Is it OK to use solid copper wire between panels and charge controller?

[SunEagle]

Do the dies imprint UL codes on the terminals when compressed.

I didn't notice any UL codes. I understand your caution. I wouldn't use this for a grid tie system only my small portable off grid one.

I did a resistance check on all of my cables before and after I used the crimping tool. Longest cable was 18". I did not see any difference with or without the crimped lugs.

[Sunking]

I didn't notice any UL codes. I understand your caution. I wouldn't use this for a grid tie system only my small portable off grid one.

I did a resistance check on all of my cables before and after I used the crimping tool. Longest cable was 18". I did not see any difference with or without the crimped lugs.

Without a DLRO you will not be able to measure anything less than an ohm of any accuracy.

[SunEagle]

Without a DLRO you will not be able to measure anything less than an ohm of any accuracy.

I will have to check my Extech meter when I get back from traveling but I believe it is accurate to 3 decimal places. I did not record the resistance readings but I do not remember any significant increase once I added the lugs.

I am also not really worried about the resistance that much since I have over sized these cables to # 1/0 which are good for 200amps and they will be seeing a max of less than 100amp instantaneous load.

[PowerSupplyGuy]

measure low ohms like this

Most people don't have a low ohms meter or a bridge. An alternate way to get a fairly accurate measurement would be to put an amp or so through the wire and use the mv scale on the voltmeter to measure the resistance. Some bench power supplies have a current adjustment. Use that to set an amp of current in the wire and there ya go. If you use the same meter to set the current and measure the voltage then you will be reasonable accurate. If you don't have current limited supply then us a 100w light bulb on a 120v line for a current source.

[Sunking]

I will have to check my Extech meter when I get back from traveling but I believe it is accurate to 3 decimal places.

You do not understand, your meter is not capable of measuring anything less than 1 Ohm. It takes a very expensive meter called a Digital Low Resistance Ohm (DRLO) meter. It is a 4-point Bridge device that pumps either 1 or 10 amps through the UUT, (1-amp for milli-ohms, 10 amps for micro-ohms) then reads out the voltage drop. Your meter only uses a few microamps to measure resistance.

[FloridaSun]

I will have to check my Extech meter when I get back from traveling

DRLO, sometimes known as a megger. That's what the UL guys use for checking before certification.

[inetdog]

DRLO, sometimes known as a megger. That's what the UL guys use for checking before certification.

One manufacturer of Digital Low Resistance Ohmmeters (DLRO) is BiddleMegger.com, but the generic term "megger" refers to a megohm meter, used for insulation testing at high voltages and very low leakage. That is definitely not what you want for this. And I am not really sure why UL would use a DLRO.

A DLRO will be a four terminal device which uses one set of terminals to supply the test current pulse and a separate set of terminals (similar to the way a CC or a shunt have separate voltage sense terminals) to measure the resulting voltage. When using a conventional ohmmeter, a large problem is canceling out the (variable) resistance of the meter leads and contacts.

[FloridaSun]

One manufacturer of Digital Low Resistance Ohmmeters (DLRO) is BiddleMegger.com, but the generic term "megger" refers to a megohm meter, used for insulation testing at high voltages and very low leakage. That is definitely not what you want for this. And I am not really sure why UL would use a DLRO.

A DLRO will be a four terminal device which uses one set of terminals to supply the test current pulse and a separate set of terminals (similar to the way a CC or a shunt have separate voltage sense terminals) to measure the resulting voltage. When using a conventional ohmmeter, a large problem is canceling out the (variable) resistance of the meter leads and contacts.

I may be getting my terminology mixed as it's been almost ten years but when UL came out to field certify my lighting products they would check for internal resistance and high voltage shorts.
The only megger I have is an old coast guard surplus, hand crank from the 50s. I can't get over 150 volts out of it. They (UL) were using a Fluke that they called a megger, putting out 600volt to test I think. The DLRO does sound different.

[Sunking]

DRLO, sometimes known as a megger. That's what the UL guys use for checking before certification.

No sir, not the same thing. Meggar Trademark name is a high voltage ohm meter to test insulation resistance by applying a stressful high voltage to try to breakdown the insulation resistance to check for leaks. Makes for a quick day of fishing.

In addition a Meggar when used as a 3-point Dead Fall Potential is used to measure th eimpedance of earth electrode systems.

DRLO is low voltage high current. It uses a high current then measures the voltage developed. In other words a current source.

[FloridaSun]

No sir, not the same thing. Meggar Trademark name is a high voltage ohm meter to test insulation resistance by applying a stressful high voltage to try to breakdown the insulation resistance to check for leaks. Makes for a quick day of fishing.

In addition a Meggar when used as a 3-point Dead Fall Potential is used to measure th eimpedance of earth electrode systems.

DRLO is low voltage high current. It uses a high current then measures the voltage developed. In other words a current source.

Got it. Did a lil research (google) and see the difference now.
So much to learn! Thanks

[Naptown]

No sir, not the same thing. Meggar Trademark name is a high voltage ohm meter to test insulation resistance by applying a stressful high voltage to try to breakdown the insulation resistance to check for leaks. Makes for a quick day of fishing.

In addition a Meggar when used as a 3-point Dead Fall Potential is used to measure th eimpedance of earth electrode systems.

DRLO is low voltage high current. It uses a high current then measures the voltage developed. In other words a current source.

They are used extensively in the HVAC business to check for insulation break down and moisture in refrigeration systems.
Haven't used one since 1977

[Sunking]

They are used extensively in the HVAC business to check for insulation break down and moisture in refrigeration systems.
Haven't used one since 1977

Dang you ole fart, you are as old as I am or older.

[SunEagle]

You do not understand, your meter is not capable of measuring anything less than 1 Ohm. It takes a very expensive meter called a Digital Low Resistance Ohm (DRLO) meter. It is a 4-point Bridge device that pumps either 1 or 10 amps through the UUT, (1-amp for milli-ohms, 10 amps for micro-ohms) then reads out the voltage drop. Your meter only uses a few microamps to measure resistance.

I understand now. Thanks for the information.

How much is too much resistance when using a small hydraulic terminal clamp?

Do you use one of these DRLO meters after terminating lugs using the tool you first showed?

[Naptown]

Dang you ole fart, you are as old as I am or older.

57 in a couple of months
My trek in life
trade school to become an electrician
electrician for 2 years moved from helper to estimator
Electrical contractor sent me to school for HVAC.
Left there went to work for AC contractor
Tired of being laid off winters so went to college for Building construction
built a couple hundred tract homes for a builder and got tired of mud.
When mortgage rates hit the 13% mark I did some property management then did the solar thermal thing for Reynolds for a couple of years before it died out.
Switched to remodeling (cleaner and less rain days) doing mostly high end kitchens and baths. (google Clive Christian kitchens and you will see some of the type of work I did) That stuff was extremely expensive and low quality and took a lot to get it to look like in the pictures.
When things went south last time I sat around and came back to the solar business.

[Sunking]

OK I got you by one year, I just will not tell you which way? Hint I qualify for Roth next birthday.