Circuit-Breakers  v  Fuses – 
The case for?

ADVERC BM Ltd. and E-T-A Circuit Breakers are now jointly involved in the development of a range of Low Voltage Protection Devices (LVPD) which, having recognised a low battery voltage condition, anything from a single piece of equipment to full battery isolation can be achieved using the appropriate relay, solenoid or circuit breaker.

E-T-A are also particularly specialised in a range of smaller circuit breakers for individual circuits, i.e. replacing the common fuse.

Our own initial understanding was that the circuit breaker is, in fact, a re-settable fuse, in effect. More expensive but convenient.

The E-T-A response is that there are two major differences: a circuit breaker not only detects a dead-short, but also the effect of an over-current fault condition, the latter causing a slow an often dangerous rise in cable temperature which, in turn, can lead to fire in the harness itself. Experience has shown it is the over-current type fault, more than the dead-short, which is the more prevalent.

Once the fault has been cleared, the second major difference applies: the circuit breaker can be reset time and time again, without the need to carry or find the correct size fuse.

Who needs a Circuit Breaker? 

Anyone who values the security offered by the circuit breaker to his vehicle, narrowboat or motorhome etc., and to the operator who wants to be able to continue quickly once the problem has been resolved.

Anyone who wants the convenience of simply pushing a small button to reset the circuit breaker, once a fault has been cleared and carrying on with the business in hand.

Anyone who wants peace of mind in the knowledge that, even when circuits are thought to be off, any over-current fault situations are being constantly monitored and protected against.

In summary - why Circuit Breakers?

While conventional fuses may be less expensive to install, their disadvantages can be particularly apparent especially in an automotive environment. The degree of electrical protection they provide is often inadequate for modern electrical systems and their potential for abuse is a serious problem for many vehicle operators.

By comparison, circuit breakers of the correct type and rating offer significant benefits for the protection of vehicle wiring.

• They are not subject to nuisance operation through transients or high rush-in currents such as lamp loads. Their rating can therefore be closely matched to the cable, guaranteeing optimum protection.
• They will discriminate between motor start and prolonged stall conditions; motor windings can therefore be successfully protected.
• They are not liable to premature failure through corrosion, fatigue, shock or vibration, or other external ageing influences.
• There is no need to carry replacements. The risk of using unsuitable temporary fuse substitutes is avoided
• They cannot be overridden but are conveniently re-settable once the fault has been rectified.
• Many different models and mounting arrangements are available to meet differing requirements.

Please Note: Literature with more information and specific detail is available on request. E-mail us on techsales@adverc.co.uk.

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