Purchased a Camroad Motor Home in Australia and it was originally fully imported from Japan, a great MH. Unfortunately during it's life in Australia there have been many electrical repairs due to equipment failure.
The work has been done from as far as I can tell from qualified persons but it is not professional work, therefore I'm repairing and testing all AC/DC circuits and creating a wiring diagram. My profession was a main frame computer engineer. Electronics is not a problem for me but I don't like to work on AC, but it is such a mess I need to check all the wiring. It's early days and have only done a mental assessment of the work needed to be done. There is an Earth Leakage Breaker (ELB) and have done no testing. Have had the MH connected to house power and all AC units work, and are they safe?
I also have a Yamaha generator GHS2000I that came with the MH. The generator works offline but don't know if it has ever been used as shore power and would like to do more AC investigation before plugging it in to the MH.
I'm not an AC expert but know enough about safety. I don't know if there is a AC leakage if the ELB will trip with the generator connected.
I also have a 4kw DC to AC pure sine wave inverter. Have connected it to the MH with the shore power disconnected. Made up an extremely dangerous male to male 3 pin lead and plugged it into the GPO point.
It ran the AC appliances with no problems, a microwave, jug, toaster and the AC fridge, an Electrolux RM4361. So far so good, have cut one of the male ends of the lead I made up. Safety.
Question 1, I need to know more about earth/neutral earth links so that if I connect the generator and there is a fault will it trip the ELB, the generator is above ground with rubber feet. My house has an earth stake and has a N/E link fitted in the meter box.
Being involved in electronics I have designed and built AC monitor that when the shore power is plugged and generator the circuit disconnects the DC/AC Inverter. Works great on the bench and reluctant to connect it to the MH circuits until I find out more about neutral and earths. The inverter has no earth connection to it's GPO outlet. 12v in and 220v AC out.
Question 2 In my design I have connected all neutrals together, AC shore power and the inverter, what happens with this sort ot connection? The neutral from the shore power is at earth potential where as the Inverter and generator are above earth and no neutral to earth connection.
Any comments would be greatly appreciated but please do not reply if you are not a well experienced electrician.
Welcome to the Forum Gazza, I will leave the advice regarding Alternating Current to others.
It is always difficult, sometimes dangerous, to work on any project that has had many supposedly qualified people making alterations to specifications.
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Possum; AKA:- Ali El-Aziz Mohamed Gundawiathan
Sent from my imperial66 typewriter using carrier pigeon, message sticks and smoke signals.
Hi Gazza welcome ! Note I am not a well experienced electrician so you might choose to ignore this post
In Australia it is not legal to work on 220V AC equipment unless you have the qualifications and ticket to do that. It does not matter if it is a house or a motorhome. For your safety possibly you should get a qualified person to do the checking.
From my limited experience the system in those imports is a dogs dinner anyway and might have been originally for 110 V as made and had foreign outlets etc and possibly has been modified to 220V without proper regard for any differences needed. Is the generator 110 or 240 V as they may come with 110 v units originally.
Who knows what the medium floating voltage of an inverter might be if not tied to anything ? it might be higher or lower than earth by any amount.
An ELB will not work if the system is not connected to earth. These have been discussed here as a better newer protection method.
As Jaahn has said only licensed electricians are permitted to work on low voltage systems.(240V is low voltage).
Get one and obtain a safety compliance certificate from the electrician.
I would recommend having it safety checked by someone else who will test the Earth Leakage Breaker for trip current and time.
Have them test and tag all your power leads too.
