Rcbo trip test

[frankie310581]

rcbo type b 6 amp feeding to lights

ramp test 25ma

1/2 test >1999ms

1x test 32.4ms

5x test >40ms

anyone now what can be causing the 5x test to fail

Rcbo has been changed and it is still the same banging my head

 

[Sidewinder]

frankie,

Where are you testing this?

 

[frankie310581]

tested at rcbo and end of circuit got the same

 

[frankie310581]

there is a pir on the lights do you think it could be that it's all I can think of

 

[NozSpark]

Did you do it with the circuit connected or did you disconnect it (fully)???

 

[Sidewinder]

^ as Noz?

 

[frankie310581]

connected

 

[Sidewinder]

Ah, there probably lies your issue!

OK think about the properties of the cable and devices in the circuit and the affect these could have on the test.

 

[NozSpark]

What supply type is it?

Did you carry out any IR tests on the circuit?

 

[frankie310581]

as I was thinking the pir? ok but how do you get round this on the cert as the pir will be in circuit under normal use

 

[Sidewinder]

Is it the PIR?

What else is in the circuit?

How long is the total cable run?

 

[frankie310581]

it is tns 0.13ze PFC 1.74ka

yes ir done >299

 

[frankie310581]

to 4in fans and 2 2d lights

4 meters max 1.5 t&e lsf ( low smoke )

 

[NozSpark]

Cool,,

Some times if you have a N-E fault on a TT installation it can give you similar symptoms

 

[Sidewinder]

OK you have the pir full of electronics, the 2d lights possibly with a ballast and/or possibly some electronics and 4" fans, with motors & possibly some electronics all connected to the cable run, which is how long in total?

 

[Doc Hudson]

as I was thinking the pir? ok but how do you get round this on the cert as the pir will be in circuit under normal use

The on site guide is an IEE publication and that suggests testing with loads disconnected so I cannot see a problem. Surely they know what they are talking about?

Doc H.

 

[Sidewinder]

Doc,

Where I'm trying to go is for the OP to understand why...

 

[frankie310581]

but that's like saying the brakes on your van work when you are parked on the drive but not when doing 70 on the motorway so I will test them on the drive

don't you agree

 

[Sidewinder]

frankie,

Think about the circuit, is it wired in T&E?

With all those devices connected yes the circuit charateristics change.

Are you familiar with Heisenberg's theories?

What meter are you using?

 

[frankie310581]

megger mft 1553

no can you enlighten me