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Hoohaa · 16-09-2021, 15:13

Quote:

Originally Posted by JoeRobertJr

Hi, Hoohaa,

The diagram looks correct to me for wiring the capacitor as a noise filter.

How physically large is the capacitor?

47000 uf. I've added a pic.

thomm225 · 16-09-2021, 15:19

It looks like some wannabe electrician/electronics guy added the capacitor which is most likely not needed at all.

So are you thinking the PO bought a fridge which needed the new owner to select the proper input voltage cap for it?!

That's pretty ridiculous.

I have never bought anything electrical or electronic where the manufacturer would have the buyer select a capacitor for the input voltage

**JoeRobertJr** · 16-09-2021, 15:19

Quote:

Originally Posted by Hoohaa

I'm thinking the fuse should be on the other side of the capacitor?

The fuse should be close to the battery as in your schematic. If you put the fuse between the capacitor and the fridge, the fuse will not protect your boat from shorted terminals on the capacitor.

Quote:

Originally Posted by Hoohaa

Noise suppression?
My fridge is happily running without it.
Could you explain why you would need noise suppression?

Noise suppression is not for helping your fridge run. It is so that the electrical noise from your fridge does not interfere with your other electronics, like your radio.

thomm225 · 16-09-2021, 15:20

Leave it to bored cruisers / sailors to make a big deal out of nothing at all......

Remove the Cap and toss it.

Hoohaa · 16-09-2021, 15:52

I've had a closer look and it appears that the capacitor is wired onto a positive bus that connects a lot of the devices on the panel. Not just a fridge. ( See 1st pic)
So it does look like it's been installed the noise suppression.
The 2nd pic is of my new panel. I'm now thinking that I need to wire the capacitor to my positive bus on this panel, which will effectively connect it to almost all of the devices. Does that make sense?

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thomm225 · 16-09-2021, 15:54

Quote:

Originally Posted by Hoohaa

I've had a closer look and it appears that the capacitor is wired onto a positive bus that connects a lot of the devices on the panel. Not just a fridge. ( See 1st pic)
So it does look like it's been installed the noise suppression.
The 2nd pic is of my new panel. I'm now thinking that I need to wire the capacitor to my positive bus on this panel, which will effectively connect it to almost all of the devices. Does that make sense?Attachment 245421 Attachment 245422

It makes sense if you are a wannabe electronics guy otherwise most probably not needed, but it appears you enjoy this so have at it or do nothing at all.

It doesn't really matter as far as your systems are concerned but you seem to enjoy drawing diagrams of your systems so one day it may come in handy for troubleshooting a "real" problem.

Tom

Electronics/Computer Tech/Manager by trade since 1975.

Hoohaa · 16-09-2021, 16:22

Quote:

Originally Posted by thomm225

It makes sense if you are a wannabe electronics guy otherwise most probably not needed, but it appears you enjoy this so have at it or do nothing at all.

It doesn't really matter as far as your systems are concerned but you seem to enjoy drawing diagrams of your systems so one day it may come in handy for troubleshooting a "real" problem.

Tom

Electronics/Computer Tech/Manager by trade since 1975.

Wannabe electronics guy? No, just don't want to burn my boat down because I didn't properly understand something.

**JoeRobertJr** · 16-09-2021, 16:22

Hoohaa,
Tom has doubts about whether it is needed. Someone in your boat's history thought it would help. You can test yourself whether it makes a difference.
Check your radio and TV for noise, especially when your fridge is running, and see if there is any difference whether that capacitor is connected or not.

Oceanride007 · 16-09-2021, 16:52

Just wonder if it was put in to assist with starting voltage droop issues. Correct method is to up the wire size, if its electrolytic capacitor you will have leakage issues, bit would be interested in knowing if this gave a little bit more starting current to fridge to avoid excessive voltage drop that would cause compressor to trip out on low voltage.

What is cable size and length of run.?

rwidman · 16-09-2021, 17:36

That is not a noise suppression capacitor. It is far too large for that.

If anything, it's a kludge to try to compensate for a voltage drop in the boat's wiring when some appliance starts up or runs.

As for the fuse, the purpose of the fuse (overcurrent protection) is to protect the wiring so the fuse should be as close to the source (the battery) as practical. ABYC would have it within seven inches of the battery.

**Wotname** · 16-09-2021, 18:07

Quote:

Originally Posted by rwidman

That is not a noise suppression capacitor. It is far too large for that.

If anything, it's a kludge to try to compensate for a voltage drop in the boat's wiring when some appliance starts up or runs.

As for the fuse, the purpose of the fuse (overcurrent protection) is to protect the wiring so the fuse should be as close to the source (the battery) as practical. ABYC would have it within seven inches of the battery.

This ^^

Plus - leave it out, it shouldn't be necessary! It the very unlikely chance it does do something useful, you will soon discover whatever that is and it can be added at that (unlikely) time.

Hoohaa · 16-09-2021, 19:03

Quote:

Originally Posted by rwidman

That is not a noise suppression capacitor. It is far too large for that.

If anything, it's a kludge to try to compensate for a voltage drop in the boat's wiring when some appliance starts up or runs.

As for the fuse, the purpose of the fuse (overcurrent protection) is to protect the wiring so the fuse should be as close to the source (the battery) as practical. ABYC would have it within seven inches of the battery.

All my batteries are rewired and fully fused.
The fuse in the sketch is a breaker switch.
Consensus seems to be to leave it out.
So I will leave it out and see if anything changes.

Hoohaa · 16-09-2021, 19:04

Quote:

Originally Posted by Wotname

This ^^

Plus - leave it out, it shouldn't be necessary! It the very unlikely chance it does do something useful, you will soon discover whatever that is and it can be added at that (unlikely) time.

Ok. I'm going to leave it out.
Thanks

CatNewBee · 16-09-2021, 19:26

Someone sought probably it is a good idea to put a large capacitor in front of the compressor to provide the power for the startup current of the compressor. This helps with crappy thin long wiring, that may cause a voltage sag and a low battery alarm at the fridge when starting.