water heater

[banburyman]

1.
I want to install water heater 8kW, separate circuit. Do I need put a switch between Fuse board and water heater?

2.
another problem - 14kW water heater 3 phase,
this is 21A, how to find right fuse? in 17Th edition there are values for U=230V,where to find max earth fault loop impedance (Zs) for circuit breakers with U=400V

 

[bongos]

1. I want to install water heater 8kW, separate circuit. Do I need put a switch between Fuse board and water heater?

I believe one would be required near the water heater for isolation. You would probably have to use a 45A isolator for a 8kW load.

2. another problem - 14kW water heater 3 phase, this is 21A, how to find right fuse? in 17Th edition there are values for U=230V,where to find max earth fault loop impedance (Zs) for circuit breakers with U=400V

Don't know. Sorry!

 

[Adam_151]

I don't understand what your issue is with point two...


Uo is 230v regardless of whether it is a single or three phase circuit... so not sure why you think the max permitted Zs should change...

 

[banburyman]

Uo is 230v regardless of whether it is a single or three phase circuit

that is the answer, I just wasnt sure about this
where to find max earth fault loop impedance for each MCB? in 17Th book
Thanks

 

[banburyman]

What I saw today, this is CU, I tried to discribe this CU on my drawing. I have no experience on domestic installation, but something like this I saw first time.
What is protected by RCD?

Untitled

• banburyman
• 10 Jan 2010
• 1

 

[mfarrow]

What's the white box? Is it connected directly to the RCD, or to the main switch?

Also is it a plain RCD/RCCB or RCBO? How many poles is it switching?

 

[banburyman]

What's the white box? Is it connected directly to the RCD, or to the main switch?

Also is it a plain RCD/RCCB or RCBO? How many poles is it switching?

main switch, 3 pole, RCD 2 pole
I dont remember now, there was difficult acces to CU,
anyway, there was not action when I pushed T - test

CU - see pic, look similar

Untitled

• banburyman
• 10 Jan 2010
• 1