High current protection

philippi High-Current Protection – Circuit Breakers, Bolt Fuses & Fuse Holders for Boats, Yachts & Vehicles

Supply lines to the switchboard, anchor winch, and bow thruster, where immediate readiness for operation without time-consuming fuse replacement is crucial, are protected by hydraulic-magnetic or thermal-magnetic circuit breakers. These combine a main switch with a main fuse and are mounted as close to the batteries as possible.

Philippi offers a complete range for high-current protection – from resettable circuit breakers to bolt fuses and strip fuse holders – compliant with DIN EN ISO 13297, for currents from 25 A to 600 A.

Briefly explained: High-current circuit breakers replace the combination of a separate battery main switch and high-current fuse with a single compact device – no fuse replacement, fewer connection points, immediate re-commissioning after troubleshooting.

Why use high-current circuit breakers instead of separate main switches and fuses?

The use of circuit breakers compared to main switches with separate fuses offers the following advantages: Space-saving installation, as only one component is needed. Easier and faster installation, as there is no additional cable connection between the switch and the fuse. No fuse replacement when the circuit fails. The cost of the circuit breaker (8345 series) is insignificantly higher than for main switches and high-current fuses combined.

All philippi high-current protection products at a glance

Series 8345 – Hydraulic-magnetic circuit breaker (40–160 A)

Single-pole hydraulic-magnetic circuit breaker with toggle lever operation. Reliable switching behavior and trip-free operation. Front mounting. Device width 19 mm. DC 80 V, AC 240 V. M6 threaded bolt connection.

Special feature of hydraulic-magnetic tripping: In contrast to thermal-magnetic circuit breakers, hydraulic-magnetic tripping reacts precisely and independently of ambient temperature – a crucial advantage in engine rooms and other temperature-critical areas on board.

Mounting panels for front panel mounting of the 8345 series up to 125 A and for the 160 A version are available as accessories (panel dimensions 160 A: W 80 × H 120 × D 2.5 mm).

TCB – High-current circuit breaker with manual operation (25–100 A / 48 V DC)

High-current circuit breaker 25–100 A with thermal protection and manual operation for surface mounting, DC 48 V, M6 connection bolts, protection class IP 67.

Not suitable for protecting starter motors. Thanks to IP 67, also suitable for damp and splash-prone installation locations.

Bolt Fuse SHB (MRBF) – Compact Solution for Main Line Protection

SHB bolt fuse for M8 bolts, rated voltage DC 58 V. SHB bolt fuses (MRBF - Marine Rated Bolt Fuses) allow for particularly space-saving protection directly at the battery terminal or in the immediate vicinity of the battery.

Mounting is either directly at the battery terminal (for one or two circuits on battery terminals with 10 mm screw diameter) or, if three fuses are to be installed, near the positive pole (max. 40 cm distance according to standard) using the triple holders.

Available nominal values: 30 A, 40 A, 50 A, 75 A, 80 A, 100 A, 125 A, 150 A, 200 A, 250 A, 300 A.

Fuse Holders for SHB Bolt Fuses – ABH 1, ABH2 or 3-way (BS 5196)

The ABH 1 holder, specially designed for SHB bolt fuses, allows the use of space-saving SHB (MRBF) bolt fuses due to the isolated bolt. Also available as a 2-way holder for up to 200 A per fuse.

3-way fuse holder BS 5196 (bridged): Bridged version with a common input. Fuse holder with transparent plastic cover for protection against contact and moisture. Maximum current load 300 A, M8 threaded bolt, suitable for SHB (MRBF) type fuses. Dimensions L 190 × W 51 × H 63 mm.

Also available as a non-bridged version (separate inputs)

Strip Fuses STS & Fuse Holders SHD

The STS strip fuse consists of a fusible link protected by a ceramic housing with a viewing window (closed design B/BN). Jaw width 11 mm.

Fuse holder SHD 1: Modular fuse holder for strip fuses according to DIN 43560/1 (STS). The base has 2 tabs for easier mounting. The connection screws and nuts are made of nickel-plated brass M10.

Strip fuses are the proven solution for main line protection where no reset function is required – cost-effective, robust, and available in a wide range of current ratings.

Class-T Fuse Holders for High-Performance Systems

For on-board networks with very high short-circuit currents – especially in combination with lithium batteries – philippi offers Class-T fuse holders:

• Fuse holder for Class-T fuses up to 200 A – with transparent plastic cover
• Fuse holder for Class-T fuses 225–400 A – for large high-current applications
• Fuse holder for Class-T fuses 450–600 A – for largest high-current applications

Class-T fuses are characterized by the highest breaking capacity up to 20,000 A / 125 V – ideal for protecting lithium battery banks with very low internal resistance.

The Right High-Current Protection – Decision Aid

Typical Application Areas for High-Current Protection

Anchor winches, bow and stern thrusters, powerful inverters, electric winches, high-current distributors and main circuits of on-board networks, lithium battery systems, and supply lines to the main switchboard.

Frequently Asked Questions about High-Current Protection

What is the advantage of hydraulic-magnetic tripping over thermal-magnetic? Hydraulic-magnetic circuit breakers (Series 8345) trip precisely and independently of temperature. Thermal-magnetic circuit breakers react to overload in a temperature-dependent manner – in hot engine rooms, they may trip earlier than intended. For on-board applications in temperature-critical areas, hydraulic-magnetic tripping is the more reliable choice.

Can I use a Series 8345 circuit breaker as a main switch? Yes. The Series 8345 circuit breakers offer a more cost-effective and space-saving solution than separate main switches and high-current fuses – they perform both functions in one device.

Where is the SHB bolt fuse mounted? Mounting is either directly at the battery terminal or near the positive pole (max. 40 cm distance according to standard). The DIN EN ISO 13297 standard requires the main fuse to be installed as close as possible to the battery.

What protection is suitable for lithium batteries? Lithium batteries (LiFePO4) can produce particularly high short-circuit currents. Class-T fuse holders are recommended for main protection, or SHB bolt fuses of sufficient rated current. The fuse must in any case be dimensioned for the maximum short-circuit currents of the respective lithium battery.

Does the high-current fuse need to be replaced after tripping? For circuit breakers (Series 8345, TCB), no – after eliminating the cause of the fault, the circuit is simply reactivated by operating the toggle switch. For bolt fuses (SHB), strip fuses (STS), and T-fuses, the tripped fuse must be replaced with a new one. Therefore, always carry spare fuses.

Philippi high-current protection · anchor winch circuit breaker · bow thruster protection · Series 8345 hydraulic-magnetic · SHB MRBF bolt fuse · STS strip fuse · boat high-current fuse · Class T lithium fuse · TCB circuit breaker · main battery fuse · DIN EN ISO 13297 · Philippi electrical systems