Element continuity?

[Scott Young]

I think I've got an element going bad in my furnace (wire melter). To check, can I just use a multimeter to check continuity (after unplugging everything...)?

The furnace just isn't going up to full temp, and it is ramping quite slowly.

Thanks!

[Cecil McKenzie]

Scott I have checked for broken elements with the ohm meter on a multi tester. Disconnect from power at the breaker box. Disconnect leads from elements. Set meter to
ohms reading. Test meter by placing probes on something that definitely has continuity to check if batteries are good and ohm meter is working then place probe on element leads, no reading means elements burnt out. Turn tester off after testing. I usually remove batteries also. Hope this helps.

[Scott Young]

Thanks, that's what I needed to know. Also, anybody have recommendations on the best type of elements to use (or what I should use to prevent the rapid deterioration?)

[Steve Stadelman]

Scott, use heavy A-1 heaters and something very fast switching like an scr or ssr.

If the element is going bad but not burned out the ohmmeter might till you resistance is up but might not.

[Ray Laubs]

When my wires go bad, Ive considered converting to a mosi2 heater, that way I can start ruining batch and not worry about destroying the wires as fast.

[Dave Bross]

The elements also gain resistance as they thin out with time. This makes them pokey too. It's a good idea to check the resistance of new elements so you can know via an ohm meter reading later how far things have deteriorated. My melters start to get slow about the point in time where I've gained two ohms of resistance per element. Your mileage may vary.

I also have a tiny melter that has a variac on it that will take the 120 voltage up to 180. Gradually increasing voltage until the volts x amps get to what the original wattage of the element was can buy you some more time but sudden failure is not far away at this point. This melter uses assay pots, so no big loss if the end comes late one night...as it always does.

[Brice Turnbull]

Use 10 gauge Kanthal A-1 wire.

[Dave Bross]

A few things to consider on what Brice suggests. Thicker wire in your elements is a good thing, but often not possible due to some physical limits usually found in most wire melters.
To get the same resisitance as the original element with a thicker wire, you will have a much longer element, then often there's not enough groove length to put it in. If the larger wire diameter element is wound on the same diameter mandrel as the original, it will have a slightly greater outside diameter than the original, so how wide the grooves are becomes an issue too.