Adjustable trip device for EHU

[ProfJohnL]

Hi Prof, What I was querying was the necessity to have private touring caravan electrical work certified. My understanding is that once you plug into a different ECU any certification you may have had done is invalid.

Hello Chris - not sure what you mean by "ECU"

 

[chrisbee1]

Hi Prof, What I was querying was the necessity to have private touring caravan electrical work certified. My understanding is that once you plug into a different ECU any certification you may have had done is invalid.

Hello Chris - not sure what you mean by "ECU"

Sorry, senior moment. I meant EHU

 

[ProfJohnL]

Hi Prof, What I was querying was the necessity to have private touring caravan electrical work certified. My understanding is that once you plug into a different ECU any certification you may have had done is invalid.

Hello Chris - not sure what you mean by "ECU"

Sorry, senior moment. I meant EHU

Ah Ok, What did you ask??? :huh:

Actually, the certification on the caravan relates to the wiring and fixed appliances inside the caravan so remains valid. What it can't do is certify the EHU cable. Generally if there is a dangerous fault on the EHU cable, either the sites bollard will trip, or the RCD inside the caravan will trip.

 

[bertieboy1]

Hello Prof,
If there is a fault on the EHU cable the van CB won't see the fault and trip - only the EHU MCB will trip.This is true for both overcurrent or earth fault conditions.
For the van MCB to trip the fault has to be after the MCB ( on the load side).

 

[ProfJohnL]

Hello Prof,
If there is a fault on the EHU cable the van CB won't see the fault and trip - only the EHU MCB will trip.This is true for both overcurrent or earth fault conditions.
For the van MCB to trip the fault has to be after the MCB ( on the load side).

I would agree Bertie,
An further on finding any verifiable links to the earlier point about parallel and series MCB's?

 

[bertieboy1]

Hello Prof,
I don't have a verifiable link to back up what I've said which is based on the commercial document of a relay manufacturer I used some years ago and have no doubt of it's correctness based on my knowledge and experience.
Not all technical issues have the comfort of verification and you have to fall back on your experience and knowledge to make up your mind of it's correctness.

 

[ProfJohnL]

Hello Prof,
I don't have a verifiable link to back up what I've said which is based on the commercial document of a relay manufacturer I used some years ago and have no doubt of it's correctness based on my knowledge and experience.
Not all technical issues have the comfort of verification and you have to fall back on your experience and knowledge to make up your mind of it's correctness.

Quite so Bertie :cheer: ,

But the information you have just given casts a different shadow on the subject. :dry: Relays do a different job and are controlled in a very different way to MCB,s, and yes I have seen references to parallel and series relays to match current and voltage requirements.

 

[bertieboy1]

Hello Prof,
You've missed the point - slightly,we're discussing the ability of contacts switching different voltages/currents with different contact configurations not the control of these devices that make contacts operate.

 

[ProfJohnL]

Hello Prof,
You've missed the point - slightly,we're discussing the ability of contacts switching different voltages/currents with different contact configurations not the control of these devices that make contacts operate.

I'm sorry Bertie, but I have only been discussing the parallel operation of MCB's, and you answered that post, so I assumed you were telling me you had experience of parallel MCB's to increase the current capacity of a circuit.
The problem is not the current capacity of contacts, but the way the MCB detects the current flowing.

 

[RayS]

What a great discussion a simple question can start.

I'm with Dusty about starting in a largely diy era and also I shall continue to to so as long as I can bearing in mind physical limitations such as vision and knowledge limitation of years of retirement.

I have been concerned with safety related and safety critical installations most of my working life and have a pretty strong regard for my own safety and that of others so do not take any risks. Equally I continue to use the professional knowledge and expertise I have to solve the problems which inevitably arise in our hobby/addiction.
What will suffice for a rig to make a one-off test in homebase circumstances dry conditions will probably not be suitable for long term use on a wet rural continental campsite with unknown electrical safety standards. Heath Robinson has his place and most of his devices could actually work in principle.