Ramp test ???

[Robj63]

Whats a ramp test when its at home? and how is it carried out?

cheers from a keen mature student

Rob

 

[Doc Hudson]

It is a function of some RCD test meters, rather than just giving the operating trip times, it will increase a trip current value until it can give the actual leakage current when the RCD trips.

Doc H.

 

[Megaohm7]

It's a way to see at what current an RCD, RCBO actually trips out. A 30mA rated device shouldn't take more than that to trip it. You will find in a lot of cases it will be around 25mA. My Megger MFT 1552 can do this test. To test a socket circuit for example that is RCD protected, You would plug in the tester on the ramp test and press the test button and that should give you the reading you need.

 

[Doc Hudson]

Just to add its not a specific requirement of the wiring regs but can be very helpful to establish if an RCD is oversensitive when fault finding. All the regs ask for is to prove its above 1/2x and that the 1x & 5x are within the max permitted times.

Doc H.

 

[Megaohm7]

+1

 

[a1]

I think he may have been hinting on how to one?

 

[m4tty]

Majority of the 30mA ones I've ramped are 22-23mA

 

[Manator]

Admin has posed a very intricate problem into the discussion, why and how!

ramp tests on any RCD's or RCBO's are a very good indication to circuit design , we try to install and design to a specific client request and restrictions imposed by clients, requires us to be on our toes and give them what they want when they want it. Ramp tests are very useful, they indicate the sensitivity, of any particular RCD, so that we can chose the most fitting for the purpose of design.

Incidentally the differences are so small it is not even worth bothering about.

My advise?

Just go with good design

 

[Robj63]

Thanks everyone for taking time to reply, much appreciated again, I get the gist of it now

thanks

Rob

 

[Doc Hudson]

It is a good example of a test that is very useful in the real world of electrical testing, but not specifically required by the wiring regulations, so is not mentioned much, or at all, in college because it probably never comes up in any exam questions.

Doc H.

 

[Zeespark]

It doesn't Doc, neither does testing the RCD in isolation, I am scouring My books to find out how to actually do both these tests (what probes go where etc), havent found anything yet though.

AndyGuinness

 

[a1]

It doesn't Doc, neither does testing the RCD in isolation, I am scouring My books to find out how to actually do both these tests (what probes go where etc), havent found anything yet though.AndyGuinness

I think an explaination of how to, would be better on the "Tips & Tricks" forum and not a public one.

 

[Zeespark]

I don't disagree Admin, but I want to try and find the information for Myself first and share it here (tips and tricks section), rather than you guys giving Me directions to find it in the first place.

AndyGuinness