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Post Info TOPIC: Strange hum, electrical
harrydiculous


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Strange hum, electrical
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Hi

I've a strange problem. There's a gentle hum when connected to 240 grid power within the 'van. All appliances & lights are off. It is still evident even if the Car/Power switch is on Car.

Checking power usage, the clamp meter shows 0.1 Amps (on the 40 amp AC mode). All plugs are firm and I've used two power points. 

I removed from the house power and plugged into the 300 watt inverter then to battery.

All systems worked, same power usage, appliances worked but no hum except for the fan on the inverter.

I can't seem to find where this "hum" is coming from.

(The length of lead is the same to house or inverter)

Any ideas where this hum might be coming from?

 

It's a Millard Weekender.

 

Thanks

 

EDIT, Typical, just found it. There's a box that looks like it might be an inverter under the seat. Omega 40. Turn it off, no hum. I'm feeling a bit silly now.blankstare



-- Edited by harrydiculous on Sunday 28th of June 2015 04:13:58 PM

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Izabarack


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harrydiculous wrote:

Any ideas where this hum might be coming from?

 EDIT, Typical, just found it. There's a box that looks like it might be an inverter under the seat. Omega 40. Turn it off, no hum. I'm feeling a bit silly now.blankstare



-- Edited by harrydiculous on Sunday 28th of June 2015 04:13:58 PM

 No need to feel silly.   What you describe is typical of 50 cycle hum that indicates that a filtering capacitor in the box under the seat is not well.

Iza



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Phil C


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Hi and welcome to the forum.

If the hum was a lower tone (frequency) then it may be a transformer lamination rattle if that box is a power supply come battery charger. If higher frequency, and in fact the box is an inverter, it may be from the high frequency transformer inside..

Anyway, you found it and fixed the noise.

Take care and be safe

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2foot6


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I'm glad you found the problem,I was going to say it was humming because it doesn't know the words ,but there's no need now ..........  cheers Peter.



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harrydiculous


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Thanks for the replies, guys. What I have to do now is find out what an Omega 40 does and probably replace it.

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03_Troopy


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Sounds like it might be a 40A battery charger, and could possibly have a cooling fan inside. Can you post a picture of the device? Especially any labels or writing on the unit.



-- Edited by 03_Troopy on Monday 29th of June 2015 11:33:48 AM

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harrydiculous


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How about an FP 10. (I now need new glasses)

Thanks Troopy

s162.photobucket.com/user/jibbonpoint/media/pics%20upload/Omege%20FP%2010_zpsqpb86knx.jpg.html">i162.photobucket.com/albums/t257/jibbonpoint/pics%20upload/Omege%20FP%2010_zpsqpb86knx.jpg">

 



-- Edited by harrydiculous on Monday 29th of June 2015 11:49:11 AM

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03_Troopy


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Unfortunately I am unable to find anything on that unit Harry, but it looks like one of the old style caravan 240V to 10A DC power supplies.

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Cupie


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There is an Australian Omega Power Company that I found using Google

 

 

http://www.omegapower.com.au/about.html

 

They might be able to identify the unit.

 



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03_Troopy


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Or maybe even Omegalec



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harrydiculous


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Well, thanks Cupie & Troopy. It's Omegalec, who are quite close. I've left two messages in two days now for the Tech Guy to ring after the receptionist confirmed that it is their unit. ('you there Tech Guy, hey! Tech Guy! are you there?biggrin )

Anyway, the path to redemption on this unit is laid out smile. If I don't get a response, I should be able to sort it out now myself. There doesn't appear to be anything that would lead me to believe that it's a battery charger and, therefore, it's 240 to 12 volt only. There was no "House Battery" in the unit when I bought it & no provision for one.

 

 

 



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harrydiculous


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Can I bother you all once again?

I have one of these I bought to run 12 volt appliances in my shed. (Compressors for tyre inflation, soldering irons and any other 12 volt stuff).

Would this, in an appropriate enclosure do the job? (Mr Tech Guy from Omegatec; where are you?)

www.ebay.com.au/itm/DC-12V-30A-360W-Switch-Switching-Power-Supply-Driver-For-LED-Strip-Light-Display-/400504612480

Thanks

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dogbox


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would that one be like a 360 watt step down transformer used for led lighting

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harrydiculous


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Could be dogbox.

Here's a picture:-

 

 

Thanks for the reply.

It runs the small compressor OK.

 

 



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03_Troopy


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That is a 12VDC switchmode power supply. Yes it would be suitable for running light loads such a a few LED lights and maybe a 12V fridge similar to Waeco or Engel chest fridge freezers (which draw between 3A to 5A), but I wouldn't like to run it near it's rated 30A for too long without some extra cooling.

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PeterD


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dogbox wrote:

would that one be like a 360 watt step down transformer used for led lighting

 No it's not  transformer, they give an AC output. It's a 12 V power supply with a 30 A DC output.



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PeterD


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That power supply unit (PSU) should be OK if mounted in a well ventilated enclosure. Make the sides and top from expanded aluminium or some mesh that you can't get fingers through. Make sure all the leads come out through rubber or plastic grommets.

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Retired radio and electronics technician.
NSW Central Coast.

 
harrydiculous


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Thanks Guys. I'll keep that one in the shed and perhaps get another identical unit or perhaps one more suitable. Although, all that it's likely to run is what's been mentioned. (Changing now to LED Globes, & a Waeco type fridge freezer)

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