ampmeter installation

[Harmony]

Hi boaters

Need a bit of help please. I have 2 alternators on my boat each with a charging (ignition) lamp to show "charging. I am in the process of fitting an updated control panel and I have seen some digital ampmeters on ebay able to handel the current output from each alternator. The gauges have 4 connections 1) battery +ve 2) battery - ve (that bit is easy) but 3 and 4 I have no idea. I presume 1 will go to the alternator and the other to the earth side. Anyone please know where etc.

 

thank folks Ivor

[Ex- Member]

Hi boaters

Need a bit of help please. I have 2 alternators on my boat each with a charging (ignition) lamp to show "charging. I am in the process of fitting an updated control panel and I have seen some digital ampmeters on ebay able to handel the current output from each alternator. The gauges have 4 connections 1) battery +ve 2) battery - ve (that bit is easy) but 3 and 4 I have no idea. I presume 1 will go to the alternator and the other to the earth side. Anyone please know where etc.

 

thank folks Ivor

 

Posting the actual item might help members!

[Harmony]

 

Posting the actual item might help members!

so very sorry but, I dont know how to (could be an age thing)

[Ex- Member]

so very sorry but, I dont know how to (could be an age thing)

 

LOL just type make and model, members will find it.

[Harmony]

3 1/2 Blue LCD Digital AMP Panel Meter AC 50A + Shunt

This is the link http://www.ebay.co.uk/itm/390221397131?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649

 

Thanks Julynian for you help

[bottle]

This is a generalisation:

 

If 1 and 2 are marked positive and negative then they are the 'supply' for the meter, be aware some meters cannot be supplied by the same battery that they are reading the amps of.

 

The other two terminals are the actual shunt connections and will go the shunt (500 amp)

 

The shunt should go in the negative cable as close to the batteries as possible

 

edit: just seen your link, go to that page and scroll down there is a wiring diagram.

Edited September 28, 2013 by bottle

[Ex- Member]

I have one of these, they work from a shunt 2 connectrions are each end of the shunt poz & neg the other 2 connections are power supply to the unit poz & neg.

 

I don't believe you wire thes type units to alternators. I'm no leccy though.

[nicknorman]

Hi boaters

Need a bit of help please. I have 2 alternators on my boat each with a charging (ignition) lamp to show "charging. I am in the process of fitting an updated control panel and I have seen some digital ampmeters on ebay able to handel the current output from each alternator. The gauges have 4 connections 1) battery +ve 2) battery - ve (that bit is easy) but 3 and 4 I have no idea. I presume 1 will go to the alternator and the other to the earth side. Anyone please know where etc.

 

thank folks Ivor

No, 3 and 4 go to the shunt, which is inserted in the circuit whose current you want to measure, normally the -ve line.

 

You mention wanting to measure the alternators' current. If you measure the alternator current it just shows what the alternator is producing. This is fine for the starter battery, but for the domestic one it means you only see what is being generated. You don't see what is being consumed by the boat services. Therefore, for the domestic system, its best to connect the shunt to the domestic battery -ve line so that you are measuring all current in and out of the battery, not just what the alternator is producing.

[Harmony]

Thank you all so very much. 1 last point please. By placing the shunt in the battery cable does this have any effect on the charge or output of battery power ? and could I take the power to the ammeter (to work it not the shunt) from the accesory side of the key switch so that when I turn the ignition off the ammeter is turned off. Thanks again

[bottle]

Thank you all so very much. 1 last point please. By placing the shunt in the battery cable does this have any effect on the charge or output of battery power ? NO

 

and could I take the power to the ammeter (to work it not the shunt) from the accesory side of the key switch Yes, do not take supply from shunt in fact that is not possible because both ends of the shunt are negative (if in the negative cable)

 

so that when I turn the ignition off the ammeter is turned off. Good idea but then you will only be able to read it when 'ignition' is on, better ti find a permanent supply and switch it, do not forget to fuse it.

 

Thanks again Your welcome

Edited September 28, 2013 by bottle

[smileypete]

Thank you all so very much. 1 last point please. By placing the shunt in the battery cable does this have any effect on the charge or output of battery power ? and could I take the power to the ammeter (to work it not the shunt) from the accesory side of the key switch so that when I turn the ignition off the ammeter is turned off. Thanks again

 

As bottle says some of these shunt ammeters can only be run from a completely separate ('isolated') supply, if it doesn't seem to work OK try a separate batt or a little isolated DC to DC converter:

 

http://www.ebay.co.uk/itm/High-Quality-Isolated-Power-Module-w-4pins-DC-DC-Converter-In-10-16V-Out-12V-1W-/290968206740?pt=UK_BOI_Electrical_Components_Supplies_ET

 

Or just buy one that says it can run from the same supply being measured, here's an example of one:

 

http://www.ebay.co.uk/itm/DC-100A-Red-LED-Amp-Current-Meter-Ammeter-With-Shunt-No-Need-Isolated-Power-/200907636081?pt=LH_DefaultDomain_0

 

Of course don't forget a low fuse in the batt end of the positive supply wire, to protect the wiring to the meter.

 

cheers, Pete.

~smpt~

Edited September 28, 2013 by smileypete