Select And Maintain A Generator

Choosing and maintaining a generator is something so simple it can be easily done but so many people fail with this and generally it is down to being idle and not bothering; it is such a simple thing to do and as any engines need attention, generators are the same and as most people know they stand for 99.9% of the time and when you do need them they fail to start.
People will have read other articles I have written about generators and know the basics which are that there are two power ratings and they are the theoretical power output which is the maximum power output and the continuous power output which is the figure we work to as this is the only true figure and if a generator is advertised as being a 3300 watt unit and the specifications state a continuous output of 2800 watts then it is a 2800 watt unit and not a 3300 watt unit.

All fossil fuelled generators need fuel and this is where most people make their first mistake as they fill it with petrol and leave it until it is needed and suddenly find it won’t start as the fuel has sat there for 2 years and is stale, it is also ethanol or E10 fuel with 10% ethanol content and this separates and eats through aluminium and destroys most pipes and something has leaked and you have lost your fuel. Many generators also have battery start systems to stop you pulling the start cord and breaking it and the start battery is flat so you buy it because it is electric start and you end up pulling the start cord and defeating the object, and to date we have dealt with petrol generators as they are the cheapest and most popular.

To begin I would suggest using a fuel stabiliser and add it to your petrol and note there are two broad types and one mixes with the petrol and ethanol and stabilises it and stops it separating while the other sits on top of the ethanol and effectively seals it from the air and moisture, anything which separates petrol and ethanol is bad and the object is to stop this separation and most fuel stabilisers are generally good for around a year meaning you can sit treated fuel in your fuel tank and leave it for up to a year.

Diesel are better generators in the respect they are cheaper to run through better fuel efficiency and the fact most are load run which means they increase or decrease their speed to run the loads placed upon it and while diesel is better for storing than petrol it has its own issues and this is something called diesel bug. Diesel bug occurs mainly with leisure boats or military reserve vehicles as they are both stood for long periods and this forms an algae on top of the separated water and below the diesel and it needs the water to survive and the diesel to feed off and with both fuels this is our starting point.

Use the correct fuel conditioner or treatment as petrol and ethanol separate and the now neat ethanol creates many issues which it doesn’t create when mixed with petrol; and diesel is fine with diesel bug treatment so what to do next. With diesel you fill your tank to the brim and seal your vents up to prevent moisture and damp air entering the fuel tank and separating and forming water globules on the side of your fuel tank and running down through the diesel and creating the conditions for diesel bug. With petrol you only fill your tank with ¼ of a tank of petrol after it is treated with fuel conditioner. All fuelled engines need lubrication and this is with engine oil and this has issues as it deteriorates both with use and with age and your engine which was serviced 11 months earlier has engine oil which is not in prime condition as any engine oil needs running up to temperature for a period as this allows it to burn off any moisture from the air or contamination from combustion and people automatically assume diesel engine oil is worse as it turns black quickly which is wrong as both fuels produce different deposits and ethanol fuels produce a lot of corrosive acid.

Curing most of these problems is as simple as running your generator every couple of months as this uses some of the fuel and allows you to top up with fresh fuel and helps your fuel from going stale; it allows the engine oil to get up to working temperature and burn or evaporate off any moisture and burn off any contaminants to keep your engine oil in the best condition it can be so rule 1 would be to run your generator for around an hour to get the oil to working temperature and allow it time to burn off everything and use a proportion of your fuel and allow you to top up with some fresh fuel while keeping your start battery charged.

This leads us to our next question and this requires thinking about as both the time of year and increased electrical loads conspire to load and overload the National Grid system and additional burdens such as the electricity gobbling heat pumps and electric cars exacerbate the problems often leading to local failures of the electrical networks, so how much fuel do I need to store? In essence this is a “how long is a piece of string” question as there are many parameters and these are determined by your specific set up and the amount and times of power outages and what you need to run followed by what you would like to run during a power outage and local legislation which generally here in the UK, generally, restricts fuel storage at home to 25 litres. Some areas allow more and some less so you need to find out the limits in your area and if it applies only to petrol or petrol and diesel along with the conditions of storage such as in a garage not attached to a dwelling and in approved containers only.
How much does your generator use is the next question followed by how much does the fuel tank hold as these can be crucial as often any fuel in an approved fuel tank such as on a car or in a chainsaw fuel tank or a generator fuel tank are not entered into the equation. If you get frequent power cuts and your generator is run a few times a year for up to 2 hours for example then filling up your fuel tank is an easy way of getting around the fuel storage problem and if it has the fairly standard 15 litre fuel tank as many do but if you are a stand-alone single use only in emergencies which only happens every few years then you will never use this fuel and end up throwing it away and wasting it.

In essence then it comes down to consumption and use, for the occasional stand by use for petrol I would say ¼ of the generators fuel tank and another 5 litre approved fuel can which is treated with the mix in type of fuel conditioner and for regular use I say fill up the generator and as you use it you top up with fresh fuel. There is some logic to this as the old fuel can often be put into your petrol car and your generator fuel tank can also be drained through the rubber tap being removed from the tank shut off valve and drained into a fuel container and put into your petrol car.

Diesel is another issue as diesel fuel has a water content and this varies from fuel producer to fuel producer and is influenced by the storage and transportation of the diesel as diesel stored in open vented fuel tanks in wet or humid conditions can draw this moisture from the damp air over time and increase its water content. Diesel can be stored for years with a little treatment and a few precautions and the first one is to buy the diesel in winter as the blend contains more additives than summer diesel to stop it freezing and then treat it with your treatment and place it into containers and seal it from the air to stop moisture being attracted and block any unsealed vents on your generator diesel tank/system to stop the air. You can now have a full tank of diesel and a large quantity potentially stored for years, and yes it is that simple.

Your third option is the dual fuel generator which uses either a petrol or diesel engine and gas such as LPG or bottled gas and these generally start on the liquid fuel such as the petrol or diesel and once warmed you switch them to gas and they run on gas; recent advancements have led solely to the gas engine which starts and runs on various gasses and as bottled gas has less storage restrictions for domestic use it may be an option worth exploring. Gas may be the most expensive option but the most feasible for the emergency only occasional user to maintain some of their essential systems and potentially run some of their preferred systems during a power outage.

Standard generator or inverter?

In theory the inverter wins on all counts as they produce clean electricity and they are cheaper to produce, but theory and practise are different things as inverters are the new kid on the block and both manufacturers and retailers mark their prices up because they are new and demand will always be high among certain groups of people who have to have what they perceive as “the best” or “the latest” and manufacturers and retailers know they will pay over the odds for them and exploit this stupidity. Just recently the inverter has started to drop in price due to their fewer components and cheaper costs to assemble and the newness bubble has burst. In simple terms mains electricity is dirty and this means it has a lot of stray harmonics and voltage fluctuations and without boring the uninitiated I will keep it simple and say the UK mains voltage of 240 volts is not a constant but merely an average as UK mains voltage fluctuates due to the way it is produced using a rotary cycle and normal UK mains electricity fluctuates between 220 to 260 volts and this is our first problem. If we take the upper and lower voltages and add them together we get 480 volts and if we divide them by 2 we get an average of these two voltages of 240 volts and a standard generator does exactly the same thing as it also works on a rotary cycle. Advancements led to something called AVR or automatic voltage regulation which is a simple unit wired into the output side of the alternator as it is only used on alternators and it limits the voltage fluctuations and generally it clips the top and the bottom of the voltage spikes and limits then to a low of 230 volts and a high of 250 volts and this alone prevents a large number of the harmonics and cleans up the electricity while still giving an average 240 volts.

The story doesn’t end there as both commercial generators and petrol or diesel generators use the rotary cycle which produces dirty electricity and is the reason so many homes have surge protection extension cables to power sensitive electronics such as computers and televisions; and they produce AC or alternating current. Inverters work differently and produce AC power which is then transformed through inversion technologies to DC or direct current where it is literally pulverised electronically and turned back into clean AC electricity and often at a very stable 230 volts and free of fluctuations. This is called pure sine wave technology and while many inverter generators claim to be clean inverters and their electricity fluctuation is often less than 0.5 volts as pure inverters maintain their voltage due to the way they work as their voltage remains constant irrespective of engine speed and loads placed upon them and they often slightly under volt as this is also beneficial for equipment to have this slight under voltage and is the reason so many inverter generators produce 230 volts and not 240 volts and equipment manufacturers claim this prolongs the life of their equipment by over 100% and evidence suggests this to be true. This is easily explained by the voltage average as equipment for older electrical supplies are designed to work from 220 – 260 volts and newer equipment from 230 – 250 volts as they are on fluctuating voltages where as pure sine wave electricity is virtually fluctuation free.

Next is a serious issue as not all inverter generators are pure sine wave generators as they use something called modified sine wave and they are different; all electricity whether digital or analogue has something called a sine wave and it is depicted as a curve in a drawing and this is the currently known form of purest electricity. Pure sine wave inverters follow this sine wave exactly and it gives pure sine wave electricity totally free of distortions or harmonics and is safe to run the most delicate of equipment with and it will run your new widescreen TV, your computers, and even a lot of your micro processor run electrical and electronic equipment without issue as it is smooth and follows the sine wave curve.

Modified sine wave is popular for many things and particularly resistive loads such as filament and fluorescent lighting and many AC electric motors as it works on something called a “chopper circuit” which is basically high speed switching and this can be extremely rapid switching on and off. From this we can logically conclude this as a series of steps and this is not following the pure curve of the sine wave exactly and the switching steps confirm this as it acts like a cleaned up version of traditional rotary power generation which is dirty and the cleaning element comes from the fact the switching is rapid and the more rapid it is means the cleaner it is generally.

If you find an inverter generator then ask for the exact specifications and it should list if it is pure sine wave or modified sine wave as modified sine wave is little better than a traditional generator with AVR so you could end up paying more for very little and your money is better kept in your pocket.
Another point worthy of mention is the engine as many are cheap and cheerful generic Chinese engines with the life expectancy of a dragonfly and you should carefully consider your engine as engines from reputable manufacturers such as Hatz, Kohler and Honda mean readily accessible spares and at reasonable prices and a little research pays dividends as Wolf and Power King both use Hatz engines on their generators.
Cheap generic engines from China have flooded the market and generally they are of poor quality and are batch built in virtually unlimited numbers and their spares back up is virtually non-existent and when you ned a spare part it may have to be pulled from their production line and shipped meaning long lead times and huge expense to you.

What Size Generator?

Many people get the manuals with any new electrical equipment and quickly scan through the operating and setting up procedures and nothing else and put it into their desired location for these manuals and eventually throw them out so it is important to become the power nerd and read the specifications and know exactly what power they consume in watts.
Next you decide what is essential and traditionally these would be freezers full of food and some limited lighting and potentially a requirement to charge things such as mobile phones or laptops and here is your first issue, what is essential as charging a laptop is not important when all your frozen food is thawing out and it is your entire winter frozen food. It is even less important when you find your modem isn’t powered and you cannot get onto the internet anyway as it doesn’t have mobile internet and the power cut means the mobile internet isn’t working. You really have to be ruthless and turn everything off and remember all those niceties you forget like your Sky box and your alarm clock and your Hi Fi unit or your landline telephone as they all consume power and in a power outage you don’t need them anyway, always remember your heating if it is gas central heating as your boiler needs power for the control electronics and the water circulation pump to run.

Once you have a list of your essentials and a list of all your niceties you can refer to your manuals and establish their running wattage and calculate your total wattage and short list suitable generators and find out if you have any spare capacity and list them also; I find creating a computer file and listing all the wattages of your essentials and niceties is a good way to go as you can instantly see what you can power and what you cannot. You also have to factor in things such as periodicals which only run periodically such as your fridge/freezer as this starts and runs for a few minutes before shutting off for another hour and wanting to run again; with this total wattage you add another 20% for something called “head” as anything electrical draws more power on start up and the head covers this.

Now you find you can run your fridge/freezer, your gas central heating and limited lighting as well as the ignition on your all singing and dancing gas cooker and potentially charge a mobile phone and now the blackmail, many parents get this as their kids try the emotional blackmail and many parents give in. You say NO when they want the television on or they want to charge their phones, I pads, and laptops and you get them doing what you want and not what they want and you prioritise and their mobile phone has to become the house phone if it the quickest phone to charge and you charge phones in order and stop children playing with them and running the batteries down and keep what you need charged.

One thing I always suggest is keeping a set of 12 volt lights and a good battery and keeping it charged and locating this near your generator so you can see to start it and stop it and deal with issues such as refuelling safely and any works you need to do to your stopped generator. In addition you may live in the middle of an estate and are surrounded by neighbours and the noise may be supressed to the best of your ability but those up early in the morning will expect you to switch it off so they can go to bed and not be kept awake by a running generator and this is where your lighting comes in as you can set your 12 volt lighting up during the day or under your limited house lights and when it drops dark or hits 10 o clock you can stop your generator and still have lighting.

What are the essentials?

Keep only the fuel you need and treat it with a fuel conditioner.

Mark the date of your fuel and every year you put the fuel from your cans into your petrol car.

Drain your generator fuel tank and add this to your car and refill with fresh fuel.

Run your generator every 2 months and run it for at least 1 hour and possibly apply an electrical load to it to get your engine oil hot for long enough to evaporate or burn off contaminants.

Keep a 1 litre can of unopened engine oil and unopened it should safely last for 3 years for mineral or 5 years for fully synthetic.

Keep a full set of spares such as oil or fuel and air filters, a spare spark plug and anything you need to service your generator with the generator.

Now for the biggie, if you limit your generator fuel as you don’t really get power outages and have 2-3 hours of fuel for your generator then you need to have the ability to get fuel and you need to know where the local filling stations are and if they are affected by the power outage and I find a printed list of all the local fuel suppliers is very useful. If you have their address and telephone number you can usually ring them before you go out and establish if they have fuel, and if they are affected by the power outage: basically can they pump fuel into your jerry can. One telephone call may potentially save you several wasted journeys looking for fuel stations locally who are not on the same section of grid as you and are not affected by the power outage.

More modern technology has given us the impressive sounding solar generator and these have issues, but with a little understanding you can successfully run a solar generator and not have to store fuel, oil, and engine spares and have any issues with the battery running flat and having to pull start it and then having neighbours moaning about the noise. Most of these solar generators run from a lithium battery and these have their own issues with thermal runaway and spontaneous combustion and if this happens in your house you may be warm but the rain will also fall on you if your home burns down.
Solar generators can recharge from the sun using only solar panels and the quantity of solar panels can dictate the recharge time and many can be charged from other sources such as mains power or from your car cigarette lighter, but they are expensive and you could build your own battery bank from solar panels and battery charging of much cheaper lead acid batteries.
Modern solar generators are currently trying to outdo each other using gimmicks and instead of producing only mains electricity they may have a cigarette lighter fitted or a couple of USB ports and a 12 volt output.
Issues arise from all of these factors and the fact to make them stand alone you often have to buy some or all the solar panels to charge them and have somewhere to site them while being totally reliant upon good weather to recharge it and as we all know; snow and ice, low sunlight levels and even heavy winter rains affect their performance. This means they cannot be totally relied upon as a constant power source for stand-alone operations unless you have some pretty expensive kit and you have to rely upon the fact your power outage won’t be for long and a one of incident and not for a series of days unless you have another source of charging your solar charger. They are currently very expensive and in my opinion they ae not worth buying as you can build something much larger for less money using lead acid batteries which you can recharge with a cheap digital charger and also have battery monitoring to stop you over discharging the batteries; they will improve with time and also become much cheaper.