Cartride Heater Contamination - Our Worst Enemy || TGID Newsletter - July 23, 2004




	Electric Heating Co., Inc

TGID
23-Jul-04

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Contamination - Our Worst Enemy

Contamination is the #1 cause for failure in cartridge heater applications. You couldn't believe the condition of some heaters returned to Dalton Electric for failure analysis ... heaters covered with oil, burnt plastic and crud (that's our technical term when we can't explain it).

Contamination is the #1 cause for failure in cartridge heater applications

The above heater had tremendous contamination in the terminal cavity. The oil on the wires had wicked into the Magnesium Oxide insulation and caused a short to ground. A cutaway of the heater (shown below) reveals the extent of saturation prior to failure.

This cartridge heater had tremendous contamination in the terminal cavity. The oil on the wires had wicked into the Magnesium Oxide insulation and caused a short to ground.

There are two possible cures for prevention of contamination. RTV rubber can be inserted into the terminal cavity. This presents the best barrier, but will only perform under standard" temperature conditions (to 450 degF). Ceramic potting will go to the temperature limits of the heater, but there is a degree of porosity that does not completely exclude liquid contamination

The Engineers at Dalton Electric are always happy to dissect a failed heater to determine how we might best deal with environmental limitations.

Next week: Non-environmental contamination !!!

Friday Funnies

Did you hear about ...

the sandwich that walked into a bar. The bartender said, "Sorry we don't serve food in here." the two peanuts that walked into a bar, and one was a salted. the jumper cable that walked into a bar. The bartender said, "I'll serve you, but don't start anything." the man that walked into a bar with a slab of asphalt under his arm and said: "A beer for me, please, and one for the road." the two termites that walked into a bar. One asked, "Is the bar tender here?"

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Dalton Electric Heating Co., Inc (978)356-9844
28 Hayward Street Ipswich, MA 01938 USA