Author Topic: Replacing thermal fuse in a fog machine  (Read 14215 times)

0 Members and 2 Guests are viewing this topic.

Offline GrafZeppelinTopic starter

  • Newbie
  • Posts: 5
  • Country: dk
Replacing thermal fuse in a fog machine
« on: May 20, 2018, 10:21:49 am »
Hello all,

I have a fog machine "IMG Stage Line" and need to replace the thermal fuse CH-15. Did not find any shops that sell these, also found only one datasheet on the web, but it's not accessible.
I have added pictures of both sides of the fuse. Does anyone know any alternative fuses that could work? By the way, I'm based in EU.

Fog machine:

https://www.amazon.co.uk/Machine-FM-708-Quality-Product-Monacor/dp/B001RGTK4S

Thanks in advance
« Last Edit: May 20, 2018, 10:39:53 am by GrafZeppelin »
 

Offline pyroesp

  • Regular Contributor
  • *
  • Posts: 180
  • Country: be
    • Nicolas Electronics
Re: Replacing thermal fuse in a fog machine
« Reply #1 on: May 20, 2018, 10:42:47 am »
Quick google search showed this webpage : http://www.wako-clinac.co.jp/product_en/ch-15_ch-152_en/index.html
If they can't sell you one or more (try asking for their MOQ), you might find a suitable replacement somewhere else. All the info you need is listed on the page.
 

Offline GrafZeppelinTopic starter

  • Newbie
  • Posts: 5
  • Country: dk
Re: Replacing thermal fuse in a fog machine
« Reply #2 on: May 20, 2018, 10:45:50 am »
Quick google search showed this webpage : http://www.wako-clinac.co.jp/product_en/ch-15_ch-152_en/index.html
If they can't sell you one or more (try asking for their MOQ), you might find a suitable replacement somewhere else. All the info you need is listed on the page.

Does the link open for you? Because for me it keeps loading forever and nothing shows... Tried multiple browsers, still the same.
 

Offline pyroesp

  • Regular Contributor
  • *
  • Posts: 180
  • Country: be
    • Nicolas Electronics
Re: Replacing thermal fuse in a fog machine
« Reply #3 on: May 20, 2018, 10:50:30 am »
It works fine on my end  ???
 

Offline GrafZeppelinTopic starter

  • Newbie
  • Posts: 5
  • Country: dk
Re: Replacing thermal fuse in a fog machine
« Reply #4 on: May 20, 2018, 10:57:51 am »
It works fine on my end  ???

Weird, all I get is "This site can’t be reached" - see attachment  ???

Would it be possible for you to make a screenshot of the specifications and post it here? I'd be super gratefull for that  :-\

**UPDATE : Nevermind, the site finally loaded! Thanks for your input anyways :)
 

Offline PTR_1275

  • Frequent Contributor
  • **
  • Posts: 561
  • Country: au
Re: Replacing thermal fuse in a fog machine
« Reply #5 on: May 20, 2018, 12:02:11 pm »
That should automatically reset, there’s normally another inline thermal fuse tucked away somewhere that has a higher temperature than the auto reset one as a “just in case”

Is the one in the photos definitely the problem?

Had a few mates with smoke machines call me after replacing these and saying the machine still isn’t working, when I’ve looked at it I’ve found the secondary fuse. In all cases something’s fallen on the machine or done something to cause the over temperature.
 

Offline GrafZeppelinTopic starter

  • Newbie
  • Posts: 5
  • Country: dk
Re: Replacing thermal fuse in a fog machine
« Reply #6 on: May 20, 2018, 12:22:08 pm »
That should automatically reset, there’s normally another inline thermal fuse tucked away somewhere that has a higher temperature than the auto reset one as a “just in case”

Is the one in the photos definitely the problem?

Had a few mates with smoke machines call me after replacing these and saying the machine still isn’t working, when I’ve looked at it I’ve found the secondary fuse. In all cases something’s fallen on the machine or done something to cause the over temperature.

To he honest, not sure if the thermostat in the pictures is the root cause of the problem. This machine was brought to me by a friend, who said that normally when the machine heats up, the light on the remote control should dim down, but it does not. The machine just gets hotter and there is no fog comming out, so I figure it must be the fault of a thermostat / thermal fuse. Another important fact he said, there was alcohol spilled on the fog machine itself, and please correct if i'm wrong, but that probably caused shortcircuit and over temperature.

Adding more pictures from the internals, maybe you can spot the secondary fuse? Thanks

 

Offline electrolux

  • Regular Contributor
  • *
  • Posts: 244
  • Country: gb
    • Photography
Re: Replacing thermal fuse in a fog machine
« Reply #7 on: May 20, 2018, 12:27:06 pm »
Pretty sure the switch you showed in the pic automatically resets, look inside and see if you see a thermal fuse that looks a little like the pic here, test it like you would test a normal fuse and if its blown check the temperature, voltage and amp ratings which should be written on the side then order a new one.

 
The funniest thing about this signature is that by the time you realize it doesn't say anything its too late to stop reading it.
 

Offline GrafZeppelinTopic starter

  • Newbie
  • Posts: 5
  • Country: dk
Re: Replacing thermal fuse in a fog machine
« Reply #8 on: May 20, 2018, 12:38:35 pm »
Pretty sure the switch you showed in the pic automatically resets, look inside and see if you see a thermal fuse that looks a little like the pic here, test it like you would test a normal fuse and if its blown check the temperature, voltage and amp ratings which should be written on the side then order a new one.

 

Thanks for the suggestion,

Looked inside and finally found the fuse. I'm learning so much today, really happy :D

Just to double check, I have tested the fuse and it reads 0 ohms, meaning it has been blown, correct?

 

Offline pyroesp

  • Regular Contributor
  • *
  • Posts: 180
  • Country: be
    • Nicolas Electronics
Re: Replacing thermal fuse in a fog machine
« Reply #9 on: May 20, 2018, 06:16:17 pm »
0 Ohms is ok. If the meter showed overload, then it's blown.
You can also use the diode mode, if it beeps it's fine.

You can check your thermal switch CH-15 the same way, although you don't know if it's a normal open or normal closed and it's not specified on the manuf. website.

Like other users said, those thermal switches automatically reset, but those things do fail too.

EDIT 2:
Just saw the last picture with the meter, that's overload, so yes the thermal fuse is blown.
« Last Edit: May 20, 2018, 06:23:23 pm by pyroesp »
 

Offline IanMacdonald

  • Frequent Contributor
  • **
  • Posts: 943
  • Country: gb
    • IWR Consultancy
Re: Replacing thermal fuse in a fog machine
« Reply #10 on: May 21, 2018, 07:47:06 am »
If the machine heats up then highly unlikely the thermal switch is the problem You can see it's wired straight in series with the element so it's basically just a temperature limiter.  More likely the liquid ingress damaged something on the PCB that controls the smoke fluid delivery. 
 

Offline electrolux

  • Regular Contributor
  • *
  • Posts: 244
  • Country: gb
    • Photography
Re: Replacing thermal fuse in a fog machine
« Reply #11 on: May 21, 2018, 11:10:05 am »
Pretty sure the switch you showed in the pic automatically resets, look inside and see if you see a thermal fuse that looks a little like the pic here, test it like you would test a normal fuse and if its blown check the temperature, voltage and amp ratings which should be written on the side then order a new one.

 

Thanks for the suggestion,

Looked inside and finally found the fuse. I'm learning so much today, really happy :D

Just to double check, I have tested the fuse and it reads 0 ohms, meaning it has been blown, correct?


Yup, looks like it. If you want to be extra sure you can turn meter to the 'beep mode' which will make it beep when the two probes make contact. If it does not beep when you connect it to the fuse that means its blown.
The funniest thing about this signature is that by the time you realize it doesn't say anything its too late to stop reading it.
 

Offline abraxa

  • Frequent Contributor
  • **
  • Posts: 377
  • Country: de
  • Sigrok associate
Re: Replacing thermal fuse in a fog machine
« Reply #12 on: May 21, 2018, 01:46:43 pm »
Just for clarification: You say that the "heating" indicator light never turns off. That would be correct since the termal fuse is blown.

However, you also say that the "machine just gets hotter and there is no fog comming out". Does it actually become hot when plugged in for 2-3 minutes or is that just an assumption? With the fuse being blown, I don't see how it could heat up but I just want to make sure we're all on the same page here.
 

Offline jmelson

  • Super Contributor
  • ***
  • Posts: 2765
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #13 on: May 21, 2018, 07:23:46 pm »
One additional comment :  When replacing these thermal fuses, DO NOT SOLDER them in!  That will cause them to "blow" as in go open-circuit, as they will be exposed to the soldering temperature.  (Don't ask how I know THIS!)

You need to crimp the terminals.  Possibly, they can be soldered with a really good heat sink applied closer to the body than where you are soldering to.

Jon
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #14 on: October 08, 2018, 05:32:38 pm »
Do you happen to know or remember the model or specs on the inline Thermal Fuse you used to replace the bad one in the Fog Machine you were working on?  I am having the same issue and need to do the same, and wanted to get fuse on way home (before I am able to take apart and confirm this on mine, myself).  Thanks!  Jason
 

Offline abraxa

  • Frequent Contributor
  • **
  • Posts: 377
  • Country: de
  • Sigrok associate
Re: Replacing thermal fuse in a fog machine
« Reply #15 on: October 08, 2018, 06:42:34 pm »
Just in case OP doesn't answer in time, the temperature range for the fuse should be between 100 and 133°C. Too low and it'll trip too quickly, too high and the fluid may pose a risk when pushed into the vaporization chamber (it contains glycerol or glycol, which are both alcohols and can ignite - in theory, at least).
If I was you, I'd start with 100°C and if that blows, try again with 110 or 120.

Also, checking the thermostat gives a hint. The fuse should have a temperature only slightly higher than its switch point.
 
The following users thanked this post: paluszak

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #16 on: October 08, 2018, 08:02:50 pm »
Thank you very much...   Just to confirm, would that be the "holding" or the "maximum" temperature?  Sorry if this is a dumb question.
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 6967
  • Country: ca
Re: Replacing thermal fuse in a fog machine
« Reply #17 on: October 08, 2018, 09:07:25 pm »
OP's thermostat is 220°C and the glycol fog fluids run that hot. I think the thermal cutoff is going to be well past that.
 

Offline Astrodev

  • Regular Contributor
  • *
  • Posts: 95
  • Country: gb
Re: Replacing thermal fuse in a fog machine
« Reply #18 on: October 08, 2018, 11:12:45 pm »
The method of operation on most of these machines is a heater mounted on a block to provide thermal mass and through which a small bore metal vaporisation tube passes, attached to the block there is usually a bimetallic thermal switch (normally closed) this is what is shown in the first picture, there is also a thermal fuse (the small axial component that looks a bit like a diode that you have also identified).


All 3 of these parts are wired in series usually across the mains with either a relay or the mains switch to turn the circuit on.

So after turning it on you can usually smell that it is warming up or feel some heat coming off if you hold your hand about 6 inches above the heated block.

If this is happening then it suggests the heater and thermal fuse are OK.

If not unplug and use the resistance measurement across the thermal fuse (up to 10ohms is usually OK), bimetal switch (about 1-2 ohms) and the heater (6-250 ohms depending on the power rating for a small DJ type unit I would expect 100-200 ohms)

Now if the unit is heating up this is where it gets a bit trickier using the meter to measure AC volts monitor the voltage across the bimetal switch, which should initially be around 0V, but should start changing between 0V and the 230V or 115V depending on your local mains voltage, this switching temperature is usually reached in 3 to 5 mins, but if this switching does not start after 7 to 10 mins it may be that the bimetal switch has failed (they sometimes weld shut) in which case keeping the unit running will probably burn out the thermal fuse (this is there to protect the heater from damage and not the fluid which is pretty inert and contrary to an earlier post is almost impossible to ignite).

If you need to replace anything in this part of the machine it is better to crimp rather than solder, the best method I have found for fitting replacement thermal fuses is to crimp them in using bootlace ferrules.



 
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #19 on: October 09, 2018, 02:43:04 am »
Forgive me if I am mistaken floobydust, but I believe that the rating on the cutout switch is in Fahrenheit (so 104.4 Celsius), That is how mine is anyway.  Thanks.  Jason
 

Offline Astrodev

  • Regular Contributor
  • *
  • Posts: 95
  • Country: gb
Re: Replacing thermal fuse in a fog machine
« Reply #20 on: October 09, 2018, 03:13:27 am »
220 Celsius would make sense as the 2 components of the fluid are water 30% BP 100 Celsius and DPG 70% BP 230 Celsius   
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #21 on: October 09, 2018, 03:53:28 am »
I thought the same, but I cannot find anything other than one on Amazon that says it is a 98 degree C variety?  Here is mine....
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #22 on: October 09, 2018, 04:06:53 am »
Okay, sorry, I think I finally found the correct "closest" example...   

See: 
https://www.amazon.com/uxcell-Celsius-Normal-Ceramic-Thermostat/dp/B008X0Y14A/ref=mp_s_a_1_15?ie=UTF8&qid=1539057374&sr=8-15&pi=AC_SX236_SY340_QL65&keywords=ksd301

The question is simply, which thermal fuse (which I have confirmed as bad) do I use in conjunction with this cutout switch? 

Thanks in advance for any assistance!

...Anyone?
« Last Edit: October 09, 2018, 03:18:52 pm by paluszak »
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 6967
  • Country: ca
Re: Replacing thermal fuse in a fog machine
« Reply #23 on: October 09, 2018, 07:31:58 pm »
Because the thermal cutoff (fuse) has a safety function, I can't give you a temperature value out of my hat. Especially without knowing make/model  :P

Antari F-80Z uses "220 degree" thermostat and "172 degree" TCO, so the TCO (location) must be monitoring pump outflow (heater inflow). You have to get water to steam to get pressure, without burning the glycol, so my money is on Celcius.

From Big Clive MAKE YOUR OWN SMOKE FLUID  "... In reality the risk of burning occurs at about 400 degrees centigrade and most machines operate down in the 200 - 300 degree region."

His detailed explanation of e-cig and fog machines:
 
The following users thanked this post: paluszak

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #24 on: October 09, 2018, 08:03:22 pm »
The machine is a Chauvet FX-800, and I cannot find information on this particular model ANYWHERE!?  I have the manual and it is completely useless as well.  Thanks again for your contribution.  I am checking out djlightingdiscount.com right now! 
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #25 on: October 09, 2018, 08:28:45 pm »
This is a picture of MY existing, tested, and fully-functioning thermostat / thermal cutoff switch (See pic).  It is apparently a 10Amp, 250V variety with a 208 Degree Celsius temp rating. 

Here is also a picture of the existing, "tested as DEAD" thermal fuse as well.  What thermal fuse do I need to buy to replace this unit?  Unfortunately I cannot read the writing on the bad unit as it is 98% rubbed off. 

Do I need to make sure it's a 10Amp fuse as well, or can it be 15Amp (like the model the local electronics store salesperson pointed me toward)?  And what model (or better yet, what Functioning, Holding and/or Maximum Temps) should this new / replacement thermal fuse have?   

THANK YOU!!!
« Last Edit: October 09, 2018, 09:10:46 pm by paluszak »
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #26 on: October 10, 2018, 07:39:27 pm »
floobydust,

I believe that I have finally found the correct TCO I need, however it is listed as 15A (NTE8167), go figure...  The Thermostat in my unit again is listed as a 10a/250v?  Is it going to be okay to put this 15A TCO inline with a 10A Thermostat / Thermal switch?   Do they make a 10A version of something like the NTE8167?   Thanks again!
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 6967
  • Country: ca
Re: Replacing thermal fuse in a fog machine
« Reply #27 on: October 10, 2018, 08:18:01 pm »
Chauvet FX-800 fog machine is 700W or about 6A draw at 120VAC.
So both the thermostat and thermal cutoff need to be capable of carrying more than this much current.
A 10A or 15A rated thermal fuse would not matter here. These fuses activate first due to pellet temperature.

NTE Inc. Thermal Cutoffs TCO datasheets says 10A continuous and 15A interrupting.
Digikey also sells TCO's by Cantherm, SDF series rated 10A or 15A at 125V or 250V, depending on the region for safety approvals.

If your thermostat is stuck on, then it will overheat and blow the new TCO. I always buy a few extra.
 
The following users thanked this post: paluszak

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #28 on: October 10, 2018, 09:32:07 pm »
Thank you again for your time and awesome help! 

So I stopped at my local electronic store after work, but they did not have the proper TCO fuse, so I am probably just going to order it online.

One quick question though before I do so (hopefully the last) if I may...  Why would the TCO temperature be slightly lower (as opposed to slightly higher) than the thermostat / thermal switch temperature rating, as you had stated previously?

Just want to make sure I get the correct one, and get this over with.

Thank you again for the assistance!

Jason
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 6967
  • Country: ca
Re: Replacing thermal fuse in a fog machine
« Reply #29 on: October 10, 2018, 10:25:06 pm »
The TCO protects the enclosure from getting too hot. The fog machine's designers don't seem to care about only the heater overheating.

The TCO is located inside an insulating sleeve, far away on the mounting bracket at the bottom of the enclosure.
It does not accurately see the heating block temperature. There is lots of heat loss and really, when the enclosure bottom heats up is when it trips.

Some fog machines have plastic enclosures, others a steel bottom, so I think that's why the TCO temp rating varies so much.
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #30 on: October 10, 2018, 11:29:02 pm »
Ahhhhhhhh....   Okay then!   So essentially, if the TCO was connected in the same manner (at the same location as the thermostat switch AND touching bare metal as that one is) it would get a much higher temp exposure (than it conversely gets now down toward the base and all insulated) ...and hence if it was this same 170 degree Celsius unit, it would fail open and "cutout" well BEFORE the thermostat?
« Last Edit: October 10, 2018, 11:32:02 pm by paluszak »
 

Offline Astrodev

  • Regular Contributor
  • *
  • Posts: 95
  • Country: gb
Re: Replacing thermal fuse in a fog machine
« Reply #31 on: October 10, 2018, 11:54:19 pm »
If you want to get the right part why not give Customer Service at Chauvet a ring and they will probably tell you what the value should be and if they are anything like the guy's I deal with at Chauvet they might even send you the correct part out.
 
The following users thanked this post: paluszak

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #32 on: October 11, 2018, 12:06:55 am »
I will do that...  Thank you!
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #33 on: October 11, 2018, 06:45:09 pm »
Ha!  From Chauvet support...

"Jason, so sorry but after speaking with our product development team it looks like we’re unable to assist. As this product has been discontinued for so long we’re unable to confirm which fuse would be a suitable replacement. Please feel free to reach out to our customer service team to confirm this 9545774455 option4"

Wow!  It's only 10-14 years old, not like 25 or 50?  I even have manuals and schematics of things I owned when I was a teenager, and that's just little ole me, not a big business creating PRODUCTS for mass consumers for decades.  Oh well.  So much for THAT avenue.

Jason
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #34 on: October 11, 2018, 06:47:36 pm »
To be fair, I did just get this from them as well (as a follow-up):

Jason, were very sorry for the inconvenience. We do keep records of all legacy products, however, we lost 2 of our servers containing this data during Hurricane Irma in 2017.

So much for digital backups I guess (esp in the year 2017?)
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 6967
  • Country: ca
Re: Replacing thermal fuse in a fog machine
« Reply #35 on: October 11, 2018, 07:16:02 pm »
Other posters (halloween fog forums) saying Chauvet will sell only the entire heater/fuse/thermostat assembly  :P

I'll bet the heater is a generic 700W one from china, you can track down the same fog machine guts but under a different label and see what the thermal cutoff rating is.
The Antari F-80Z (heater block) looks the same and 172 degree TCO, also used for a few other models ice, 1000, 1100.
I think that's the best guess out there until someone else repairs one and posts here.

The TCO is to stop the fog machine from burning down the house if the thermostat failed, stuck on. Paper ignites at 233C so the enclosure (bracket) better stay way cooler under that fault condition.

Maybe try out the NTE part and see how it does?
« Last Edit: October 11, 2018, 07:29:14 pm by floobydust »
 

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #36 on: October 11, 2018, 08:02:07 pm »
Yep.  TOTALLY AGREE with you... and thank you again for the 4insight.   I definitely want to put "something" in for safety-sake and I don't want it to be TOO high, not work and then catch on fire, however, I also don't want to use one too low and have it FAIL every single time I use the fog machine!  ha ha
« Last Edit: October 11, 2018, 08:40:41 pm by paluszak »
 

Offline floobydust

  • Super Contributor
  • ***
  • Posts: 6967
  • Country: ca
Re: Replacing thermal fuse in a fog machine
« Reply #37 on: October 11, 2018, 10:23:26 pm »
Most fog machines have fake or no safety approvals.

The FX-800 is claimed to "Intertek ETL Listing" but does not exist in the product certifications database. No fog machines by Chauvet and Sons, Inc. FL USA are in there. It must have been taken by the hurricane. They seem to purchase from HESHAN TONGFANG LIGHTING TECHNOLOGY CO., LTD - Heshan, Guangdong CHINA.

Some fog machines are only basic electrical (grounding, electric shock) tested, and a few for Europe I found tested to the appliance standard IEC 60335-1 which covers fire.

My point is the thermal fuse was never formally tested to provide fire protection in this model.
 
The following users thanked this post: paluszak

Offline paluszak

  • Contributor
  • Posts: 15
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #38 on: October 12, 2018, 07:56:09 pm »
Dang pesky hurricanes...  Anyone else see the irony here, given that this is one of Chauvet's leading Fog Machine model names?   ;)
 

Offline noall666

  • Newbie
  • Posts: 1
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #39 on: October 14, 2018, 11:13:39 pm »
I need help with this fog machine, heres a quick run down. 400 watt, pump works, heating coil heats up, BUT, it shuts off and doesn't go on, when you would think it does, not sure if there is a wiring problem, anyone know how these things are suppose to be wired, or if my temperature controller thing is shot. this thread has been some help, but maybe specifics,wiring diagram etc, would be even better.

cheers

side note , i think the switch has been altered, so lets see if i can figure out how to add some photos.....
 

Offline squinta

  • Newbie
  • Posts: 1
  • Country: pt
Re: Replacing thermal fuse in a fog machine
« Reply #40 on: February 16, 2020, 07:31:26 pm »
Hello!
I own the same machine.
If it warms up and the command light doesnt go off, then you have a default switch.
If it doesnt wrm up you have a default termal fuse.
Check both for sure.
 

Offline FlightRisk

  • Newbie
  • Posts: 1
  • Country: us
Re: Replacing thermal fuse in a fog machine
« Reply #41 on: August 27, 2021, 07:07:46 pm »
Tough choice whether to revive a dead post or start a new one, but perhaps people still follow this and it is the same issue, different machine. I have an old Gemmy fogging cauldron and it stopped making sounds and blowing fog. But it gets very hot. I tested the pump and power supply, they work fine. I believe it is a thermal switch. I have never seen anything like this before and want to replace it. I shorted the contacts on the board and get sound when I do. If I remove the jumper, it still makes sound. So I *believe* this must be a NC switch that opens at a certain temperature. How can I tell? This has a 50VA power supply (120V 500mA in / 12VAC 50VA (4.2A) out).

Can anyone tell me how these work? Something waits 10 to 15mins or when it gets to a certain temperature and then pumps fog. It must have a timer to pump for a certain time and stop. At first I thought this sensor tells the unit when it is hot enough to fog. Now I think it cuts off at a certain temperature and makes a tiny fan blow. But I have no idea. Can anyone translate the markings? It has a theta symbol and 104 on the outside silicone sleeve (another clue that RT silicone and the flesh colored silicone sleeve must have a max temp) and inside it has VW -1. I see what looks like identical parts available from China, but you need to know NC or NO and what temp. They only go up to 75C on the site I found.

 

Offline mansaxel

  • Super Contributor
  • ***
  • Posts: 3554
  • Country: se
  • SA0XLR
    • My very static home page
Re: Replacing thermal fuse in a fog machine
« Reply #42 on: August 27, 2021, 07:39:33 pm »
I've been servicing such machines. What Astrodev writes is pretty much on the spot.

Higher-end machines have a regulator circuit that will control the temperature a bit closer. They'll usually have a temp sensor on the block too, as input to the regulation.

Here, it's much simpler, with the hysteresis of the bi-metal giving a somewhat jagged regulation curve.  :-DD

I'm also leaning towards the bi-metal thermostat being welded closed, if the machine does not stay sensibly warm but instead races to glowing.

The absence of smoke can be down to a lot of things. Normally, a membrane pump or similar will push the fluid through the block. Even if you have the best fluid, there's going to be some residue, which will clog the block. Best cleaning method is to safebloc the pump to the mains (assuming it's a mains voltage pump, of course.) and push distilled water through the cold block. When the water's clear and comes out of the block in a long urination-like arc you're good.


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf