Can anyone help me identify this transformer?

[R_J]

Re: Can anyone help me identify this transformer?

connect it across 120v a/c line all by itself, if it gets hot its bad

[budm]

Re: Can anyone help me identify this transformer?

Thanks bud, it's interesting because once I changed it out the same thing happened, you want me to measure the resistance of the MOV? Surely I didn't replace the bad one with another bad one........that current must be coming from somewhere it shouldn't be, maybe I'll test that with a working panel.....

Are you sure you got the correct Voltage rating?

[WHaThEFLuX]

Re: Can anyone help me identify this transformer?

Not sure what you mean....

[budm]

Re: Can anyone help me identify this transformer?

That MOV has the correct P/N on it for sure?
MOV has Voltage rating, unless the AC feeding those two terminals is not 120VAc but much higher so the MOV starts conducting.

[WHaThEFLuX]

Re: Can anyone help me identify this transformer?

Absolutely, it was taken from the exact location on an identical board

[budm]

Re: Can anyone help me identify this transformer?

So it was removed from working board and it was not heating up on the other board but when put into this board you are working on, it heats up like crazy.
120VAC is the only power being fed to this unit?
Right now something is not making any sense, that part will not conduct any current until the Voltage reaches the conducting point. So it is bad or the Voltage feeding it is too high. It is a simple part that is connected across the AC line and that is, nothing special. Any wiring diagram or description of this unit?

[WHaThEFLuX]

Re: Can anyone help me identify this transformer?

I agree, this unit has been extremely frustrating......I almost suspect it was exposed to water, that blew the transformer and who knows what else.

Anyways, here you go: https://customer.honeywell.com/resou...0s/65-0126.pdf

[budm]

Re: Can anyone help me identify this transformer?

If you remove that MOV off the board and connect it directly to 120VAC nothing will happen, at this point I would say you have bad MOV if you are sure that it is getting really that hot.
Or may the AC is much higher than 120VAC that was the caused of the burnt out transformer. I would verify the AC as suggested.

[redwire]

Re: Can anyone help me identify this transformer?

Not making sense- no (new) 150VAC MOV should heat up on 120VAC.
Unless it's too hot from soldering? Panasonic says 400°C/5 seconds max.
Or your variac or something is dialed up too high.

It's a 120VAC-powered board, driving relays to small solenoids. The MOV's are to protect against mains surges. If you have found a way to make more than 150VAC with 120VAC power coming in, start the DeLorean lol

Honeywell sure makes some ugly hardware. Repairing burner controllers is big money though, because the stuff heated is worth a lot.

[WHaThEFLuX]

Re: Can anyone help me identify this transformer?

The plot thickens........

With power to the test panel only, I'm getting 120VAC from the wall as expected.


When the unit is plugged into the panel and powered up, I'm getting ~220VAC from both of those MOVs, yes you read that right. The MOV above the one that fried stayed cool but read 220. The MOV that originally blew(the one I replaced) started to drop voltage, getting to ~210 before starting to smoke and sizzle.

As an interesting side note, with the blown MOV still in place I was able to power up the unit and cycle it through several different operations for about 20 min or so before I'd notice it was getting too hot. The replacement started burning up immediately.


A buddy of mine actually has a DeLorean, might just hook this up to the ECU and hit 88mph


Gentlemen, the floor is yours........

[budm]

Re: Can anyone help me identify this transformer?

Are you getting 220VAC on the hot and neutral of the feeding wires to the unit? Sound like you may have open or bad neutral in the breaker panel. Plug the 40W light bulb in that socket and see.

[WHaThEFLuX]

Re: Can anyone help me identify this transformer?

No sir, the wires are reading 120VAC, as well as the pins on the test panel

[budm]

Re: Can anyone help me identify this transformer?

No sir, the wires are reading 120VAC, as well as the pins on the test panel

Since the wires connected to the two legs of the MOV then you cannot have 220VAC between the two legs of the MOV, MOV is connected between HOT AND neutral.
Must be measurement error, you are 100% sure that you have 120VAC feeding into the unit.
You can easily verify how the Line and the Neutral are connected to the two legs of the MOV by using Ohm meter.

[budm]

Re: Can anyone help me identify this transformer?

Ref to Post 36 picture.
Post 37"If you're looking at the picture, the terminal farthest to the right is ground and the other one is 120VAC" do you mean Neutral, not safety Ground right? You get 230VAC between those two terminals, is that what you are saying?

[WHaThEFLuX]

Re: Can anyone help me identify this transformer?

Those two terminals are G and L2(N), that's what was reading 220VAC.

[budm]

Re: Can anyone help me identify this transformer?

The Neutral of your house is bonded to the safety GND at your service entrance of the breaker panel. So for you to have 230VAC between Gnd and NEUTRAL you have bad wiring in your house!

[WHaThEFLuX]

Re: Can anyone help me identify this transformer?

I can assure you the wiring in my house is fine, let me take a pic of the test panel, maybe that will clear things up...

[budm]

Re: Can anyone help me identify this transformer?

It cannot be fine when you have 230VAC between GND and Neutral, but if you insist that is normal then I do not know what to say.

[budm]

Re: Can anyone help me identify this transformer?

May be you look at this and tell me how you can have that 230VAC between Neutral and GND.
http://hyperphysics.phy-astr.gsu.edu...ic/hsehld.html

[WHaThEFLuX]

Re: Can anyone help me identify this transformer?