New install in US. My shore powers voltage is 125.7 and the output is 134.1. Is this a problem? When I get to EU and switch the input jumpers what should I expect?
In marinas with chronically high shore voltage (e.g., 130–135 V in the US or >245 V in the EU), the standard boost can push output too high (e.g., your 125.7 V in → 134.1 V out, or worse under light load). Bucking brings the output closer to (or slightly below) the input, protecting sensitive equipment like MultiPlus inverters/chargers that may cut out above ~135–140 V on 120 V systems or equivalent on 230 V.How the Reconfiguration WorksThe transformer has two half-windings on the primary side and two on the secondary side. The standard boost configuration connects them in a way that gives the slight step-up. To buck:
-
Owners swap the primary winding connections with the secondary winding connections (typically four specific spade terminals).
-
One commonly reported swap for the 2000W model (and similar on 3600W) is moving the wires at these points:
-
Swap J18 J30
-
Swap J15 J27
-
Swap J16 J28
-
Swap J11 J26
-
After swapping, the terminal order (left to right) becomes something like J30 / J27 / J28 / J26 on one side and J18 / J15 / J16 / J11 on the other (exact order depends on your unit’s layout).The input and output voltage jumpers (for 230 V in / 120 V out, or whatever you choose) stay the same as before.
This is not in the official Victron manual and is a DIY modification done at your own risk. It does not void the warranty in all cases, but Victron support may not assist if issues arise after the change.