Multi meter for boat?

sly_karma

sly_karma

Crew Member
About time I moved up to a decent quality multi meter and I'm looking for recommendations. Main purpose is working on boat and outboard electrical systems and telephone cable testing at the ski hill (signal cable for timing ski races).

Features I want are:
* auto power off
* auto ranging
* DC milli amp (looking for current leaks)
* frequency/duty cycle

Anyone have one they can recommend? Post pros/cons or in service review if possible. Thanks in advance.
 
Fluke 87 excellent meter, but if you want to check for current leaks the meter has to be configured in a series circuit which means you have to take wiring apart and run it through the meter , a really good option is a amp probe where you can just clamp meter around wire and look for current flow and also can be used a volt meter
 
Is the clamp meter sensitive enough to pick up milliamp draws?

Someone had a good idea about pulling the negative lead from the battery and putting the meter between the lead and the post, when all circuits are open, then close one at a time to see if there is any action on the meter.

This is likely my spring project, so I am very interested in this discussion.
 
Gong Show said:
Is the clamp meter sensitive enough to pick up milliamp draws?

Someone had a good idea about pulling the negative lead from the battery and putting the meter between the lead and the post, when all circuits are open, then close one at a time to see if there is any action on the meter.

This is likely my spring project, so I am very interested in this discussion.
Click to expand...
I looked for milliamp DC clamp too. Rare bird and pricey as a result.
 
Here is an article that speaks to measuring parasitic current drains:

www.hagerty.com

How to Use a Multimeter, Part 4: Measuring Current (amperage) - Hagerty Media

First, we discussed how to use a multimeter for measuring voltage, or simply verifying that voltage is present. Last week, we addressed measuring resistance—verifying that a wire is continuous and not broken somewhere. Today we’re discussing how to use a meter to measure current, also referred...
www.hagerty.com www.hagerty.com

It goes into what levels of current are "normal"/acceptable.

You would then need to find a meter that was this sensitive.

From Fluke:
Most digital multimeters can only measure dc or ac current up to 10 A. Higher current must be scaled down with a current clamp accessory, which can measure current in a circuit from .01 A to 1000 A by measuring the strength of the electric field around a conductor.


So smallest value readable from above using a clamp would be 10mA.
 
Gong Show said:
Is the clamp meter sensitive enough to pick up milliamp draws?

Someone had a good idea about pulling the negative lead from the battery and putting the meter between the lead and the post, when all circuits are open, then close one at a time to see if there is any action on the meter.

This is likely my spring project, so I am very interested in this discussion.
Click to expand...

I have one at work for checking for loop current....4-20mA on field instruments. I can’t remember the exact Fluke model but will check next week when I’m back. It works well and clamping on is nice since you don’t need to break the loop.
 
Thanks everyone. Especially liked the article posted by @ericl. I couldn't find anything with a clamp that measured DC mA at sufficient accuracy for under $250 so I'm resigned to using a non-clamp. The electrical wholesaler where I occasionally deal put me into this unit from Greenlees for $80.


greenlee-dm-45-catiii-600v-auto-ranging-digital-multimeter.jpg
 
volt meter works best to find leakage but you need a very long neg meter lead. if you have positive going to ground you will have current flow, areas to check , bilge pumps , bow and stern lights, battery isolators, battery box, metal super structure your radar sits on. IF SALT can get to the positive it will probably track to ground.
 
Gong Show said:
Looks nice.
Rated for DC Micro-Amp200µ A
I have no idea if that is good enough for looking for leaky current in a boat.
Click to expand...
From what I have read while research this, 30mA is fine - at 200uA you are over 10x more sensitive.
I think the non-clamp method (remove neg battery lead & connect meter is series) will be fine for determining whether or not there is a leakage/parasitic drain issue, but then you must find out exactly where that is within the whole circuit that consists of all your devices. For a problem caused by a corroded terminal (the resistance of the corrosion will cause current to flow AND a voltage drop) looking for voltage drops by measuring voltage with the meter leads on both sides of the terminal in question will be easier; if there is current flowing with device truly powered-down, then there is also a voltage drop.
 
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I believe I found the current leakage. A memory struck me and I took a look at the documentation that came with the Blue Seas ACR I installed 5-6 years back. Its schematic shows an optional toggle switch that can be installed to prevent battery drain during storage. I found a switch in my parts bin and wired it in. Before I installed the switch, I was measuring 11 mA drain with the main power shut off. With the switch in place and open, drain is down to 9 uA. I can live with that, a thousandth of what it was.

May not have needed the new meter but it does confirm the switch works. I've no doubt it will be useful over the years to come between marine work and the timing cables I work with. Thanks to all who provided input.
 
sly_karma said:
I believe I found the current leakage. A memory struck me and I took a look at the documentation that came with the Blue Seas ACR I installed 5-6 years back. Its schematic shows an optional toggle switch that can be installed to prevent battery drain during storage. I found a switch in my parts bin and wired it in. Before I installed the switch, I was measuring 11 mA drain with the main power shut off. With the switch in place and open, drain is down to 9 uA. I can live with that, a thousandth of what it was.

May not have needed the new meter but it does confirm the switch works. I've no doubt it will be useful over the years to come between marine work and the timing cables I work with. Thanks to all who provided input.
Click to expand...
I have same issue . Wire in switch to negative post when not in use
 
ReelSlim said:
I have one at work for checking for loop current....4-20mA on field instruments. I can’t remember the exact Fluke model but will check next week when I’m back. It works well and clamping on is nice since you don’t need to break the loop.
Click to expand...
 

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