HELLA 2843 Series 100A Rating Battery Master Switch with Removable Key (002843011)

If you are building a buggy for competition use or for hardcore off road usage, we recommend adding in a master switch. For one, many racing sanctions require a battery master switch. These add to the safety of the driver and the racing affiliates just in case an emergency happens where the battery needs to be isolated.

The last thing you want in a high profile race is a meltdown on a switch. Hella has been known for years for making a superior product.  Replaceable keys are available as well.

From Hella's Instruction Card:

Purpose:
Interruption of the electrical circuit between battery and starter also other consumers. An effective safeguard
against theft and the danger of fire while the vehicle is parked. Also suitable for boats as protection against theft, fire and damage caused
by short circuits. Complies with inland waterways insurance requirements in Great Britain.

Regulations:
According to a regulation of the ONS (Supreme National Sports Commission for Automobile Sports in Germany), all cars taking part in circuit racing or hillclimbing
contestants must be equipped with a clearly indicated electric circuit breaker. Closed vehicles, should have two switches fitted, one within reach of the driver and the other in an easily ascertainable position outside the vehicle, e.g. below the dashboard on left (inside vehicle) and protected against dust and spray water in the engine compartment, so that only the switch lever protrudes from the body sheetmetal. The fitting of circuit breakers is also recommended for rally purposes. The circuit breaker must interrupt the battery and ignition current, also while the engine is running, and cut out the electric fuel pump, if installed.

Mounting:
To ensure that the current is correctly interrupted, the cable +30/51 must lead from the dynamo or regulator to the battery. If connected differently, the wiring should be carried out as shown in the diagram. The leads should be kept as short as possible. The size of the starter cable must be retained.