Cruisers Forum
 


Join CruisersForum Today

Reply
 
Thread Tools Rate Thread Display Modes
Old 25-06-2016, 16:13   #1
Registered User

Join Date: Feb 2008
Boat: Cape Dory 330
Posts: 157
Multimeter Mystery, Solar Troubleshooting

I'm wondering if someone can explain what I'm seeing with my multimeter.

I have two multimeters, one standard and one clamp meter.

I'm trying to trouble shoot problems with my solar setup and the meters are giving me readings I don't understand.

My solar controller (Solar Boost 2512ix) is not showing any LEDs after I installed 2 new panels. So I am trouble shooting.

Both meters show me 20v coming into the + at the solar controller. So that's good (I have three panels in parallel setup)

Then for current, first I tried with the clamp meter and it showed 0 amps coming through the positive wire.

Then I set up the regular multimeter in series on the positive wire, and it showed me 4.49 amps. I put the clamp meter on the positive meter wire to verify that the clamp meter is working....



It is.

My question is what does this tell me?
Does the clamp meter showing 0 amps through the solar controller when that is wired up suggest the controller is not drawing any current/is broken.

If that's the case where does that 4.49 Amps come from/go to when the multimeter is connected, is the multimeter itself drawing that ??

I'm confused

Thanks
__________________

__________________
A good traveler has no fixed plans
and is not intent upon arriving -Lao Tse
sgtPluck is offline   Reply With Quote
Old 25-06-2016, 17:23   #2
Senior Cruiser
 
Opie91's Avatar

Join Date: Apr 2009
Location: CT
Boat: C&C 34
Posts: 810
Re: Multimeter Mystery, Solar Troubleshooting

A few questions:

What is your voltage at the output side of the controller?

Do you have some type of current protection on the output side of the controller that is now too small for the increased output?

It is highly unlikely that the multi-meter is drawing the amperage. Please explain exactly how you hooked up the meter to obtain this reading. Output side of controller, positive side of output? Be specific as possible.

Good luck
__________________

__________________
Opie91 is offline   Reply With Quote
Old 25-06-2016, 17:45   #3
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 11,440
Re: Multimeter Mystery, Solar Troubleshooting

Assumption: that you have the VOM in series between the output of the controller and the battery bank.

if this is correct, then I'd suspect that the clamp meter is defective. The 4+ amps shown by the VOM must be going into the battery, and sounds like a reasonable value for a small solar array in good sunlight or a larger one in less good light.

Jim
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is offline   Reply With Quote
Old 25-06-2016, 17:50   #4
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Multimeter Mystery, Solar Troubleshooting

A clamp on multimeter will read 0 if you clamp it over both the negative and positive wires. I suspect this may be be the problem given your conventional multimeter and your clamp on multimeter is reading 4A+ in the photo with just the positive wire used.

For the clamp on multimeter to work just the positive, or negative wire needs to pass through the jaws. Not both. If both wires are used the net current is zero.

I know in your post you said that you measured the positive wire, but my best guess as to the cause of your unusual readings was that the negative wire was also included within the jaws of the clamp on multimeter. It is an easy mistake to make.
__________________
noelex 77 is offline   Reply With Quote
Old 25-06-2016, 18:23   #5
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 11,440
Re: Multimeter Mystery, Solar Troubleshooting

Quote:
Originally Posted by noelex 77 View Post
A clamp on multimeter will read 0 if you clamp it over both the negative and positive wires. I suspect this may be be the problem given your conventional multimeter and your clamp on multimeter is reading 4A+ in the photo with just the positive wire used.

For the clamp on multimeter to work just the positive, or negative wire needs to pass through the jaws. Not both. If both wires are used the net current is zero.

I know in your post you said that you measured the positive wire, but my best guess as to the cause of your unusual readings was that the negative wire was also included within the jaws of the clamp on multimeter. It is an easy mistake to make.
Nolex, I considered that too, but the photo shows the clamp around only the red wire.

Jim
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is offline   Reply With Quote
Old 25-06-2016, 18:42   #6
Registered User

Join Date: Jun 2013
Location: canada
Posts: 1,688
Re: Multimeter Mystery, Solar Troubleshooting

Is your clamp meter in AC amps?
__________________
smac999 is offline   Reply With Quote
Old 25-06-2016, 20:02   #7
Registered User
 
zboss's Avatar

Join Date: Sep 2011
Location: On a boat
Boat: Cabo Rico 38
Posts: 3,425
Re: Multimeter Mystery, Solar Troubleshooting

Some multimeters have different internal fuses for different functions. Check to make sure both fuses are OK.
__________________
zboss is offline   Reply With Quote
Old 25-06-2016, 20:39   #8
Registered User
 
pesarsten's Avatar

Join Date: Jan 2012
Location: St Pete
Boat: Sabre 34
Posts: 461
Re: Multimeter Mystery, Solar Troubleshooting

I suspect that you do not have your clamp on amp meter set for DC amps, set it to 20 amp scale and I think you have to push the blue button for DC. Check the manual.
__________________
All that is necessary for the triumph of evil is that good men do nothing. Edmund Burke
pesarsten is offline   Reply With Quote
Old 25-06-2016, 21:09   #9
Registered User
 
Viking Sailor's Avatar

Join Date: Nov 2006
Location: San Francisco Bay
Boat: Fantasia 35 - s/v Feeling Good
Posts: 1,074
Re: Multimeter Mystery, Solar Troubleshooting

Pardon me - but when I look at the two meters I see the hardwired one display showing the number 4.49 and the clamp on meter display showing the number 4.43. I have no idea what the parameters and ranges these meters are set to display. However, these displayed values seem close enough to be displaying the same thing.
__________________
Viking Sailor is offline   Reply With Quote
Old 25-06-2016, 21:40   #10
Senior Cruiser
 
Jim Cate's Avatar

Cruisers Forum Supporter

Join Date: May 2008
Location: cruising SW Pacific
Boat: Jon Sayer 1-off 46 ft fract rig sloop strip plank in W Red Cedar
Posts: 11,440
Re: Multimeter Mystery, Solar Troubleshooting

Quote:
Originally Posted by Viking Sailor View Post
Pardon me - but when I look at the two meters I see the hardwired one display showing the number 4.49 and the clamp on meter display showing the number 4.43. I have no idea what the parameters and ranges these meters are set to display. However, these displayed values seem close enough to be displaying the same thing.
Crikeys, you're right!! I hadn't looked closely at the photo and was going on the posted info. Your observation is spot on, and the meters agree within reasonable error.

Jim
__________________
Jim and Ann s/v Insatiable II , lying Port Cygnet, Tasmania once again
Jim Cate is offline   Reply With Quote
Old 25-06-2016, 22:17   #11
Sponsoring Vendor
 
Neptune's Gear's Avatar

Community Sponsor

Join Date: Oct 2012
Location: Gulf Harbour, New Zealand
Boat: Farr Phase 4, 12.8m
Posts: 992
Re: Multimeter Mystery, Solar Troubleshooting

The Uni-T meter does not have a setting for AC or DC amps - it auto senses. They are a great meter, and likely to be more accurate than the yellow one( unless its a Fluke?) I suspect the issue was that when it was used directly on the solar cables, rather than the other MM cable as shown, it was around both cables?
__________________
Matt Paulin
Neptunes Gear Ltd
www.neptunes-gear.com
Neptune's Gear is offline   Reply With Quote
Old 26-06-2016, 08:09   #12
Registered User

Join Date: Jun 2009
Location: still in a roll of fiberglass around Cape Town
Boat: Leopard 40 (new model)
Posts: 1,201
Re: Multimeter Mystery, Solar Troubleshooting

Quote:
Originally Posted by Neptune's Gear View Post
The Uni-T meter does not have a setting for AC or DC amps - it auto senses. They are a great meter, and likely to be more accurate than the yellow one( unless its a Fluke?) I suspect the issue was that when it was used directly on the solar cables, rather than the other MM cable as shown, it was around both cables?
The manual I have for that meter says that you have to choose between AC and DC for clamp current measurements

Sent from my SM-G9287 using Cruisers Sailing Forum mobile app
__________________
svlamorocha is offline   Reply With Quote
Old 26-06-2016, 08:53   #13
Moderator
 
noelex 77's Avatar

Cruisers Forum Supporter

Join Date: Jul 2007
Location: Living on dirt waiting for our new yacht to be built.
Boat: Half built Bestevaer.
Posts: 10,618
Re: Multimeter Mystery, Solar Troubleshooting

Quote:
Originally Posted by Jim Cate View Post
Crikeys, you're right!! I hadn't looked closely at the photo and was going on the posted info. Your observation is spot on, and the meters agree within reasonable error.

Jim
Yes the photo shows the clamp on meter working correctly when attached to the multimeter wire. The mystery is why it reads zero when attached arround the solar panel "+" wire.

My guess is that the solar panel wire is not a + but both + and - conductor bundled together in which case zero current is the right answer for a clamp on meter. It is easy to ignore the negative wire especially when it's referred to as "ground" but it conducts the same current as the positive wire.
__________________
noelex 77 is offline   Reply With Quote
Old 26-06-2016, 12:25   #14
Registered User

Join Date: Nov 2015
Posts: 19
Images: 1
Re: Multimeter Mystery, Solar Troubleshooting

Quote:
Originally Posted by sgtPluck View Post
I'm wondering if someone can explain what I'm seeing with my multimeter.


Thanks
Conditions changed while you were manipulating your meters which took probably 2-3 minutes.
Controller changed its mind and decided to draw/output current(you probably had to disconnect input /output to get your VOM connected and inadvertently reset it) or clamp meter was not set up correctly or some other connections were not good. Put things back together and try again.
__________________
facciatosta is offline   Reply With Quote
Old 26-06-2016, 15:56   #15
Registered User

Join Date: Jun 2013
Location: canada
Posts: 1,688
Re: Multimeter Mystery, Solar Troubleshooting

Quote:
Originally Posted by noelex 77 View Post
Yes the photo shows the clamp on meter working correctly when attached to the multimeter wire. The mystery is why it reads zero when attached arround the solar panel "+" wire.

My guess is that the solar panel wire is not a + but both + and - conductor bundled together in which case zero current is the right answer for a clamp on meter. It is easy to ignore the negative wire especially when it's referred to as "ground" but it conducts the same current as the positive wire.
well does it have one wire or 2 coming off the panel?... if there is only one wire then they are together. every panel I've seen has 2. with mc4 connectors.
__________________

__________________
smac999 is offline   Reply With Quote
Reply

Tags
solar

Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Solar Multimeter Testing RolfP Electrical: Batteries, Generators & Solar 50 12-02-2016 17:47
Blue Sea Systems Multimeter tardog Product or Service Reviews & Evaluations 4 11-04-2009 18:19
digital multimeter Khamles Electrical: Batteries, Generators & Solar 36 03-12-2008 07:10
How do I test charging with only a Multimeter? MarkJ Electrical: Batteries, Generators & Solar 73 18-09-2008 17:11
in market for multimeter jimbim Electrical: Batteries, Generators & Solar 23 06-01-2007 10:11



Copyright 2002- Social Knowledge, LLC All Rights Reserved.

All times are GMT -7. The time now is 03:35.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2017, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.