Re: T87 Thermostats

[chasbo@xxxxxxxxx]

"Midland" should be "Winland."

On Mon, 26 Oct 2009 23:40:19 -0400, 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?