Ammeter installation MC 7

[Tenor]

Has anyone installed an ammeter in an MCI 7?  How about an MCI 8?  I have the scematic, but it only shows power entering the unit on one contact.  The light is grounded through the case, but the ammeter shouldn't be.  It's like they only printed half of the diagram.  My 24V 60A ammeter has a positive and a negative terminal.  Thanks!

Glenn

[luvrbus]

The only amp gauges I have installed are hot on both sides one from the battery the other from the alternator   good luck

[Len Silva]

I doubt that your 60 amp meter is direct reading, that would take a very large cable in and out.  More likely you have an ammeter shunt close to the battery and smaller leads running to the meter.  In this case, the meter must be matched to the shunt and the lead length from the shunt to the meter must be part of the calculations.

[Tenor]

Len,
The manual doesn't show anything about a shunt.  It just shows a particular terminal in the front junction box ( 26 ) running to one side of the ammeter.  I know that there is a major battery line running to the front juction box that can be pulled from to give a good battery reading to the ammeter.  Would that eliminate the need for a shunt?  If that works, then it's the other side of the ammeter that I wonder about. 

Glenn

[Len Silva]

Glenn,

I'm not familiar with your bus but I don't think you are looking at a true ammeter.  More likely a voltmeter or a charge/no charge indicator.

An ammeter must be connected in series with the measured load and must carry the full load current, thus the heavy cables.  The use of a shunt allows you to remote the ammeter using smaller wires.

You are correct that an ammeter requires two connections and no connection to ground (except for the light).

[Hartley]

High current reading ammeters all require a shunt module to be inserted into the main batter cable. Then usually 2 wires go to the actual meter.

Look for military surplus shunts that would be in the 1,000 amp range and get a meter with the right .ua ( MicroAmp) input. Like 0-10 ua or 0-100 ua.

Dave...

[Tenor]

Thanks guys.  It really sounds like I should just let this go, and use a voltmeter instead!  I have a spare 12V one that I just tapped into my vanner 12V output.  I can just double that and see what is happening to the house batteries.  I'll keep my eyes out for a 24V voltmeter.  Thanks again!

Glenn

[belfert]

If you're monitoring house batteries you should consider the Trimetric battery monitor that gives you all kinds of info on your batteries.  This reminds me I should buy one before this year's big trip.  The Trimetric will help you to not overdischarge your house batteries.

[Tenor]

It really wasn't meant for the house batteries.  The ammeter would have kept me aware of how the new alternator was doing, since the original 50DN is now junk.  While traveling down the road with the house tied into the bus system, I'll be able to see if there is any voltage drop.  Not ideal, but somewhat useful.  The gauge plugs a hole in the bracket.    I do plan to get a nice monitoring system eventually for the house batts and a remote panel for my Xantrex 4024.  Thanks!

Glenn

[poppi]

Totally out of the box and of course beyond my capabilities but there are those here who could.....

  Why couldn't someone take and use a hall effects transducer and with a little circuit design create
a amp meter set up. Or probably some other high tech method. That way the only wires run are
from the taping point.


  Just a thought

 Skip

[larryh]

Go to any CAT tractor dealership most of the equipt have a 24 volt  voltmeter in them may be a bit smaller diameter than the one in your bus but get a underdash mount and cut off the mounting lip and two small screws and mount the whole thing on your dash I did that on my 4905 Bufalo

total cost abt 60 dollars and quality equipt.

LarryH

[ol713]

Hi;
    Never mind a amp meter,  I put a volt meter on my MC-7.  It
    will tell you if the alt.  is charging and will also tell you where
    the battery volts are.  If , when you turn on the master switch,
    the volts show less than 24vdc, the engine probably will not 
    start.    Works for me.
                                    Good luck
                                              Merle.