360Views17Replies

Author Options:

Not getting an amp reading from panel? Answered

I am a newbie, I built a panel and I am able to get the voltage but I am not able to get a reading for amps.  Any help will be greatly appreciated.

Natalie

17 Replies

user
NachoMahma (author)2010-02-26

.  Do NOT place an ammeter across a power source! The meter is, for all intents and purposes, a dead short and you will be putting whatever the max current of your supply is through the meter. Place the ammeter in series with a load that will limit the current to below the max allowable for the meter.
.  You say you haven't blown the fuse, but I'm betting you've either done that or fried the ammeter section of your meter electronics (if you have a DMM).

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)NachoMahma2010-02-27

I wonder if that's in a Guide ? To us, its second nature, and I forget it isn't

Steve

Select as Best AnswerUndo Best Answer

user
Re-design (author)NachoMahma2010-02-26

Sounds like you have ruined a few meters also.

Select as Best AnswerUndo Best Answer

user
NachoMahma (author)Re-design2010-02-26

.  ROFLMAO  Yeah. More than one.
.  Bent the needle on a few analog meters, too. ;)

Select as Best AnswerUndo Best Answer

user
frollard (author)2010-02-26

Silly suggestion:  I effed this up the first few times - Are the probes on the multimeter plugged into the voltage slot? 

You often have to move them to a different set of holes (common ground) marked with (A) or (I) next to them

Mine are Ground, V+, 2A, 20A.  You need the red lead in the appropriate A socket.

Select as Best AnswerUndo Best Answer

user
frollard (author)frollard2010-02-26

Other ridiculously silly suggestion (but its an option) - are you testing with the ammeter in SERIES with the load (batteries, charge controller, etc)?  Measure voltage in parallel, but amperage needs to flow through the meter.

Select as Best AnswerUndo Best Answer

user
kelseymh (author)2010-02-26

You might want to edit your title and text to be more clear that you mean a "solar panel" (i.e., photovoltaic cell).  "Panel" in electronics can also mean a meter mounted on a metal panel in a rack.

You need to provide more information on what you are actually doing, in order for someone to help you.  Are you using a multimeter?  If so, where are you connected the red and black leads?  What are you setting the meter to read when you try to look at the current?  What voltage are you (successfully) reading?

Select as Best AnswerUndo Best Answer

user
Kumachun (author)kelseymh2010-02-26

Sorry,  Yes it's a multimeter. I put the red to the positive and the black to the neg. of the panel.  the voltage it reading 20.45.   The setting is 200m in the amp area the the meter.

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)Kumachun2010-02-26

200mA ? Check the fuses.

Select as Best AnswerUndo Best Answer

user
Kumachun (author)steveastrouk2010-02-26

The fuse is fine but I will try to do as kelseymh said and set it to the max range and turn it down step by step.   I will try this in the morning.  But just in case I still am not able to get a reading any other suggestions.

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)Kumachun2010-02-26

Put a known load on the panel, and measure the voltage across the load.

What is the power rating of the panel ? What current would you expect, in best conditions.

Steve

Select as Best AnswerUndo Best Answer

user
Kumachun (author)steveastrouk2010-02-26

Like I said I am a newbie, me and my son built it. We have 36 cells of 3x6 in one panel.  He did get a voltage reading of 20.45 on a good day just no amp reading no matter how many times he tried. When we got it when we tested the cells seperate though.

Nat

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)Kumachun2010-02-26

I reckon/guess that'll deliver well over an amp in full sun.

Select as Best AnswerUndo Best Answer

user
Kumachun (author)steveastrouk2010-02-26

I will try everything you suggested. 


Thanks, Steve

Wish me luck

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)Kumachun2010-02-26

Luck ? No, I wish you success !
;-)
...and good luck.

Steve

Select as Best AnswerUndo Best Answer

user
kelseymh (author)Kumachun2010-02-26

I think Steve is probably right.  Check the internal fuses on the meter.

When using an ammeter, you need to check what amperage you expect with the maximum reading the meter can handle.  Then you should set the meter to maximum range, and turn it down step by step until you get enough precision for your needs.

Select as Best AnswerUndo Best Answer

user
steveastrouk (author)2010-02-26

How many Volts/ amps is the panel rated for ? 
If you put the meter, on amps straight across a panel that can deliver >10A, its odds-on you've blown the meter fuses.

Select as Best AnswerUndo Best Answer