Built A tiny home, but it has solar issues

[The_realTW]

Sorry everybody I messed up I said 9 to 10 A but the issue isn't amperage it’s wattage I guess I’m gonna have to revisit this when I can look at it more

[littleharbor]

You may have a problem with your panel wiring. You have two very different panels. How are they wired? Could you have reversed the polarity when connecting them?

[The_realTW]

You may have a problem with your panel wiring. You have two very different panels. How are they wired? Could you have reversed the polarity when connecting them?

hey there thanks for responding

to answer your question the main panel and the smaller panel run into a splitter, from what I understand it’s not possible to wire them wrong as they are “dummy proof”, that is to say you cannot plug them in wrong. Also let’s say that your right and it is a panel configuration issue, that would have been located when I ran the “single panel” test. Doesn’t matter which panel is hooked up or if it’s both, still only 9-10 watts. Honestly can anyone tell me what I “should be” receiving at the SCC?

it’s supposed to storm here tomorrow and I’ll be able to update with good photos of al the components (if the site lets me)

[littleharbor]

hey there thanks for responding

to answer your question the main panel and the smaller panel run into a splitter, from what I understand it’s not possible to wire them wrong as they are “dummy proof”, that is to say you cannot plug them in wrong. Also let’s say that your right and it is a panel configuration issue, that would have been located when I ran the “single panel” test. Doesn’t matter which panel is hooked up or if it’s both, still only 9-10 watts. Honestly can anyone tell me what I “should be” receiving at the SCC?

it’s supposed to storm here tomorrow and I’ll be able to update with good photos of al the components (if the site lets me)

I would still try to positively verify the polarity of all connections and panel outputs. Also sounds like you have two very different panels wired in parallel. Can you give us the specs of both panels?

Are all connections in your system clean and tight? Where possible check to see if all connections are warm/hot to the touch around mid day.

[The_realTW]

I would still try to positively verify the polarity of all connections and panel outputs. Also sounds like you have two very different panels wired in parallel. Can you give us the specs of both panels?

Are all connections in your system clean and tight? Where possible check to see if all connections are warm/hot to the touch around mid day.

I’m not sure how I would be able to check the main panel as it is cemented to the roof with some goo, if I could check it at the splitter side that would be easier. Is there a test I can run with my meter?

as for panel identification I suggest you read this thread a little bit more, not being condescending, however all the details have clearly been written out including links to their spec sheets, where I could identify. I again appreciate the help it I highly doubt the polarity issue as those connectors simply will not connect any other way, they physically will not go into the splitter any other way but the correct one.

also if someone could please answer try question of how many watts “should I see” on the MPPT readout, it would help greatly.

thanks everyone!

[sdold]

At mid day with full sun and flat (horizontal) orientation, I'd expect around 34V and 5A into an MPPT charge controller with discharged batteries, assuming nothing is shading any part of the panel. If I wasn't getting that, I'd do an open circuit voltage test to see if it matches the spec, and a short circuit current test of the panel with an ammeter across the panel output wiring, looking for at least 5A or more depending on panel orientation. I'd throw a blanket over the panel when connecting/disconnecting the ammeter wires to protect the MC4 contacts from arcing and pitting.

Edit: If you're doing much of this it would be useful to have a clamp-on DC-capable current meter.

[The_realTW]

At mid day with full sun and flat (horizontal) orientation, I'd expect around 34V and 5A into an MPPT charge controller with discharged batteries, assuming nothing is shading any part of the panel. If I wasn't getting that, I'd do an open circuit voltage test to see if it matches the spec, and a short circuit current test of the panel with an ammeter across the panel output wiring, looking for at least 5A or more depending on panel orientation. I'd throw a blanket over the panel when connecting/disconnecting the ammeter wires to protect the MC4 contacts from arcing and pitting.

Edit: If you're doing much of this it would be useful to have a clamp-on DC-capable current meter.

i understand some of that, I never get 34volts ever! Most is like 20, also I have a bypass fuse on the SCC that allows me to effectively put the panel to sleep , I always pull that when disconnecting MC4 plugs, that way the system is not under load.

I know the meter you refer to , it’s at home depot for like 50 bucks, a bit pricey but if you say i need it.

Also I’ll do the tests but a lil more instructions will be needed, I understand electricity and whatnot , but those exact tests are not familiar to me.

[sdold]

Also I’ll do the tests but a lil more instructions will be needed, I understand electricity and whatnot , but those exact tests are not familiar to me.

This will help: https://www.youtube.com/watch?v=eh6hzMb69gY&t=116s

I know the meter you refer to , it’s at home depot for like 50 bucks, a bit pricey but if you say i need it.

Be careful, at that price it may be AC only.

[The_realTW]

582CAD5E-D538-48BA-9093-7F0067C39E50.jpeg

This will help: https://www.youtube.com/watch?v=eh6hzMb69gY&t=116s

Be careful, at that price it may be AC only.

the video was really helpful, looks like I can measure across the MC4 leads coming from the panels , so I do not have to move them. Also as for the meters I found some on Amazon, I’m not doing this professionally so I won’t be buying the Fluke, although yes I know they make good meters!

I think one of the top two would be a nice addition to the tools I have.

I also could probably just buy one at Home Depot, I plan on doing the tests tomorrow and even Amazon is not that fast.

I’ll report back then on my results, the sun comes back tomorrow!

[The_realTW]

Would this work, I checked the specs and it claims to measure up to 400amp ac And the Manual says AC/DC measure, I know it’s incredibly cheap but sometimes it’s all you need. I’m not buying a Klein Tools from HD, those are marked up beyond belief!

https://www.harborfreight.com/digita...ter-96308.html

[SunEagle]

Would this work, I checked the specs and it claims to measure up to 400amp ac And the Manual says AC/DC measure, I know it’s incredibly cheap but sometimes it’s all you need. I’m not buying a Klein Tools from HD, those are marked up beyond belief!

https://www.harborfreight.com/digita...ter-96308.html

If you look at the details that meter is only rated for AC currents not DC.

I purchased a Uni-T UT202A meter for under $30 on amazon. It works just fine on my solar equipment.

[bcroe]

Would this work, I checked the specs and it claims to measure up to 400amp ac And the Manual says AC/DC measure, I know it’s incredibly cheap but sometimes it’s all you need. I’m not buying a Klein Tools from HD, those are marked up beyond belief!

The $15 meter in your link only clamps on for AC current measurements. For PV solar a
DC clamp on is required, a completely adequate meter might be $50. A clamp on is
immediately useful around an array, where all the wiring is sealed up against weather.
In a hurry it will show where power is flowing, and where it is not. I do not pull out a
voltmeter until I must find a weak panel in a low performance string. Bruce Roe

[The_realTW]

If you look at the details that meter is only rated for AC currents not DC.

I purchased a Uni-T UT202A meter for under $30 on amazon. It works just fine on my solar equipment.

These?

F3C781C9-700D-43D7-90B5-A243819F9E20.jpeg

[The_realTW]

The $15 meter in your link only clamps on for AC current measurements. For PV solar a
DC clamp on is required, a completely adequate meter might be $50. A clamp on is
immediately useful around an array, where all the wiring is sealed up against weather.
In a hurry it will show where power is flowing, and where it is not. I do not pull out a
voltmeter until I must find a weak panel in a low performance string. Bruce Roe

yeah I saw that, harbor freight likes to do a lot of double talk with their labeling

as for the clamp on meter I have lots of my wire runs exposed on the roof, they are weather sealed but I can get the clamp around them.

csn I also use this clamp meter to take an audit when I am ready, would be real handy for devices that give no label or way to see what their usage level is!

[bcroe]

. can I also use this clamp meter to take an audit when I am ready,
would be real handy for devices that give no label or way to see what their usage level is!

It will give you a rough idea, but will NOT account for AC power factor. For that use a
KILL-A-WATT or equivalent which compares AC voltage and current phase. Bruce Roe