Can I add a Class T fuse to a Victron Lynx M8 busbar system?

Answered by RV Parts Giant · Upland, CA · October 8, 2026

Short answer: Not by bolting on Victron's module. The Lynx Class-T Power In is made only with M10 busbar joints, and Victron says M10 modules cannot connect directly to M8 ones. Either build the Lynx line on M10, or put the Class T fuse in its own holder on the battery cable and land that cable on the end of the M8 line.

Why it does not just bolt on

Lynx modules join side by side through their busbar joints, and those joints come in two sizes, M8 and M10. Victron's Lynx manuals are plain about it: M10 modules cannot be connected directly to M8 modules, and vice versa. The Lynx Class-T Power In (Victron part LYN060404010) is only made in M10. So if your line is built from M8 modules, there is no Class-T module that slots into it.

One thing that confuses people when they check their own parts: on the Lynx Distributor, "M8" or "M10" describes only the busbar joints. Its fuse and cable studs are M8 on both versions. Look at the joint between two modules, not the cable studs, to see which system you have.

Option 1: move the Lynx line to M10

If the system is still on the bench, this is the tidy fix. The Class-T Power In then bolts on like any other module and becomes the place your battery cables land. What it takes:

Two Class-T fuses, one per battery or battery string, in 225, 250, 300, 350 or 400 A. They are bought separately; Victron does not supply them, and we do not stock standalone Class T fuses either.
Up to 800 A through one module (two 400 A fuses). The whole Lynx line is rated 1000 A, so the fuses on all modules together must not exceed that. For three or more battery strings, add a second Class-T Power In.
M10 cable lugs, up to 120 mm² or 4/0 AWG.

We stock the Lynx Power In and the Lynx Distributor in M10, and the Lynx DC Distribution Pack is built on M10.

Option 2: keep the M8 line

Fit the Class T fuse in a separate holder on the battery positive, close to the battery, and run that cable to the first or last connection on your M8 Lynx line. Victron allows batteries to land directly on the end connections of a Lynx line, while noting that extra fusing may be needed when you do. A Class T fuse on that cable is that extra fusing. With more than one battery string, each string gets its own fuse.

Fitting details from the Class-T manual

The fuse nuts are 3/8-inch and marked black. Do not swap them with the M10 nuts on the cable and busbar studs, or you damage the threads. Units with a serial number starting HQ use M10 fuse screws instead, and those are not marked.
Class T fuse flanges are not always straight. If one does not sit flat on the busbar, turn the fuse 180° along its length.
Torque cable and fuse connections to 33 Nm. If the cables heat up, a loose connection is the first thing Victron says to check.
Joints between M8 modules are torqued to 14 Nm, M10 to 33 Nm.