Blowing Controller Output Breaker on Midnite Solar XW-E Panel

[Halfcrazy]

The XW inverter has a percentage setting. I thought the XW charge controller had a numerical setting up to 60 amps?

I guess I need to back up and ask questions?
Is the breaker in question between a XW charge controller and the battery?
When you swapped the tripping breaker for another breaker did the new breaker trip?
You are not using this breaker on the Inverter in any way are you?

[Emerald Power]

Hey Ryan,

I see you know your stuff. The XW controller does display amps, but I am using the optional remote system monitor which displays percentage of capacity. In this case that's 60 amps.

The breaker in question is between the XW controller and the battery.

I have tried 3 brand new  MNEPV63 breakers on this problem. The all get warm and trip. BTW, I understand the polarity of these type of breakers and the + side, or bottom connection is connected to the battery buss bar. The - side or top of the breaker is connected to the output of the controller. This is the way that the instructions stated to connect the "most positive" side to the battery.

I am not using this breaker for any purpose other than what is intended, that is, protection between the output of the XW controller and the + battery buss bar on the MS XW E-Panel.

[zoneblue]

I have tried 3 brand new  MNEPV63 breakers on this problem. The all get warm and trip.

Thus, your problem lies elsewhere!

[Halfcrazy]

Also the % adjustment is for the inverter. I need to go plug my XW charge controller in but it has a number you set. The XW inverter has a % you set. It is a 100 amp charger and 60% of that is 60 amps but that's from the inverter not the charge controller. 2 separate items

If you have tried 3 different breakers than the issue is 99% for sure what I told you. The charge controller for some reason is not showing the current correctly and the breaker is to small. So I would
A- change to an 80 amp breaker simply because the 63 is to small mathematically
B- get a clamp on DC amp meter and verify the amperage
C- call Schneider after A and B are done and ask them why the amperage is reading half or so

[Emerald Power]

Hey Ryan,

The XW system remote display can control the functions of the XW controller or the inverter. When the controller is selected, the percent value on the remote mimics the actual amp value on the controller's LCD screen. If you change one, the other will follow suit.

A.  Can I use the two 63 amp breakers I have and build a parallel type breaker as the MNEPV80 is, or would that be overkill for my #4 wire.

B. DC Clamp on meter is ordered and will be here Monday.

C.Have already been in touch with Schneider/Xantrex and a tech fellow as reviewed all my info but has yet to come up with a solution. He has also suggested I buy the clamp on DC meter to verify the output before he can send out a replacement unit.

[Vic]

Emerald Power,

Personally,  would avoid paralleling two of the 63 A breakers.  As I read the tables,   #4 AWG cable has an Ampacity of about 85 Amps (at 75 F).   So,   this cable might be stressed in the event of a catastrophic event.

And,  I know nothing about just how the breakers are selected when CBI makes breakers that are paralleled for double Ampacity,  but,  perhaps they are selected for very close curves ...   dunno.

Just my $0.0001,   FWIW,     Vic

[Halfcrazy]

Yes #4 in free space is good for over 100 amps but the pair of 63 amp breakers wold land you a 126 amp breaker. This is more than I would recommend. Schneider recommends an 80 amp breaker.

[Emerald Power]

Hey Guys,

Thanks for the input. I have ordered the 80 amp breaker and will let you how it goes.

[Emerald Power]

Hey Ryan and others,

Today my new clamp on DC ammeter arrived and I checked the output from the XW controller to the battery buss bar. It reported 53.1 amps on the new meter and the XW's display reported 32.3. Wow, over 20 amps more being delivered that what it says! This accounts for the ability to blow the MNEPV63 breaker way more easily than one might think. So Xantrex will replace my controller under warranty.
Now on to the breaker. I have the manual current limiter  the XW controller set so the breaker is not blowing, but it is getting fairly warm to the touch. The infrared thermometer says 118 degs. Anymore than this and it will trip. So that would be around 54 amps when the MNEPV63 trips. Midnite Solar says all of their breakers are rated for full labeled amps continious duty, as opposed to thermal breakers that  must be de-rated by 20%, so I should be able to put 60 amps through this. I have tried 3 new breakers, and they all trip around 54 amps. I am now thinking that Midnite Solar lies about their breaker ratings. Am I missing something here?
I have ordered  a new MNEPV80, but this ordeal has cost me some bucks that could have been avoided.

EP

[Halfcrazy]

Well I can say we do not LIE about our breakers and I am so positive about that I am willing to personally pay shipping both ways and get those 3 back to test myself.

My real suspicion is the Clamp on is not spot on as well. Does it show absolute 0 before installing it? Then try this take the wire and loop it around and run it through the meter 2 times and see what it measures. Some DC clamp meters are not extremely accurate.

I would be more worried about the fact the XW is reading so Wrong.

Ryan

[Emerald Power]

Hey Ryan,

I appologise for being so blunt. I didn't realize you were part of the company. I am just frustrated that I keep spending money for something that seems so simple.
I just tried your suggestion and made a loop of #4 wire and ran 2 wires through the inductive pick up of the meter and this just doubled the amp reading. At the moment it was reading 49 amps on a single wire and it doubled to 98 with the additional loop. The meter I bought has a zero function button, so it was at zero before the test.

I would be happy for you to test 2 of my MNEPV63 breakers after I install the new 80 amp model. I need to keep one because that is the PV input to the XW controller and it is working fine.

Kind Regards,

EP      Tom

[Emerald Power]

Hey Ryan,

My new meter is a Craftsman model 82369. While reading through the owners manual and specs, it states the accuracy is +or- 2.5% while reading 0 to 300 ADC. At 50 amps this is only about 1.25 amps if it is at the far end of the inaccuracy range. My MNEPV63's are tripping at 54 ADC as read on the meter, so I kind of doubt the meter is that far off. Just trying to get to the bottom of things. Your help and suggestions are greatly appreciated.

Kind Regards,     EP   

[zoneblue]

I have ordered  a new MNEPV80, but this ordeal has cost me some bucks that could have been avoided.

It would have been avoided if you designed and specced the breaker correctly in the first place!
Still lesson learnt, good old clampmeter is an essential part of your kit. Keep it handy.

[zoneblue]

BTW clampmeters are funny things. Try this:
positive lead, one way, then facing the other way.
negative lead, ditto.

Four diff readings, yippee. To get the best reading (at least according to my ones manual)
- measure on the positve lead, with the positive side of the meter should facing bat pos. wire positioned at the mark point, as far from other wires and magnetic objects. delta 0 just before you start  each reading.

And using it right near a water pump or other motor will give you real whacky results!

[Vic]

Emerald,

And,  with these inexpensive DC Clamp meters,   zero is quite the moving target.  Zero the meter,  and note if it is really zero.   Then,  open the jaws and close them ...   is it still zero?

Also,  they are sensitive to radiated noise,  and to external fields,  as zoneblue mentioned.

Regarding breakers that you mentioned,   have you looked at any ambient temperature de-rating?  These are NOT Thermal breakers,  but  there still may be a de-rate for ambient temp.   BTW,  what IS the ambient temp in the area where the breakers are operating?

Will look for curves for these breakers ...   But as also mentioned the 80 A breaker really IS called for.

EDIT,  and since you appear to have a IR Thermometer,   have you measured the temperature of each of the Lugs on this breaker?  The thermometer may not have a small enough spot size to really see the connection screw,  or the contact foot (shoe?).

In looking at the breaker spec,  the temperature noted,  was 30 C,   FWIW
Vic