Norcold N611 | N620 | N621 | N641 | NX611 | NX641 | NXA611 | NXA641 | Specification Table

To save money and improve safety on Norcold N611, N620, N621, N641, NX611, NX641, NXA611, and NXA641 the Fridge Defend failure prevention device needs to be installed. This page is an overview of the installation process and includes a specification table for troubleshooting your fridge.


Table of Contents

Before reading this page, please click here and view our wiring video.

Click here and view our ARP sensor install video.

REQUIRED TO DOWNLOAD INSTALLATION INSTRUCTIONS - WEB PAGES ARE SUPPLEMENTAL - EACH VERSION OF CONTROL HAS INTRICACIES REQUIRING THE WRITTEN INSTRUCTIONS.

Instructions: Subjects are listed on left. Click the link to the right to go directly to the subject matter on this page.


Norcold N611

Norcold 6xx Fridges with Thermo Switch

The first installation drawing shows the early models of the Norcold 6 cubic foot fridges.

(1) The power is delivered from the RV power supply to the cooling unit compartment. The power supply wires differ in every RV and are dependent upon the manufacture of the RV. We show the standard colors for the power supply where green is ground and red is +12 volts.

(2) For the factory wiring, the power first goes to the boiler housing thermal switch and then back to the Norcold control (4).

(3) The ARP control will be put inline with the power source. The ARP may be either wired as shown here or the ARP may be wired between the thermo switch (2) and the Norcold control (4). The ARP red wire is connected to the RV power source (1) and the ARP yellow wire is connected to the side that supplies power to the Norcold control.

(4) This is the Norcold factory control.

(5) The boiler housing is show, but the ARP green/white wires are not shown connecting the boiler temperature sensor.


Norcold N611.3

Early N611.3 & N641.3 3-Way Fridge

This next drawing shows how to wire the early 3-way fridges. The ARP can not pass enough power for the 12V electric heaters so a load relay is needed for these fridges. We at ARP do not use the 12V heaters because they generally do not have enough power to run the fridge properly.

(1) The power is delivered from the RV power supply to the cooling unit compartment. The factory wiring runs directly to the Norcold controller (2). Please see (4) how to wire the ARP.

(2) The Norocld control is shown with terminal identification as follows:
Terminals 1 & 2: 12 volt heater, see (3) below.
Terminals 3: +12VDC power in.
Terminals 4: -12VDC power in (ground).

(3) Please see the following link for the 12 volt heater wiring: 3-Way Heater Relay

(4) The ARP is wired by removing the wire going to terminal 3, the +12VDC power supply from (1), and connecting it to the ARP red wire. Now connect the ARP yellow wire to the terminal 4 and this completes the circuit.

(5) The boiler assembly is shown without the ARP green/white temperature sensor wire connected. Please see photo above for sensor location.


Norcold N611.3 Factory Wiring

Late Model N611, NXA611, N641 & NXA641 2-Way Fridge

From the factory the Norcold control box (2) is wired directly to the RV power supply (1). We show green for ground and red for +12VDC, all of the manufactures use different wire colors so your wire colors may vary.

In order to wire the ARP Control just disconnect the +12VDC from the Norcold control (2) and connect it to the ARP Control (3) red wire. Now connect the ARP Control yellow wire to the Norcold control (2) where the +12VDC was disconnected in the first step.


Norcold N611.3 Factory Wiring

Late Model N611.3 & N641.3 3-Way Fridge

This drawing shows how the late model 3-way fridge is wired from the factory. Please note the purple (color of your wire may vary) jumper wire with the brown arrow pointing at it.

The next image will show how to wire the ARP Control.

Norcold N611.3 Factory Wiring

Referencing the drawing above, remove the purple jumper wire and plug the ARP Control red wire into terminal-6. Connect the ARP Control yellow wire to terminal-2 to complete the circuit.


Norcold N611.3 Factory Wiring

This is the wiring for the newer Norcold refrigerators that have the recall box. Note that the ARP is wired in-line with the power supply to the Norcold controller.


Norcold N641

Boiler Housing

The next photo shows a Norcold N641 with the door to access the electric heaters opened. This photo will help the installer understand what the inside of the cooling unit boiler housing looks like.

The red arrow points to the cooling unit boiler tube at the approximate location where the ARPrv temperature sensor will be located. On this particular cooling unit the flue tube is behind the boiler tube, this makes the installation on the 6xx series very easy. Please make sure the ARPrv temperature sensor is insulated as per the example on the Boiler Temperature Probe Install page.

The yellow arrow points at the slot where the cooling unit heater access door tab is engaged. Just bend the tab to open the door.

The orange arrow points to the electric heating element, the electric heating element is always attached to the cooling unit boiler tube, and this is the best way to identify the boiler tube for the installation of the temperature sensor.


ARP Sensor N611

This photo shows the ARP boiler sensor properly clipped onto the boiler tube. Note that insulation is places under the ARP sensor wire. The entire sensor shall be insulated so that the electric heater and ambient air can not enter the boiler housing.


Fault / Error Codes 611; 620; 621; 641

FAULT CODE MEANING POSSIBLE SOLUTION
No Display No DC to Fridge Make sure fridge is on.
Check power and ground to fridge.
ARP Control detected an overheat situation, check ARP display to see if a count down period tells when control will turn back on fridge.
dr Door has been open for more than 2 minutes. Close the door.
no FL LP gas burner did not ignite. LP gas turned off.
Low LP pressure.
Click here for pressure test.
Manual shutoff valve is closed on LP solenoid.
no AC No AC voltage to control. Check for shore power at plug.
Check RV circuit breaker, or if equipped, the GFI.
Try RV generator.
Click here for improved AC heater safety.
AC LO Low AC voltage at fridge. Check with DMM to see that AC voltage is in range at fridge.
Click here to check AC heater.
dc LO Low DC voltage at fridge. Check with DMM to see that DC voltage is in range at fridge.
no co The fridge started, but did not cool within 2 hours. If the fridge has an ARP Control, this message should not appear.
Fridge thermistor has failed.
Click here to check thermistor.
Click here to reset 'NO CO' fault.
Temperature number flashes when TEMP SET button is pushed. The refrigerator is operating in Back Up OS mode. The control unit is not getting an input it needs to run.
Fridge thermistor has failed.
Click here to check thermistor.
Check all wiring connections, power down the fridge and then power up.
AC rE Norcold states that "this is a fault within the controls" We assume this is a fault with the AC relay on the Norcold board? We at ARP Control want to help everyone with a Norcold fridge. If a solution to this issue is found please share with us so we can post it to share the joy.
dc rE Norcold states that "this is a fault within the controls" We assume this is a fault with the DC relay circuit? It is possible that this means that the DC relay is stuck? We at ARP Control want to help everyone with a Norcold fridge. If a solution to this issue is found please share with us so we can post it to share the joy.
AC HE Norcold states that "this is a fault within the controls" Fault with the AC Heater circuit.
Click here to check AC heater.
Sr Flame sense circuit failure Turn off fridge and restart.
Check LP Gas pressure and electrode gap.
Click here for gas valve and igniter check.

Norcold 611, 620, 621, 641 Specification Table

Please note that all of the following specifications are believed to be accurate. If any errors are found, please bring them to our attention as soon as possible. For critical specification please contact Norcold as they make changes to their specifications without notice.

Item Value Units
ARP Control Boiler Temperature See Note 1 Below
N6xx Volume 6.3 cu. ft
N8xx Volume 7.5 cu. ft
Off-Level Operating Limit See Note 2 Below
Temp Setting Range 1 - 5 5 = Coldest | See Note 3 Below

Fuses

Item Value Units
Board 12V Fuse/Heater Fuse 5/30 Amp
120VAC See Note 4 Below Amp

DC Power

Item Value Units
Automatic Ignition 0.5 Amp
Flapper Heater 0.25 Amp
DC Heater N6xx.3 (at 12.0 VDC) 13.79/0.87 Amp at 12.0VDC/Ohms
DC Heater N8xx.3 (at 12.0 VDC) 13.79/0.87 Amp at 12.0VDC/Ohms
ARP Control Fan (25cfm blower type) 0.36 Amp
Total Amp Draw 14.9 Amp

AC Power

Item Value Units
Operating Range 108 - 132 VAC
AC Heater (S/N before 854647) 2.7/41 Amps/Ohms
AC Heater (S/N after 854647) 2.5/48 Amps/Ohms
Measurement Conditions 110/120 VAC

LP Gas

Item Value Units
Gas Pressure 10.5 - 11.5 inch w.c.
Heat Input 1500 BTU/hour
Gas Jet (new style) LP16
Gas Jet (old style) 0.155 Jeweled
Electrode to Burner Gap 1/8" to 3/16" inch

NOTES

Note 1: 185-195°C - 365-383°F

Note 2: Dependent on ambient and ARP boiler temp.

Note 3: Thermistor Values

Note 4: 8 Amp type AGC fast acting.