GENERATORS 101

Malcolm Street — 20 January 2016

To generate or not to generate? For the RV traveller who spends long periods of time in remote areas or without mains electricity, the answer might seem fairly obvious. However, there are a few ‘ifs’, ‘buts’ and ‘maybes’ to consider!

In the RV world, where packing space and weight are at a premium, generators are yet another appliance that , while handy, will add weight and require you to carry a separate fuel source, usually petrol or diesel. They can also be noisy to run and there are places where their use is either banned outright or restricted to certain hours, such as in national parks.

In many cases, a well setup RV – that is, one with adequate battery and solar panel capacity – won’t need a generator. However, there are two devices that most battery/solar panel systems generally don’t cope with – air-conditioners and microwaves. So, for RVers who are regular users of these appliances, a generator can be a welcome addition.

RATINGS AND OUTPUTS

Generators come in a variety of power outputs but, for most RV camping situations, a generator rated between 1kVA and 3kVA is pretty common. The kilovolt-ampere (kVA) figure is arrived at by multiplying voltage (240V) by operating current. So let’s say you have a kettle that draws 5A, the result will be 1200VA or 1.2kVA. And, for the tech-heads, there is something called ‘power factor’ which is normally included in the equation to give the kilowatt (kW) figure (see p160).

For those who aren’t so good with numbers and calculations, here is a rough guide. A 1kVA generator will be good for running things like camp lights, a car fridge, battery chargers, a radio or a TV. A 2kVA generator will be good for just about all caravan and camper appliances used simultaneously and maybe an air-conditioner.

I say ‘maybe’ because air-conditioners are relatively high power items and will draw a high starting current when first switched on. In many cases, with a 2kVA generator, everything else will have to be switched off when starting the air-conditioner and then turned back on again after it is up and running. For larger capacity air-conditioner units or if switching other devices on and off is not desirable, then either 2.4kVA or 3kVA generators are available.

There are a few things to consider here. If cost is not an issue, then a 3kVA unit might seem like a good idea at first, but you need to keep the weight in mind – because you’ll have to be able to lift it and move it around, and you’ll have to consider the weight it adds to your RV. At the other end of the scale, you may want to consider whether an adequately-rated battery/solar panel system might be a better deal than a 1kVA generator.

Also keep in mind when you’re doing load calculations that a 2kVA generator might actually be a 1.6kVA generator as, frequently, the higher rating is a short time figure (for motor/compressor starting), not a constant load. In terms of efficiency, the best use of a generator is to recharge batteries, rather than run individual devices. Battery charging is a fairly constant load and so the generator will be running at its most efficient.

ON THE VOLT

In Australia, generators are rated for 240V AC/50Hz. If you plan to charge electronic devices such as laptop computers, then you will need a generator with a sine wave inverter. Sine wave inverters regulate the power output and frequency identical to mains power. Voltage is a product of the speed of the generator and, when a sudden load is added to the generator, it may briefly slow down, resulting in a subsequent voltage drop. The sine wave inverter is designed to cope with that contingency.

Many generators also come with 12V outlets, but be aware that not all 12V outlets are good for battery charging. The best choice is a generator with a purpose-designed battery charger outlet or, better still, to use the existing multi-stage mains charger that is built into your caravan or motorhome.

Some generators can be operated in parallel which means that if, for example, you are camping with friends and common higher power output is required, then two generators can be connected together. Keep in mind that the manufacturer’s purpose-designed leads may be required to do this.

STORAGE AND FUEL

Before buying a generator, give some consideration to where it might be stored in your RV. Apart from anything else, they are highly portable and, therefore, very easy to steal. Some caravans and motorhomes have a purpose-built generator bin but many do not, and under the bed or in the back of the car are really not suitable places, given the possibility of leaking fuel or oil. Sometimes, the drawbar of smaller caravans and camper trailers may suffice but you need to keep in mind the increased tow ball weight. A rear bumper bar might look like a tempting location but, particularly with motorhomes, the protruding generator might cause the overhang to exceed the 60 per cent rule and could, therefore, make your RV illegal.

Most generators are four-stroke engines fuelled by unleaded petrol (ULP), with liquid propane gas (LPG) generators also an option. Somewhat annoyingly for diesel-powered motorhome owners, diesel-powered generators are generally not available in the 1kVA to 3kVA range. Meaning that instead of using the main diesel tank as a source of fuel, as diesel-powered heaters and cooktops can do, a second fuel supply has to be carried. In addition to storing the generator, safe storage of fuel also needs to be considered.

LOCATION, LOCATION

There is a considerable list of places throughout Australia where the use of generators is banned. These places differ from state to state and, in some cases, within the same state. Additionally, there are places where nothing larger than a 1kVA generator can be used. A prime example is in national parks, where some ban them outright, some have restricted hours, some have separate areas set aside for RVs with generators and some require written consent from the relevant authority.

The use of generators for medical reasons (for example, sleep apnoea) is often allowed where others are not, but some sort of medical certificate may be required. The bottom line is not to assume when it comes to generator use and to do a prudent check on your intended destination.

KEEPING FRIENDS

Generators can affect pleasant social order and general campsite bonhomie. They can be noisy (although that has improved a lot in recent times) and they do give off fumes as well as the more dangerous carbon monoxide. Before running a generator, decorum strongly suggests checking with your neighbours about operating your generator and, perhaps, even offering to charge their batteries for a while! Unless there’s a good reason, I reckon that restricting use to daylight hours only is a good move to maintain campsite relations.

Generator technology has improved considerably in recent years, with better power outputs, more regulated outputs, lighter weights and less noise. Generators really aren’t a ‘must have’ item for most of us but they are a particularly useful asset for those who enjoy extended remote camping.

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generators

Photographer

Malcolm Street