Vintage Italian breakers

Early Italian breakers looked and functioned quite differently from modern-day ones; for starters, they had a much more complex mechanism, which made them physically larger and much more expensive. As such, it took decades for them to become affordable enough to be used in household installations.

They way these old breakers worked generally tended to differ from modern-day ones. Modern circuit breakers are all thermal-magnetic, with a thermal element that acts on overloads and a magnetic one for short-circuits. Early breakers, however, typically only had one of these two elements and are thus unsuitable to be used nowadays.

Zeus Rapizzi breaker

Rating: 3A 275V

Zeus Rapizzi was one of the first companies to produce breakers in Italy, shortly after WW2. Being so early, their breakers were initially only used for industrial or commercial uses or as limiters for power companies.

Despite its age, this breaker has a surprisingly modern appearance, as power is controlled by a lever just like on modern ones. However, its operation is significantly different from modern ones, as is clear once the front cover - held on by a single screw - is removed. The breaker operates purely magnetically: there are two coils with a metal piece inside of them, which is free to move. Once the current is high enough, it gets pulled upwards and causes the mechanism to trip.

The two coils are there as the breaker is double-pole, which was common at the time. However, the two sides are entirely independent, so, like with fuses, a fault causing only one side to trip would still leave the other one live. The trip current is fixed at 3A and isn't user-adjustable.

BTicino double-pole breaker

BTicino breakers were some of the most popular ones sold in Italy back in the day. As was common on breakers of this era, it's quite large and is built on a ceramic base with a metal cover on top of it. Large buttons on the front allow the user to turn the power on or off, with a satisfying "clunk".

Interestingly, unlike some other models, this one doesn't allow the user to manually change the trip current, which is set to 9A, as is written on a label readable from a window on the front cover. The controls for it are likely there, but they're covered by a sealed plastic cover. It's likely that breaking the seal would void the warranty of the device, as well as any guarantee of protection.

BTicino single-pole breaker

Rating: 25A max, 380V

Later styles of BTicino breakers - which were much more popular - moved to plastic front covers, similarly to their contemporary fuse holders, and had removable plastic pieces on the top and bottom to feed a cable or conduit.

The trip current was adjustable by the user simply by installing shunts (special metal strips) on the back, which would have originally been supplied with the breaker, and turning the fine adjustment knob if necessary.

A label is present on the inside, to boast about the special metal composition of the contacts and provide a space to write down the current that's been set, which, like with the previous breaker, can then be read from a window on the front cover.

AVE type 1902 breaker

Rating: 12-25A 380V

AVE was another popular manufaturer of breakers in Italy, though with nowhere near as much success as BTicino. It's functionally the same as the models shown previously, with two large buttons to turn the power on or off and a magnetic trip mechanism.

The trip current can be changed thanks to a metal wheel on the side, which adjusts the spacing and thus the force needed for the metal piece inside the coils to trip the breaker. It can be set from 12 to 25A. This example is, unfortunately, in poor condition and thus the covers over the terminals are missing, but they'd originally have been able to be closed with a seal. This would have allowed power companies to use it as a limiter breaker.

AVE "PIM" breaker

Rating: 15A 220/380V

As technology progressed, the size of breakers got progressively smaller and smaller and they became much more affordable. This change is evident with this model, which, while definitely not as compact as later DIN rail ones, has a similar appearance to them and is still noticably more compact than earlier designs.

The model name of this breaker, moulded on the side of the plastic casing, is "PIM", meaning "small magneto-thermal breaker". The size difference was evidently an important selling point to AVE.

Siemens DIN rail breaker

Rating: L16 220V

This is an early style of DIN rail breaker, which may still be found in some older installations. Functionally, there's no real difference from modern ones, but the design language is noticably older and there are still some minor differences.

Unlike all the previously-shown breakers, this one mentions the type of its trip curve, in this case the now-obsolete type L. The terminals are simply comprised of a screw which holds the wire against a metal surface, similarly to American power sockets, and doesn't have much in terms of protection from accidental contacts.

RCDs

The humble RCD is a crucial safety device, nowadays ubiquitous (and legally required) in Italy. It measures the difference in the current flowing through the line and neutral conductors and trips if this exceeds a certain amount, generally 30mA. Due to the way in which they operate, in Italian technical terms they're referred to as "differential interruptors".

The earliest RCDs in Italy were sold by BTicino under the "Salvavita" (life-saver) trademark; while initially very expensive, they became smaller and cheaper over time and have been mandatory since the 90s. The "salvavita" name was so popular that it's now the way in which RCDs are referred to colloquially in Italy.

Early RCD breaker from AVE

This is an early RCBO (RCD breaker), made as part of the PIM family of breakers from AVE. It's considerably larger than later DIN rail RCDs and, while it did come with a plastic bracket to adapt it to a DIN rail, it's only supported from one side and thus isn't very secure. On the top, a paper piece is present, with a schematic showing how the RCD functions.

On the front, aside from the usual lever and test button, there's also a sensitivity adjustment to set the trip current to 30mA ("maximum protection") or 300mA ("reduced protection"). The former is the standard RCD trip rating in Europe, and would be the setting used to actually protect people, while the latter would be useful to provide protection to earthed circuits on a TT system (the main one in use in Italy). Note that this control is actually hard-set to 30mA, with a seal to prevent it from being changed.