Switching on Main Switch in Meter Box after new/replacement installations

[natkingcole]

Hi Everyone,

My name is nathan. I am a newbie, just completed my bachelor degree in electrical engineering which has quite a broad scope. I recently taken up attachment works which possibly deals house wiring and minute equipment repairs which I am begining to like.

A question I woukd like to ask you seasoned pros in domestic house wiring, is when turning on the main switch(MS) after a new installation. At times, when MS is switched on, power is not received, in that, lights and connected loads remain off. However, after switching it off again and then turning it on again (2nd time) does the lights work and so as the outlets.....Is this normal????...Or does it present a possible fault???..If so, what might it be?

Thanks,
Nathan.

 

[littlespark]

It may be there’s a fault in the wiring... a loose connection, or a fault with the mainswitch itself.
I don’t know the types of switches you have there, but some in the uk have a central “tripped” position and you need to switch it fully off to reset before turning on. The switch wouldn’t operate from trip to on directly.

Is there any testing procedures you perform before energising a circuit?

 

[natkingcole]

It may be there’s a fault in the wiring... a loose connection, or a fault with the mainswitch itself.
I don’t know the types of switches you have there, but some in the uk have a central “tripped” position and you need to switch it fully off to reset before turning on. The switch wouldn’t operate from trip to on directly.

Is there any testing procedures you perform before energising a circuit?

No testing bro. Just your usual visual inspection...Testing connection points by yanking the line a bit..(When they are off of course)..Thats bout it.....What sort of tests do you carry out???

 

[littlespark]

We have quite a few tests we carry out before and after energising.. too many to describe here in detail. But in summery;

Insulation Resistance - checks for thing connected to each other when they shouldn’t be. Dead test
Continuity - checks that things that should be connected, are. Dead test
Earth loop impedance - Resistance of the return fault path. Live test
RCD test - Times how quickly our rcd operate. Different names in different countries

Test kits are expensive, and we are required to test, and certify every job we do, however trivial. Sometimes it takes longer to test and write up than it takes to do the actual job.

 

[natkingcole]

We have quite a few tests we carry out before and after energising.. too many to describe here in detail. But in summery;

Insulation Resistance - checks for thing connected to each other when they shouldn’t be. Dead test
Continuity - checks that things that should be connected, are. Dead test
Earth loop impedance - Resistance of the return fault path. Live test
RCD test - Times how quickly our rcd operate. Different names in different countries

Test kits are expensive, and we are required to test, and certify every job we do, however trivial. Sometimes it takes longer to test and write up than it takes to do the actual job.

Thanks for the info...Much Appreciated...And yes, those test kits are expensive. I work for gov. even they cant afford such things.