Re: OT will honeywell chronotherm T882A work with no transformer?
co_f...@yahoo.com
> http://www.google.com/search?hl=en&ei=WMsvS7_cBcqLkAWIxIT2CA&sa=X&oi=...
>
> The Thermostat reads:
>
> Honeywell Chronotherm
> T882A 1054 1
> The clock stopped working years ago and is not needed.
>
> the Transformer reads:
> AT 75A 1036 2
> OC 24V NEC Class 2
> 120V 50-60 CY 3VA
>
> and it has been making a fairly loud humming noise for years.
>
> Question: Could I just remove the transformer since I have no use for the
> clock functions?
>
> The second item in the search above is a four page manual but it is also
> unclear to me - I know nothing except most thermostats do not need a power
> supply.
> I see no harm in just unhooking one of the two wires and see what
> happens????
>
> Any suggestions?
> m
>
> PS.
> This is all for a gas heated Carrier forced air heating and cooling unit
> in the attic.
Well, first, you are certainly mistaken about thermostats and power
supply. All thermostats need power. Sometimes it's internal to the
furnace and sometimes you need to supply the power separately with an
external transformer.
Second, I have never seen one of that type of transformer that didn't
hum rather loudly. You might try remounting it directly to a wall
stud, or other solid piece of framing so the vibration is not
amplified by thin material.
Paul
Stormin Mormon
electronic thermostats need the 24 VAC power to run their
own circuit.
The furances I've serviced, the 24 VAC also opens the gas
valve. So, if you take the transformer out of the picture,
you get no heat.
But, it would be quieter. I suggest you take the the
transformer out and try it for a couple days. Be prepared to
put it back in. Let us know how it works, for you.
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
<nom...@noplace.org> wrote in message
news:osjvi5l4k269l3hs8...@4ax.com...
RoyJ
programmable thermostat section running off AA batteries and the gas
valve section running off of the 24 volt transformer. If yours is the
same, you will NOT be able to run it without the transformer.
Just disconnect the transformer, see if the gas valve come on .......
ever. You won't hurt anything.
You might check to see if your "hasn't worked for years" is due to no
battery.
RoyJ
try page 249 at www.grainger.com
In particular
http://www.grainger.com/Grainger/items/4X744
for $15.52
I have several similar units for various circuits, NONE of them make a
peep.
These mount to a 7/8" hole (1/2" conduit size) in the side of any
convenient electrical box. It should be connected to the furnace
circuit, AFTER the furnace shut off switch. When the switch is OFF,
EVERYTHING on the furnace is dead. And the furnace should be the only
thing on that cirucit.
nom...@noplace.org wrote:
> On Tue, 22 Dec 2009 08:36:56 -0600, RoyJ <spam...@microsoft.net> wrote:
>
>> A quick check of some similar Honeywell Chronotherm units shows the
>> programmable thermostat section running off AA batteries and the gas
>> valve section running off of the 24 volt transformer. If yours is the
>> same, you will NOT be able to run it without the transformer.
>>
>> Just disconnect the transformer, see if the gas valve come on .......
>> ever. You won't hurt anything.
>
> I'm sure you guys a correct - the 24 v IS needed to run both heating and
> cooling. It was only a hope of mine that I could do without the
> transformer - since after more than 30 years of service it is 'due to
> fail' any time. I was (am) somewhat confused about how or where I get the
> correct replacement. I did a google and that did not help.
>
>
>> You might check to see if your "hasn't worked for years" is due to no
>> battery.
>
> It has no indication of a battery in the manual or on the clock itself.
Stormin Mormon
transformer say the VA rating?
--
Christopher A. Young
Learn more about Jesus
www.lds.org
.
<nom...@noplace.org> wrote in message
news:0iv1j5t1846kcl3p6...@4ax.com...
On Tue, 22 Dec 2009 08:36:56 -0600, RoyJ
<spam...@microsoft.net> wrote:
>
>Just disconnect the transformer, see if the gas valve come
>on .......
>ever. You won't hurt anything.
I'm sure you guys a correct - the 24 v IS needed to run both
RoyJ
page 3820 at www.grainger.com
The full deal Honeywell version with 'heat-Off-cool' is
http://www.grainger.com/Grainger/items/1JUB1 for around $40
Any home store will have a similar equivalent for less $$
Grainger has the basic model for $22
http://www.grainger.com/Grainger/items/4PU47
The basic thermostat has 3 wires, adding the sub base with the switches
for changing from heat to cool with change that to 5 or 7 wires
depending on the options. You need to pull the existing one off the wall
and check to see what wires need to be hooked up. The heat/cool
changeover switch may be mounted somewhere else, you may not have the
fan switch in your system.
nom...@noplace.org wrote:
> My search for the Honeywell T882A thermostat replacement was unsuccessful.
> Saw no info as to it being discontinued or what the replacement may be.
> What would be good places to search?
>
> Thanks again
> m
>
> PS I really do NOT need the clock feature.
> I DO need both heating and cooling. (I will eventually get it right)
RoyJ
controlled furnace to an older multizone furnace control. Lets just say
that they don't play well together. It looks like I will have to build
my own custom controller. A microprocessor is the nifty way to go,
reliability and maintenance considerations dictate relay logic. I can
get all the functions I need with about 8 ice cube relays with 4pdt
contacts along with about 3 time delay relays. Oh joy.
nom...@noplace.org wrote:
> Thanks again Roy - fantastic information and source!
> m
RoyJ
http://www.allelectronics.com/make-a-store/item/4PRLY-120N/4PDT-120VAC-ICE-CUBE-RELAY/1.html
Picture about 8 of these, surface mount, lots of wire running around.
http://www.allelectronics.com/make-a-store/item/MT14-PC/14-PIN-SCREW-TERMINAL-SOCKET/-/1.html
The guys at school want me to do a full microprocessor system but making
changes in 5 years or having a real HVAC tech try to troubleshoot it
makes me stick with relays.
New furnace is in, a LOT of tin bending (LOTS of metal content!), and
the house is warm but the controls are not right.
Old system was 50's with a 60's retrofit o 3 zones on a forced air
system. Old ductwork near the furnace was poorly installed, first 6 to
10 from furnace got trashed and replaced. Old furnace was installed
before they put a new layer of concrete on the basement floor, had to
hammer it out and pour a new concrete slab. Old zone dampers were simply
huge bimetallic strips that got hot when you pushed 1/2 volt at xx amps
through them, they got trashed.
I bought a 4 zone controller and modern dampers, had it ready to install
with the modified ductwork. The zone damper controller is a "single or
more" call system where any zone can call for heat, furnace fires up to
respond. New furnace has MUCH better fan capacity than the old unit,
MUCH more air. Some testing shows that I need at least 2 zones open or
the system gets way overpressure. (You can hear the ducts bulging!) So I
have to do a new controller that will open the calling zone PLUS select
another zone to dump the rest of the air. Of course there is a different
algorithm for summer and winter as well as time of day or even outside
temp. Now to try and get some of my money back on the purchased unit.
Whole project gave me a new appreciation for the old foggies that could
flop a 4'x8' piece of 26 ga sheet down on the work table and make up
some twisted corkscrew piece of ductwork with nothing more than a
straight edge, huge dividers, and a snips.
nom...@noplace.org wrote:
> four-pole double-throw (�f�r 'pol �d?b�?l 'thro)
> (electricity) A 12-terminal switch or relay contact arrangement that
> simultaneously connects two pairs of terminals to either of two other
> pairs of terminals. Abbreviated 4PDT.
>
> Had to look it up - Did you actually get it all to work as intended?
> Sounds like lots of effort and money with an uncertain outcome - that is
> if I were doing it.
> m
>
>
>