PIR Test high Zs on 32 Amp RCBO

[Guest 004]

for what reason is it on a type C?. if no need for it, fit a type B.

I want to know if a 'C' will conform as it is on a RCBO.

 

[Chr!s]

Well if its been designed so that the rcd gives earth fault protection, then the Zs is acceptable

 

[IQ Electrical]

Well if its been designed so that the rcd gives earth fault protection, then the Zs is acceptable

Perfectly true, once continuity of protective conductors is confirmed, Zs is almost superfluous.

 

[lockwood]

sorry to say that last statement is wrong....page 49 of brb says type c requires 0.72 max zs to operate in required time to protect cable...type b requires 1.44 ohms, so as many others have said before change to a type b....unless there's a good reason not to

 

[Deleted member 9648]

what about Phase to Neutral faults?

See 435.1....A protective device meeting the requirements for overload protection can be assumed to meet the requirements for fault protection.

 

[Deleted member 9648]

sorry to say that last statement is wrong....page 49 of brb says type c requires 0.72 max zs to operate in required time to protect cable...type b requires 1.44 ohms, so as many others have said before change to a type b....unless there's a good reason not to

There is a good reason not to.....an RCD can be used to provide earth fault protection,as the protective device incorporates an RCD a max Zs of 1667 ohms applies.....you are incorrect....
Reg 411.4.9 and table 41.5

 

[Guest 004]

sorry to say that last statement is wrong....page 49 of brb says type c requires 0.72 max zs to operate in required time to protect cable...type b requires 1.44 ohms, so as many others have said before change to a type b....unless there's a good reason not to

what do you say that then IQ??

 

[IQ Electrical]

what do you say that then IQ??

I say refer to post 21 where it is summed up perfectly.

You are not using the overcurrent protective device to meet disconnection times, you are using the RCD.

 

[Guest 004]

I say refer to post 21 where it is summed up perfectly.

You are not using the overcurrent protective device to meet disconnection times, you are using the RCD.

excellent thank you

 

[lockwood]

an rcd does nothing to protect against overcurrent, which is the the thing you are trying to avoid by having a good continuity measurement...too high a continuity will delay tripping which could result in cables melting.....

 

[IQ Electrical]

What garbage, you think you need 'good continuity' for overcurrent protection?

I'm out.

 

[Sintra]

an rcd does nothing to protect against overcurrent, which is the the thing you are trying to avoid by having a good continuity measurement...too high a continuity will delay tripping which could result in cables melting.....

Think you need to do some reading up mate.


Sent from my iPhone using Tapatalk.

 

[Deleted member 9648]

an rcd does nothing to protect against overcurrent, which is the the thing you are trying to avoid by having a good continuity measurement...too high a continuity will delay tripping which could result in cables melting.....

411.4.9.....an RCD for earth fault protection is used as well as overcurrent protection.
435.1 ....A device meeting the requirements for overcurrent protection will also meet the requirements for fault protection.

 

[domestic spark]

There is a good reason not to.....an RCD can be used to provide earth fault protection,as the protective device incorporates an RCD a max Zs of 1667 ohms applies.....you are incorrect....
Reg 411.4.9 and table 41.5

dual rcd splitload board. 30ma. you dont have to meet the maximum ZS calculations for each circuit @ 80% because you also have an RCD? is that correct??? thanks

 

[jamie-spark]

check out page 44 in the OSG