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MCCB with RCD bolt on, anyone know how to work these settings out? Ignore settings now but this is upfront RCD TT system so I want to top one to be 0.3 for 300mA but unsure on bottom?
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Yes I know lol not set it yet, obviously it’s upfront RCD so for discrimination I’m gonna set to 300mA as various other panels have 100mA but how would I set msTop one is currently set to 500ma
Bottom one is currently set to 500ms.
put a screwdriver in the slot and turn it..Yes I know lol not set it yet, obviously it’s upfront RCD so for discrimination I’m gonna set to 300mA as various other panels have 100mA but how would I set ms
New to me didn’t know that so it’s wants to be 1 for TY?I not sure I understand the question. You do realise that the time setting on the device is marked in seconds, and so you need to convert milliseconds to seconds?
It was left on 0.1 so 100mA and was nuisance tripping, hench I’ve changed to 300mAAs a matter of interest, why does it need to be changed?
Yes that was all, couldn’t find anything online I knew how to set current just the timeIs the question, what is the appropriate time delay setting for the installation?
The minimum that doesn't cause a nuisance and at or below the reg requirement or customers spec.
Yes I’ve only seen a couple of these, on another vary similar model it also has the option for ON and TEST which is a good featureThat is commonly called a vigi module. You will notice when set for 30ma there is a line down indicating to set to no delay so additional rcd protection is provided.
Yes all sub circuits and feed from mains all tested fine with IR, now set to 300mA it’s all fine there’s discrimaination now 300mA to 100mA and so on, just didn’t understand the bottom dialSo does that acheive disconnection times satisfactorily now that you have changed it to 3 x the original ma? Is it not the case if it is tripping that some investigation may be due? Maybe IR tests if it is possible?
Yes all sub circuits and feed from mains all tested fine with IR, now set to 300mA it’s all fine there’s discrimaination now 300mA to 100mA and so on, just didn’t understand the bottom dialSo does that acheive disconnection times satisfactorily now that you have changed it to 3 x the original ma? Is it not the case if it is tripping that some investigation may be due? Maybe IR tests if it is possible?
It’s at 1Out of interest,what did you set the delay,to?
???Has anyone set one up before and could tell me? Or know how to
It’s the bottom dial I can’t understand? So it just works on disconnection time but in milliseconds? So say I have no greater than 32A final circuits on TT which is 0.2 seconds then what do I set it?It's a wind up this one. Guaranteed
Ok so it’s TT, in this panel you have Main MCCB/RCD one in picture then 3 X BS88 fuses which feed some electric boxes with 16A sockets with relevant 30mA RCBOsBut you were asking what delay a TT circuit should be set to. Are you saying you know this, but need to convert seconds to milliseconds?
To answer that, there are 1000mS in a Second.
Thanks is there a way to understand how to set the time delay?It is a variable earth leakage modual that is used with a mccb eather bolted on or using a shunt trip module
The top part is to set trip current
Bottom is to set a time delay
They are mainly used on sub circuits or large motors ect were the time delay can offer some sort of discrimination
Remember earth leakage is cumulative
Thanks is there a way to understand how to set the time delay?It is a variable earth leakage modual that is used with a mccb eather bolted on or using a shunt trip module
The top part is to set trip current
Bottom is to set a time delay
They are mainly used on sub circuits or large motors ect were the time delay can offer some sort of discrimination
Remember earth leakage is cumulative
I’m not sure what the regs require? I know how to set trip current but not the trip delayI'm still confused. Do you not know what the regs require, or do you not get the seconds/milliseconds thing?
It’s TT system so this is the upfront RCD, all there is down stream is 30mA RCBOs at boxes protecting socketsFirst you need to know what function it is required for. Secondly you need to consider upstream devices and how they are operating then the vigi module can be set to ensure coordination is achieved.
No, of course not.So my final circuits are no greater than 32A on TT which is 0.2 seconds so I can set the trip delay to 0.3
Supply to 3 X BS88 in same panel, then onto some boxes with 16A sockets and relevant 30mA RCBOs in boxesWhat is the mccb which the module is fitted to supplying.
So just set to your diconnection time?No, of course not.
You have to set it to 0.2, or less.
Yes, you can’t set it to higher than the maximum disconnection time allowed.So just set to your diconnection time?
If you were using it to protect distribution circuits or other circuits greater than 32A, yes you would set it to 1s.Thanks guys really appreciate your time
So if it was more than 32A TT system I’d set it to 1.0 second for instance?
That is commonly called a vigi module. You will notice when set for 30ma there is a line down indicating to set to no delay so additional rcd protection is provided.
BS7671 appears to have dropped the requirement for 30mA RCDs to operate within 40ms.
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