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Portable Generators.

I'm thinking of buying a suitcase type 4 stroke petrol generator at a good price and want to know if these or any portables simply plug into the boats Blue Mahle socket and supply the power like a Marina electric hook-up landline does?. Also what amp power would be best ?. thanks in advance.

Asked by: Trevor Smith  | 10.03pm, Tuesday 29 July

WW says:

The generator can be plugged into the blue marechal sockets (16A inlet) of the boats system and this is the safest way to connect, as it then will pass through the RCB protection.
However, it is essential that the generator is earthed properly. Most generators will have an eartt connection and this should have a thick insulated wire attached, which you should then connect to a metal rod (like a mooring spike) embedded into the earth. Some boaters use the spike to both ground (earth) the generator and to secure it with a padlockl and chain to reduce the threat of opportunistic theft.
Avoid running the generator on deck, unless you really have to- and ideally still earth the generator ashore (or to the hull as a last resort). Petrol generators will leak petrol vapour, as they warm up and petrol vapour, which is heavier than air, will sink and potentially collect in the bilge, which can for explosive mixtures. Running them on the bank is better. Also, never run them inside the boat, or inside the back doors, as carbon monoxide poisoning is highly likely (and has recently caused deaths on boats).
Take care storing the generator as well- petrol should be stored as you would gas and the generator itself should be stored where any vapour can safely leave the boat without entering the cabin, engine space or other enclosed areas. Petrol is very searching and small leaks can be problematic on boats. Don't be tempted to store the generator inside the boat, even if the tank is empty (as it will still contain petrol).
As for power, it depends on what you are intending to run. A 1000W generator (producing just over 4amps at 230V) will power most tools, run battery chargers, TV's, etc- but not most microwaves. Most microwaves need around twice the power of their rated output. To find out what you need, sum up the total input power of all the appliances you might want to run (and at the same time) then go for a generator with a slightly higher power rating- the maximum power of a generator is for one hour in six, normally- so a 1000W generator might only produce 900W or less continuously.
Something else to consider is that inverter generators produces (better than) mains quality output with a very pure sine wave and stable frequency and voltage. More conventional generators can produce less stable frequencies and this can cause issues with some sensitive electrical equipment, such as some satellite systems and TV's.
Let us know if we can be any more help.

Mark Langley  | 10.04AM, Wednesday 30 July

You are right about other boaters- I often see them running inside engine rooms or on the back step. Also, there have been a number of serious fires recently caused by leaking petrol on boats from cans or generators. Alas some boaters have a "it wont happen to me" approach. CO poisoning is a serious risk, as you can imagine.
You can always convert a 4-stroke petrol generator to LPG and have a fitting outside, so you can run them- and then you can store the genny in the boat safely when not in use. Plus you don't then have to store petrol, which is a bonus!

Mark Langley  | 5.57PM, Wednesday 30 July

Readers say:

Thank you Mark. My NB has a 1500w pure sine wave inverter into the system. I understand what you mean about having petrol and/or the generator running onboard and/or being stored onboard. I am a very safety conscious person yet it seems that looking at generators running on boats on the canal most people are not like me.

Trevor Smith  | 4.51PM, Wednesday 30 July

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