Get at least 5% off today, on all items over £50.
Cart is empty

Tripping the Fuse Fantastic: Start Up Demand

Good to Go

Here at ParkerBrand we always want you to get the most out of the kit that we supply.  So, there you are you are – you’ve order, it’s been processed and delivered with efficiency and speed (we know that you want it now!) and you’re keen to get on with tasks in hand.  Just like us you are hyped to get started and get done!

Plugs and Fuses

As you would expect ParkerBrand are in the business of making sure that you are safe.  Be sure that your piece of equipment meets or, in nearly all cases, exceeds the safety requirements as stipulated by HM Government or for the time being the EU.

Your machine will have been supplied with the absolutely correct fuses and plug designated by the safety standards in place.  This may be a simple household plug or indeed a 16 amp plug or otherwise. We in no way recommend changing these plugs or indeed the fuses – clearly, they are there for a reason.

Start Up Demand

It is important to make sure that you have the right power source for you machine. In order to avoid any scenario such as your fuse box tripping etc it’s important to know that start up demand of you kit.  The start up demand is the amount of power that your machine needs on starting – as simple as that. The start-up demand (often referred to as ‘headroom’) is frequently greater than the average power demand of your machine while working.

This is an important calculation for example when it comes to choosing the right generator and has been covered by one of our techies in a previous blog article.

My Machine is Tripping my Fuse

When talking about fuses it is important to remember there are a number of mechanisms in place to ensure your electrical appliance functions safely and also ones that ensure your other household items are not effected by a malfunction.

Plug Top Fuse

The first and simplest form of safety is the fuse found in your plug top which acts as a link between the power being consumed by the appliance and the electrical current itself. In English - it is a link which is designed to break when the power demand made by your appliance is in excess of what's considered the norm.

All plug tops must have a fuse and can vary in size (Size being the current in which it needs to break). The most common sizes are:

  • 3 Amp - Designed for small electronic devices which require small amounts of current.
  • 5 Amp
  • 10 Amp
  • 13 Amp - Designed for larger household appliances and usually demand high currents of electricity such as kettles, toaster, hair dryers, vacuum cleaners etc.

In a standard domestic UK plug top, 13 amp is the largest size you can install. Should your appliance need a larger current then a different plug must be used.

It's important to remember that once your fuse has blown it needs to be replaced. In some instances a blown fuse can just be an indicator that the product has been overused but if the fuse continues to blow it could be a sign of a more serious issue and needs to be investigated by either the manufacturer, there representative or a qualified electrician.


All homes built in the UK are now required to have both MCB and RCD circuit breakers installed in your domestic fuse board / consumer unit. You've probably seen them all lined up with writing underneath ("Kitchen Sockets", "Upstairs Lights", "Cooker", etc)...

They both serve to protect you and your home from fire and electrocution. They also serve to protect other appliances from damage and in most cases they will rarely do anything other than stay "ON".

Both work independently of each other but if you are having to reset them frequently then it can be a sign of either a faulty appliance or a poorly designed circuit that needs revising.


MCB is an abbreviation of Multiple Circuit Breaker and are installed in all modern homes or when your home renovated and all electricity that comes into your home will pass through one. They are designed to detect overload on a circuit in your home and trip accordingly. Once tripped all power that is supplied through that MCB is stopped.

Each home is designed differently but will usually have a MCB for each electrical supply grouped together such as:

  • Lights
  • Electrical Socket
  • Cooker
  • Kitchen
  • Garage

Each MCB will have a different threshold to cut electrical supply based on the demand (measured in amperage) made on that particular circuit. For example - your lights will have a much lower threshold than your sockets because they use a lot less electricity.

Your kitchen will most likely have the biggest threshold and in most instances your cooker will have its own MCB.

Have you ever noticed that your upstairs lights have gone out and the downstairs are still on? This will most likely be due to the MCB tripping.


RCD is an abbreviation for Residual Current Device work by detecting current leakage or imbalance in a current which could result in electrocution.

Usually there will only be one of these installed on your electrical fuse board and it serves to protect the whole home. If this trips then it is likely all power to your home will be cut.

Usually a RCD tripping is an indication of a serious fault on one or more of your electrical circuits, and if after resetting it continues to trip it is recommended you call a qualified electrician to investigate as soon as possible.

So what's the score?

If the fuse in your plug is continually blowing, we recommend you contact the appliance manufacturer or if outside of warranty it maybe time to consider its replacement.

If your MCB is tripping then it means the circuit in which the appliance is powered from is not sufficiently designed to cope with the demand being made from the appliance or appliances.

If your RCD is tripping then it means a fault is present on one or more of the circuits and unless you know the offending appliance it maybe wise to contact a qualified electrician to investigate further.


The most common call we get at ParkerBrand is complaints that an appliance is causing the home MCB to trip. Unfortunately most consumers will immediately consider this to be a problem with the appliance without considering the above facts.

If an MCB is tripping then it is most likely the demand being requested is too high for the circuit which powers it.

The most common example if appliances powered by an electrical motor, which on startup demand a HUGE electrical load, only later to reduce back to the normal quoted operating values.

Consumers maybe further confused that in previous the MCB was fine and did not cut electrical supply, but do not consider that previously there may have been less demand on that circuit from other household appliances.

Help is at Hand

For sure we hope this has helped you. if you would like to get it touch with our Customer Care team here in Louth Lincolnshire, then they will certainly be ready to offer a solution or direct you to the boffins down in the Technical Workshop.

Connect with us