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I like ceiling fans & EMT
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Discussion Starter · #1 ·
The building I'm working on at the moment has a bunch of HVAC stuff from the early 80s. Several relay panels, several 120vAC timers, several dozen 24v transformers, multiple thermostats for each zone, and an obscenely complicated array of selector switches and wiring.

Most of the package units have been replaced with those less than 10 years old (there are still three of the original 1980s units remaining) and over the years a lot of the wiring for the relays and such has been hacked. I dont know that any of the original stuff is fully functional, and I'm ripping out 90% of it.

Still, I think the original design is really cool and creative. The timers operate(d) the relays which switch(ed) between several different thermostats depending on the time of day. I'm not old enough to have paid attention to HVAC before programmable thermostats were standard, so this my first exposure to such a thing.

There is one wing of the building where the current room arrangement still reflects the zones (the rest of the building has been remodeled too many times and I have eliminated the zones in favor of one thermostat per unit) and I am, eventually, going to try to restore the relay board and array of thermostats to it's original functionality. Ironically it's one of the new units.

I took pictures of some of this stuff before I started ripping it out. If I can find them, I'll post them.

Anyone else care about this stuff? Was this commonplace in the 80s? Anyone still come across it now?
 

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Barber Coleman was big-time on that stuff. Lots of hard-wired relays, timers, etc.

I saw a system installed in a church that included occupied and un-occupied thermostats on each zone. There was a switch where you could select the mode, but if you forgot and left it in occupied mode, it would eventually timeout and go back into unoccupied mode that evening.

I was called upon one day to troubleshoot why there was no heat. Traced it out to a bad set of contacts in one of the ice-cube type relays. Swapped it with another one and heat was restored.

Those were the days ....
 

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I like ceiling fans & EMT
Former commercial, occasional (small) residential
Joined
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1,317 Posts
Discussion Starter · #3 ·
I forgot to mention, all of the 120v stuff was wired with #14 on 20 amp breakers. Except for one 24v transformer in a closet on the third floor, which was tied into the exit light circuit. Looks like the HVAC guys did their own electrical.
 

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I like ceiling fans & EMT
Former commercial, occasional (small) residential
Joined
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1,317 Posts
Discussion Starter · #4 ·
There is one wing of the building where the current room arrangement still reflects the zones (the rest of the building has been remodeled too many times and I have eliminated the zones in favor of one thermostat per unit) and I am, eventually, going to try to restore the relay board and array of thermostats to it's original functionality. Ironically it's one of the new units.
I managed to do this, only took an hour or two and one new timer. I'll post pictures.
 

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I like ceiling fans & EMT
Former commercial, occasional (small) residential
Joined
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1,317 Posts
Discussion Starter · #5 ·
This was before:




I started to clean it up a bit:



Before realizing that it was worth the effort, for my own piece of mind, to remove everything that was no longer connected/relevant, and repair the stuff that could still be used.

This is the result:




That's all that's left of everything pictured.

Ripping everything out was easy, but I'm proud of reverse engineering what could still be used, and reconnecting/repairing it. We'd had a few HVAC guys out this past summer and they all refused to touch it.
 

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I like ceiling fans & EMT
Former commercial, occasional (small) residential
Joined
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1,317 Posts
Discussion Starter · #8 ·
Forgot to mention, that IS a new timer (obviously?).

All but one of the existing timers had either failed or were missing crucial pieces. Since the timers only operate 24v transformers and relays, I didnt need anything heavy duty. The replacement was $15 at Menards plus another $1.50 for the decora box cover. My only materials expense for the project.
 

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The building I'm working on at the moment has a bunch of HVAC stuff from the early 80s. Several relay panels, several 120vAC timers, several dozen 24v transformers, multiple thermostats for each zone, and an obscenely complicated array of selector switches and wiring.

Most of the package units have been replaced with those less than 10 years old (there are still three of the original 1980s units remaining) and over the years a lot of the wiring for the relays and such has been hacked. I dont know that any of the original stuff is fully functional, and I'm ripping out 90% of it.

Still, I think the original design is really cool and creative. The timers operate(d) the relays which switch(ed) between several different thermostats depending on the time of day. I'm not old enough to have paid attention to HVAC before programmable thermostats were standard, so this my first exposure to such a thing.

There is one wing of the building where the current room arrangement still reflects the zones (the rest of the building has been remodeled too many times and I have eliminated the zones in favor of one thermostat per unit) and I am, eventually, going to try to restore the relay board and array of thermostats to it's original functionality. Ironically it's one of the new units.

I took pictures of some of this stuff before I started ripping it out. If I can find them, I'll post them.

Anyone else care about this stuff? Was this commonplace in the 80s? Anyone still come across it now?
I am the same way in my thinking. It is cool to come across older methods and when you "do it again", it verifies your own knowledge of the industry.
 

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I like ceiling fans & EMT
Former commercial, occasional (small) residential
Joined
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1,317 Posts
Discussion Starter · #10 ·
RIVETER, I would "thank" your post, but I seem to have run out!
 
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