Does one need to s scrape wire before connecting; oil furnace questions

[micky]

1) Do I need to clean the wires making connections?

Normally I use a knife to clean the dark coating off of wires before I hook them up. Certainly before I solder them but even when using screws or wire nuts.

Tonight I replaced the primary controller on my oil furnace and because my work bench is only a foot from the furnace and so it was awkward to get to the wires, and because today my back was sure to start hurting in

10 or 20 minutes, I skipped that part.

Bad connections were not part of the previous problem. I tightened the screws firmly. The furnace is working fine. Still, is it likely that a bad connection will arise in the future because I didnt' scrape the wires???

When summer comes, I can redo it, pausing whenever need be if my back is still hurting.

There are 4 wires from the thermostat, 2 wires from the cadmium flame sensor, 2 from the fan relay coil, and 2 to the compressor contactor coil, all 24-volt.

The next 2 questions might require experience with oil furnaces:

2) The diagram of the inside of the controller shows a "solid state switch" but the one in my old controller was mechanical**. Clear plastic cover showing contact pins like a relay, some little round thing (looks like a little motor but isn't), and some other stuff (it's in the basement. I'll give more details if you think it will help.)

**Except maybe for the solid state heater, which is part of its timer

This is the device with the red reset button, that trips if the furnace runs without a flame. And this's the part that failed this time. Normally one just pushes the button once and, sometimes after waiting 2 minutes, the furnace starts up again. But Monday, it was necessary to press the button usually 5 or 6 times, later in the week up to 30 times, and then, every time the house was warm enough for the furnace to turn off, it wouldn't restart automatically. I had to go press that button again. The thing on occasion makes 2 or 3 different clicking sounds, one after some timer somewhere, and one when it's ready to reset, and maybe one when it actually connects and starts the furnace.

Does this thing have a name besides "solid state switch", especially since most or all of it is mechanical??? Or where could I learn more about it??

3) I bought the new controller, used, because it was an exact replacement for the one that was there, including the extra terminal, and it was only 75 miles from here, but I could have bought similar, NEW, for even less money! The big difference is the safety delay (lock out) time. That is the length of time the furnace can spray oil into the firebox without a flame before it turns off? Therefore, is the proper time that definite? The flame start within 3 seconds almost always, and if not always, then within 8 seconds the rest of the time. So should it use a 15-second delay, or do they use a 30-second delay just so the furnace will still work when it's having a bit of trouble sterting?*** Or are there furnaces that don't light for 20 seconds? ***If this is the reason why not wait 45 seconds?

Oil sprayed but not burnt is disposed of iiuc by dropping some sort of flare (what are they called?) in the bottom of the firebox, where it burns off the excess oil. Though iiuc, the oil can sit there for years without causing tremendous problems. ???

This one is new, but it's 45 seconds:

For completeness, nothing you really need here:

4) Even though it was only 75 miles from here, its delivery path was surprising. (It met its predicted arrival day.) Xmas I noticed house was cold and also I had to press reset more than once. 2 hours later, bought replacement on ebay. 5PM Xmas, email says it's shipped (although that usually just means the paperwork was done). Still, it was in Quakertown by 2PM Tuesday and Philadelphia by 10PM.

Could easily get to Baltimore, 70 miles away, by Thursday (maybe even Wednesday), but instead goes to Rochester NY on Wednesday, Hyattsville Md on Thursday, and Baltimore on Friday. Of couse Rochester is 100's of miles in the opposite direction. I don't know if this was the plan, a fluke, or an error in the routing database. ??? I'm not going to complain but I will write them in case they don't know they're doing this.

[Andy Mann]

An electrical connection subject to corrosion would prolly benefit from some DeoxIT L260 electrical grease.

[trader_4]

I never bothered cleaning wires when making a mechanical connection. They typically look OK after you strip the insulation. Sometimes they are badly discolored if the connection was loose and it was overheating, but that's another story.

Sounds like it's a solid state relay and google works.

Because the longer you wait, the more oil gets sprayed into the firebox and when it finally does start, it presents a potential hazard. Especially when you keep resetting an oil burner that won't start

30 times like you said you did. I'd hope that after a couple attempts you'd know something is wrong, that it's not lighting and you're just filling it with more oil. The timing differences probably are just one company being more conservative than another. Me, I'd prefer a delay on the shorter side. A properly functioning one lights immediately. I'd rather get a trip so I know something is starting to go wrong, if possible, instead of having a long delay that hides it, until it gets worse and maybe won't restart at all.

It's burned up when the burner finally lights. Never heard of any flare things chucked in there.

[philo]

The the copper is clean, no need to scrape.

Back in the old days when winding coils with enameled wire, they did have to be scraped. I still recall helping my little cousin get his crystal set working. He was amazed that I knew the wires were enamel coated

[micky]

LOL. It's good to have a little cousin.

[micky]

But I didn't re-strip anything.

Well, it occurs to me, now that the 3rd controller is in and the second is out, I was going to take the relay from the first controller and put it in the second one, to have a spare controller, and that means I'll have the broken relay out and I can take it apart. If I find anything interesting, I plan to post back.

It definitely has "leaf contacts" or whatever they might be called. contacts on the end of flexibile springy copper-colored "slats". And it goes click when you reset it, and sometimes it goes click all by itself!

It didn't do a thing for the first 29 times. Sometimes a little click in the relay. but the furnace never goes on at all. No excess oil.

I bought an oil furnace manual written buy a retired oil furnace repairman, and maybe I also even had an email address for free questions, but that was 10 years ago, and I don't know where either are. ;-(

Even though it's in a puddle on the floor of the firebox? Even gasoline won't burn when in a puddle, I'm told.

IIRC, two different guys used one (different years, probably worked for the same company, no extra charge, just part of annual maintenance) and just for standard practice, not because he had actually started the furnace without ignition, or that I said I had. I might have bought 3 of them from Grainger, but can't remember and can't find them. Not that I need them.

[micky]

Separate oil (or gas) furnace question.

Everyone says that if too many of the heating ducts are closed off, probably at the grill where the heat comes out of the wall or floor, it's bad for combustion, so don't close too many. But why should that be?

Closing off heating ducts lowers the volume of air that goes through the furnace, (and I guess it slows down the air as it passes, which means the air gets a little hotter than otherwise) and that means the firebox gets a little hotter, but the fire still has plenty of air. Is a firebox that's a little hotter really enough to impair the fire?

[philo]

I'm the 2nd oldest of them all.

[trader_4]

A solid state relay doesn't have mechanical contacts. So, IDK what you have.

Try it with gasoline sometime. I guess all those arsonists that pour it around to burn a house down are using the wrong stuff. And in this case it's in a firebox that's full of fire from the burner when it runs.

[trader_4]

I guess you'd have to ask those everyone people. I've never heard it before. I have heard the advice that it's bad to close off too many vents, because if it causes the temp of the air to increase too much, it decreases the efficiency of the furnace, can cause the high limit to trip, and maybe shorten the life of the heat exchanger. It's more of a problem with AC.

I don't see any significant effect on the fire side either.

[micky]

It was on ahr I saw this answser. I've noticed, but not recorded, that there are answers to questions that are popular for a year or two, and then a few years later, a different contradictory answer will be popular. This might be the 2nd or 3rd instance of that.

[micky]

I didn't find the manual I paid for, but I found one I'd downloaded 10 years ago published about Honeywell and Protectorelay. "Tradeline Oil Controls Service Handbooks", that someone was nice enough to scan and post. It also covers fan limit switches.

The thermostat closes another relay, within the control box, that turns everything on.

Including a heater in the relay I've been talking about. If the heater/timer gets hot enough (in either 15, 30, or 45 seconds), it has its own switch to turn everything off.

The flame sensor lowers its resistance to zero or close when it sees flame and that closes another relay that bypasses the heater, so as long as there is flame, the heater doesn't heat and the furance runs. Until the thermostat no longer calls for heat.

Somewhere in that clear plastic box is a heater.

You'll probably ride me for this but the main relay used to chatter and not close easily, so for a year and a half I had a stick resting on the plastic part of the armature to help out the magnet. The stick is almost vertical and leans against the inside of the cabinet. It's one of those

3/4 by 1 x 12" long, pointed at one end, that advertising signs are stuck into the ground with, at least around here. (Most of the advertising is illegally posted so sometimes I go around removing it. There are a couple other guys who do this too.) I used this stick just temporarily when I saw the relay was chattering, was desperate for heat at night or over a weekend, and planned to replace the part within a day.

I thought the weight was so much the furnace would never turn off and I'd have to go to the basement to turn it off, and it might have been like that the first time, but a couple hours later, almost by chance I found the sweet spot, and it worked so well I left it that way for a half winter and then a full winter. Didn't have to touch it.

Eventually there was some problem so I switched to my spare control box, scavenged from the people across the street when they got a new furnace, replacing one just like mine.

I thought that would work perfectly and indeed it chattered less, but it too needed the stick!!

So this is the first time in 2, 3, maybe 4 years that I've run the furnace without the stick. I even have the cover on the box. Life is good.