Where to find a 100amp ammeter

[Dougal]

I fitted an 85amp alternator to my P4.108 and now need a better ammeter.

It was not a top quality peice of kit, so actually appears to top out at more like 70amps. Still, that's too much for the standard 60amp meter.

An 80amp ammeter would do, but i don't there is one.

So, if anyone knows where to obtain this, please let me know.

 

[VicS]

The Vetus one is avilable calibrated for 100amps using an external shunt for starters.
http://viewer.zmags.com/showmag.php?mid=hggds#/page78/

also from Index marine. http://www.marineelectrics.co.uk/pages/instruments.htm

Must be many more. How about VDO?

 

[whipper_snapper]

Has anyone tried these ammeter/voltmeters ?



They look interesting and much cheaper than comparably specced marine products. I wondered about using one for mounting on a switch board, the present 'shuntless' meter on the board is a real weak point that I want to avoid.

 

[TradewindSailor]

You really should use a shunt when measuring high currents.

The meters shown here appear to be the ones that you connect in series (or in-line) with your alternator and battery. If it goes open-circuit you will probably blow your alternator too.

The marinised meters are worth the money ..... and I would also go for one that calculates amp hours too, like the Link 20 or similar units.

Spend the money and look after your batteries.

 

[whipper_snapper]

No, this uses a shunt, that is the point. I have a BM-1 for monitoring the batteries, this would be an extra to put on the switch board to allow me to see V and domestic current draw without going up to the cockpit.

 

[vyv_cox]

Just bought one but yet to install it. The manufacturer seems to know what he is talking about and builds each unit to order, then tests it for 24 hours. As you say, a very reasonable price compared with many others.

It was recommended to me by an owner I met in Greece. He was very pleased with his.

 

[KRG]

Yes I have, I fitted one on the boat and I use one for general monitoring of battery charging in my garage. They work well and the service is excellent with very helpful follow-up if required.

They supply 50 and 100 amp shunts but will match the meter to any shunts you want if you ask them to.

 

[William_H]

OK the trap with the digital panel meters is that they require 200mv to reach full scale ie max reading.(unless the DPM is very unusual and has aDC amplifier to operate on less voltage) So if you have a 20 amp shunt and you actually draw 20 amps then 200mv will be dropped in the shunt. That is .2 volt which can be significant. ie it is comparable with the volt drop of cables to a mast head light.
If you order with a 200amp shunt then you would only lose 20millivolts (.02 volt) at 20 amps which is a lot more acceptable but you lose some of the accuracy and pecision. ie one l;ess decimal point of reading.

A moving coil analogue meter will not need a power supply and will operate on a lot less voltage drop.Try RS or Maplins.You often can open the meter and remove the shunt to a remote location if you need.
olewill

 

[KRG]

Yes, i take your point; to be fair he explained this in detail to me when I enquired about different shunts.

I have a 100 amp shunt which gives accurate enough readings down to .1 amp without too much loss for the money.

 

[whipper_snapper]

Thanks all. Just ordered one with a 100A shunt. I got an instant and informative response to a email on a Sunday evening, which is quite impressive!