What are the standards for cable tray?
I‘ve asked my sparkies and no one seems to really know.
I‘ve seen TPS cable tied to cable tray less than 2ms from the ground without mechanical protection.
To me the cable is just exposed? Shouldn’t it be in conduit if it’s likely to be disturbed (AKA less than 2m in height).
Does the cable tray itself provide mechanical protection?
Cheers,
Heyo guys,
Just here to clear a few misconceptions I have about the purpose of an earth stake.
I’ve had other sparkies tell me the earth stake is to allow fault currents to travel back to the transformer.
Which I can understand. But I’ve been doing my own research into the TN-C-S earthing design and the only intended earth fault loop is meant to be via the MEN and service neutral back to the transformer.
Therefore, a small amount of current might flow through the earth stake to the transformer but that’s not it’s purpose.
Why else would you have an earth stake? For lightning? Redundancy? I’ve heard it’s to also have a reference to 0V (ground)?
If anyone else could please help to clear my confusion that’d be amazing!
Cheers,
Heyo guys!
Looking at putting a changeover switch for my inverter (not a solar electrician) and was just delving into when it is okay to switch the neutral.
From what I’ve gathered, if the load / alternative source itself has a MEN connection that is when you would switch the neutral (to prevent a parallel path where current flows through the earth under normal operation).
Is there any other weird or whacky situations you’ve come across where you’ve switched the neutral?
Heyo guys!
NSW apprentice here, don’t really do too much domestic but still trying to get my head around it.
My switchboard at home has XLPE 16mm^2 all the from POA (obviously) through the SPDs and all the way tonthe CB that feeds my DBs.
Seems excessive to me? Also super hard to fit a clamp meter over a cables inside the switchboard enclosure.
I know consumer mains have to be 16mm2 XLPE up to the SPDs. But after the SPDs can you just go with 16mm2 SDI V90 to wire up the busbar.
Is it just the sparkies using extra protection? What’s your preference?
Cheers!
Morning guys!
Another apprentice question for you. Please correct me if I’m wrong aha
SPDs are service protection devices AKA only Level 2 Electricians can touch them.
MPDs are for bigger installations like strata buildings, commercial buildings. A fuse / CB for each individual metered supply. Any licensed electrician can touch MPDs?
For domestic installations, SPDs and MPDs can be the same device. Meaning it gets downgraded to 80As.
In your experience are most commercial / multiple dwelling installations SPDs 100A and MPDs are 80A?
Cheers!
Please correct me if I’m wrong (apprentice)
For consumer mains to be protected it means there’s a short circuit device at the beginning of the consumer mains.
Unprotected consumer mains means there’s short circuit protection at the MSB.
Is it more common to have unprotected or protected consumer mains? Are there a lot of service fuses on the distribution lines?
cheers
mainly for single phase houses. with most houses opting for three phase, how do they balance the load across three phases?
is it kinda like:
1st house - A phase
2nd house - B phase
3rd house - C phase
4th house - A phase