IMMERSION HEATERS

[JIM COTTRELL]

I HAVE 3 IMMERSION HEATERS IN 4 TANKS ALL ON 480VAC SINGLE PHASE CIRCUIT THE CONTROL BOX WIRES BURN RIGHT BEFORE THE CONTACTOR. I HAVE SIZE 10AWG WIRE FROM BREAKER TO BOXES ALL WHICH HAVE BURNED BEFORE THE CONTACTOR BEFORE IVE BEEN REPAIRING WIRES EACH TIME IN ORDER TO KEEP THEM RUNNING. THEIR RATED AT 6.3 AMPS 3000W THATS 18.9AND 9000W TOTAL ON TWO WIRES. WHAT SHOULD THE BREAKER BE RATED AT. SHOULD IT BREAK BEFORE THE WIRES BURN. THE HEATERS ARE IN NICKLE TANK SOLUTION.

 

[Lucien Nunes]

There's no issue with the #10 wiring carrying 19A so I suspect the damage is caused by heat being conducted from the contactor contacts to the terminals, or from the terminals themselves not making a good connection.

Is the wiring copper? What is the current and voltage rating of the contactor? Can you post pictures of the burnout damage?