Submersible Heater Cable dimension and grounding

Thread Starter


Joined Feb 6, 2018

I'm planning on creating my own sous vide device and have bought a submersible heater from aliexpress. I choose one with a contact that indicated it had ground. However, i had to cut the cable open to be able to connect it to a relay, and to my surprise, there were only two wires present in the cable, Brown Live, and Blue Neutral, i.e. no ground running down to the heater.

At the same time i also noticed that the cables running in the cable seemed to be a bit under dimensioned at 0.8 mm cross diameter since it is rated at 1500w, i.e. ~10 Amps of current. I did some quick reading on the internet and found that 0.8 mm of diameter is really only rated at about 5 Amps of current, i.e. half of the power the heater is rated at.

So to my questions:

1: Since i am going to cut off the bigger part of the cable and leave only max 30 cm, will it still be safe to use the current cable even though it is somewhat under dimensioned? The cable will be inside an ABS plastic box with little to no ventilation.
2: About the grounding. I am planning on connect a separate ground cable to the stainless steel metal cage so if there's any current leak, the cage will lead this current to the ground and the ground circuit breaker will trigger. Is this a suitable solution to grounding the device or should i ground somewhere else?


Joined Sep 17, 2013
Welcome to AAC!
:eek: Personally, I wouldn't trust my life to one of those heaters. An internal fault in the element could make the outer sheath LIVE! I would advise using a properly earthed immersion heater element. Such elements are available in various shapes.