switching appliance with low voltage switch?

I bought a bare bones dehumidifier. However I need to add a condensate pump to it to pump the water to a sink. There are many brands/models of condensate pump, I'm interested in the ones with an overflow safety switch so I can turn off the dehumidifier in case the pump fails.

These safety switches are float-activated micro switches and are not rated to switch a dehumidifier (120V 7A).

I would have to add a switching relay like this:

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Costs $20.

Since this is a mechanical device (relay), it is bound to generate arc and the contacts are bound to fail. More so if the load is inductive.

Also, the dehumidifier along with this device is placed in a sealed crawlspace with natural gas pipe running though. In the unlikely case event of a gas leak, I prefer there be no arc generating switches

Would it be better to use a TRIAC to switch this appliance? Something like this:

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The S1 would be the safety switch (normally closed)

The triac is even cheaper than the relay module. Are there reasons not to use the triac? I understand the triac would have a voltage drop of about 1 volt, in this case amounts to 7W, which is no big deal and probably needs a small heat sink.

And if I do use triac, what rating should I get? It's not just 120V 7A. If the load is inductive, I would need a higher rating, but not sure how high.

Reply to
james
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"james" wrote in news:i9fcm5$5pu$ snipped-for-privacy@speranza.aioe.org:

A triac should be fine, but because it's switching an inductive load you can easily do worse than start with this LT (Linear Technology) document on triac switching..

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It might also be possible to use a switching MOSFET but I'm not at all sure they deal with mains voltages. Usually high current, low voltage, from what I've seen. They'd be useful if they did though, bidirectional main channel, on resistance of a few milliohms.. But I'd stay with a triac for mains switching, I think.

Reply to
Lostgallifreyan

Lostgallifreyan wrote in news:Xns9E1525EA1D43Bzoodlewurdle@216.196.109.145:

ST. Not LT. But this file is a keeper, for certain.

Reply to
Lostgallifreyan

Fortunately, neither ST or LT have Apple's business model, else they would have trademarked the use of "T" in naming device manufacturers.

;-)

--
Rich Webb     Norfolk, VA
Reply to
Rich Webb

Rich Webb wrote in news: snipped-for-privacy@4ax.com:

I ought to trademark the fact that I exist, and charge everyone royalties for the fact thay they also exist. It could even work, some of those no-win-no- fee lawyers will try anything. >:)

Reply to
Lostgallifreyan

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