# Chauvet F-1700 Fogger



## jedi (Aug 28, 2010)

first the machine wouldnt make fog anymore so after cleaning everything I could possibly clean I figured the pump was bad so I bought a new sp35A pump. The old pump has a yellow and a black wire with a resistor on one of them the new pump has two black wires so I added the resistor to one of the wires hooked it up and the pump runs but it puts out hardly any fog the old pump buzzed loudly the spit out tons of fog this one just hums a little any ideas? and if its a 110v pump whats the resistor for? and does it make a difference if its 50hz or 60hz? any help would be great.

Jedi


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## spinman1949 (Jun 29, 2009)

Jedi,

You may be confusing a diode with a resistor. The diode only allows current to flow in one direction. This is how the pump works. The pump gets AC current and the diode chops one side of the wave. The bussing you heard from the old pump was the on and off current being supplied to the magnetic solenoid coil at 30 cycles per second. If all you hear now is a hum, then you likely are not getting the chopped wave or perhaps the diode is not stopping the current completely as it should in one direction. If you have a voltohm meter, you can check the diode. The diode should be black and have a symbol that indicates it is a diode. Google symbol for a diode. Positive on one side and negative on the other will give continuity will little evidence of resistance. Reverse the leads and you should have a totally open circuit. 50 or 60 hz has no effect. Or very little. One easy test is to plug the pump into a wall socket. Don't worry you won't hurt the pump. But keep the diode out. I used an electrical cord to do this. Like the kind you power a PC with. The center post is ground. If the pump sounds exactly like it does with the diode in the circuit, then likely your diode is the problem. 

Hope this helps.


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## jedi (Aug 28, 2010)

wow quick response! 
spinman1949 Thank you for the info. Just so I understand the one wire from the pc board to the motor gives 110v and the wire coming back from the motor to the machine gets the diode which drops the voltage right, I'll try it this afternoon. I have four foggers I use for Halloween 2 1000 watt 1 900 watt and the 1700 I'm working on now which kills me because the other three are cheap ones and all three didn't cost as much as this thing! one more quick question can the heating element be taken apart and chemical cleaned without ruining it? 

thanks again
Jedi


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## spinman1949 (Jun 29, 2009)

It does not matter which line the diode is in. What I found was when I ordered a replacement pump, I got exactly as you described. Before putting it into my unit I tested the brand new pump by hooking it to an ac line like I described. When I did the pump did nothing but buzz. Boy was I ticked. But then I saw that one of the wires I needed to connect the pump too was odd looking. Like a snake that swallowed a mouse. So I peeled off the shrink wrap and that is when I found the diode. I had taken the pump apart and now it all made sense. The pump has a spring loaded piston. The piston is in the middle of a coil surrounding a metal cylinder. The piston sits in the middle of the coil. So when the coil gets current it creates a magnetic field and pulls the piston down. Buy if not for the diode, the piston would just stay down. One would think that when the AC reverses polarity, then the pistoin would go the opposite direction, but that is not the case. So the diode stops the current and the spring pushes the piston back upwards toward the middle of the coil. This happens a either 30 cycles per second or 25 hz depending on the full ac circuit. So instead of a buzz , you should hear a kind of clatter sound. This is the piston moving up and down likely less than a 1/16 of an inch at a very fast pace. One way valves are are what make the whole thing work. One valve allows the fluid to be drawn into a chamber when the piston springs up on the off current phase. Then when the current hits the piston drives down and pushes the fluid through another one way valve out to the heater. Like a squirt gun pump actually, but able to deal with the back pressure that the heated fluid in the heater creates.

As to cleaning the heater? Well first make sure it is clogged. Maybe get a squeeze bulb. Just fill it with water and put the rubber nozzle into the tube that feeds the heater. If water does not squirt out the end where the fog comes out, then it is clogged. There is another post here that talks about unclogging the heater. You can try regular vinegar at first, but lilkely you well need to use a solution similar to what fog juice is made of which is glycerin. Anti Freeze may work. But Otaku has the answer. I will find the link and report it in another post. Oops I can give it to you now. http://www.hauntforum.com/showthread.php?t=22935


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## spinman1949 (Jun 29, 2009)

Jedi,

Read Otaku's directions carefully. You can remove the heater unit. In fact you will need to to clean it. The plugs are not actually plugs, but a long spiral shaft. I know cus I got mine out. Destroyed the heater unit, but I got the bloody thing out. The fittings on each end you do need to remove, and you will need the tape to make sure they don't leak when you put them back.


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## jedi (Aug 28, 2010)

Man I'm glad someone knows more about this crap than I do! Well I did as you suggested and plugged the motor minus the diode onto an old AC cord and it just hummed in my hand. So I checked the diode with my meter and figured out which way the voltage went and hooked everything back up and it sill just barely spits out fog in fact it wont even prime with the tubing the machine came with I had to use a really small piece of tubing to get it to work. It will run with the small tubing but makes little fog. So I guess the diode is bad maybe? or maybe the new motor I bought is bad? I'm getting frustrated with such a simple thing (I thought) like this to fix. I hate to call defeat and send it out to get fixed but it may be my only choice. Is there a vendor you can recommend I can take it to I'm in Southern California.

Jedi


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## spinman1949 (Jun 29, 2009)

*Dont get frustrated*

Jedi,

I am a technician. I am also 60 years old. So I have a lot of experience. The key to diagnosing problems is to not get ahead of yourself and not get frustrated.

So lets look at what you have found out. First you know the pump does pump.
But your not getting very much fog. So lets test the pump a bit further.

First forget the fog juice. We can test with water. Fog juice has a lot of water in it. To play it safe get a gallon of distilled water. Fill the tank with water.

Disconnect the pipe that runs from the pump to the heater. If you like you can disconnect it from the pump and then reconnect it at the pump but have the other end sticking out away from the interior of the unit. This will allow you to check the flow of the pump.

So go ahead and turn the unit on and let the heater run up to temp. Then use your manual control to run the pump. don't worry the heater will not be damaged. It is controlled by a thermistor. That is that round gismo that is on top of the heater. The other control is a thermostat. It controls when the pump can be activated. That shiny wire is a temp probe. It is inserted in a hole in the heater and the thin wire is actually a very thin tube. Be careful not to kink it. Fluid heated inside the probe actually expands and controls the contact plate in the thermostat. This is a relay controlled by heat. When the heater gets hot enough it closes a contact in the the thermostat and the pump circuit is completed. That click you hear when the pump ready light comes on is that relay closing.

The volume of fluid should be a steam of water about a cup of water every minute. It should be a stream and not a dribble. The output is much less during actual fog output. This is due to the back pressure of the heater.

Now if the pump output is good, then you know where the problem is. The heater is clogged.

Let me know what you find. Worse case you can send me the pump and I can test it for you. There are adjustments on the pump, but they are tricky.


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## jedi (Aug 28, 2010)

Thank you for all the info. I'll give that process a try after work tomorrow I predict you are correct with the heater being clogged. I am curious though of what the two set screws do on the pump I haven't moved them but I would like to know what they do it a SP35A pump.


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## niblique71 (Dec 2, 2009)

That was the most amazing and simple explanation of how a diode works with our foggers... Now I totally get it... CLUNK!!! Ya know how you can't get quadratic equasions in 8th grade??? and then all of a sudden it makes sense cause your teacher was good and knew just what words to say to make the principal simple and then VOILA!! you get it??? You just did that for me... I LOVE This forum...


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## jedi (Aug 28, 2010)

Well I'm happy to report that after all the generous help given to me by spinman1949 my hurricane 1700 is pumping out more fog than it did when it was new! (I wish I could post pics or video) I tested the pump the way he suggested and it was fine. So I took the heater apart and soaked it in 80 -20 mix of alcohol and heated it up in a pan on the BBQ and blew compressed air through it every once and a while and eventually it cleared up. I was amazed at how much crap was stuck in there what a nasty mess! no more cheap fog juice for me. So now I'll have three working foggers for Halloween this year thanks to spinman1949.

Again thank you for the help

Jedi


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## spinman1949 (Jun 29, 2009)

*My pleasure*

Oh and best give a nod to our friend Otaku as well. We all learn from each other.


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## jedi (Aug 28, 2010)

Correct sir! A special thank you to Otaku for the write up on heater cleaning.


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