If you could write a course on controls...

Mark Eatherton1

I've been asked by numerous of my students, and my boss at the college to come up with a sylabus for a hydronic controls course. What would you like to see in a course on hydronic controls? Some on the old mechanical controls, most on the solid state controls? Reading wiring schematics? Understanding relay logic!

The course would be 15 weeks long, 4 credit hours, with half the class taught in class, and the other half taught in the hands on lab.

This of course means that I'd have to give up one of my hydronic classes (Basic Hot Water Heating) but would hang on to the radiant course. Only so many hours in the week...

What thinks ye wallies?

TIA

ME

Weezbo

layout of electrical devices in an intelligent manner.

it matters not what the thing can do if it looks like THAT ! I dont want you Touching my boiler! AS A Matter of Fact! Dont Even LOOK at it! in other words stress the need for consideration of other tradesman, have a basic pre requisite of a seperate cuirct, light,receptacle and switch for a boiler room ... Minimum...call it a standard even if it isnt in the code. stress the presentation of the finished control wiring follow clean lines and be as invisible as possible ( Leave the Duct Tape At home!)Use directories in low voltage that can be modified removed and replaced.... theres what id like to see someone actually take the time to Teach in a wiring course. repeat the words till your blue in the face that way if any of them show up on the job it will take less than a few Years to further illustrate those points

Murph'_5

control strategies

Teach them how to draw out the diagrams/circuits and think them out before ripping in to test them. At least how to isolate pieces and what thier relationship is to other parts of the system. Hard to tell sometimes if the smoke got let out, but to pinpoint what a piece of the puzzle does first will show them how they relate to one another.



Murph'

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ScottMP

Mark

I would include alot on the 24 volt side of things. The interaction between the gas valve and the rest of the controls. This si what took me the longest to grasp ( yea, like I know what I am doing now ! ).

I think the relays fall in pretty quickly, but the gas valve solinoid always seems to take a while to sink in.

The next thing would be re-set curves and how they effect the system. I think in the next few years Every System will have this feature.

Keep up the great work you are doing teaching the newbies.

Have a very Christmas and have a Holidaze brew for me, I like the Hefenwiezer.

Scott

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David Sutton_5

Hi Mark,
i think the the eletrical side is what most people have ahard time with, i have seen some pretty scarey stuff out there,i agree with Scott, the low voltage side, zone valve wiring, controls like tekmar,also multi-zone controls. what relay runs what and why. ( and tell them no zone valves for inderects please) this will be a great study course...David

Firedragon_4

Hi Mark,

> I've been asked by numerous of my students, and

> my boss at the college to come up with a sylabus

> for a hydronic controls course. What would you

> like to see in a course on hydronic controls?

> Some on the old mechanical conttrols, most on the

> solid state controls? Reading wiring schematics?

> Understanding relay logic!

>

> The course would be

> 15 weeks long, 4 credit hours, with half the

> class taught in class, and the other half taught

> in the hands on lab.

>

> This of course means

> that I'd have to give up one of my hydronic

> classes (Basic Hot Water Heating) but would hang

> on to the radiant course. Only so many hours in

> the week...

>

> What thinks ye

> wallies?

>

> TIA

>

> ME

Firedragon_4

Hi Mark,

I've been teaching controls for a long time (1975) but have an advantage since before coming into this business I was a graduate of a Vo-Tech in electronics.

Bottom line, basic electricity!

Base it on practical applications.

Don't just teach Ohm's Law, use it on actual examples.

Don't just teach schematics and wiring diagrams, use them on actual lab experiments. I said experiments BTW, not hands on.

It's been my experience that guys/gals who have done this for years don't like hands-on, too basic, FACT! Give them actual problems and I do that in hotel rooms on small trainers. Alan Mercurio has a dandy as does Big H.

The control companies are a great resource, check out Honeywell's stuff: http://content.honeywell.com/training/

As many have said 24 volt systems are a puzzle to a lot of people, funny thing is it's just the same circuit multipled over and over gain. I think it's the duplication, hehehehe.

And the 24 volt circuit is just based on a basic circuit, many don't get the basics, so when it gets tougher they fold.

Much success and may you complete your goals.
Happy Holidays,
George Lanthier

Firedragon_4

Oooooops, wrong link,

that's commercial.

Try this:
http://customer.honeywell.com/Business/Cultures/en-US/Support+and+Resources/Homes/Contractors/Training/Default.htm

Glen

basic electricity to start -

and build a skills based body of knowledge from there. At the end of the course they should be able to look at most schematics and follow the control paths (complete understanding comes much later). This would include both the 110 and 24 volt side of things. this should draw in any number of basic and not so basic controls - so that when things go south in the middle of the night - the brain can zoom in on the problem at hand. I really like Mr. Fireydragon's idea re electrical experiments - correct wiring is important but understanding incorrectness is supreme. Controls do not run on electricity - they run on smoke. And when you let the smoke out - they stop running. Teaching your students the foul ups is sometimes easier than getting them to understand a schematic. Highly recommend the following for additional reading: Electricity for Refrigeration, Heating and AC, Mr. Russell Smith, and Fundamentals of Gas Utilization, Industrial and Commercial Gas Burner Systems, both by Mr. John Dutton (Centennial College Press). And if it is still in print - the United Associations Gas Handbook - excellent basic electricity and schematics examples for entry level technicians. Good luck - keep teaching.

Mark Hunt

All good replies so far


Maybe a brief history lesson? Showing what new technology replaced? The evolution of controls and strategies?

Control wiring has always been the toughest part in training a new recruit. THE most dreaded phone call you can ever get is the one where you are trying to resolve a wiring issue over the phone! Ahhhhhhhhhhhh!!!!!!!!!!!

Explaining that electricity is color blind is fun too. No such thing as "red, green or yellow electricity.HAHAHAHHA!!!

I sent two guys out to install a boiler one day, and I called to check on their progress. "I'm just starting to wire it up now" said the meachanic. "Get the wiring diagram book I made you" said I. "Yah, ok" answered the tech.

Next morning a very tired tech comes in my office and tells me he worked until midnight to get the boiler on line.(I called him a 4:30 pm) "What was the problem?" I asked. Tech 2 chimes in, "He wired it wrong!" pointing at tech 1. "Did you?" I asked. Now comes my all time favorite answer, "Well I didn't really wire it wrong...uh..." "Well maybe we have different definitions of wired right and wired wrong" I said. "I consider it wired right if it works when you turn it on, and wired wrong if it doesn't. What is your definition?" Now I used to keep a little white flag in the top drawer of my desk for just such occaisions, and before he could get too far into his explanation I handed him the flag and said, "Surrender".

He decided that he didn't need no stinking wiring diagram and wired it the way that made sense to him. He was wrong.

Mark H

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jerry scharf_2

my thoughts

ME,

(I read some of the other posts, and clearly I have a more academic bent on this stuff.)

I think there needs to be more than "this is a thermostat and this is a tecmar." I am sure others will come up with ideas for outdoor reset, TRVs, etc. Many people hate learning some theory behind things, but in controls it's important. It doesn't tell you how to do things, but it sure can tell you things that won't work. Anyway, it's a college course and they would feel cheated if there was nothing to study for the exam.

I would introduce them to the concepts involved with human comfort. I learned about ASHRAE 55 a couple months ago (thanks Tim) and think that's an excellent place to start. Maybe you can silently torture your students a bit and make their understanding a bit more intuitive. I'm not sure you could set it up, but have some stations where there is some nominal lab experiment, but put them in disconfort situations like moving air, cold feet... Make sure they are trying to write and concentrate. Then tour them around and explain the comfort problems and see if they can see how it impacted their work.

I don't think it needs to be dry, but to do controls you have to understand things like goal selection, feedback, overshoot, lag time, stiff vs. relaxed vs. critically damped controls... Understanding how independent controls are integrated and which things do what in this case (smart boiler and thermostats as one example.)

One good fun thing for the lab is to get a radio controlled blimp, car and airplane. With the same controls, how do you need to act differently to keep the object under control?

If it were an upper level engineering course, I would have a project where you give them some path tools and output tools to drive an RC car. They write and test their controls. At the end of the project, you design a test course, and each group get's to race the course. Best tracking and time wins.

I love to tell the story of how Alexander Graham Bell did some of the first pioneering work on flight controls. In the first 2 decades of the 1900s, Bell was an active and successful airplane designer. A test pilot who had worked with him crashed and was killed working on a larger (for that time) Wright airplane. He knew the pilot, and tried to figure out how the crash had occurred. He kept running through the crash in his head, then realized that the human instincts in the situation caused the pilot to add wrong controls and make the situation unrecoverable. He starting building planes that always corrected when instintive human reactions were input. We take all this for granted today, but someone had to stop saying it was pilot error and say the control systems weren't right.

How about breaking up into small teams and "designing" a thermostat that fixes the "I'm cold, let's turn it up to 90" problem. I think that humans don't really understand what 72 degrees is anyway. IMO, the whole basis for human/heating interaction was based on what an engineer could figure out rather than what is optimal control interface. TRVs at least have meaningless numbers. If there are some really good ideas that come up, maybe you should post them to the wall.

I'm sure I can come up with more trouble should you wish.

jerry

Nron_9

teacher

well the first thing to do is move to western canada Hey the boys in the US wont mind ,
then set up your course here starting with basic understanding of how power works 24-220 volts ac how to test, and sequence of operation for controls ,series and parell wiring then go into controls systems and reset boiler systems and everything else ,

Jed_2

Definitely include

Internal wiring schematics. Many times techs want to know how a switch reacts, and why. The field wired stuff is great, but why, and "how come" gets asked a lot. Common, neutral, powered, unpowered, reference to ground, reference to common, parallel, series. I'm not a Tech, but I get asked a lot. I'd love to take a good meat and potatoes controls course that(with reference material so I don't have to "store it")clarify's the control's internal functioning. Now there's the rest of the story.

Jed

Bill Nye_2

\"Zen\"

Mark, teach them what controls do, and why. I am so sick of "Give me a wiring diagram......" In real life there are not always wiring diagrams.

You have to know what you want the stuff to do and why. That way you can know when it don't. And, you can make it do other stuff if you have to in the middle of the night. Outside the box wiring so to speak, The late John Gates stuff


Teach them there are more colors of wire than black and white. Green is ground, not another conductor because that is all you have. Never ever break the neutral. Basics first, like the fire dragon said.

Safeties first! Like high limit, MRHL, LWCO, etc. I attended NEFI in '89-'90 and to this day the wiring ladder from the service panel to the burner is still etched in my brain, thanks **** Sanborn and George L.

chuck shaw

towards the end of the class

get into ladder diagrams and sequence of operation. On a call for heat, the circuit through the thermostat is completed, engergizing this (or that) relay, which sends a 120vac signal to the....etc. etc. etc.

I have heard so many times, I have replaced the (fill in part here) 4 times and it still doesnt work. Guess what, it wasnt that part!!!!

Chuck

MikeR_3

Troubleshooting...

No course on wiring would be complete without some basic troubleshooting. So, the breaker trips as soon as you turn on the service switch. What do you do then? Where do you start? What if it is a fuse instead of a breaker? I don't know about you. but I learned how to wire a new boiler and controls in school, but I was never taught how to trace down a short.

hr

Could you incorporate

some of Carol Fey's basic control writings? I think she does a good job explaining with the basic understanding of controls. I'll bet she would be glad to help.

Call up your buddy John Myrtle in Hotchkiss. He built a really neat simiulator that he teaches VoTech control classes with. Again he would share his materials and experiences with teaching controls, me thinks.

Be a nice drive up to his place, also



hot rod

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Jed_2

Try finding

a mis-wired molex connection from the factory! Anyone run into this? Pins that don't line up. Contractor kept tripping the breaker. Took quite a while to discover the Factory error.

Jed

jim lockard

Switches and loads

The electrical circuit is made up of switches and loads. You can have a hundred switches in a circuit but only one load between hot and neutral. A load being a part that consumes or converts electrical energy So knowing this when you start to trouble shoot go to your loads first disconnect them and check for power. work your way back from the load to the source. Best Wishes J.Lockard

J.C.A._3

Mark,

I'd also throw in a sub-course on "How To Read Tekmar Control Manuals", for non-engineers.

The guys that write this stuff go FAR too deep in the details! It takes them 4 paragraphs to tell me that this 512 (or whatever) turns the heat on or off. They write like engineers and need to understand that most of us want them to get to the point quickly. Don't confuse us with all the crap we really don't need to know. Make it "TECT speak".

My .02. Chris

Mike T., Swampeast MO

Non-electric proportional flow control. After all, it's the original way of controlling hot water systems. Automation of such has been around since at least 1899.

jerry scharf_2

One other thing

Teach them that the rest are just parts and pipes, it's the controls that make it all a useful system. No matter what the level of controls, this is a great time to hit them with a systems view (I'm sure you already do this, but don't pass up another chance.)

jerry

Firedragon_4

That's a great concept

and I use that a lot. The more examples you can make to water, pipes, etc. the easier it is to understand.

Dale

Great topic

I agree with what the other guys said but can't resist adding a bit, I guess first you'll need to define what "controls" are. Limiting the topic is always the hardest part for me. Seems simple but are zone valve end switches part of a control system? Sometimes I think so if they can be stuck closed and bring and keep on the burner. Are ignition systems controls, perhaps not, you may want to end the "control" when the call for heat signal reaches the ignition device. Sounds like you'll keep it at elect. controls. (I have guys that get the most confused by the hydronic specialties since we don't do that much wet heat.) I guess I would start simple and go more complex. I always start with what is the LEAST controls to be legal. I always state the safety controls and the operating controls. I start with a steam boiler as that has the most simple controls IMHO. I remind them the min. code is 2 ways to control pressure, one is the mechanical relief valve. 2 operating controls also required. The 24v tftm to the thermostat ( one of the operating controls) to the pressuretrol ( a combination safety and operating control) to the lwco, a safety control,to the gas valve and back to the tfmr. I'm a big fan of the normally open and normally closed concept. On a steam system I'll then add probe type lwco's and different elect water feeders although these aren't controls. I train on a working boiler that is steam or hot water, the techs have to wire it all together test that all the controls really control then fix some troubleshooting problems like a plugged pig tail, stuck closed lwco ect. Then on to hot water where the aquastat and tstat are all that's min. legal. The aquastat if fun to discuss as it's one of the few safety controls designed to cycle. Please let us know what you end up with as a course design.

Kal Row

right on.....

when i get to a system with control trouble and the wiring is a mess... i take all the wire out and rewire it from scratch nicely, time and again has proven to me, that it's the quickest way to solve the problem

hydronicsmike

Mark

If you think I could help you with some of this, please give me a call. You know were to reach me.

Thanks,

Mike

Tom Anderson_2

The number one problem I observe with control technicians is a lack of understanding of HVAC *systems*. My work involves commercial buildings.

In general, these control techs seems to know their wires, relays, etc. But they woefully lack understanding of systems, cause and effect, etc.

Example: New Buderus boilers installed to replace a couple of old units. CLient calls me during the next cold morning.. about -20F, close to design temp.

"My building is cold, can't get space temps above 63F". We don't have enough boiler capacity! Never ever had this problem before with the old boilers." (new boiler total capacity was 2 million Btuh, old units 2.5 million).

I asked what the HWS temp was, and was told 180F.

"Have the technician bump the HWS temp setpoint up to 200F", I recommended.

That afternoon, client calls back, "Technician says boiler not designed to operate above 180F. Refuses to make adjustment".

I felt like saying, "Bullsh*t", but held my tounge. Went to site the next morning, observed 180F HWS. I took the facility manager to boiler room, and read the large nameplate on the front of each boiler:

"Max Temperature: 256F at 30 PSI".

I instructed the client to "order" the technician to change setpoint to 200F. Technician did so, after pointing out boiler label.

The next morning, also -20F ish, owner calls me,

"I came to work and the entire building was a toasty warm at 72F"

Another project, part of a building chronic cold. I told owner he needed to get the supply air temperature warmer. Owner had control technicial visit site. Technician adjusted the pulley on air handler to reduce rpm and corresponding cfm.

"Look", the technician told the onwer, "I'm getting more heat, look how the supply air temp got warmer".

That method failed to solve the problem, and, of course, it only made the problem worse.

So, from what I see, it is poor understanding of *HVAC SYSTEMS*, not so the much the controls.

Tom Anderson

Firedragon_4

Amen brother!

The biggest problem in teaching HVAC and in my backyard, oil, is that everyone tries to do too much.

I've been there, done it. I originally put out my first wiring book and its seminars in one shot, holy moly, what a screwup! It's too much.

Now, we've broken the book into what will be six pieces. It looks like at least 16-18 seminars right now.

Book 4 and it's new seminar is out now and that's just residential oilburner controls.

Books 1 and 2 are due out early next year. Book 1 is just the basics or fundamentals. Book 2 is just on systems, air, steam, water.

Book 3 will be on gas controls and coal stokers, (no kidding).

Book 5 will be just diagrams of everything and if I live long enough Book 6 will be on commercial controls.

I'm now of the mind that we need to take education in little pieces and tackle each piece thoroughly.

If you read through these postings and other sites it becomes quite apparent that we have a trade that is chock full of jacks of all trades, masters of none.

Look at the medical and legal segments. Specialists. You can't know everything, I sure don't, but I've learned more about what's wrong on the way, FACT!

Unknown

I usually start

everyone with my course on Circuitry and Troubleshooting. If the students you are teaching are going to work on systems they should first understand basic wiring skills and use of a meter for troubleshooting. I am short on theory and long on practical application. I find that all the laws Ohms, Kirchoffs and etc can be incorporated into real control application other wise it is boring and takes up valuable time.

I then take student into basic hydronic controls starting with aquastats, switching relays and then into combination relays and triple aquastat relays. This is all done with diagrams, actual controls and real life applications using these controls. It includes both 24 volt and millivolt systems. It is also important to help then understand control replacement and cross referencing of controls for replacement. I then introduce zoning and zone valves. They are then ready for multizone panels and more complex wiring applications.

I am assuming these students have already had a course on hydronic systems and piping so the next step would be controls being used today for more complex hydronic applications. In that phase introducing them to staging controls and modulating systems along with various indoor/oudoor applications. It would also be a good idea to touch on Electric Ignition controls.

If you need any materials I would be more than happy to send you some info on what I have to offer from our courses.

Weezbo

Part two.

then ...go into simple line voltage control.Line voltage t stat controls pump ...discuss wave formation and three phase switching (motor starters) and harmonics...../ after that it might be good to speak to dedicated circuits once again and how it relates to newer controls. maybe the hint that they are not liking destructive interference would be sufficent before setting in on 24 volt system controls............

Kal Row

better yet...

teach how to seperate control loads from motor loads to that you can put a 600wat computer UPS on the controls to ride through a power outage, even though the boiler and pumps wont acctually run

it's actually simple - all pumps even ones driven by boiler controls are on relays switching external power to the pumps and said external non backed up power also drives a realy whose contacts are inline with the boiler heat demand (tstat), we dont want to cut is at the gas valve, cause we still want the "freez protection" on the new boilers to cycle the burner even though the combustion fan has a serious currrent draw - all of the above is an easy do on a WM ULTRA - as the optional pump/s on a relay is already in their diagram

ps - if you put "da boy-lah" on a plug - the socket had better be a Ground Fault Interupter (code for plugged staionary applience) i put the whole boiler room on a inline GFI- makes it easy

Mark Eatherton1

Thanks to ALL for your input

I will let you know what the final product ends up looking like. Any other suggestions on what book I should use?

ME