RCD Ramp Testing - Tripping the RCD

[Nicholas Owen]

I am new to this site.

Am I right in saying that the Ramp Test should not trip the RCD during the tests?

I am using the Metrel MI3000, just had it, been using a different one without the ramp test prior to this

The results I am getting are:

t3 (IΔN, 00) 27ms - Tripped RCD

t4 (IΔN, 1800) 26ms - Tripped RCD

t5 (5

 

[septiclecky]

Yes a ramp test should trip a RCD as it shows at what the actual current the RCD trips at.

 

[Robin Spark]

Hi Nic,

although I am not familiar with the Metrel, from your post it does not look like you are doing a ramp test.

to me it looks like the standard sequence of an auto test on a rcd.

Also your first 2 tests have not tripped the rcd at 1/2 x I delta n

Your 3rd and 4th tests at 1 x I delta n have tripped the Rcd with the greatest reading at 27ms

Your 5th and 6the tests at 5 x I delta n have tripped the rcd with the same value at 14ms.

To me everything looks fine as it should be

Are you new to testing?

Also a ramp test will tell you the mA value in which your RCD operated and wouldnt give a millisecond value.

 

[Nicholas Owen]

Im new to Ramp Testing - never used it before, but time came for a new meter so got one with a ramp test.

Does anyone know how to set up the Ramp Test on the MI3000?

The test was an auto Test, but I presumed it was the Ramp Test as said above not used this before, and it is a new meter to me.

Help would be great.

---------- Post Auto-Merged at 18:51 ---------- Previous post was made at 18:47 ----------

Just thinking then, if it gives the trip current thats not what I am mainly after, it has a trip current as well which does trip the RCD at 22.5mA

Of course this still passes as it is a 30mA RCD.

As I thought I probably not setting it up correctly as I am not familiar with this meter at all

---------- Post Auto-Merged at 18:55 ---------- Previous post was made at 18:51 ----------

When doing the RCD Trio Current Test it also gives me (as well as the current) VC - 0.0v (as before) and t1 - 18ms (as before) which is what I would expect.

I have a big job on Friday testing over 20 circuits in this one house so the Ramp Test would be great as it would save me alot of time running back to the meter resetting the RCD every test I do.

Thanks in advance

---------- Post Auto-Merged at 19:02 ---------- Previous post was made at 18:55 ----------

Just been reading another forum about ramp testing and found out that I got a little mixed up with the function of the ramp test. - woops!

Thanks everyone

 

[m4tty]

A ramp test gives the amperage that the rcd trips at ie normally around 22mA. The auto test on your meter you set to start, leave the meter and stand at the rcd when it trips you reset it and wait till its finished tripping then go read the results off your Meter

 

[Sharpend]

Nic it sounds as though you are getting confused with terminology.

There are two types of RCD test. The first is the trip time tests of 1/2, x1, x5 this is the test required for bs7671 certification. The second test is a current test. The result of this is not required for certs it indicates the tripping current needed to trip the RCD.

Most testers now have the Auto function for the trip time test thus saving you running back and forth.

Although if you are testing as per the regs then tests should be carried out as close to origin as possible.

 

[lineman]

Ramp test on the metrel is displayed as ms and mA before testing. Think it's setting 11 and 12? Maybe wrong there but it will let you know trip time in ms and trip current at RCD rating at both 1x and 5 x

 

[SPECIAL LOCATION]

Ramp test is NOT Auto test...

two different beasties....

headbang

If you don't know how to use your meter now I would suggest you re-arrange the appointment for Fridays big job....

Until you have learned how to use your tools!! :C

 

[lineman]

Two different tests.... In fact three trip time on one setting, trip current on another and auto on another.

 

[OnOff]

Have another read of the manual IMO. On my Megger, when doing the ramp test a little "ramp" shaped icon (black triangle) comes up. On ramp it increases the tripping current until it trips then records that.

Metrel for some bizarre reason call what most people know as a "ramp test", "TRIP OUT CURRENT", same thing just odd. Just looked at the Metrel manual, have you actually got this? Link here:

MI 3000 Easi PLUS: Metrel d.d.

It also appears to use the little black triangle symbol for "ramp" testing!

p.s. If I were you I'd refer to it as ramp testing rather than trip out current in future!

 

[Andy™]

i think you need to cancel your friday job and learn how to use your test kit & how to test an RCD.

also, if you dont know what a ramp test is, then are you sure your competant to be I&T

 

[Jono Pashley]

Eh? press the up down arrows and cycle through the different tests, left and right arrows to select a different parameter to change. Pretty simple meter to operate..

 

[Nicholas Owen]

Nic it sounds as though you are getting confused with terminology. There are two types of RCD test. The first is the trip time tests of 1/2, x1, x5 this is the test required for bs7671 certification. The second test is a current test. The result of this is not required for certs it indicates the tripping current needed to trip the RCD.

Most testers now have the Auto function for the trip time test thus saving you running back and forth.

Although if you are testing as per the regs then tests should be carried out as close to origin as possible.

Sharpend hit the nail on the head.

I had several meters and was fed up of changing between each one to do different tests.

The RCD Test Meter I had didnt have the auto test nor did it have a ramp test - an old unit but still calibrated with no problems - sold on ebay so thats gone.

I had a play last night and worked out all the new features on it. When I was sold this meter I was told I would not have to leave and the ramp test will do all the required tests without tripping the meter - I went along with it and paid

 

[ProDave]

Why are you testing the RCD from 3 floors away?

Yes you test your Zs at the end of the circuit.

But unless I'm unique, I test the RCD's at the board. I thought that was easiest and what you are supposed to do. No running about to reset them.

 

[Doc Hudson]

ProDave is correct RCDs should be tested as near as practical to the RCD itself and with all loads disconnected. So there wont be any running up and down floors.

Doc H.

 

[elec dept]

Agree with Doc Hudson.

As stated in the OSG 11.1 "The tests are made on the load side of the RCD,as near as practicable to its point of installation and between the line conductor of the protected circuit and the associated circuit protective conductor. The load supplied should be disconnected during the test."