Humming Noise

[drluam]

Newbie here.
Just bought a 1997 Gulfstream Ultra.
For right now. I have it parked in the backyard.
I'm hooked up to a powercord for Elec. in the MH
The panel with the fuse's and switches makes a humming noise..
Wondering if this is normal.
Or If this is something,,,I don't need to be doing ?

[Jim Jackson]

It would be a lot worse if there was not a humming noise, I'd say normal unless it's loud. It's probably converting 120 volt to 12 to charge the coach battery.

[gklehner]

I second the opinion on the hum coming from the power converter. Have a '97 gulf stream conquest. When ever I'm plugged into shore power and the coach battery charges, it has a low hum which is really only noticeable when all is quiet in the coach.

Greg and Karen, we are also new to the RV scene, but learning fast!

[drluam]

Thanks for the help.
I feel alot better now.

[wa8yxm]

You typed a key prhase "The panel with the fuses and switches" On my motor home there is no such panel... There is a panel with fuses, and right below it one with switches but they are two, completely separated panels.

So.. Why is that a key phrase?

Because often when the panel has BOTH fuses and switches, on the back side, where you can't see it, because you very likley never need to, is a handy, dandy converter that converts 120vac to 12vdc.... And some of those are hummers.

Can you tell us the make and model of that panel?

More info: The Magnetek 6300, as an example, is such a box, You see the breakers and fuses, I know where to look for the converter (on the back side, you can kind of see it through a hole where some wires come up) the 6300 is based on a ferro-resonant transformer. I won't go into this but it is a very inefficient but low cost way of making a somewhat regulated power supply.

The core of a transformer is often made up of many iron "leaves" held together with something resembling varnish.. As the varnish ages it dries and flakes off leaving you with loose laminations. They vibrate in step with the AC current.

The result, 60 hz (very bass) hum

[drluam]

Went down and took a look.

This is what it states:

Power Converter With Battery Charger
Series : 6300 A
Model 6345

45 AMP

Again, Thanks for all help !!

[wa8yxm]

Yup, that's a Magnatek 6300.. The hum is the transformer in the converter which is behind the fuse/breaker panel.

Now the bad news.. This is an old single stage unit, you need to check your batteries and may need to disconnect them to prevent overcharging,, This unit is well known for boiling batteries dry and damaging them.. A upgrade to a good 3-stage or 3-stage plus converter is highly recommended..

Some of the better converters:

Progressive Dynamics 9200 series
Progressive Dnamics 9100 with the optional charge wizard (The difference in those two is the 9200 the wizard is not an optin, it's built in)
IOTA with IQ-4
WFCO
Xantrex True Charge

I am biased toward the Progressive Dynamics myself.. but note that is a bias.. That said, in researching converters it is among the best.. So Ranks right up there with the rest of those I listed.
BestConverter - Converters, Inverters, Electrical Supplies, Electronics

Has both information on upgrading (Scroll down to the "Extra Info" frame) and good prices on the upgrade.. They also have an upgrade kit that makes it easier.