ECN Electrical Forum - Discussion Forums for Electricians, Inspectors and Related Professionals
ECN Shout Chat
ShoutChat Box
Recent Posts
You will never guess
by grich - 02/24/21 07:18 PM
Lock-down Thread
by Bill Addiss - 02/24/21 04:40 PM
New tool
by SMOKEYBOB - 02/15/21 04:59 PM
Split Bus Breaker Panel
by gfretwell - 02/15/21 02:30 PM
Sierraplex recpts
by gfretwell - 02/15/21 02:27 PM
New in the Gallery:
Facebook follies, bad wiring
FPE in Germany pt.2
Who's Online Now
1 registered members (Scott35), 15 guests, and 19 spiders.
Key: Admin, Global Mod, Mod
Previous Thread
Next Thread
Print Thread
Rate Thread
Page 1 of 2 1 2
Tankless Water Heater #164059 05/24/07 01:55 AM
Joined: Aug 2001
Posts: 545
A
aldav53 Offline OP
Member
Residential home - I'm wiring a tankless water heater that calls for 2 - 40 amp 240 volt ckts. It has 2 separate heaters. I was going to run 4-#8's and 1-#8 ground to a junction box on the flat roof (splice there) of the house then go in with 2-#8 NM's into the attic then down to 2 disconnects then to the tankless water heater.
Would it be legal to run 2-#4's instead to the junction box then split off with the 2-#8 NM's to the water heater (2 ckts). Probably be better to keep both cicuits separate all the way.


The Golden Rule - "The man with the gold makes the rule"
2017 / 2014 NEC & Related Books and Study Guides
Re: Tankless Water Heater [Re: aldav53] #164060 05/24/07 02:39 AM
Joined: Jan 2003
Posts: 4,391
I
iwire Offline
Moderator
It would be fine as long as you use fused disconnects at the taps.

I don't see much specific benefit to keeping them separate.

But I have no idea which way will work out better as far as costs.

By the way some power companies have rules regarding these units, it may come back to haunt the customer if their new water heater makes the neighbors lights flicker.


Bob Badger
Construction & Maintenance Electrician
Massachusetts
Re: Tankless Water Heater [Re: iwire] #164071 05/24/07 11:00 AM
Joined: May 2003
Posts: 2,876
E
e57 Offline
Member
OCP(panel) or fused discos, otherwise it could be a tap rule violation. Depending on where the discos are. Why not go the whole distance as a feeder with a panel between them?


Mark Heller
"Well - I oughta....." -Jackie Gleason
Re: Tankless Water Heater [Re: e57] #164096 05/24/07 08:22 PM
Joined: Apr 2002
Posts: 7,233
HotLine1 Offline
Member
I came upon a very confused resi guy a few weeks ago; he had a instant wtr heater that needed three (3) 40 amp 240 feeds! That poor boy was a lost soul!

Funny thing was...he did not have any mfg info, no book, no diagram, etc. The unit had one (1) 1-14 KO on the bottom, no place to punch any other KO's

John


John
Re: Tankless Water Heater [Re: HotLine1] #164104 05/24/07 11:44 PM
Joined: Aug 2001
Posts: 545
A
aldav53 Offline OP
Member
Its a 400 amp service. I fed it with 2 - 40 amp 240 volt breakers. The sub-panel on that side of the house was too small, so I just ran both circuits all the way from the main 400a panel. Fused at the panel plus 2 disc at the tankless WH area for convienience. Had to run the pipe across the roof, the only way to get there.


The Golden Rule - "The man with the gold makes the rule"
Re: Tankless Water Heater [Re: aldav53] #164108 05/25/07 12:42 AM
Joined: Oct 2004
Posts: 803
mxslick Offline
Member
Sometimes being a sparky is a tankless job!! smile

I got lucky, just had to drop a single 120v, 20 amp to a gas-fired unit here at the apts. while helping the landlord.


Stupid should be painful.
Re: Tankless Water Heater [Re: mxslick] #164137 05/25/07 11:24 PM
Joined: Oct 2006
Posts: 745
E
EV607797 Offline
Member
Yeah, but you got lucky because you are in Southern California where gas is the norm. You guys use gas for everything; I don't see how electricians make any money in Southern California. It's all dinky 15 or 20 amp circuits, maybe an occasional 30. Even 100 amp services that are practically unheard of in these parts!

Many other parts of the country don't have insane electricity rates that you guys have.

These tankless units are perfectly acceptable in many other areas of the country. Not to mention that many places don't have access to gas! Here were I live, gas is more expensive than electricity. My 3,000 SF house has a panel full of 30, 40, 50, 60 and 80 amp loads and my average electric bill is about $200.00.


---Ed---

"But the guy at Home Depot said it would work."
Re: Tankless Water Heater [Re: EV607797] #164141 05/26/07 12:35 AM
Joined: Jul 2004
Posts: 9,568
G
gfretwell Offline
Member
At my house, if it doesn't come from FPL we ain't got it, I don't even have a water bill (well) We still get by on $200 or less most of the year. This spring it has been in the $150 range. The A/C will bump that a bit


Greg Fretwell
Re: Tankless Water Heater [Re: gfretwell] #164240 05/28/07 09:22 PM
Joined: Oct 2006
Posts: 745
E
EV607797 Offline
Member
Well, they do say that everything is insanely overpriced in California, Greg.

We have the same thing here; total electric costs about half of what using gas or propane costs. My house is also like you indicated, using well water, septic, etc. It's not so much the cost for electricity, but the lack of the need for gas or water/sewer cost. We have a few bumps during the extremely cold or hot swings in temperatures, but the average is still $200.00 for ALL utilities.

We are seeing a lot of conversions back to electric heat pump being done here where people made propane/NG conversions a few years ago. Propane costs as much as super unleaded gasoline! NG prices in the same ballpark and are too unstable.

My neighbor put in a pool at the end of the season last summer. They included a propane heater. After 1.5 months and $750.00 for propane, they shut it off and decided to let Mother Nature heat it.


---Ed---

"But the guy at Home Depot said it would work."
Re: Tankless Water Heater [Re: EV607797] #164244 05/28/07 10:36 PM
Joined: Jul 2004
Posts: 9,568
G
gfretwell Offline
Member
My wife got a propane heater for free but we have the same situation. It costs about $20 to bring the pool up 10 degrees and the bottom is still cold. I have done it 3 times in a year.
I use my solars and they work pretty well, virtually for free. If I had a cover they would work real well.

Home heat is such a rare thing that toaster wire is the norm. It is not worth the extra money to buy a heat pump for the 3 or 4 days a year we have the heat on. She will turn it on for a few minutes some mornings just to knock the chill off the house but I am not sure we ever use it all day.


Greg Fretwell
Page 1 of 2 1 2

Featured:

2020 National Electrical Code
2020 National Electrical
Code (NEC)

* * * * * * *

2020 Master Electrician Exam Preparation Combos
2020 NEC Electrician
Exam Prep Combos:
Master / Journeyman

 

Member Spotlight
The_Lightman
The_Lightman
Orlando, Fl, USA
Posts: 49
Joined: August 2001
Show All Member Profiles 
Top Posters(30 Days)
Popular Topics(Views)
275,352 Are you busy
209,224 Re: Forum
196,526 Need opinion
Powered by UBB.threads™ PHP Forum Software 7.7.3