How do you install an ammeter - layman language

[Realdon]

Re: How do you install an ammeter - layman language

Well I think all of you need to look at the E-Bay link he posted above.

The display clearly shows 50 (Amps, I assume). The text clearly says, "Gauge has threaded stud terminals for wiring - Ground, Ignition, Sender, plus an extra threaded stud for the gauge bracket".

Sounds to me like it might use a sender. (snipped)

A couple of you almost had me convinced that it does take a shunt to install this particular ammeter so I e-mailed A & A Marine (where I purchased it) and ask if it needed a shunt or not. Although the e-bay auction clearly states that it has a sender terminal, following is the answer that I got from A & A Marine:

"Don, thanks for your e-mail. I am very sorry...I do not know myself. I would not think it would need it...but cannot say for sure. I had thought there were some instructions in the box? Also, worse case scenario, Quicksilver is a division of Mercruiser so it is possible someone in tech support at Mercruiser could get you that information using the part number. Sorry I am not any help. Dave, A & A Marine, 231-723-8308"

As you can see, they don't have a clue either but they don't think that it does need a shunt. Personally, I think that it does need a shunt because the terminal posts are quite small and simply don't look like they were meant for a wire in the 10 gauge size range which would be required without a shunt.

 

[rwidman]

Re: How do you install an ammeter - layman language

It should be quite clear by now that there is no "one" way to install an ammeter on a boat. Nor can the installation be described in "layman terms". The ammeter must be installed according to the manufacturer's instructions. If these are missing, they need to be located. If the meter requires a shunt, it's useless without it.

Once one has the installation instructions, one then has to understand the boat's wiring and what is to be measured. At that point, the installation is pretty straightforward for an experienced marine electrician.

 

[rwidman]

Re: How do you install an ammeter - layman language

The display clearly shows 50 (Amps, I assume). The text clearly says, "Gauge has threaded stud terminals for wiring - Ground, Ignition, Sender, plus an extra threaded stud for the gauge bracket".

Sounds to me like it might use a sender. (snipped)

Since an ammeter with a shunt measures the voltage drop across the shunt, there will be two wires from the shunt to the meter. Ground and ignition are not used.

An ammeter that does not use a shunt does not have an "ignition" or "ground" terminal either.

If you understand how an ammeter works to measure current, you will understand the above.

An ammeter is wired in series with the circuit to be measured.

 

[TerryMSU]

Re: How do you install an ammeter - layman language

Since an ammeter with a shunt measures the voltage drop across the shunt, there will be two wires from the shunt to the meter. Ground and ignition are not used.

An ammeter that does not use a shunt does not have an "ignition" or "ground" terminal either.

If you understand how an ammeter works to measure current, you will understand the above.

An ammeter is wired in series with the circuit to be measured.

Ron:
You are mostly correct. This one obviously does have a ground terminal and an ignition terminal. My suspicion is that the ground and ignition terminal are for lighting on the gauge. If so, they do not directly impact the "amp-meter" portion of the function. As you said, there is likely no "one way" to install an ampmeter, nor is there a generic Layman's instruction.

Sorry, Don.

By the way, none of us should feel too bad. I teach electronics and my students often screw up the installation of ampmeters. I have even screwed up one or two myself. The good news is that when we screw up in a controlled lab situation, the worst case is usually a blown fuse. If you screw up an ampmeter in a boat, it can get expensive or even seriously dangerous very quickly.

TerryMSU

 

[Realdon]

Re: How do you install an ammeter - layman language

Ron:
You are mostly correct. This one obviously does have a ground terminal and an ignition terminal. My suspicion is that the ground and ignition terminal are for lighting on the gauge. If so, they do not directly impact the "amp-meter" portion of the function. As you said, there is likely no "one way" to install an ampmeter, nor is there a generic Layman's instruction.

Sorry, Don.

SUCCESS! I definitely am not a experienced marine electrician and I did not have the manufacture's instructions but it is installed and it seems to work fine. Actually installation was quite simple once one realizes that the meter simply needs to be wired in a series with the wire that is carrying the current to be measured. There was a wire of approximately 10 gauge running from the positive terminal of the battery to the fuse buss in the console. I cut that wire at the console and hooked the "-" terminal of the meter to the battery side of the cut wire and hooked the "+" terminal of the meter to the balance of the wire which went to the fuse buss. Hooked the appropriate positive and negative to the light and bingo everything appeared to work. I have not started the engine to see a positive charge but just turning on the lights shows a discharge so one would assume that the reverse would also work.

All in all, it was just like DianneB suggested on October 10th at 5:03 PM.

Thanks Dianne,

Don

 

[bruceb58]

Re: How do you install an ammeter - layman language

All you are measuring is the current draw of anything turned on at your helm. It will tell absolutely nothing about what the charging system is doing. If that's all you wanted it to show, then you are done but its not very useful in my opinion.

 

[DianneB]

Re: How do you install an ammeter - layman language

Thanks Dianne

You are most welcome Don. Glad it all worked out the way you hoped.

 

[Silvertip]

Re: How do you install an ammeter - layman language

I go along with Bruce 100%. You will not measure any charge current going into the battery. You have a one-way path (from the battery to the loads). Charging current flows (generally) from the large post on the starter solenoid where the Positive battery cable is attached) to the battery. There are two electrical systems on a boat. The one powered by the 10 gauge wire from the battery to the helm, and the engine harness which powers engine related stuff as well as the gauges. To measure charge current that meter would need to be inserted in the engine harness (solenoid to battery). That then means the meter would not register current draw in the "boat harness." So as you can see, unless you have two meters or move the accessory loads to the engine harness you cannot install this ammeter in a way that provides any useful information although it would serve a more useful purpose in the engine harness.

 

[Bondo]

Re: How do you install an ammeter - layman language

To measure charge current that meter would need to be inserted in the engine harness (solenoid to battery).

Ayuh,.... In the olden days, when We still used Ammeters,....
Weren't they tapped into the Generator/ Alternator main wire/ lead,..??

 

[bruceb58]

Re: How do you install an ammeter - layman language

Ayuh,.... In the olden days, when We still used Ammeters,....
Weren't they tapped into the Generator/ Alternator main wire/ lead,..??

Yes they were and the console was driven off that feed. The output of the ammeter was then sent back to the battery. That way you could actually measure the current going in/out of the battery from all loads/sources except for the starter.

This was terribly inefficient and that is why nobody uses ammeters anymore because the entire current capacity of the alternator had to be taken into account when running a wire up to the ammeter.

 

[rwidman]

Re: How do you install an ammeter - layman language

It's interresting to note that boats are not typically outfitted with ammeters by the manufacturer. It might be because they serve little purpose on a boat.

 

[Silvertip]

Re: How do you install an ammeter - layman language

They could still serve a valuable purpose, just not at the helm. Like an hour meter, why not install it in the engine bay. If the VOLTMETER at the helm seems to indicate an issue, pop the cover and see what the ammeter says. A charging system can be working (indicating 13+ volts on a voltmeter), but not be delivering much current. That would be the job of the ammeter to help in the diagnosis. But since many folks don't even look at the instruments (gas gauge maybe) adding an ammeter has no benefit to the manufacturer and just one more thing for someone to complain about not working because they mucked with the wiring.

 

[rwidman]

Re: How do you install an ammeter - layman language

The average boater, just like the average motorist, has little understanding of the workings of the engine or electrical system. Auto manufacturers long ago replaced meters on cars and trucks with warning lights because people didn't look at the gauges or understand what they meant.

I don't see a use for an ammeter on a boat. If the voltage reading on the voltmeter goes up when the engine is started, the alternator is working and probably charging the battery. That and an unlimited membership to TowBoatUS is good enough for me.

Actually, I have a prety complete set of tools on my boat and know how to use them.

 

[dlngr]

Re: How do you install an ammeter - layman language

And So,, they invented the Idiot light!!!

 

[wire2]

Re: How do you install an ammeter - layman language

....
I don't see a use for an ammeter on a boat. ....

From Realdon's OP;

1.) I made a new dash and left a hole for an ammeter.
2.) I have a new ammeter.
....
....

..... I am going to install it whether it works or not just for decor.

Seems pretty straight forward to me.

 

[rwidman]

Re: How do you install an ammeter - layman language

From Realdon's OP;

1.) I made a new dash and left a hole for an ammeter.
2.) I have a new ammeter.
....
....

..... I am going to install it whether it works or not just for decor.

Seems pretty straight forward to me.

Not to me. I wouldn't cut a hole in the dash for something I don't need and doesn't work.

 

[rwidman]

Re: How do you install an ammeter - layman language

SUCCESS! I definitely am not a experienced marine electrician and I did not have the manufacture's instructions but it is installed and it seems to work fine. Actually installation was quite simple once one realizes that the meter simply needs to be wired in a series with the wire that is carrying the current to be measured. There was a wire of approximately 10 gauge running from the positive terminal of the battery to the fuse buss in the console. I cut that wire at the console and hooked the "-" terminal of the meter to the battery side of the cut wire and hooked the "+" terminal of the meter to the balance of the wire which went to the fuse buss. Hooked the appropriate positive and negative to the light and bingo everything appeared to work. I have not started the engine to see a positive charge but just turning on the lights shows a discharge so one would assume that the reverse would also work.

All in all, it was just like DianneB suggested on October 10th at 5:03 PM.

Thanks Dianne,

Don

Well, if you're happy then I'm happy. You didn't need the instructions and you're not a marine electrician but you got it to "work fine". It measures the current consumed by your lights, radio, etc. You could get that information by adding up the current draw of the different accessories and lights.

What it doesn't tell you is anything about the charging system. Is the alternator charging the batteries? It doesn't indicate this. Is there a current draw from something not powered through the dash (bilge pump. engine trim, etc.? It doesn't indicate this either.

You did what you were told and installed it in series with a circuit and it measures the current flow in that circuit as I suggested above.

It would tell you a lot more about your boat's electrical system performance if you had installed it in a different circuit.