Plug in Galvanic Isolator.. which one

[Big Bob W]

42 minutes ago, Sea Dog said:

So, anyway, after all that lot ^^^^, have you considered a built in one? There's a greater choice, it's not going to get damaged or dropped in the cut and it's always in circuit so you avoid the chance of forgetting to connect it.  Its a very easy thing to fit taking only minutes, so if you are not able to fit it yourself, it shouldn't cost much - likely enough still within the cost of the in line versions you're considering.

It’s not going to get nicked either!

It really is a simple job.

[blackrose]

3 hours ago, WotEver said:

The explanation has already been given and yes you are correct, none of those are any good. 

I thought Safeshore were meant to be some of the highest spec GIs?

[WotEver]

8 minutes ago, blackrose said:

I thought Safeshore were meant to be some of the highest spec GIs?

Not really. Their web page is flashy and their products are low cost. Just compare their specs with this: https://www.newmarpower.com/wp-content/uploads/2016/02/Manual-GI-3050.pdf

[blackrose]

1 hour ago, WotEver said:

No!

 

Safeshore fault current: 70A

Newmar fault current: 5000A

 

Can you see the difference?

I can see the difference but is the 500amp current rating given in the plug in GI in the original post the same as a fault current rating? I'm not completely convinced by what you say only because I know that Safeshore are some of the best.

[WotEver]

1 minute ago, blackrose said:

I know that Safeshore are some of the best.

Based on what?

[blackrose]

4 minutes ago, WotEver said:

Not really. Their web page is flashy and their products are low cost. Just compare their specs with this: https://www.newmarpower.com/wp-content/uploads/2016/02/Manual-GI-3050.pdf

Can't read that on my phone as I'm getting pop-ups asking me to pay not to see ads. 

[WotEver]

1 minute ago, blackrose said:

Can't read that on my phone as I'm getting pop-ups asking me to pay not to see ads. 

No idea why, it’s only a pdf

[blackrose]

Just now, WotEver said:

Based on what?

Based on discussions on this forum over several years, some of which included Gibbo who said if you must use a GI rather than an IT get a decent high spec one. He agreed it was a decent spec and so did Chris W who has an electronics engineering background and who I am still in contact with. Both have long left this forum.

[ditchcrawler]

Personally I wouldn't put anything that can fail in my earth conductor, but that's me.

[blackrose]

I'll do a bit more digging and if Safeshore do turn out not to be any good as you say, then I'll get rid of it and buy something else.

Just now, ditchcrawler said:

Personally I wouldn't put anything that can fail in my earth conductor, but that's me.

Anything can fail including an IT. That's also been discussed here many times. Or do you mean no isolation at all?

[WotEver]

7 minutes ago, blackrose said:

Based on discussions on this forum over several years, some of which included Gibbo who said if you must use a GI rather than an IT get a decent high spec one. He agreed it was a decent spec and so did Chris W who has an electronics engineering background and who I am still in contact with. Both have long left this forum.

That was years ago. Things have moved on. The AYBC spec was created for a reason and I do not believe that the Safeshore GIs meet that spec, although I’ll be happy to be corrected on that if I’m wrong. 

 

Fwiw, I speak with Gibbo daily. 

 

Oh, and I have an electronics engineering background too...

 

3 minutes ago, ditchcrawler said:

Personally I wouldn't put anything that can fail in my earth conductor, but that's me.

There’s at least two of us

 

Edited January 16, 2019 by WotEver

[David Mack]

Is the Newmar GI actually available in the UK? A quick google only finds US suppliers (or Amazon - out of stock).

[WotEver]

2 minutes ago, David Mack said:

Is the Newmar GI actually available in the UK? A quick google only finds US suppliers (or Amazon - out of stock).

Probably not. I was searching for the AYBC spec when I came across it. I simply used it as an example to compare specs. 

 

You’ll know the difference when you find one that meets the spec because they’re a lot more expensive. 

[WotEver]

A couple of Sterling GIs that I believe meet the AYBC specs (note the difference in cost):

https://www.sp-shop.co.uk/Pro-Save-FS/

[blackrose]

19 minutes ago, WotEver said:

That was years ago. Things have moved on. The AYBC spec was created for a reason and I do not believe that the Safeshore GIs meet that spec, although I’ll be happy to be corrected on that if I’m wrong. 

 

Fwiw, I speak with Gibbo daily. 

 

Oh, and I have an electronics engineering background too...

 

There’s at least two of us

 

I wasn't questioning your background but I was questioning your statement that the Safeshore GIs were no good. Things may have moved on but the GIs are still as good as they were when Gibbo and others agreed they were decent spec. 

 

So you have no form of isolation too? Is that what you mean?

4 minutes ago, WotEver said:

A couple of Sterling GIs that I believe meet the AYBC specs (note the difference in cost):

https://www.sp-shop.co.uk/Pro-Save-FS/

So they are good despite only being rated at 30 amp and 60 amp? Something isn't quite right... I think we may be comparing apples and oranges when it comes to the earlier current ratings.

Edited January 16, 2019 by blackrose

[WotEver]

Victron’s GIs have a 3200A failure rate which is good:

https://www.victronenergy.com/isolation-transformers/galvanic-isolator

[blackrose]

1 minute ago, WotEver said:

Victron’s GIs have a 3200A failure rate which is good:

https://www.victronenergy.com/isolation-transformers/galvanic-isolator

But Sterling only have a 30A and 60A failure rate and they are good too? I don't get it?

[TheBiscuits]

2 minutes ago, blackrose said:

But Sterling only have a 30A and 60A failure rate and they are good too? I don't get it?

Pro Safe FS Features UL Certified 205007 ABYC A-28 July 2008 Compliant and Fail Safe Certified: certified by Underwriters Laboratories.(UL). Insures shore power safety ground wire is maintain through the isolator. Flat Pack High Power Semiconductors: robust high power diodes allow the FS Series to meet the new FailSafe criteria for conducting inrush currents of 5000 amps for the required duration

 

 

 

You are doing what @Flyboy was doing earlier in the thread.

 

The 30A or 60A is the continuous current the GI can carry in normal usage.

 

The 5000A current is the current it can withstand long enough for the trip to blow in a catastrophic fault condition.

Edited January 16, 2019 by TheBiscuits

[WotEver]

2 minutes ago, blackrose said:

I was questioning your statement that the Safeshore GIs were no good. Things may have moved on but the GIs are still as good as they were when Gibbo and others agreed they were decent spec. 

Agreed, but a good 1960’s car wouldn’t be considered as a good car today. In the same way more is understood about failure modes of GIs and what used to be considered a good spec a few years ago wouldn’t be considered a good spec today. The IEE regs have now progressed to the 18th edition not for fun but because more is understood, better products are available, better working practices are mandated etc. Likewise a GI that can fail and give you no earth protection at all is obviously not a good idea, hence the AYBC guidelines. 

10 minutes ago, blackrose said:

So you have no form of isolation too? Is that what you mean?

No. You either have a GI that fails ‘safe’ in accordance with the AYBC spec, or better, use an IT that doesn’t concern itself with such matters. 

7 minutes ago, blackrose said:

But Sterling only have a 30A and 60A failure rate

No they don’t. It’s 5000A for the FS GIs. 

[WotEver]

9 minutes ago, TheBiscuits said:

You are doing what @Flyboy was doing earlier in the thread.

 

The 30A or 60A is the continuous current the GI can carry in normal usage.

 

The 5000A current is the current it can withstand long enough for the trip to blow in a catastrophic fault condition.

Spot on

 

[WotEver]

54 minutes ago, blackrose said:

I'll do a bit more digging and if Safeshore do turn out not to be any good as you say, then I'll get rid of it and buy something else.

Simply ask them if their GIs meet the AYBC specification.

 

If they say “Yes” then that’s great; please let us know. If they say “Waffle, waffle, it’s only theoretical, it’s not necessary...” then that’s another way of saying “No”. 

[cuthound]

10 hours ago, ditchcrawler said:

Personally I wouldn't put anything that can fail in my earth conductor, but that's me.

 

When I was working in the critical power industry, where reliability and availability is paramount, every failure was recorded, investigated and analysed.

 

Wound devices (transformers, inductors, relays etc) were about three times more likely to fail than semi conductors. Although everything was well designed and built - no cheap Chinese stuff in data centres (even though Huawei provide the equipment for BT's "21st Century" VOIP Network ?)

[Sofia]

Thank you everyone

[Sea Dog]

8 hours ago, cuthound said:

 

When I was working in the critical power industry, where reliability and availability is paramount, every failure was recorded, investigated and analysed.

 

Wound devices (transformers, inductors, relays etc) were about three times more likely to fail than semi conductors. Although everything was well designed and built - no cheap Chinese stuff in data centres (even though Huawei provide the equipment for BT's "21st Century" VOIP Network ?)

Interesting stuff CH, I hadn't come across such a statistic. I'm scratching my head to try to think whether my own experience bears that out, but first I thought it might be different with milspec stuff anyway, and then I thought critical power industry stuff is likely to be built to similarly high specifations, so I'll stop before I tie myself in knots!

 

No cheap Chinese stuff in data centres?  I wonder if that is because, as alleged spy equipment, it may also be milspec?

 

[cuthound]

6 minutes ago, Sea Dog said:

Interesting stuff CH, I hadn't come across such a statistic. I'm scratching my head to try to think whether my own experience bears that out, but first I thought it might be different with milspec stuff anyway, and then I thought critical power industry stuff is likely to be built to similarly high specifations, so I'll stop before I tie myself in knots!

 

No cheap Chinese stuff in data centres?  I wonder if that is because, as alleged spy equipment, it may also be milspec?

 

 

Data Centres don't use milspec, which is usually to allow kit to be dropped out of planes or survive extremes of temperature, but good quality commercially available stuff.

 

Plenty of Chinese equipment, but only high quality, high spec stuff (think iPhone quality).

 

Many spying concerns when BT bought Huawei equipment, but nothing proven to date. One concern was whether the Chinese could turn off our communications in the event of a war, again unproven (not sure how you could test for that).