Ammeter connection

[bridor15]

I have a 1973 Tradewind with a univolt converter that had served its time. I replaced it with a new intellipower converter. Everything works fine with the exception of the ammeter and battery condition indicator. I have a fused black and a fused red wire that I think went to the ammeter in the control panel. The black wire was hooked to the negative battery post and the red wire to a positive battery connection on the univolt. There is no shunt that I can see on the univolt. Does anyone have an idea how the connection should be made? Is there an internal shunt somewhere in the control panel?

[barts]

There was almost certainly a shunt in the univolt; it looked like a piece of steel w/ two terminals at either end. The negative side of the battery connected to one end, the ground lines to the other.

- Bart

[boatdoc]

Originally Posted by bridor15

I have a 1973 Tradewind with a univolt converter that had served its time. I replaced it with a new intellipower converter. Everything works fine with the exception of the ammeter and battery condition indicator. I have a fused black and a fused red wire that I think went to the ammeter in the control panel. The black wire was hooked to the negative battery post and the red wire to a positive battery connection on the univolt. There is no shunt that I can see on the univolt. Does anyone have an idea how the connection should be made? Is there an internal shunt somewhere in the control panel?

Hi bridor15;
Ampmeter must be hooked in line into positive wire only. If the meter indicates opposite, [charge-discharge] swap location of wires on back of the ampmeter. Do not hook up the ampmeter between pos and neg terminals, you may blow the meter by direct short. Thanks, "boatdoc"

[azflycaster]

It is on the 12 volt distribution panel which looks like this on my 75 TW.

[bridor15]

Thanks for your help but I am still confused. As you can see from the pictures there is no shunt in the univolt at the front or rear of the panel. I know that the black fused wire was connected to the negative battery wire coming from the battery adjacent to the negative battery fuse. I think that the red fused wire was connected to the negative post on the univolt. Does this make any sense? Can I test the circuit with my multimeter?

[TG Twinkie]

In order for the ammeter to function properly it must be connected to a shunt. Which is in fact a resistor with a large current carrying capacity. The shunt and ammeter are a matched set. The ammeter is really a voltmeter that reads the voltage drop across the shunt to determine the current flowing in the circuit.
In order for the ammeter to function properly, the shunt must be wired into the circuit in series. If you are reading battery charging current with the ammeter it must be wired in such a way that the lead from the positive terminal of the battery connects to one end of the shunt and the other end of the shunt is connected to the univolt.
Where does the red wire in the center picture go?
Where did the red wire in the top picture go?
Where did the black wire in the top picture go?
Is that a white wire on the lower left of the center picture?
It looks like the white wire? on the back connects to the black wire on the front and the red wire on the back connects to the red button looking device on the upper right in the top picture. Is this correct?
Did you remove this unit? If so where did the 2 small wires go on the terminal (lower right) and the 1 wire go that is on the terminal marked 50 amp battery?
Can you trace the wires from the ammeter? Maybe the shunt is mounted somewhere else.
Is there any way you can show us a photo of the back of the control panel if that is where the ammeter is mounted?
If the fused red and black wires you mentioned went to the control panel, maybe the shunt is mounted there.

[TG Twinkie]

It would make sense to me that the ammeter would only be in the house battery circuit and not in the TV charge line circuit.
Since I don't know the relative position of the control panel to the battery or the univolt this will only be a guess.
Perhaps the cable that comes off of the battery positive terminal goes to the control panel and connects to the shunt: then from the other end of the shunt a cable connects to the univolt. It would only be a #10 wire maybe #8 at the most.
Is the ammeter a center zero type? Meaning it will read in both positive and negative values. Giving you the charge and discharge current readings of the house battery. Reading charge when you are connected to shore power if the battery requires a charge. Thusly reading a negative charge when you are off the grid and using the battery.

[pgr32e]

Aren't electrics fun???? Your low voltage distribution panel should look like the one in azflycaster's post. The ammeter shunt is the copper coloured plate at the bottom of the panel, which looks to be missing from yours. The white wire on the right is the negative load and the black wire on the left goes to the negative side of the battery. The red and black wires at the center ( with the fuse holders), go to the ammeter. So, two possibles. Your shunt has been removed if PO installed replacement converter in the past, or it is installed elsewhere. I kind of lean towards the first because the the shunt needs to be between the neg load/converter and the battery. I can scan a couple of my 74 manual pages if you need more.............all the best...Phil.

[boatdoc]

Originally Posted by bridor15

I have a 1973 Tradewind with a univolt converter that had served its time. I replaced it with a new intellipower converter. Everything works fine with the exception of the ammeter and battery condition indicator. I have a fused black and a fused red wire that I think went to the ammeter in the control panel. The black wire was hooked to the negative battery post and the red wire to a positive battery connection on the univolt. There is no shunt that I can see on the univolt. Does anyone have an idea how the connection should be made? Is there an internal shunt somewhere in the control panel?

Hi bridor15;
Sorry for the confusion so let me try again. Amp meter in simple words; It is a meter which reads VOLUME of current flow [number of electrons flowing in a wire which is measured in Ampere units when any circuit is activated. Most function based on electrical flux field in a wire and will read charge or discharge pending the hook up polarity. In a DC circuit amp meter reads the volume differential between amps used, vs the number of amps supplied by the charger back into the battery circuit. If your rate of charge is higher than the rate of amperage you are using it will show the difference in number of amps on positive side as charge. When the demand for amps exceeds the number supplied by the charger, it will read Negative or discharge. Delivery of amperage [volume] is depended on type and size of the wire, much like the diameter of pipe supplying water. The larger the pipe the bigger volume of water it can pass through.

Voltmeter; Is a unit measure of pressure. In case of 12 VDC circuit, that pressure is preset at about 12-13.5 Volts. Since the volume is required to build up pressure within a storage container [battery], there cannot be pressure [voltage] without volume. Pending the size of storage container [battery], it will determine how much volume [amps] you can store within that pressure. Volume under preset level [not pressurized to 13.5 Volts] will be indicated by Volt meter as low battery voltage. If that pressure in a container [battery] is exceeded, the Volt meter will indicate high voltage at at some point the battery may burst under pressure. This is why the pressure [voltage] must be regulated.

Much the same applies to Amperage in reference to the size of the wire.
If the demand for amperage [volume] under specific pressure [voltage] exceeds the capability of the wire to pass high volume of flow, it will create resistance which heats up the wire until it [bursts] melts the wire.

Since you are installing the Intellipower substitute the Amp meter with Voltmeter. Unlike the Amp meter, the Voltmeter is a much better instrument to monitor the condition of the battery. In case of a dual battery set up use two voltmeters wired via individual switches separately to each battery. If one battery is going down [not holding charge] you can disconnect it before it drags down the working battery. Remember this no Volts no Amperage. If the Voltage drops below 12.5 Volts, Huston, you have a problem, Thanks, "Boatdoc"