High earth loop on bathroom light with fan?

[whazza22]

Hi there

I was testing the earth loop on a bathroom light with the fan pull switch turned OFF (not double pole) and got a reading of 330 ohms.

When I turned the fan on, the reading was down to 0.60 ohms which is obviously ok.

Would this be due to the neutral not being switched from the pull switch?

Thanks

 

[ExArmy]

how is it wired up exactly? It won't be anything to do with the neutral, earth fault loop is just the resistance of live and earth

 

[Silly Sausage]

With the switch off, I reckon that you're measuring the loop resistance of the fan load, neutral and earth conductors.
Switch on, the Line conductor is in parallel with the fan load & neutral, so your Zs of 0.6 will be slightly less than if you measured it with the fan disconnected.

 

[telectrix]

all depends on where you are measuring at. if you're measuring at the fan switched L, then the fan switch needs to be on

 

[whazza22]

I was measuring at the bathroom light between perm live, neutral and earth then between switch live, neutral and earth. Both giving a reading of 300+ ohms. The insulation resistance is fine.

The fan is wired directly from the light with a perm live, switch live, neutral and earth so the fan runs after light is switched off.

As soon as I switch the fan on, the readings are all fine. It's just when the fan switch is off so I'm assuming its because the neutrals aren't switched?

 

[tony mc]

What are you R1 R2 results for the circuit when dead testing as this doesn't sound right!


What tester are you using?