
Jean Müller KETO-1 NH1 Fuse Switch-Disconnector 250A 440V DC 2-Pole for Batteries
The KETO-1 is the next size up in fuse switch-disconnectors, the one you reach for when a storage system’s DC current outgrows the KETO-00. It sits between the battery bank and the inverter: the handle opens the circuit safely for maintenance or an emergency, while the NH fuse links inside protect against short circuit and overload.
This version is two-pole (Jean Müller code T100112002, designation KETO-1-2/F): two poles, exactly what DC asks for, one on the positive and one on the negative. The NH1 links are not included and should be chosen on the battery’s real charge and discharge current with a safety margin: the range runs from 35A to 250A, which is the body’s rated current.
Jean Müller rates it at 690V AC and, on DC, 250V per pole, reaching 440V DC with the poles in series. Terminals are M10 flat, with an R150 box clamp for 35mm² to 150mm² or a P1 prism for 10mm² to 150mm² in aluminium or copper as alternatives. Width is 184mm, system size 300mm, and mounting is on a baseplate, on DIN rail with the retrofit kit, or on 60mm and 100mm busbar systems. The range is moving from blue to black. Installation is a job for a qualified electrician.
Key strengths
Technical specifications
| Feature | Value |
|---|---|
| Product code | KETO-1 |
| Jean Müller article no. | T100112002 |
| Catalogue designation | KETO-1-2/F, 2-pole with flat terminal (Jean Müller data) |
| Manufacturer | Jean Müller |
| Type | NH fuse switch-disconnector, body without fuse links |
| Fuse size accepted | NH1 |
| Rated current | 250A |
| Rated AC voltage | 690V (Jean Müller data) |
| Rated DC voltage | 250V DC per pole, up to 440V DC with poles in series (Jean Müller data) |
| Number of poles | 2, one for the positive and one for the negative |
| Fuse links required | 2, ordered separately, 35A to 250A |
| Terminals | M10 flat terminal; alternatively R150 box clamp 35mm² to 150mm², or P1 prism 10mm² to 150mm² Al/Cu (Jean Müller data) |
| Width | 184mm (Jean Müller data) |
| System size | 300mm (Jean Müller data) |
| Mounting | baseplate, DIN rail with the retrofit kit, or 60mm and 100mm busbar systems (Jean Müller data) |
| Degree of protection | IP20 at the front with the device fitted (Jean Müller data) |
| Impulse withstand voltage | 8kV (Jean Müller data) |
| Conditional short-circuit current | 120kA at 500V, 100kA at 690V (Jean Müller data) |
| Operating temperature | -25°C to +70°C (Jean Müller data) |
| Standards | DIN EN 60947-3; NH fuse links to DIN VDE 0636-2 |
| Colour | moving from blue to black: both versions may ship during the changeover |
| Weight | 1.8kg |
| Pack length | 0.34m |