Traulson Refrigerator Retrofit

About the project

Retrofit older commercial refrigerator with digital controls and web interface

Project info

Difficulty: Moderate

Platforms: Raspberry Pi

Estimated time: 4 days

License: GNU General Public License, version 3 or later (GPL3+)

Items used in this project

Hardware components

More terminal blocks More terminal blocks x 1
1008238 6 1008238 6 x 1
Terminal blocks Terminal blocks x 5
din rail din rail x 1
2 Channel DC 5V Relay Module 2 Channel DC 5V Relay Module x 2
DEV-14643 Single Board Computers Raspberry Pi 3 B DEV-14643 Single Board Computers Raspberry Pi 3 B x 1

Software apps and online services

Node Red Node Red


I have an old Traulson refrigerator/freezer that is very inefficient and costly to run.   I've added digital monitoring and control using a Raspberry Pi and Node Red, as well as new LED lights .  The goals were to:

1- Make the unit more efficient by removing the old analog controls.

2- Provide accurate monitoring to adjust for lowest amount of power used to achieve acceptable internal temperature .

3- Replace old dim and hot incandescent light bulbs with LED strips.

4- None of these modification could look non stock.  

5- Replace 4 watt heater for the ice maker feed tube and replace with a controlled heater.

I started with the lighting last year, this had a dramatic improvement in the appearance of the unit as well as being able to see what you were looking for.  I then added the temperature probes and monitoring using Cayanne/My Devices.  This involved drilling holes through the freezer and refrigerator compartments and installing new temp probes.  In about 1 week I was able to decrease the temp setting on the analog control from 9.5 to 4 and still maintain a temp of  zero degrees F inside the freezer.   Since I did not want to be at the mercy of an outside vendor for the control of my food safety, I used Node Red to write a control loop to monitor temps and turn on the freezer and fridge compressors when needed.  Over all I am very pleased with the final product and all of the goals were achieved.

Schematics, diagrams and documents

Traulson wiring

Wiring diagram

CAD, enclosures and custom parts

Traulson front view

View from the front

Inside lights

Detail of upper lights

Side lights

Self adhesive LED's on side of door frame

Raspberry PI, Relays, terminal blocks

Din rail mounted Raspberry PI, Relays, terminal blocks


Dashboard of the 4 temp gauges


Node red code

Sorry for the weird formatting


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