DC Fuse Panel Voltage

[Half Fast Hugo]

2021 LE2 with the platinum solar package purchased used earlier this year. I was tying into the DC fuse panel to install a TPMS booster and was just double checking voltage before hooking anything up and adding a fuse. Interestedly enough, there is voltage on each leg of the fuse holders. 11.75 volts on each of the unused load side and just over 13 volts on the feed side of the unused ones. Over 13 volts on all the load sides with fuses in.

I've owned and worked on campers and boats for many decades and assumed that the load leg shouldn't have any voltage whatsoever until a fuse is plugged in. However, I'm new to the solar game. I've read through the manual a few times and nothing mentioned in there and I've had no problems with the camper so far. The inverter is on and shore power is not hooked up. Might try plugging in and see what happens next.

Questions for the collective minds. Is this normal or is something possibly back feeding or causing a problem somewhere?

[topgun2]

Sounds "half fast" to me Hugo 😁.

Even though I stayed in a Holiday Inn last night I'm not an electrician nor an engineer - by any means.  However, Something seems amiss here.  

If it were me, I'd turn that inverter off (I never have it on in the first place unless I intend to need 120 volts for something).  I would not plug into shore power.

Are you able to look at the back side of that fuse panel?  Is there anything (wire) on that leg where you are getting the 11.75 volt reading?

Bill

[Half Fast Hugo]

15 minutes ago, topgun2 said:

Sounds "half fast" to me Hugo 😁.

Even though I stayed in a Holiday Inn last night I'm not an electrician nor an engineer - by any means.  However, Something seems amiss here.  

If it were me, I'd turn that inverter off (I never have it on in the first place unless I intend to need 120 volts for something).  I would not plug into shore power.

Are you able to look at the back side of that fuse panel?  Is there anything (wire) on that leg where you are getting the 11.75 volt reading?

Bill

LOL! I've kept the Half Fast name as I also have a YouTube channel to capture my mountain biking escapades.

The fused load sides with wires connected do have over 13 volts. The load sides with nothing connected have the 11.75 volts. Nothing looks amiss on the back of the panel. I've been camping with it hooked to shore power and not with no issues, so far. I'll shut down the inverter and will have to do some more investigating...

[dewdev]

I agree with Topgun2. I never have the inverter on unless I need to turn on something that need 110 V and am not connected to shore power.

Do you have a switch to disconnect the solar panels from the system?

 

[Half Fast Hugo]

17 minutes ago, dewdev said:

I agree with Topgun2. I never have the inverter on unless I need to turn on something that need 110 V and am not connected to shore power.

Do you have a switch to disconnect the solar panels from the system?

 

I do have the switch. Disconnected them and get the same thing. I'm assuming that when you say turn off the inverter you're going into standby mode, correct? I've looked at my model in the manual and the power button on the remote says that when it's off, it's in standby mode and the green light is lit which is the case with mine. Shutting off the disconnect gives it the direct battery voltage. I find it hard to believe that the fuse panel would be bad but, you never know. I'll be talking with Oliver service tomorrow and still doing some research.

We've had no issues camping with it and everything seems just fine. I just happened to put a volt meter on it when tapping into the panel and was surprised that the load side already had voltage!

[Steph and Dud B]

That doesn't make any sense... Just to be sure, because I can't see it in the photos, what jacks do you have your multimeter probes plugged into on the meter? Want to be sure this isn't a test equipment error.

[Half Fast Hugo]

10 minutes ago, Steph and Dud B said:

That doesn't make any sense... Just to be sure, because I can't see it in the photos, what jacks do you have your multimeter probes plugged into on the meter? Want to be sure this isn't a test equipment error.

Didn't make any sense to me. The test meter negative lead is connected to a jumper wire with alligator clips that goes to the negative ground block under the rear dinette seat where most of the negative wires converge. I tested a few other connections just to make sure as it seemed really strange. I even used a jumper wire to the ground block on the back of the DC fuse panel with the same result. Since that bottom terminal has voltage on both sides, I have to believe that it's a bad fuse board. There are LED lights on the fuse board that are supposed to come on if a fuse is burnt out which tells me they should have some voltage feeding them from the board. I'm thinking something is back feeding on that board as there's really nowhere else for the voltage to come from if there's no wire connected to the fuse terminal. Only other possible solution might be a really weird grounding issue somewhere which is why I tried using a jumper wire to the fuse board ground block on the back (which isn't used).

[Half Fast Hugo]

19 minutes ago, Steph and Dud B said:

That doesn't make any sense... Just to be sure, because I can't see it in the photos, what jacks do you have your multimeter probes plugged into on the meter? Want to be sure this isn't a test equipment error.

Missed that part of the question about being plugged into the meter! I'll double check and follow up.

[Steph and Dud B]

You have a Xantrex inverter, correct? On the wall panel remote for the Xantrex, when the silver button is out, the inverter function is off. There should be no LEDs lit if you're not connected to shore power. When the silver button is in, a green LED and the display on the LCD screen indicate that the inverter is functioning. 

[Steph and Dud B]

Do the fuse failure LEDs come on when you pull the fuse from a connected circuit? They look off in the photos.

[Half Fast Hugo]

13 minutes ago, Steph and Dud B said:

You have a Xantrex inverter, correct? On the wall panel remote for the Xantrex, when the silver button is out, the inverter function is off. There should be no LEDs lit if you're not connected to shore power. When the silver button is in, a green LED and the display on the LCD screen indicate that the inverter is functioning. 

Verified that the multimeter is set up correctly per the owners manual. Thought it was but figured it would be good to double check. I do have the Xantrex 3000. I'll check that in the morning but I seem to recall that I couldn't really see the button being in or out made a difference as I thought there was still a green light on either way. I'll check it out in the morning. Appreciate the input!

[Half Fast Hugo]

12 minutes ago, Steph and Dud B said:

Do the fuse failure LEDs come on when you pull the fuse from a connected circuit? They look off in the photos.

No they do not. The bottom four slots are empty and both side have voltage. When I do pull out a fuse from a connected circuit most LEDs do not come on. The ones that do have voltage around 11 or so. The couple of ones that did have the LEDs come on were around 4 volts.

[Tom and Doreen]

The LED is wired across the fuse and will light when the fuse is blown AND a load is attached to complete the circuit.  There must be a load applied and the fuse must be blown for the LED to light.  As far as reading a voltage with your meter on the load side of the fuse ( when no actual load exists ) this may cause your meter to falsely read a voltage because your digital meter is completing the circuit between the LED and ground. Because your digital meter has high impedance inputs the LED may not actually light but it is completing the circuit between the LED and ground, thereby drawing a small current,  and as such will indicate a voltage.  You can think of your meter as a very high value resistor in this application.