My (4,500 watt) water heater burst. So instead of simply replacing it like-for-like, I decided to upgrade to an electrical tankless (11,800 watt) water heater. It's much smaller and should give me great savings. Best yet, I won't run out of hot water if I'm not the first in the shower!
So here's my problem: I have a 220v Titan 54 Amp unit model N-120 (plumbed in, water flowing through) from Niagara Industries, which is pre-wired with AWG #8 2 conductor wire (with ground). I have this going to my non-fused 60A disconnect box. From there I have AWG #6/2 w/ground going approximately 25 feet to the breaker box, to a two-pole 60A breaker. I had the hot water turned on a few minutes before turning on the breaker, so I didn't burn out the coils in the unit. When I did the whole-house switch at the top of the box tripped!
I tried a short time later with the water turned off, and got the same trip.
The third time I turned off all the double-pole breakers in the box, in case the draw was greater than my incoming amps from the main service line, which I believe is 150A, per the box outside. It again tripped the whole house switch inside.
What could I be doing wrong?
I've rewired my whole house last year, and this has got me stumped. I was planning on getting AWG #4, but my contractor friend, a plumber, told me to use #6, and I read a reply in an electrical forum (on another topic) that the 80% safety rule only applies to continuous loads, so I didn't question my friend, especially as he had installed 3 of these same units in his house.
What is weird to me, is that the unit has #8 wiring. My friend didn't know why the company used it, but his heaters work fine.
(Before you ask why I'm not asking this of him, my friend is going through some difficult health issues right now and I don't want to pester him)
Spec info: As I can't post a link until I have 5 posts, the address of the product is: tanklesswaterheater.com/products1.html
So here's my problem: I have a 220v Titan 54 Amp unit model N-120 (plumbed in, water flowing through) from Niagara Industries, which is pre-wired with AWG #8 2 conductor wire (with ground). I have this going to my non-fused 60A disconnect box. From there I have AWG #6/2 w/ground going approximately 25 feet to the breaker box, to a two-pole 60A breaker. I had the hot water turned on a few minutes before turning on the breaker, so I didn't burn out the coils in the unit. When I did the whole-house switch at the top of the box tripped!
I tried a short time later with the water turned off, and got the same trip.
The third time I turned off all the double-pole breakers in the box, in case the draw was greater than my incoming amps from the main service line, which I believe is 150A, per the box outside. It again tripped the whole house switch inside.
What could I be doing wrong?
I've rewired my whole house last year, and this has got me stumped. I was planning on getting AWG #4, but my contractor friend, a plumber, told me to use #6, and I read a reply in an electrical forum (on another topic) that the 80% safety rule only applies to continuous loads, so I didn't question my friend, especially as he had installed 3 of these same units in his house.
What is weird to me, is that the unit has #8 wiring. My friend didn't know why the company used it, but his heaters work fine.
(Before you ask why I'm not asking this of him, my friend is going through some difficult health issues right now and I don't want to pester him)
Spec info: As I can't post a link until I have 5 posts, the address of the product is: tanklesswaterheater.com/products1.html