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#83094 - 01/09/03 04:47 PM conductive vs. resistivve
Tom jr Offline
Junior Member

Registered: 01/09/03
Posts: 1
Loc: west islip,n.y.,usa
I have not been able to get an answer i can understand to my electrical question about line volt. thermostats. The honeywell t451 has proven itself to be a very unreliable stat. So i bought 6 t498 electric heat thermostats and installed them at 6 different houses. They are working well, with no call backs. Before i install more i called honeywell to ask if this was ok to do?The answer they gave me was that the t451 is a "conductive" stat. & the t498 is a "resistive" stat. there for the 498 should not be used on oil hot water system. The lady i spoke to on the Honeywell tech. support line could explain further. Before i purchase any more and get myself in trouble what do you think.
Thank You in advance,
From Tom jr

2014 / 2011 NEC & Related Books and Study Guides
#83095 - 01/09/03 06:36 PM Re: conductive vs. resistivve
electric-ed Offline

Registered: 07/08/02
Posts: 184
Loc: Canada
Tom, I think they probably meant inductive, not conductive.
Inductive loads, involving motors, transformers, and relay coils, causes more arcing and require contacts that will withstand the increased wear.

Electric heat is a resistive load.


#83096 - 01/09/03 09:03 PM Re: conductive vs. resistivve
ElectricAL Offline

Registered: 10/10/01
Posts: 615
Loc: Minneapolis, MN USA

I think Ed nailed it. The T498 has a rating of 22A noninductive (resistive), and nothing is listed about inductive load.

The T451 shows up in a '89 catalog and has an inductive rating of 4A Full Load @ 208/240/277, 24A Locked Rotor, and 7.2A resistive.

Ah, the difference a decade makes.

Al Hildenbrand


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