	0	D
20	1	-	A
20	1	-	B
20	1	-	B

Note: If options 2, 5, 7, 9 or 12 are chosen, check the configuration of parameter I11 according to the pressure switch type used. (See diagram included with the device).

Step 2:

Use keysandto enter the desired Temperature Set Point value and press SET. The wizard has finished. The unit will begin to regulate the temperature.

IIf this is not the first time you run the wizard, after completing the last step the display will show the message dFp (default parameters). You may choose between two options:

0: Only change the parameters which affect the wizard. The other parameters will remain the same. 1: All parameters return to their factory setting except those which have been modified by the wizard.

<![if ! IE]>

<![endif]>Danfoss 80Z8119

Important: The wizard will not start automatically once the unit has been powered up at least once. To start the Wizard at any time turn off the controller by pressing the power button for 3 seconds and wait until the power symbol is ON. The press the buttons listed here in sequence,and SET.

If the pump down function is active, a certain amount of time may elapse between starting the stand-by function and the controller stopping (see page 8).

BC364433930186en-000101 | 5

User Guide | Temperature controller for walk-in coolers and freezers, Type AK-RC 251

Wizard parameters list

Pd	Pump down active?	0=No	1=Yes

o00	Configuration of relay AUX1	0=Deactivated	1=Compressor/Crankcase heater
o00	Configuration of relay AUX1	2=Light	3=Virtual control
		2=Light	3=Virtual control

I00	Connected probes	1=Probe 1 (Cold room)	2=Probe 1 (Cold room) + Probe 2 (Evaporator)

		0= Deactivated	1=Door contact	2=External alarm
I10	Configuration of digital input 1	3=Severe external alarm	4=Change of SP	5=Remote defrost
		6=Defrost block	7= Low pressure switch	8=Remote Stand-by

I11	Polarity of the digital input 1	0=Activates on closing contact	1=Activates on opening contact

		0= Deactivated	1=Door contact	2=External alarm
I20	Configuration of digital input 2	3=Severe external alarm	4=Change of SP	5=Remote defrost
I20	Configuration of digital input 2	6=Defrost block	7=Register probe	8=Probe 2° evaporator
		6=Defrost block	7=Register probe	8=Probe 2° evaporator
		9=High pressure switch for Hot Gas	10=Remote Stand-by

I21	Polarity of the digital input 2	0=Activates on closing contact	1=Activates on opening contact

d1	Maximum defrost duration (0=defrost deactivated)

d7	Type of defrost	0=Resistors	1=Air/fans	2=Hot gas
d7	Type of defrost	3=Reversal of cycle
		3=Reversal of cycle

F3	Status of the fans during the defrost	0=Shut down	1=Running

8. Operation

Display messages

Pump down malfunction error (stop), the time configured in parameter C20 has been exceeded (see page 8).

Only displayed on screen.

Pump down malfunction error (start-up), the time configured in parameter C19 has been exceeded (see page 8).

Only displayed on screen.

Probe 1/2/3 failure (open circuit, crossed circuit or temperature outside the limits of the probe)

Only E2 and E3: Damp evaporator probe (see page 12).