HVAC went bad after installing new thermostats.. please help!

[dx]

Rich, those wires are tinned copper so the ends do not oxidize (as bare copper would). That way they make better contact, whether you screw them to a terminal block, crimp them or solder them.
Aluminum wires are never used in control wiring. Period. Only in power wiring.
You "professional members" need to stop making statements on subjects you know nothing about. It just shows your embarassing ignorance. Drop your all-knowing attitude and maybe some of us laypeople will teach you a thing or two.

[rich pickering]

Don't have all the links for all the sites I looked at, but this was the first.

http://www.coonerwire.com/Products.html

Your right, most is plated copper, I scraped the plating off of the transformer. All of the wires on the thermisters on those chillers that are so impressive are not copper. They are specific to the type of thermister K,J etc.

http://www.alphawire.com/pages/326.cfm

Man, I hate to lose an argument.

[Edited by rich pickering on 08-15-2005 at 01:36 PM]

[ravenx]

You "professional members" need to stop making statements on subjects you know nothing about. It just shows your embarassing ignorance. Drop your all-knowing attitude and maybe some of us laypeople will teach you a thing or two.

Now I've heard it all.

[dx]

Rich, thermistors (check the spelling) are thermally sensitive resistors and have, according to type, a negative (NTC), or positive (PTC) resistance vs.temperature coefficient. They have copper leads.

No such thing as type j, k, etc. thermistors. Those are thermocouples. They consist of two dissimilar metallic conductors connected in a closed loop. Each junction forms a thermocouple. They generate a voltage that is a function of temperature. The type refers to the metals used.

Neither thermistors nor thermocouples are "control wiring", or wiring of any kind. They are sensors. Guy in the temperature control business ought to know this stuff. Stick around, you'll learn

Now, about that site that sells stainless and aluminum wire, well, the bailing wire holding your rusted-out muffler is also not copper. It's not control wiring, either

[Twilly]

Originally posted by amsoma
If this is not a DIYer site then why are you pro's wasting so much of your valuable time replying to this thread? Move on to one from one of the other professional members. Sounds like the first two replies gave this guy all he needed. Get over yourselves.

Oh were just having a little hissey fit. Let us be. Were not ready to take a time out yet. Plus we haven't had anybody to gang up on in a while.....

[rich pickering]

dx, you are right, I meant thermocouples. my bad. They are two different things.
However, thermocouple wire is used in process control. Industrial ovens, etc. The world is bigger than just a simple rwyg stat.

When I was responding to helicalrotoman, I should have left out "especially in controls"



[Edited by rich pickering on 08-15-2005 at 11:34 PM]

[dx]

Rich, I am not nitpicking, but you have to be careful with what you call "wire" and "wiring". Wiring is conductors used to make connections between devices. Control wiring (as opposed to power wiring) is simply interconnects that are of relatively thin gauge and carry no significant power. As such, all control wiring is copper.

The expression "thermocouple wire" is a totally different animal. Thermocouples are complete loops and only work when connected as a loop with "thermocouple wire" of the type specific for that thermocouple. It is part of the loop, i.e. the entire loop is the sensor. It is not "control wiring".

Similarly, even though transformers, solenoids, relays, motors, etc. are mostly made of copper wire, they are devices, not wiring.

[rich pickering]

dx, is thermocouple extension wire part of the loop or part of the control wiring?

Relax, like I said, I should have omitted "especially in controls"

What do you consider low voltage?

This would be more fun over beers.

[dx]

Thermocouple extension wire is part of the loop. You will note that if you have a Fluke multimeter or similar with thermocouple capability, it comes with a special cable. You cannot use the regular leads that you use for volt/amp/ohms. That's because anytime the thermocouple is in contact with the wrong metal(s) it generates voltage out of whack.

I do not consider anything low voltage. I said low power. That means a control signal, i.e. a signal that conveys information of some kind, rather than power that will perform end work, such as running a motor, heater or light bulb.

[rich pickering]

So, would a 208 volt signal to a contactor or relay be low power?

[dx]

Depends. If the contactor is the size of your fist and the coil only takes a few milliamps, yes. If the contactor is the size of a car and the coil takes 500 A in order to switch 50,000A at the contacts, no. The voltage is not necessarily a disqualifier. Example: in the old days, when vacuum tubes were used, the control logic was done at the very high voltages required by the tubes. 400V ac and dc was commonplace inside everything from radios to 'computers' to industrial controls. However, the currents were very small. So the power in those circuits, while greater then today's controls, was still small compared to the "power" circuits.

[Carnak]

Originally posted by rich pickering
dx, is thermocouple extension wire part of the loop or part of the control wiring?

Relax, like I said, I should have omitted "especially in controls"

What do you consider low voltage?

This would be more fun over beers.

Hey rich, I am wiring up a control panel for another company here, I read the spec told them to get me so many switches, relays and terminal strips, what size transformer etc.

It was really cool the transformer leads were tinned just like dx said. But I do not know what to do with the toggle switches with the aluminum wire pigtails. I hope all the LED lights don't have aluminum leads too.

[dx]

I know what you should do. Call the company that makes the toggle switches and ask them why the pigtails are aluminum. Then tell us what they said, except for any profanity they might use

[Carnak]

Originally posted by rich pickering
So, would a 208 volt signal to a contactor or relay be low power?

That's definetly line voltage, just like a 120V actuator or a redundant gas vale on a big gas train.

Most likely be electricans work, especially if it was outside of a piece of equipment.

[rich pickering]

Well I'm just a dumb plumber/gas fitter, but if its after the j box on gas fired equipment, it's all mine regardless of voltage.

[rich pickering]

I just tried scraping the silver colered spade conectors on that honeywell transformer. No copper there. Magnet sticks to them too. Must be steel. Does that mean they are not part of the control circut?

[Carnak]

Ontario gas fitting license allowed you to run 120V controls, only ran into 208V coils on water cooled AC and deli ovens.

Down here if you have to run more than 24 volts, like a 120V line to a damper motor in duct work, its for electricans only.

[dx]

Rich, terminals and connector pins are not wires and are not always copper. They are mostly brass, with or without some sort of plating. Brass is springy, yet still a good conductor. And more expensive. Some cheap ones are steel with some type of plating.