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Blog posts of '2026' 'June'

How to Choose the Right Manual Transfer Switch Size for Your Property

While purchasing a generator, consumers usually concentrate only on the engine capacity and tend to ignore the switchgear that operates with it. The selection of the appropriate manual transfer switch is as important as choosing a proper engine. The switch that is not adequately rated will have trouble bearing the load, and the oversized one will be overpriced without giving extra benefits. 

At Blades Power Generation, we always recommend sizing the switch around the actual power demands of the property rather than guessing. Here’s a guide to help you make the right choice.  

Start With Your Essential Circuits 

The first step is deciding what you need to keep running during a power cut. 

For a home, that may include: 

  • Lighting 

  • Fridges and freezers 

  • Heating controls 

  • Internet routers 

  • Water pumps 

For workshops or commercial buildings, priorities are often: 

  • Security systems 

  • Refrigeration 

  • Roller shutters 

  • Machinery 

  • Server equipment 

Not every circuit needs generator backup. In many cases, selecting only the essential loads keeps the system simpler and more affordable. 

Match the Switch to the Generator Output 

Your transfer switch should match the output rating of the generator and the incoming electrical supply. 

Most domestic properties in the UK use: 

  • 63A 

  • 100A 

Larger commercial or agricultural properties may require much higher ratings, especially on three-phase systems. 

At Blades Power Generation, we often see problems caused by people pairing small generators with oversized switchgear or attempting DIY installations without checking load requirements properly. 

Think About Future Expansion 

A transfer switch is not something most people want to replace after a year or two. 

If you are planning: 

  • EV chargers 

  • Workshop expansion 

  • Additional refrigeration 

  • New machinery 

it is sensible to leave some room for future demand. A small amount of planning now can save major rewiring later. 

Indoor or Outdoor Installation Matters 

The location also affects the switch choice. 

Outdoor installations in the UK need weather-resistant enclosures with suitable IP ratings. Damp conditions, coastal air, and cold winters can all shorten the lifespan of poorly protected equipment. 

This becomes even more important when the system is relied upon for emergency power during storms or unexpected outages. 

Getting the Sizing Right 

A properly sized transfer switch keeps the system safe, reliable, and easier to operate when mains power fails. 

Blades Power Generation ensures that our clients get suitable solutions based on the reality of their properties instead of complicating things unnecessarily. No matter if you own a residential workshop, farmland, or commercial premises, having the proper setup begins by assessing the load. 


The Most Common Automatic Transfer Switch Faults and What Causes Them

A correctly functioning automatic transfer switch responds swiftly in case the main source of power gets cut off, automatically shifting the electrical load from the main to the generator. In case the system functions perfectly, there won’t be any problems, but faulty systems mean that everything will fail at the most critical times. 

At Blades Power Generation, we often find that many ATS problems come down to maintenance, environmental conditions, or incorrect installation rather than the switch itself. 

Contact Wear and Burnt Connections 

The most frequent fault encountered is that the contactors within the switchgear are worn. This situation can be caused by: 

  • Excessive heat 

  • Accumulation of carbon 

  • Erosion of contacts 

Failure to address this issue can result in delayed switching or even total switching failure. In the business environment where generators undergo periodic testing, wear develops more quickly. 

Battery and Starting Issues 

In such instances, the fault may be attributed to the transfer switch, while actually it lies with the generator starting system. 

Flat battery, faulty charger, or starter connections could prevent the generator from spinning at its rated speed and, hence, the ATS would recognise an unstable source and not transfer the load. 

This issue is especially common with older or poorly maintained used generators that may spend long periods sitting idle between outages. 

Moisture and Condensation 

The UK climate can be unforgiving on electrical equipment. The formation of condensation within enclosures can lead to: 

  • Corrosion 

  • Relay malfunctions 

  • Faulty sensors 

  • Inaccurate voltage measurement 

In open systems lacking IP-compliant enclosures, winter and coastal climates pose an increased risk of such issues. 

At Blades Power Generation, we always recommend checking enclosure condition and ventilation as part of routine inspections. 

Incorrect Voltage Sensing 

An ATS relies on voltage monitoring to know when to transfer between mains and generator power. 

Incorrect setting up of the sensing parameters can result in the following: 

  1. Premature switching 

  1. Delayed switching 

  1. Failure to identify good generator input 

That is why it is essential to commission an installation properly. Even top-of-the-range switches can work improperly due to incorrect settings. 

Lack of Routine Testing 

Perhaps the biggest problem of all is simply neglect. 

Many systems are installed and forgotten about until a real power cut happens. By then, seized mechanisms, weak batteries, or damaged components may already be waiting to cause trouble. 

Regular testing helps identify small problems before they turn into complete failures. 

At Blades Power Generation, we believe reliable backup power starts with proper maintenance, sensible installation, and equipment designed for real operating conditions. A well-maintained ATS should provide dependable service for many years without unnecessary complexity.