MPPT 100-20 electric shock

Why am I getting an electric shock from the heatsink?
Thanks.

Because you didn’t connect a grounding cable - apparently :wink:

And this might help too.

Is there any reason one mppt does it and the other identical unit doesn’t? I was always under the impression that when the case of an electrical appliance goes live, it’s because of a fault.

Lot of devices have a tiny error current all the time. In case of the mppt, I’m not even sure, if that may also originate from the panels.

That’s probably something victron staff has to answer.

It could also be completly static charge building up, with no functional impact or risk at all. (Once you touch it, and touch again a second later, still getting another shock?)

grounding wouldn’t eliminate the failure current, or static charge, but it will avoid getting (eventually dangerous) shocks, when touching the device.

Yes, if I hold the device it gives a continuous shock or tingle, it’s definitely not a static type shock.

What is the PV voltage, as it might be that voltage you are feeling when you touched the MPPT.

Can you check that the PV negative is not connected to ground or the MPPT heatsrink and not shorting anywhere (just one strand of wire at the PV input would be enough)

I would also disconnect the PV + & - for safety reasons.

Using a multimeter you can then check if there is voltage still on the heatsrink .

If ok reconnect and recheck, and let us know what you find.

Hello Dave,

The voltage is around 80v, 2 x 500w panels.

There is definitely no stray wires.

I will test tomorrow if the tingle is still there with the panels disconnected.

Cheers,

Marc.

Hello Dave,

I think I must first explain my system.

I have three 5kw server rack batteries.

A multiplus II 48/5000.

Two MPPT 100/20.

And 2kw of panels.

So I did what you suggested and disconnected the panels but the MPPT is still live, so is the usb lead coming from the VE direct connection in the MPPT.

The other MPPT however, has no issues.

Cheers,

Marc

so is the usb lead coming from the VE direct connection in the MPPT.

That’s unlikely but try disconnecting and see if the voltage is still there.

So now you just have it connected to the batteries correct? And the voltage is present?

Can post a picture of this MPPT please just so i can see the environment it’s in and how connected/mounted, it might help.

Look forward to your response.

Yes, it’s only connected to the batteries. No solar.

Marc

Thank you. In the pic you has the pv wire’s connected please disconnect them even if the pv are not connected.

Ok your going to need to measure some voltages now.

With the batteries connected to the MPPT what’s the voltage on the heatsrink? (PV disconnected)

Now carefully measure the voltage on the + - from the battery.

Report back your findings.

It appears you are using some home grown ve direct cable and are not grounding the device.
Please try a proper official victron cable and following the grounding guidance in the manual.
https://www.victronenergy.com/media/pg/Manual_SmartSolar_MPPT_75-10_up_to_100-20/en/installation.html#UUID-9081d1b1-04dd-86ad-98dc-64bdc006a7ce

Hello Dave,

I unplugged both the leads in the photo as you asked and knocked the MPPT with my hand, it’s no longer live so unfortunately I can’t take a reading.

The batteries are at 53v

There must be something touching inside the MPPT.

Marc.

Ok.

Please make sure you follow all instalation instructions, is the MPPT grounded? (if not do it now as its not clear in your picture) and as suggested by Nick i would replace the VE.Direct cable with an official victron cable.

When grounded (if not already) and with a new VE.Direct cable fitted reconnect everything and monitor, please reported back in due course.

Hi Dave,

The VE lead has nothing to do with it as I only made and installed them this morning.

No the MPPT is not grounded but this is surely not the problem as the earth would only protect against a fault, which I appear to have.

I may just send this unit back, it’s only two months old.

I appreciate your time, I’ll keep you updated if anything changes.

Cheers,

Marc.