Faulty AC Disconnect? You guys ever seen that happen?

[HX_Guy]

Trying to trace why the inverter and meter are not getting power and it seems the problem is the AC Disconnect, though I can't for the life figure how this would go bad.

The top wires are coming from the main panel and I get a reading of 241v on the top two terminals. With the disconnect in the ON position, the bottom either reads 0V or fluctuates all over the places from 0...10...43...7. Seems all the disconnect should do is snap the bars into place when it's turned to the ON position, and the bars do snap in and visually look like they are making good contact.

Anyone ever run into this before?

[Amy@altE]

Have you tried taking the power off and measuring across the switch with an ohm meter to see if it is making the connection?

[HX_Guy]

Have you tried taking the power off and measuring across the switch with an ohm meter to see if it is making the connection?

I'll give that a try, thanks.

[SunEagle]

I'll give that a try, thanks.

Make sure the wires from both you solar inverter and the main panel are not energized when you take your resistance reading.

[control4userguy]

That test may or may not be appropriate. I see two connections already that could be faulty. Are the conductors torqued properly at the lugs? Are the blades making contact and not through oxidation. That disconnect is not of higher-quality...

[sensij]

That test may or may not be appropriate. I see two connections already that could be faulty. Are the conductors torqued properly at the lugs? Are the blades making contact and not through oxidation. That disconnect is not of higher-quality...

This disconnect is what was called out on the permit drawing, and while not industrial quality, it ought to be fine for this. The appearance in the posted picture matches the appearance in the catalog.

I agree that the connections do not look very good, and the grease on the blade is also worth questioning. Did it come already on the disconnect, or was it added by your installer?

[HX_Guy]

Thank you guys for the OHM test suggestion...IT'S ALIVE!!

I wasn't getting any continuity across the left side with the disconnect on. Took a close look at the top clamp was too spread apart, took a screwdriver and bent it a little and boom, continuity restored! Everything is up and running and making POWER!

[HX_Guy]

This disconnect is what was called out on the permit drawing, and while not industrial quality, it ought to be fine for this. The appearance in the posted picture matches the appearance in the catalog.

I agree that the connections do not look very good, and the grease on the blade is also worth questioning. Did it come already on the disconnect, or was it added by your installer?

The disconnect came with that grease.

[control4userguy]

Thank you guys for the OHM test suggestion...IT'S ALIVE!!

I wasn't getting any continuity across the left side with the disconnect on. Took a close look at the top clamp was too spread apart, took a screwdriver and bent it a little and boom, continuity restored! Everything is up and running and making POWER!

I see what you mean now that you mentioned it. Nice job troubleshooting.

[inetdog]

I see what you mean now that you mentioned it. Nice job troubleshooting.

By clamp are you talking about a wire termination or the contacts that mate with the blades of the knife switch disconnect?
If the switch contacts got spread apart, I would at least look carefully to make sure that when I bent them back the flat or curved contact surfaces are aligned just like the others and that the spring tension holding the contacts against the blades is close to that of the other line connection.

[SunEagle]

By clamp are you talking about a wire termination or the contacts that mate with the blades of the knife switch disconnect?
If the switch contacts got spread apart, I would at least look carefully to make sure that when I bent them back the flat or curved contact surfaces are aligned just like the others and that the spring tension holding the contacts against the blades is close to that of the other line connection.

Good idea. Chances are there is now more resistance on that left set of contacts.

If it was my installation I would just replace the switch with a new one. I would hate to see that whole system go up in smoke.

[HX_Guy]

By clamp are you talking about a wire termination or the contacts that mate with the blades of the knife switch disconnect?
If the switch contacts got spread apart, I would at least look carefully to make sure that when I bent them back the flat or curved contact surfaces are aligned just like the others and that the spring tension holding the contacts against the blades is close to that of the other line connection.

Correct, the contact that made with the blades. The upper left contact was spread too far apart and the blade wasn't making good contact when it was switched on.

So just visually check it to make sure it looks the same as the others?

[Mike90250]

Those spring blades that make the contacts, are deadly. The metal is good for 1 bend only, bend it again and it's on it's way to crack or fail. Get it on line as is, but order a replacement. When the contact is bad, it heats up and starts to oxidize and get hotter - but your PV will disconnect first and stop a fire, but it's not doing yourself any favors keeping it around.

[HX_Guy]

Those spring blades that make the contacts, are deadly. The metal is good for 1 bend only, bend it again and it's on it's way to crack or fail. Get it on line as is, but order a replacement. When the contact is bad, it heats up and starts to oxidize and get hotter - but your PV will disconnect first and stop a fire, but it's not doing yourself any favors keeping it around.

I figure it should have some sort of warranty? I'll get a hold of the manufacturer.

[Mb190e]

Those spring blades that make the contacts, are deadly. The metal is good for 1 bend only, bend it again and it's on it's way to crack or fail. Get it on line as is, but order a replacement. When the contact is bad, it heats up and starts to oxidize and get hotter - but your PV will disconnect first and stop a fire, but it's not doing yourself any favors keeping it around.

How does the AC disconnect "disconnect" if there's an issue without any fuses? Here's a picture of my AC disconnect.