How to configure a Multi RS Solar to accept a wider AC IN frequency range?

So this one's been rattling around my head since I sorted out a similar headache on the boat last winter.

We've got a micro-hydro feed coming into the system — nothing as beefy as a 6kW turbine, but enough to cause grief — and the Multi RS Solar was throwing fits about AC IN frequency whenever the turbine load shifted. The inverter just wasn't happy accepting anything that drifted outside its default window, which on a real-world hydro or generator source happens constantly.

The fix lives buried in VEConfig (or via the Victron Remote Management portal if you're doing it remotely). There's an AC Input frequency range setting that defaults to something quite narrow — I widened mine to accept 45–65Hz and the ghosting/disconnects basically stopped overnight.

Worth noting:

• You'll need the VE.Bus Smart Dongle or an MK3-USB interface to access VEConfig properly
• Changes need to be made with AC disconnected first, or it can be a bit temperamental
• If you're running Pylontech batteries alongside this (which it sounds like you are), double-check the DVCC settings haven't been knocked out of whack after saving

For EV charging off a turbine-fed system, frequency stability is genuinely critical — my EVSE plays up long before the Multi RS even blinks.

Anyone else running hydro or a non-standard generator into a Multi RS? Curious whether people have had luck with the UPS function enabled or disabled in these setups — I've gone back and forth on it and still not sure I've landed on the right config.

@Deano micro-hydro is such an underrated source — dead jealous, genuinely.

On the Multi RS Solar specifically, you'll want to dig into VEConfigure (or VictronConnect if you're on the newer firmware). There's an AC Input tab where you can widen the acceptable frequency window — default is something like 47–53Hz, but you can stretch it depending on your grid code settings.

The catch is your country code selection locks certain parameters. If you're set to Other rather than a specific grid profile, you get much more flexibility.

Worth noting — micro-hydro frequency can wander a bit under variable load, so I'd also look at the weak AC input setting. Stops the inverter getting twitchy when the turbine hunts around a bit.

What's your turbine controller outputting — is it doing its own frequency regulation or are you seeing drift?

Had a similar puzzle when I was setting up emergency backup on the boat — the generator I was using had variable frequency under load and it was causing all sorts of grief with the Victron kit.

Worth checking in VictronConnect under the inverter/charger settings — there's a frequency acceptance range you can widen. If that's not giving you enough headroom, VEConfigure (via a MK3-USB adapter) gives you much finer control over the AC input parameters, including min/max frequency thresholds.

One thing that caught me out: widening the range too much can affect how the unit qualifies the AC source as "acceptable," so you might see unexpected transfer switching behaviour.

Has @Deano confirmed what frequency variance the micro-hydro is actually producing? That'd help narrow down whether this needs a software tweak or whether there's a deeper conditioning issue upstream.

Right, so picking up where @Taffy's reply presumably got cut off —

The key thing people miss with the Multi RS Solar is that frequency tolerance isn't buried in the inverter settings directly. You're actually adjusting it through VEConfigure under the AC Input tab, where you'll find the acceptable frequency range fields. Default sits at 45–65 Hz, which should accommodate most micro-hydro wobble, but you can nudge those bounds.

The gotcha I hit on my motorhome setup was that UPS mode interacts oddly with frequency variance — the transfer relay gets twitchy if frequency drifts, even within your declared tolerance. Worth disabling it if your hydro output isn't rock-solid.

Also worth noting: the Multi RS Solar's frequency settings are separate from anything you configure in the MPPT side, so don't confuse the two when you're deep in VEConfigure at midnight questioning your life choices.

@PanelLouise is right that it's easy to miss, but worth adding — in VEConfigure (or via VictronConnect if you're on firmware that supports it), there's a UPS function toggle that interacts with the AC acceptance window. If you've got that enabled, it tightens the frequency tolerance significantly because it's prioritising fast transfer over flexibility.

For micro-hydro specifically, where frequency can wobble a bit under load changes, disabling UPS function and widening the AC low/high frequency limits manually is usually the move. I run mine accepting 45–55Hz for a similar reason — shepherd's hut setup, not hydro, but a temperamental genny with the same drift issue.

Just double-check your grid code settings aren't overriding your custom values — some regional codes lock the window.

Done this exact dance with a temperamental micro-hydro feed in my motorhome setup — the magic checkbox everyone skips is "Accept wide input frequency range" in VEConfigure under the AC Input tab, which opens her up to roughly 45–65Hz instead of the default tight band.

Worth noting: once you tick that, also check your UPS function setting, because the two don't always play nicely together and you'll get phantom transfer switching that'll drive you absolutely mental at 2am.

@WattCharlie's VictronConnect route works fine but VEConfigure gives you the fuller picture on the frequency thresholds — don't neglect the minimum and maximum frequency fields just below that checkbox, dial them to match your actual turbine's real-world variance with a bit of headroom either side.