Remember the old type charge / discharge ammeters, where used a couple of turns of cable which used to sometime be fitted to vehicles ? I have one fitted to the tractor mower which is not marked + and - and I'm sure it reads the wrong way. The needle goes left when on charge, I seem to remember the norm is to move to the right.
Can anyone remember, before I take steps to correct it?
My Lard Roller ammeter is marked - to the left, + to the right, as have all the others I've used. Has your tractor mower been converted from +ve to -ve earth at some point?
No, it is not that old - I suspect the coil windings (2 turns) were simply fitted the wrong way and it has bothered me since I got it.
Is it fitted upside down?
Bill
I think you're right, but you can have it how you like
Fleming?s Left Hand Rule
Oh wait, maybe it's the right hand rule
hth ;-)
The usual orientation for a charge/discharge ammeter is with the quiescent needle pointer resting at 12 O'clock (needle pivot at 6 O'clock); the negative (-) discharge sector to the left (anticlockwise) and the positive (+) charging sector to the right (clockwise).
Some ammeters (like yours) rather unhelpfully are not marked + and -. However, they are usually colour-coded (blue or green sector for charging; red sector for discharging), or annotated 'Charge' and 'Discharge' or simply 'C' and 'D'. Doesn't your ammeter have any of these legends or markings?
There are some versions of these ammeters designed to be mounted the other way up, with the quiescent needle pointer resting at 6 O'clock. If your ammeter is actually mounted upside-down (as has already been suggested), then the needle would appear to read the wrong way. However, there must be some lettering on your ammeter ('Amps' or 'A', or the manufacturer's name) that would be inverted if the ammeter has been mounted the wrong way up.
When you say, "The needle goes left when on charge...", is that when charging from an external battery charger, or when charging from an engine mounted alternator? If the latter, then your alternator could be faulty and not generating enough output to meet demand.
Check the wiring diagram (if you have one!) to see where in the circuit the ammeter has been located. Also check the ammeter connections to see if it has been connected reverse polarity.
No, someone had wound it the wrong way when the tractor was built :-?
It uses a couple of turns of the main wire feed, wrapped around a metal bracket at the back of the meter and the wire had a sticky label on it showing the direction of flow.
I have rewound it so it reads charge with needle moving to the right.
This one has the pivot at the bottom and points to 12. There are no markings apart from 30 amp at either end and a 15amp marker. It kicks left slightly (or did) when the starter solenoid engaged, then with the engine running, would show around 5amps. No marks to indicate which side was which at all.
No, when the engine is running it went to the left - which seemed wrong to me.
Its in series with everything, apart from the starter main feed - just the ignition circuit the interlocks and alternator really. The lights rather oddly, are run from a separate output of the alternator.
Does it matter? As long as *you* know which way is charging.
Arfa Daily was thinking very hard :
Sorry - now kicks to the left as the solenoid is engaged. Previously it kicked to the right.
if you don't like the way it goes just reverse the wires
HomeOwnersHub website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.