Lost amp meters

[J.T kearney]

Hi All
I lost my amp meters on both ac and dc sides at my main panel!!.
My boat is a 1998 350 and has 25 years on it. I pulled the panel off the wall and notice a ring or band around the cabling going to the meter. this band has a lot off black electrical tape wrapped around it. Where to start on diagnoses? I have yet to find a shunt on this boat!!!.
Any suggestions will be appreciated.
J.T

 

[tiltrider1]

In order for a shunt to be affective it would be between the battery bank negative post and all other negative wire connections.

In the old days DC Amps were measured by running the full power through the meter rather than measuring the differences on a shunt. These meters would burn out frequently.

Now we measure AC amps by measure field changes around the wire. In the old days we ran the full power through the meter, again the reason why they burned out frequently.

 

[J.T kearney]

Lost amp meter

Hi.
So your thinking my meters are toast? Is there a simple test to check? My ability to operate a meter still eludes me.
Thanks J.T.

 

[tiltrider1]

Posting a picture of the meters both front and back would give a better indication of what you are working with. Until we know which style you are working with it’s hard to give you a diagnostic procedure.

 

[J.T kearney]

Tiltrider
I'm about 4 hours away from our boat in central Wa. To have them both die at the same time is odd but not impossible. I'll try to get some pics before Christmas. My fuel gauges went about the same time!!!!
Thanks J.T.

 

[Mainship Pilot]

Tiltrider
I'm about 4 hours away from our boat in central Wa. To have them both die at the same time is odd but not impossible. I'll try to get some pics before Christmas. My fuel gauges went about the same time!!!!
Thanks J.T.

Sounds to me one of three things.....a ground problem, probably on your Neg Buss Bar, a connection problem that could be as simple as loose wire or connection, or corrosion, assuming a salt water environment. This is the simple stuff that should always be gone thru first. Check for continuity from the buss bar to your faulty meters to see if there is a connection problem with your multimeter.

 

[porman]

ammeter

In order for a shunt to be affective it would be between the battery bank negative post and all other negative wire connections.

Hi Tiltrider. I'm thinking of replacing my old analog ammeters with Blue Sea Systems mini oled meters. The installation instructions have the shunt on the positive side, which would work out better for me. Do you see any problems wiring them that way?

 

[tiltrider1]

In order for a shunt to be affective it would be between the battery bank negative post and all other negative wire connections.

Hi Tiltrider. I'm thinking of replacing my old analog ammeters with Blue Sea Systems mini oled meters. The installation instructions have the shunt on the positive side, which would work out better for me. Do you see any problems wiring them that way?

If that’s the manufacturer’s instructions I would do it their way.

 

[J.T kearney]

hi
I'll figure out the testing in a few weeks. I'm interested in digital meters as long as they fit in the panel!!
Cheers J.T.

 

[High Wire]

Hi All
I lost my amp meters on both ac and dc sides at my main panel!!.
My boat is a 1998 350 and has 25 years on it. I pulled the panel off the wall and notice a ring or band around the cabling going to the meter. this band has a lot off black electrical tape wrapped around it. Where to start on diagnoses? I have yet to find a shunt on this boat!!!.
Any suggestions will be appreciated.
J.T

That ring or band as you call it is the current sensor. Its leads should connect directly to the meters. The wires will probably be very small gauge, usually twisted, and could have been easily damaged. No shunt needed for those panel meters.

 

[88FuHwa]

Dear High Wire - to follow up on his question, the 'band' that he referring to is a current transformer (CT) isn't it? That is also called a donut by some electricians. Some are split so that one does not need to disconnect the cable.
It turns out the amp meter on my boat is not even connected so I wonder if installing a CT on one of the battery cables would energize the amp meter so that it will function? If so, where would I get such a CT for the DC system? Thank you.

 

[Circumnavigator]

Note to all -- when working on current transformers be very careful to be sure that the power is off before you connect or disconnect them. Either action can produce a very high voltage spike that will probably ruin the meter.


88FuHwa -- as noted above, some ammeters run all the current through them while others use a current transformer. Installing a CT will work only with the latter. Also note that CTs are for AC systems. DC ammeters typically use a shunt -- a very precise very low resistance which is installed in series, usually, but not always, in the negative battery lead. The meter measures the voltage across the shunt, but is calibrated in amps because it knows the resistance of the shunt and uses I=V/R to calculate Amps.


Jim.

 

[J.T kearney]

Hi
So in theory I can put my amp meter contacts on both connections at the meter on the panel and find out if it's the meter at the panel or the band around the power cable
Thanks all J.T.

 

[88FuHwa]

I went through the boat document file that the PO had left. The original wiring diagrams were provided by the ship builder Fu Hwa Boating Company LTD of Taiwan. It shows the am meter connection to a shunt. The shunt is missing but is shown in the diagram with the positive to the daisy-wired positives on the panel at 12 VDC and the negative to the common on the battery switch. That seems to be consistent with earlier posts. My research indicates that I need get a shunt rated for the 50 mV 200 Amp meter which I have selected as a Blue Sea Systems p/n 9230. Can any of you experts confirm my choice before I order? thank you much.

 

[Comodave]

I went through the boat document file that the PO had left. The original wiring diagrams were provided by the ship builder Fu Hwa Boating Company LTD of Taiwan. It shows the am meter connection to a shunt. The shunt is missing but is shown in the diagram with the positive to the daisy-wired positives on the panel at 12 VDC and the negative to the common on the battery switch. That seems to be consistent with earlier posts. My research indicates that I need get a shunt rated for the 50 mV 200 Amp meter which I have selected as a Blue Sea Systems p/n 9230. Can any of you experts confirm my choice before I order? thank you much.

I would call Blue Seas and ask them.

 

[Bmarler]

I went through the boat document file that the PO had left. The original wiring diagrams were provided by the ship builder Fu Hwa Boating Company LTD of Taiwan. It shows the am meter connection to a shunt. The shunt is missing but is shown in the diagram with the positive to the daisy-wired positives on the panel at 12 VDC and the negative to the common on the battery switch. That seems to be consistent with earlier posts. My research indicates that I need get a shunt rated for the 50 mV 200 Amp meter which I have selected as a Blue Sea Systems p/n 9230. Can any of you experts confirm my choice before I order? thank you much.

I looked up that part number and it says it’s a 100 amp shunt rated for 66% continuous. You’ve got a 200 amp meter, what’s your average and maximum draw?