Low Voltage at water valve


  #1  
Old 06-26-06, 08:59 AM
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Low Voltage at water valve

Hello and thanks for the great forums here.

I have a kenmore side by side fridge that is approx 6yrs old with a water/ice dispensor that recently stopped working while i was away. I removed the water fill solenoid and dissassembled and reassembled and all was good for a day. Following day, again no water (neither ice nor water dispensor). I ruled out clogged lines and any other options right down to this solnoid not passing water.

This is a single style solenoid that is only receiving 80v, instead of expected 120v. This water valve also feeds two more valves where one is used for dispensor, and the other ice. Can i just remove the 'first' valve (being the problematic one) so water will always be available to the secondarys? Following the schematics, it's apparent theres seveal different connections and splices to the wire, everything looks fine from the bottom of the refrigerator, but i haven't torn it completly apart, and would rather not have to if i am missing something simple.

The model number starts with 970, which i beleive denotes this as a Frigidaire?

Thanks,

Shawn


edit: I forgot to add, the secondary set of valves have proper voltage, 135vac
 
  #2  
Old 06-27-06, 08:51 AM
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I've removed the 'guts' to this valve so it always passes water onto the secondary valves and so far so good. Does anyone know what the intended purpose for this valve is though? My geuss is some type of protection incase one of the secondarys sticks open??

Still stumped on the low voltage though.
 
  #3  
Old 06-27-06, 09:16 AM
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Shawn, my refrigerator (Sears) has four valves. I think the reason for this is to accommodate an internal filter that is used for both water and ice. The purpose for multiple valves is circuit isolation....I think. You need the internal valves to direct the water flow. If you only had one external valve, you would need some kind of circuit to isolate the "water" valve from the "ice" valve when you select one or the other. By using two valves for each, you never connect the two electrically. At least, this is my theory. I can't read the engineer's mind.

Anyway, these systems should never be under pressure, i.e. external valve open and the internal valve closed. The tubing connections are not designed to take it. By bypassing the first valve, you have pressurized the tubing. It may, and probably will, pop loose at some time in the future, probably when you aren't home. It can ruin your day, and much, much more.

Maybe someone else will chime in with a different explanation.

Good luck,
 
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Old 06-29-06, 03:31 PM
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Thanks for the response Randy. I've been busy but am working with it again tonight, and i did disconnect it afterwards for your very reason.

I may have narrowed the component down, but am not sure yet. After looking at the service schematic a little bit, it shows all three valves on the diagram. Main, Water Dispense, and IceMaker (they're labelled something else, but this makes it easier). It looks like when voltage is applied to WaterDispense, it is also spliced through a diode and into Main, energizing both valves. When icemaker calls for water, it powers up IceMaker, and also spliced into Main through a diode.

When i measure voltage at WaterDispense, i get the proper 120v, but again, only 60-80 at Main. I can't get anything from IceMaker but i ASSume it will only energize once the icemaker actually needs water.

So connections between valves Water, and Main, both test out okay for continuity since they're essentially spliced directly together expect for that diode which is preventing backflow of voltage to Icemaker when not needed.

Would a faulty diode perhaps cause a voltage drop this large? Resistance tests show inifnite in one direction and low in the other. Furthermore, Kenmore engineers decided to cover the diodes/splices in glue then heatshrink it. This kinda prevents me from determining diode type, etc. Does this make sense? I'm not sure if a diode can even cause this type of symptom when faulty. Any insight is greatly appreciated.

I can cut the harness in order to swap the diodes between the icemaker and water dispensor, but don't really want to muck it up incase i need a service rep to look at it.

Shawn
 
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Old 06-30-06, 04:36 AM
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Hi Shawn. I'm afraid I'm gonna have to tell my age, now. I haven't worked on appliances for quite a while. A lot of the new appliances have some form of solid state controls. The diode trick is new to me for icemaker controls. Of course, when you're talking diodes, you're getting away from pure AC circuits, which all refrigerators were until recently.

Anyway, diodes can convert AC to DC, and they may be used for isolation in DC circuits, which I think may be your case. I would love to see your schematic. They fail most often by shorting. Sometimes, however, they can open. If used for isolation, a short would probably have you putting water out two places at once.

To be sure, are you measuring with the AC or DC settings on your meter? Also, 135V sounds high. Of course, the 80 is probably low as well. Makes me wonder about the readings. Again, a schematic would help. To check the diodes with an ohmmeter, you must have at least one end out the circuit. On the X1 scale of your meter, you should read continuity one way (not a short), but not the other.

Again, maybe someone with more recent appliance experience will pop in and help. Meanwhile, if you can provide any more info, it may help.

Good luck,
 
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Old 06-30-06, 07:30 AM
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I have been making all measurements in AC, as everything looks to operate on AC, and thats what the solenoids have stamped on them. I've attached a link to the schematic I scanned in. The diodes look to be used for isolation.

http://swalker.servepics.com/fridgeschematic.jpg
 
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Old 06-30-06, 09:07 AM
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Hey Shawn, it's me again. Well, as I said, diodes in refrigerators are new to me. That said, I loaded your schematic. It's a little fuzzy, but I see the diodes. It looks as if the two cathodes are tied together and connect to the "Water Valve One." I'm not absolutely certain due to the loss of resolution in the drawing. However, I believe the note next to it is telling me almost the same thing.

IF THAT IS THE CASE, then you are dealing with DC at that valve. I can't tell whether it's DC before the diodes or not. I don't know enough about the system. If it is simply rectified 115VAC, then it would energize the valve regardless of whether is an AC valve. Try measuring the voltage on the DC scale with the negative lead on the other side of the valve and the positive lead on the side connected the the diodes. If it still reads low, the move the lead to the annodes, one at a time. As I said, it could be AC there, so you may have to change the meter back to AC.

In the end, it may easiest to isolate the diode and check with an ohmmeter.

Let me know what you find.
 
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Old 06-30-06, 11:33 AM
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When measuring voltage I've found

DC Scale
~55v at valve connection
0v before diode

AC Scale
~75v at valve connection
130v before diode

Now i'm confused. I didn't think the configuration of those diodes would act as a rectifier, but i am a little rusty on my electronics skills.
 
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Old 06-30-06, 11:47 AM
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Hey, hang in there. I'm not rusty on electronics..it's my daily bread, so to speak. If the cathodes are pointing to the relay, only positive voltages at the annode will result in current flow throught diiode and the relay. The diodes will definitely rectify the voltage going in. A lot of what you read with AC or DC with ripple will depend on the type of meter you are using. You can really get some strange readings.

Have you tried the ohmmeter test yet? It looks like the diode could be bad.
 
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Old 06-30-06, 12:11 PM
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Thanks alot for helping me out with this..

I've just tested both diodes, and both give the same results

Approx 20kohm in one direction, and inifinte when reversed. Using the diode option on the meter, they both show a forward voltage drop of .642

For some reason, this doesn't make sense to me anymore..

Thanks again
 
  #11  
Old 06-30-06, 12:28 PM
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A forward voltage drop of .642 is just about as perfect as you can get for a silicon diode. The 20k is probably ok. It depends on your meter characteristics. All your tests you performed on the diodes look good.

I just went back and look at your original post. The fact that the thing worked after you cleaned the valve for awhile may be trying to tell us something. I would ignore the low voltage reading for a bit (it could be false...it isn't AC, and it isn't pure, ripple-free DC) and try a new valve. The voltage is present on the annode of the diodes (again, I assume when you press the appropriate button). Both water and ice are affected. It seem worth a try. What do you think?

I will be unavailable after about 4:30 EST for the rest of the day, but I can check on you tomorrow.
 
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Old 06-30-06, 01:02 PM
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I agree 100%, I just put it back together and it works (for now). Its a national holiday tomorrow up here, so it will be atleast tuesday before i get a new valve. Unless i can buy just the solnoid?

I think this is just another classic case of turning something simple into something complicated.

Again i appreciate all the help and hope u have an excellent weekend. In any case, i'll be sure to follow this up next week!

Thanks Again!

Shawn
 
  #13  
Old 07-14-06, 03:56 AM
dadams14
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I think it is just stuck

I have a 9 year old kitchen aid refrige and the cold water does not dispense. I would work then not work then work and sometimes work after a couple of seconds.
I removed the solenoid in the back and took it apart. It is a dual solenoid , one side for ice , the other for cold water.. I tried to clean it out and put it back together and it worked for 1 day.. No diodes involved here.. ( I think your diodes are ok). I am going to replace the solenoid now..$50 online.
Good luck,
Dennis
 
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Old 07-19-06, 11:02 AM
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Its now been a week with the new valve (single) and was still okay. I found the valve cheaper at a local supply shop rather then online.
 
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Old 07-19-06, 11:17 AM
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Good deal. Thanks for keeping us up-to-date.
 
 

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