top of page

When should you upgrade your Consumer Unit (Fuse Box)?

There are some considerations to bear in mind when it comes to changing your electrical Consumer Unit... for example, is there RCD protection? Or, if yes, how many circuits are protected by the RCD? If you have six circuits protected by one RCD, then any problem on any of those circuits will trigger the RCD and therefore cut the power to all your circuits and not just the one with the problem! This can be incredibly inconvenient.

This video below explains most of what you need to know as a Home Owner and explains when it's possibly time to change:

The different types of Fuses and Circuit Breakers

There are many different brands of Circuit Breaker, however they all do the same thing... in the event of a fault they BREAK the CIRCUIT and stop the flow of electricity and therefore protect YOU! Here are just a few, there are more, but these are the most common and can be expected to be found in British Homes, in Midsomer Norton, Radstock, Chilcompton and indeed across the UK!

BS 3036 (BS = British Standard)

The British Standard effectively means that all of the "Circuit Breakers" must conform to the 3036 disconnection times (basically put) within the BS 7671 Wiring Regulations! They are rewireable fuses, are semi-enclosed, and when a fault occurs the weak link (the wire) melts away and breaks the circuit and electricity or danger from you, the home owner. All of the Circuit Breakers and RCDs in this blog are all from Consumer Units in our Local Area, Radstock.

They can still be used but certain conditions apply i.e. de-rating of circuits and Low Perspective Fault Currents which are usually only found within TNC-S earthing systems. For TT earthing (where you have your own Earth Rod, they're a NO, NO and an RCD must be present.

The 3036 rewireable fuse.
The Semi Enclosed, Rewireable Fuse (BS3036) - this one was made out of ceramic!

BS 3871 - The Miniature Circuit Breaker (MCB)

These are common, offer no RCD protection but took over from the 3036 in which a switch is tripped when a fault occurs and all you need do is flick it up (so long as the fault has been fixed by a Local Electrician)! Most of you will have this type of Circuit Breaker or MCB.

The 3871 meant you didn't need to change the wire anymore... you could just flick the switch back up so long as the fault had been cleared by your local electrician
The BS 3871 was a MCB was an upgrade from the 3036

BS EN 60898 - Circuit Breaker

Probably the most common Circuit Breaker to be found in our homes today, these superseded the 3871! These are often found in conjunction with the BS 61008 RCDs (such as the one below).

BS 60898 is the most common type of Circuit Breaker found in homes across the UK and Radstock
BS 60898 Circuit Breaker superseded the 3871 and the 3036 before that!

In the image above you can see that this 60898 Circuit Breaker was rated at 16A, this would be commonly found supplying the electrics to a garage or a radial socket circuit.

BS EN 61008 - RCD (Residual Current Detection)

This is a very common type of RCD found in many homes in Radstock, Oakhill and all across our local area! This is an RCD that guards and protects circuits that are protected by 60898 Circuit Breakers, you could even describe them as Guardian Angels. They do what 60898 Circuit Breakers cannot do and that is detect Earth Faults, which happen when an appliance starts to break down or there is earth leakage, which happens when there is a fault in general. So, you see, the 60898 and 61008 work in tandem, they compliment each other!

An RCD that detects problems on circuits, especially faulty applicances!
The RCD... detects 30mA residual current (faults in appliances) and is for AC circuits!

BS EN 61009-1 - RCBO (Residual Current Circuit Breaker with Over-current Protection)

This is the all-in-one device... well almost! It has overload and residual current detection! AND, unlike the previous example only the circuit with the problem loses power, so you can go about most of your daily activities or be less inconvenienced!

The RCBO is a combination of RCB and Circuit Breaker!
The all singing and all dancing RCBO - this detects 30mA of Residual Current as well as overloads! And detects AC and DC currents!

If you would like me to take a look at your installation you can book me in for an appointment by filling in the following form!

I am your Local Electrician covering Chilcompton, Radstock, Midsomer Norton and ALL other surrounding areas!

You can call Rich now on 01761 325 007 or email and visit my website here:

29 views0 comments


bottom of page