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D2-A16
Dec 6, 2016 19:04:52 GMT
Post by elec573 on Dec 6, 2016 19:04:52 GMT
Don't see how that would help ? If the winding are going to ground ! Would it not still go to ground ? Plus I don't have an isolation transformer .
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D2-A16
Dec 6, 2016 19:11:45 GMT
Post by Travis on Dec 6, 2016 19:11:45 GMT
Ray and I were trying to discuss this yesterday. I am not sure if an isolation transformer would help. If it did run, wouldn't the unit still be hot?
I wonder if my DR35 that Gill has would run with one? I am still not cool with an electrically live unit though. The domes are fun to touch and I might forget and zap!
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D2-A16
Dec 6, 2016 19:36:42 GMT
Post by elec573 on Dec 6, 2016 19:36:42 GMT
That's what I was thinking too ! In effect the whole machine becomes part of the circuit and electricity is always looking for a way to ground it doesn't care if it's through you!
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Post by Travis on Dec 6, 2016 19:46:20 GMT
Maybe that's what foot pads are for
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Post by cablehack on Dec 6, 2016 22:15:10 GMT
Don't see how that would help ? If the winding are going to ground ! Would it not still go to ground ? Plus I don't have an isolation transformer . An isolating transformer allows the motor to work with an insulation breakdown because the supply is no longer referenced to earth. Therefore it can be run without being a shock hazard. The motor does not care whether one side of the mains supply is connected to the casing or not. It will run perfectly well, unless it has shorted turns as well. The only problem is if a human or other living creature gets between the casing and an earthed object. Depending at what point the insulation has broken down along the winding, and the polarity of the mains, the voltage from casing to earth will be anything from nothing to the full mains supply voltage. The only reason a shock might be received is because the mains supply has the neutral connected to earth, not only at the domestic switchboard, but throughout the whole distribution system. So, by introducing a double wound transformer between the mains supply and the motor the neutral is no longer earthed. The supply is now floating, and as neither side is earthed there is nothing to complete the circuit if someone touches the side of the fridge. I suppose in your part of the world where monitor tops are a dime a dozen, you'd get another DR for the price of an isolating transformer, but I merely point out that one can still safely use a motor with broken down insulation.
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D2-A16
Dec 7, 2016 1:44:11 GMT
Post by elec573 on Dec 7, 2016 1:44:11 GMT
Ok cablehack you make a convincing theory ! So with an iceo transformer you think it might just fire up ! Humm have to think on that With no reference to ground the neutral would float so would not the voltage also be all over the place ? Thinking of the moter would not the start windings be affected ? But it's a worth while project!!! Have nothing to lose so what's do you suggest ??
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D2-A16
Dec 7, 2016 4:36:46 GMT
Post by cablehack on Dec 7, 2016 4:36:46 GMT
Ok cablehack you make a convincing theory ! So with an iceo transformer you think it might just fire up ! Humm have to think on that With no reference to ground the neutral would float so would not the voltage also be all over the place ? Thinking of the moter would not the start windings be affected ? But it's a worth while project!!! Have nothing to lose so what's do you suggest ?? Before spending any money on a transformer, you can just power it up with it sitting on an insulated surface and see that the motor runs. Don't touch it of course, in case the mains polarity is such that the casing is live. From my experiences with monitor tops and transformers, the transformer needs to be rated at least at 500VA. This is partly because of the low power factor of the compressor motor, and also the very high start up current. While any decent transformer can handle the start up current for the second or so, the problem is lesser rated transformers will drop their output voltage too much which delays the motor coming up to speed, leaving the start winding in circuit for longer than normal (not good). I experimented with several transformers for my CA-2 and the 500VA toroid has been perfect. Others ran warm or had unacceptable voltage drop on start up. My CA-1 uses an 850VA rated transformer which is overkill, but it's what came with the fridge. I should also point out for those not aware of my situation that these are stepdown transformers - the motor insulation in both my fridges is OK.
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D2-A16
Dec 7, 2016 5:46:05 GMT
Post by elec573 on Dec 7, 2016 5:46:05 GMT
Ok sense it's not working anyway it miles we'll be a Gina pig . Right now have it upside down I we'll have to right side it up give it some time for oil to get back where it needs to be . So I we'll attach new wires to terminals . Have them marked where they were on relay . Well give you an up dated pitcher later ! Thanks for your help ! May take a couple of days to get back to you !
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D2-A16
Dec 7, 2016 22:22:08 GMT
Post by elec573 on Dec 7, 2016 22:22:08 GMT
Ok soldered on new wires on terminals ! Do I use the run wire or do I need to hook up control rely temporary? Have it setting on a wooden box so it we'll be isolated .
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Post by elec573 on Dec 13, 2016 2:33:14 GMT
Ok going to try what cablehack talked about tomarrow I have isolated the d2-a16 on a wooden box . Have put a nordec heater in it to wearm it up over night my garage is 32 right now !Tomarrow I we'll hook up the relay controls and then try it . Hopefully no sparks !
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D2-A16
Dec 13, 2016 11:44:50 GMT
via mobile
Post by timeswelding on Dec 13, 2016 11:44:50 GMT
I would think that a 12 watt heater will never get that oil up to temperature in a 32 degree garage. A DR is too large of a heat sink for that to work. It'd be the equivalent of absolutely no heater at all. Just my opinion, though.
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Post by tommythecube on Dec 13, 2016 13:59:56 GMT
You may be right but I don't think that there would be a specific temperature that the oil should be at. I'd think that the heater is there primarily to create a "Difference " in temperature between the oil and the rest of the high side since refrigerant will always migrate to the coolest part of the system thus preventing liquid refrigerant from dissolving in the oil. Just my thoughts. Good luck!
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D2-A16
Dec 13, 2016 21:21:21 GMT
Post by elec573 on Dec 13, 2016 21:21:21 GMT
Thanks for the thoughts the good news the heater did something . I could hear what sounded like water dripping in the evap. Bad news hooked up control relay no difference on the motor when I turned it on . Made sure everything was on wood and not going to ground. The moter did not do anything no noise just relay hum.
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D2-A16
Dec 13, 2016 22:04:51 GMT
Post by cablehack on Dec 13, 2016 22:04:51 GMT
Seeing as your motor appears to have continuity in the windings, it should draw current and therefore do something even if it doesn't actually rotate. My suspicion falls on the control/relay/start resistor. I'd try running the motor without all that, and just briefly use a capacitor to start it.
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D2-A16
Dec 14, 2016 1:46:54 GMT
Post by tommythecube on Dec 14, 2016 1:46:54 GMT
Do you have an amprobe?? That would help a lot if you could provide current draw as you apply power on the windings.
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