Suggest getting a mirror and reading the markings on the sides.
Electrical Connections
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We've used the range hood a lot over the 8 years we've owned the house. The way it's set up the fan always starts out on speed #2. But we've mostly used speed #1 as it has quite adequate air movement and is very quiet.
Speed #2 moves a lot of air but doing that is also noisy. We didn't even know there was a speed #3 which really moves a lot of air and is even noisier.
Whether that blue cube is a relay or a transformer I don't like it getting that warm either. You can keep your finger on it but it's getting pretty warm. I've thought about how to improve the heat radiation but don't have any good ideas. The cover for that area is plastic and quite close to the blue cube and it isn't discoloured or anything like that.
At some point I'm going to try to see what's written on the side of the blue cube. If it's still available it probably wouldn't be very costly to get a new one for future reference.
Update: For whatever reason it's still working fine on all speeds. Maybe cleaning the connections was all it needed. I still don't trust it enough to put it back up though.
I've unplugged it and will be taking out the capacitors this morning for testing. Fingers crossed.
Do you have an IR Thermometer? Check the "blue cube". Rated at 70°C
Took the 2 capacitors out after being unplugged for an hour or so. Neither had any measurable voltage and there was no spark when the terminals were shorted. That surprised me. I was expecting something.
Did the resistance test. Both capacitors initially were something like 7 - 10 Ohms, then quickly went to infinity. Reversed leads and tested several times with the same results.
Conclusion - both capacitors are fine.
As expected really
Don't have an IR thermometer. But one of my friends might. I'll check.
I don't think I could keep my finger on it (which I could if I had to) if it was over 70C. But it gets pretty uncomfortable so it might be close.
The blue cube is still a mystery. If we could see pictures of the circuit board around it that might help. There are wires covering that. That and the markings on the top are not helpful and don't tell me that it's a relay. That and a relay really shouldn't get hot (but I would expect a transformer to at least get warm). Is there anything written on any of the sides of the blue cube?
Otherwise, it does look a lot like one of these transformers:
Otherwise, it does look a lot like one of these transformers:
Yup, on closer examination, it does appear to be a transformer. Even worse it gets hot. But easily replaced. A schematic would really help.
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The blue block in the link is very similar (practically identical) to the blue block in my unit.
I had a close look at my blue block. It has a number of symbols on top that don't mean anything to me.
There is text on only one side:
Typ E1 30/18 04/06T
BV 030-73300 T
PRI 115V 50/60 Hz (Pin 1- 5)
SEC 12V 2.3 VA (Pin 7 - 9)
The text is tiny but I'm pretty sure that's what it says.
Can anyone translate that into a product? It's presumably a transformer.
It has 4 soldered joints underneath, close to or at the corners.
That's a transformer, with part number BV 030-73300 T
Possibly this one:
Possibly this one:
030-7330-0 PULSE ELECTRONICS CORPORATION, 030-7330-0 Datasheet
Request PULSE ELECTRONICS CORPORATION 030-7330-0: Audio & Signal Transformers 2.3VA EI30/18.0 115V 12V online from Elcodis, view and download 030-7330-0 pdf datasheet, Audio specifications.
elcodis.com
I haven't been able to track down an IR thermometer.
I've done a bit of reading on the internet and it seems you can touch a 60C (140F) object for up to 5 seconds without irreversible skin damage. The pain threshold is 42 - 45C. And skin proteins start to break down at about 50C.
So while the blue block is getting a bit hot, I have to think it's less than 60C, probably less than 50C. I can easily put my finger on it for 5 seconds, longer if I needed to.
Keep in mind that a range hood is a hot working environment. Steam coming off a stove top could be pretty hot.
I've done a bit of reading on the internet and it seems you can touch a 60C (140F) object for up to 5 seconds without irreversible skin damage. The pain threshold is 42 - 45C. And skin proteins start to break down at about 50C.
So while the blue block is getting a bit hot, I have to think it's less than 60C, probably less than 50C. I can easily put my finger on it for 5 seconds, longer if I needed to.
Keep in mind that a range hood is a hot working environment. Steam coming off a stove top could be pretty hot.
What is the 12V for? Control circuit??
That looks right.
The one in the link requires a minimum order of 10 (which I don't need or want). But knowing the part number, it can probably be found elsewhere.
I don't think that transformer should be warm to the touch. Not unless if there is a big load hanging off 12V when being tested.
To your point, if this was that hot doing nothing, and then you do some cooking... it's going to be worse. Sure, it should handle 100C w/o issue, but still, I would not expect it to be more than just above ambient when doing nothing.
To your point, if this was that hot doing nothing, and then you do some cooking... it's going to be worse. Sure, it should handle 100C w/o issue, but still, I would not expect it to be more than just above ambient when doing nothing.
What is the 12V driving?
That’s what I was wondering maybe the lights?
It's a good question. Just a swag but I'm guessing 12V is being used solely for relay power, probably runs the micro too, everything else is probably using regular AC. Just a guess. 2.3VA seems low, never worked with transformers but I think VA is RMS voltage times RMS current, regardless of phase angle, so it's not proper to call that 2.3W. Ignoring that bit, it's clearly not much umph to run anything (200mA?).
The light are standard push in Halogen bulbs so I'd think they be 110 - 120Volts.
My friend who dealt with electronics during his career says that transformers are often warm but shouldn't be hot.
So this one is hotter than it should be, but if they have a working range is up to 70C as Pablo suggests, it's not (yet) in the junk category.
I'll get a new one for future reference if I can buy a single one. I wouldn't enjoy soldering the joints though. Might have to contract that part out! [I once replaced a couple of components on a circuit board off a Maytag Neptune washer and it didn't look too pretty when I was done - but it worked.]
If the transformer is a problem, yes. The heat might be more of a symptom, as in some sort of excess load might be making it hot (and doing a slow cook on it). Or the transformer might be undersized for the application.
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