Marina eWof requirements

[wheels 543]

 Sure. Below is a basic SMP to demonstrate. Note that the Output is isolated from the input side. Now in the case of this being a computer PS built inside a metal case, the Input and output Earth will be linked. But as you can see, as a circuit on it's own, the output is actually isolated and the design of the equipment the circuit is being used in, will determine if the grounds on both sides are linked or not.

[wheels 543]

To add, some very basic PSs based on a simple transformer, can use a simple auto-transformer. This is a single winding and is cheaper to make than an isolated secondary winding tx. Also, with some simple trickery using a capacitor, a certain amount of current regulation can be set up and make the very simple circuit a regulated circuit of sorts. Many Chargers that have the option of dual voltage output, or current control via a simple switch or rotary switch can be made using an auto-transformer.

[smithy09 50]

Wheels, I thought that most SMPTs had a full transformer with isolation on the secondary. Most battery chargers should be fine I would have thought. I must test mine.. 

[mattm 98]

Some of the smart chargers link AC earth to DC negative, that's why CTEK now do a marine charger that does not link them. It also doesn't cost much different to the standard charger - no 'marine' = usual price^2. Good on them.

[mattm 98]

Does it occur to anyone else, that with all the recent noise about what YNZ do / don't do for the average non racing boater, that this would be a great opportunity for them to get involved as advocates for all boaties, and ensure we have a voice against silly rules, lack of consistency, an input into new standards or revisions etc. seems glaring obvious way for them to be able to stand up and say 'we effected change that will save all marina based boat owners $$$$'.

 

We otherwise lack a combined voice to challenge things like this. Are YNZ not our combined voice?

[smithy09 50]

Nice idea Matt M. YNZ, feel free to wade in!!

[bazzathemammoth 37]

Thanks for that wheels. How many of those power supplies have a transformer in them do you reckon similar to what you posted? In your second diagram with the auto transformer, the secondary is still linked to the primary N, so will it still have stray current issues potentially causing corrosion?

[wheels 543]

All SMPs have a Transformer, because that is how they work. Transistors switch a DC pulse backwards and forwards in Polarity at a very high frequency, through the Tx. and that creates the voltage in the secondary winding.
But that part is not really the issue to worry about. It depends totally on whether the Primary side the Secondary side have a common Earth. Most usually, it will. Simply because it is easy to solve certain issues of RF noise and safety etc. So if the output is to be isolated, it is designed to be that way for a reason and a Marine charger would be one of those reasons.
The auto-transformer units can be both el cheapos or more expensive large workshop chargers that have current or voltage selection. As you can see, one winding makes it real easy and thus cheap to make a transformer.
Chances are, chargers will be as you have expected, BUT!!!! don't just assume. You really do need to check just in case.
 

[smithy09 50]

http://www.stuff.co.nz/nelson-mail/news/92737138/tahuna-holiday-park-tenant-evicted-after-7-years-my-rights-have-been-taken-off-me 

 

This is where the stupid regs can take you!!

[Chloe 7]

http://www.stuff.co.nz/nelson-mail/news/92737138/tahuna-holiday-park-tenant-evicted-after-7-years-my-rights-have-been-taken-off-me 

 

This is where the stupid regs can take you!!

 

I would suggest that it is abuse of the reg's. 

[ScottiE 174]

Sadly we for people like this we live in a sad world.

[marinheiro 352]

It is not as if the basic requirement for an EWOF is something new in NZ. I know on the marine side it was not until after ~2000 that the marinas started enforcing this, but I remember as a kid when we went on family caravan holidays a long time before that (like when the One ton cup was first raced in NZ) that the caravan had to have an EWOF. When we arrived at a caravan park the manager would usually walk around the caravan to check for it being there/current

Maybe it was unfair for the guy to be kicked out after getting his EWOF, but he should never have been connected in the first place and spent years flying under the radar.

[Island Time 1,214]

OK, an update to this older thread.

The 1st point to note is that the 2014 version of the "regs" IS NOT LEGAL. It has not been sighted, and is therefore not (yet accepted) by the electrical regulators. So the 2008 version is the one that is actually current.

Many marine electricians and inspectors were wrongly trying to enforce these "new" regs. That has mostly been stopped, according to my inspector.

 

I have just installed, and had inspected and passed this morning, a new AC install in Island Time (only had the Ebox before). The Ebox IS LEGAL , but is not accepted by some (most?) marinas at this point.

 

What I added was this: 

A 16 amp supply socket in the boat,  Earth wire form that broken by a galvanic Isolator, Phase and Neutral leading directly to an RCD, then a BEP AC Panel (Source selectable, shore-power or inverter, with breakers and restrictive switching so you can only have one AC source at a time), then to a double plug socket. There is a connection between the AC earth and the DC - . IMO this is essential - if you want to understand and know why, read this http://www.smartgauge.co.uk/earthing.html 

 

Total cost, incl inspection and issuing of ewof, about $1200. I will add a 2nd RCD on the Inverter output, as I think that would be sensible - but not required.

 

Finally, NO electrical standards are retrospective - they mostly only apply to vessels built after they were published AND sighted!!

[Beccara 25]

Thanks for the update!

[w44vi 17]

I am very confused about all of this, I have asked the marina but they don't know and could not tell me what code they are working to ! They just gave me a name of an electrician I could employ to tell me what I need.

 

All I want is to have a battery charger on from time to time to top up the batteries, so it would be unattained.

They are telling me I need to wire the boat up with an RCD, I would have thought the RCD on the pedestal should be protecting the lead and hard wiring the boat up is just duplication of this    

[wheels 543]

 

The 1st point to note is that the 2014 version of the "regs" IS NOT LEGAL. It has not been sighted, and is therefore not (yet accepted) by the electrical regulators. So the 2008 version is the one that is actually current.

Many marine electricians and inspectors were wrongly trying to enforce these "new" regs. That has mostly been stopped, according to my inspector.

How on earth did the 2014 reg get into the hands of sparkies if it had not be "accepted" and made law?

 

 

 

All I want is to have a battery charger on from time to time to top up the batteries, so it would be unattained.

Did you mean " unattended" ? If unattended, then no you can't leave it plugged in via an extension lead to shore power. You must have an " installed" system.

 

They are telling me I need to wire the boat up with an RCD, I would have thought the RCD on the pedestal should be protecting the lead and hard wiring the boat up is just duplication of this  

      Yes it is easy to think it is just doubling up, but it is not quite so. RCD's on the jetty are usually 60mA trip current and a slightly slower trip speed. The RCD on your boat, should be 30mA trip current and a much faster trip speed. This means that if your boat RCD trips, the fault should not trigger the RCD on the Pedestal. The one on the Pedastool is there to protect an possible fault on the Pedestool or the Lead running to any vessel. The RCD on the boat protects the Boat system. As there can be more than one vessel plugged into some Pedestals, it is not good to have a Fault on the boat tripping the main Shore power and taking other vessels off line.

 

[Black Panther 1,579]

A small solar panel?

[w44vi 17]

Thanks for you reply's

 

A small solar panel?

I think that is probably best, just a bit of a nuisance having to take them in with winds regularly over gale force 

 

 

Did you mean " unattended" ? 

Auto correct 

[Island Time 1,214]

Why take in solar panels? Mine, on top of the bikini, flexible type, have survived winds over 60 knots, no problem. Make a decent mount, and it will be fine. Don't let the wind get under them.

[Myjane 40]

I have a silly question , I brought a new 15 mtr power lead of heavy duty size for building work and any other use , boat , etc but it does not have a safety tag , so I have to take it to an electrical outfit to have it cleared for use , well ,