Re: T87 Thermostats

[JoeRaisin <joeraisin2001@xxxxxxxxx>]

CH®IS wrote:
> <chasbo@xxxxxxxxx> wrote...
>> Win one for the environment; zero for low temperature monitoring.
>>
>> Have been using Honeywell T87 thermostats for many years to monitor
>> low-temperatures in homes, usually set at 48 degrees, but because of
>> new environmental regulations mercury is no longer a part of the T87.
>>
>> Since mercury in the glass envelope is no longer a part of Honeywell
>> thermostats, most if not all new Honeywell stuff contain a printed
>> circuit board consisting of the usual transistors, resistors, etc.,
>> and must "see" ac voltage in order for the thermostat to act properly,
>> which, in the case of home heating systems, is present, and is what
>> the product is designed for. Hence the product is not designed for DC
>> use.
>>
>> I have not tried using an ac transformer and ac relay in conjunction
>> with the new CT87K, using the dry contacts to trip a zone.  Even if it
>> worked, I would not want to rely on it  because AC power could be lost
>> in the middle of a New England winter, rendering the new CT87K
>> useless.
>>
>> I have used a Midland thermostat twice and find the product crude, and
>> pain in the butt to perform a test.  There is one moving part in their
>> product, a rod, which moves towards a contact point as the temperature
>> rises.  When contact is made, the alarm panel is tripped; but I have
>> found that contact pressure is not always sufficient to produce the
>> desired result (a short across the EOL resistor).
>>
>> Have any of you found a reliable substitute for the best
>> low-temperature T87 thermostat ever made?
>
>
>
> These are all from Winland Electronics...
>
> http://www.alarmsbc.com/enviro.htm
>
> http://www.winland.com/TempandHumidityAlerts.htm
>
> EA-200 - Can be used for both high and low temperature without any
> additional sensors and is programmable for the high and low temp limit
> and NO/NC I believe.  Doesn't look bad on a wall either, even if it does
> stick out 1.25" off the wall.  The programming is fairly intuitive
> although you'll want to have a manual on hand for your first one, and
> then perhaps afterwards since you won't remember how to unlock it again
> later.
>
> TA-40 - Not sure what's inside one of these units, but being the size of
> a surface contact it can pretty much be mounted anywhere.  Not
> programmable at all, doesn't need power.
>
> TA-1 - Basically a thermometer with a contact on either side of it.
> Very ugly on a wall but very easy to use and seemingly the most reliable
> way to go.  There's also the TA-2HL for 2 separate zones and "custom
> graphics" although I don't think I've ever seen one in use.
>
> Perhaps there's no more mercury in thermostats because it's all needed
> to make CFL bulbs that we're supposed to believe are saving the planet?
> That is... until one breaks at least.
>
> - Chris

Winland also has the MTA-1 which is really just a smaller TA-1 but in a
much more attractive case.  Good enough that is can be out in the open
without making the living room look like a factory floor.