Using existing 60A service for sauna

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  #1  
Old 06-17-13, 12:24 PM
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Using existing 60A service for sauna

We removed a hot tub which was fed by 60A 240V service, and we'd like to use it now for a sauna heater, a light within the sauna, and an external outlet (the sauna is a free-standing structure about 5 ft from the house, and about 6 feet from the existing hottub subpanel).

I spoke with our Electrical Inspector on the phone, and being the only person, I tried to keep the call short, and instead I think I might have missed a piece of information here & there in order to give him the complete picture of what I'm trying to accomplish. Nice guy, but I could tell he was preparing to head out in the field.

I went into the call with this:
Install a subpanel on the side of our house (which is where the hotub's subpanel is). Backfeed a 60-amp breaker, and then put in a 30A 240V breaker for a heater rated at 25A, then a 20A 120V breaker for an outlet (GFCI at the socket itself) and then a 15A 125V breaker for the light inside the sauna. This was something that an electrician also suggested, although once I heard his quote, I thought I should try & do it myself. Wiring would be in conduit, running the 6 ft along the ground, underneath a deck, secured to the deck beams.

I came out of the call with this:
Install a main breaker on the surface of the sauna. I guess I am ok with that, but it just seems like overkill, especially since I can't seem to find anything NEMA 3r rated that is smaller than 125A and almost 2x3 ft in size (the sauna is about a 5.6'x7.6' structure). I couldn't tell if he just didn't like the backfed breaker, thought it wasn't code, or just wanted me to have a huge panel with room for growth (which he mentioned).

I'm also thinking that if I go with a panel & a backfed breaker, and if the structure is so close to the house, that I can just use the existing ground for the house, and not have to sink some additional grounds if I went with the main breaker route.

Mostly I'm just trying not to waste our inspectors time, because I think that I could keep him on the phone for 30 minutes, in order to make sure there aren't any missed details for the rough-in. Maybe after I get some guidance here, I can more efficiently ask him for anything he'd like me to do specificially.

Thanks,
Starsky
 
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  #2  
Old 06-17-13, 01:51 PM
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Does the spa panel have additional spaces for breakers? If so replace it with a weather proof junction box, extend the feed to the sauna, and mount the spa panel on the sauna.
 
  #3  
Old 06-17-13, 04:29 PM
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Unfortunately, the existing junction box has to go. It's more or less a self contained junction box meant to hold a single 60A gfci breaker. I am going to give it to the friend who inherited the hot tub.

Sounds like you're thinking I should put whichever box I choose (main breaker or junction box) on the building itself?
 
  #4  
Old 06-17-13, 05:51 PM
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I was just focusing on the location of the junction box/main breaker, as my preference would be to have it on the side of our house. My initial thought was to put the external outlet on the house. Then I thought that I'd like to put the lightswitch for the sauna also on our house, so that we could light the the place up before getting too far outside (pretty dark & rainy here in Oregon in the winter).

I can definitely live with other design decisions if the box is required to be on the sauna itself, but those were my first preference.
 
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Old 06-17-13, 06:01 PM
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Sounds like you're thinking I should put whichever box I choose (main breaker or junction box) on the building itself?
Not sure what building you refer to but it must be on the Sauna. Code says you can only run one circuit to a detached structure. From your description the sauna would probably be considered a separate structure by an inspector. Have you looked at maybe a four or six circuit 60 amp main lug panel? If it will only hold six or less single pole breakers you do not need a disconnect which is what the main breaker on a subpanel is used for.
 
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Old 06-17-13, 07:16 PM
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I was referring to the sauna, yes. Ok, that helps, one circuit to the building. So I need to put the box on the sauna's structure itself.

I have definitely been looking at a 60A main lug panel, but the Inspector made it sound like he wanted a disconnect of some kind for all electricity going to the building/sauna. So I figured backfeeding a circuit was the easiest way to do that.
 
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Old 06-17-13, 08:16 PM
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Easiest way would be a 60 amp either fused or unfused air condition disconnect switch.

However the NEC does not require a disconnect if there are 6 breakers are less. That number is based though not on the number of breakers installed but the total number of breakers that could be installed. If you mentioned only a 125 amp panel that rule would have been moot so that may have been why he insisted on a disconnect. Or local rule may not permit.

NEC 2008

225.33 Maximum Number of Disconnects.
(A) General. The disconnecting means for each supply
permitted by 225.30 shall consist of not more than six
switches or six circuit breakers mounted in a single enclo-
sure, in a group of separate enclosures, or in or on a switch-
board. There shall be no more than six disconnects per
supply grouped in any one location.

225.30 Number of Supplies. Where more than one build-
ing or other structure is on the same property and under
single management, each additional building or other struc-
ture that is served by a branch circuit or feeder on the load
side of the service disconnecting means shall be supplied
by only one feeder or branch circuit unless permitted in
225.30(A) through (E). For the purpose of this section, a
multiwire branch circuit shall be considered a single circuit.
 
  #8  
Old 06-17-13, 08:34 PM
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Thanks for the help, btw ...

Just curious why you're thinking that the 60A air conditioning disconnect is the easiest way to go. I guess I could put that in the same place as the hottub's 60A GFCI junction box, since I'm going to need a junction box there anyway for the splice.

It just seemed to me like the 60A breker I'd use for the backfeed is something I'd just snap in. Although I guess I would need to buy the kit which fixes that breaker in place.
 
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Old 06-17-13, 08:45 PM
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No the disconnect would have to go on the sauna. The breaker would be easier if you had enough space* and they sell a hold down clip for the panel you use. (You can't use a backfeed breaker without a hold down clip.)

*A 4 space panel would only have room for one 240 volt breaker and two 120 volt breakers. No room left for a backfeed breaker.
 
  #10  
Old 06-17-13, 09:51 PM
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I'm not opposed to using a 6 space panel. It would still take up less space than both a disconnect and a 4 space panel, it would seem. I'll check on the availability of hold-down clips for what's locally available.
 
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Old 06-18-13, 05:59 AM
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We sometimes have to read the inspectors mind. No guarantee of accuracy. NEC also has a "line of sight" rule in some cases for disconnects so on further thought you might convince an inspector a disconnect on the house if visible from the sauna is okay but you'd need prior approval beforehand to be sure. If you can't find a hold down run the six throw rule by the inspector quoting the number of the code section I posted.
 
  #12  
Old 06-19-13, 05:16 PM
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i was thinking, I built the sauna on my deck. Any chance that qualifies is as part of our house, and not an external structure? It's just a small 5'x7' structure.
 
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Old 06-19-13, 05:48 PM
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All of this comes down to what the inspector thinks. We can't answer that. In this case though it actually doesn't matter based on the NEC. If it is not a separate structure you don't need a disconnect. If you have a panel with a six circuit or less capacity you do not need a disconnect so either way is the same. But again it is up to the inspector.
 
  #14  
Old 06-20-13, 01:12 PM
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So the heater is 6000 Watts, 25 amp single-phase 240 V. It could take 30-45 minutes to reach operating temperature, but then you'd likely only stay in it for 20 minutes, 30 max. So that's, let's say 90 minutes (generously rounded) of continuous activity.

I was planning on using a 30 amp breaker. But, 25amps x 125 = 31.25 amps. Should I instead go up to a 40 amp breaker, even though we'll never use it for a continuous 3 hours?

I just don't want to have to tear apart anything later, if the breaker starts to trip.
 
  #15  
Old 06-20-13, 01:21 PM
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If the breaker proves too small in use it is only a 10 minute or less job to replace but a 40 would be okay. I'd up the wires to #8 if I did that.
 
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Old 06-20-13, 02:40 PM
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Did the heater's manufacturer specify, either on its nameplate or in its installation instructions, "Max. Overcurrent Protection?"

If not, stepping the circuit up to 40A with #8 wire might be a good investment.

On the other hand, are you planning to turn your heater on and off with a simple switch? Have you thought about using a timer instead? I'm thinking doing that might be good foresight against broiled young'uns down the road, as well as protecting the circuit and holding your electric bill down.
 
  #17  
Old 06-20-13, 03:10 PM
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There's a 1-hour cutoff, built into the on/off switch, which it's just a timer on the face of the heater.

That's why I was thinking the 30A would be ok. At least in terms of never breaching the "3 hours of continuous activity" as understand it.

I suppose it wouldn't hurt to go bigger, it's not much wire. The heater salesman verbally said to use 10 gauge wire, but I'm not seeing anything that descriptive in the manual.
 
  #18  
Old 06-20-13, 03:27 PM
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What does the nameplate on the heater say? Can you post links to the heater specs and installation instructions?

In the absence of good information, I like Ray's suggestion of pulling the #8 wire and protecting it at 30A for now.

In terms of the continuous load requirement yes, that 1-hour timer gets you there.
 
  #19  
Old 06-20-13, 04:06 PM
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Sauna Kit, Sauna Heater, Sauna, Modular Sauna - Finlandia Sauna, Saunas, Sauna Accessories

Weird, here they mention a #10 write too. It's the FLB 60.
 
  #20  
Old 06-20-13, 09:05 PM
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here they mention a #10 wire too.
Interesting, #10 AWG copper is rated for 30 amps, so they're implying a 30A circuit. Here's what we need to see (from the Finlandia Specifications For Architects/Contractors). Can you post this for us?
ELECTRICAL CONTRACTOR SPECIFICATIONS:
(Must be licensed and bonded)

Rough-in for Sauna controls, heater, room light shall be as per Finlandia wiring diagram (provided with control box or in heater box)

Hookup of controls, heater, light shall be as per Finlandia wiring diagram. COPPER WIRE ONLY
 
  #21  
Old 06-20-13, 10:00 PM
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Sorry for the late response. Here are the installation instructions (note that the FLB60 is the version that does not have a separate wall panel with the controls. The wires go directly into the heater, and the on/off timer is also on the heater itself):

http://authenticsauna.com/FLBMANUAL.PDF

And I checked, and the nameplate says nothing special beyond 6K Watts, 25 amps, 240V, phase 1. The remainder of it is devoted to listing the distance from the floor and other objects that the heater should be.
 
  #22  
Old 06-20-13, 10:05 PM
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It looks like page 5, figure 5.
 
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Old 06-21-13, 07:54 AM
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Wire size is minimum recommended. Nothing wrong with going up one size. I'd say 30 amp breaker and #8 wire but that is "gut" engineering. Final decision is yours. Unlikely but if you could find a 35 amp breaker for the breaker panel you choose that would be ideal.
 
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Old 06-21-13, 08:46 AM
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Thanks for the link to the manual.

You have a 6kW 25A load that is made non-continuous by the built-in timer. A 30A 240V single-phase circuit with #10 AWG wire is what they're recommending, and I'd just go with that. No need not to.

Notice that in Figure 1 and Figure 2 they show the power from the breaker coming to the contactor assembly on the outside of the sauna. Wiring from there to the heater elements must also be 10 AWG. In figure 6 they show #14 AWG wiring from the contactor to the overhead light. The neutral does not appear to be connected to anything in the contactor, so you can either pull it in #14 from the subpanel, if you're using conduit, or splice the #10 to #14 in the contactor if you're using cable.
 
  #25  
Old 06-21-13, 09:07 AM
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Since I'm already installing a junction box, and I've got 60 amps coming in, I was going to run the light on it's own circuit. So the breaker going to the heater will be for the heater only. Then I was going to continue the light's circuit onto a gfci protected plug in the eaves, where we could plug in some rope lights. Seemed like it would be a nice effect, at least.
 
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Old 06-21-13, 11:54 AM
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Then I was going to continue the light's circuit onto a gfci protected plug in the eaves, where we could plug in some rope lights. Seemed like it would be a nice effect, at least.
The eaves of the sauna? Sure, why not? On a separate switch? Switches outside or inside?
 
  #27  
Old 06-21-13, 12:54 PM
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The long description is .. I'll start by installing the main breaker on the house, which is where I originally wanted the main lug panel (over the spot where the old junction box for the hot tub was at). Then I'll put a lightswitch immediately adjacent to it, which will run to the inside light of the sauna and then onto the outlet in the eaves. I'll also put an outlet on a third 20A circuit right next to the main breaker also, for just general use in the backyard.
 
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Old 06-21-13, 01:31 PM
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I'll start by installing the main breaker on the house, which is where I originally wanted the main lug panel
What main breaker? Do you mean a main breaker panel? If so why? All you need is a junction box. The main lug panel on the sauna is the only panel you need.
 
  #29  
Old 06-21-13, 01:53 PM
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It's sort of outlined below, but the inspector wants a shutoff, and it's just easier for me to put in a main breaker, than a backfed breaker in a main lug (which he didnt want to see) or a 60A shutoff and a main lug.
 
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Old 06-21-13, 02:22 PM
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It's sort of outlined below, but the inspector wants a shutoff, and it's just easier for me to put in a main breaker, than a backfed breaker in a main lug (which he didnt want to see) or a 60A shutoff and a main lug.
Way over complicated. Is it only the aesthetics of size that prohibits you from putting the main breakers panel on the sauna? Why is a backfeed breaker in a main lug more difficult. Why do you even need a disconnect? Have you discussed the six throw rule with the inspector ? If so what did he say?
 
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Old 06-21-13, 03:24 PM
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The inspectors time is short, and I work in a different town, so meeting in person is tough. So I'm trying to limit the number of rough in inspections by doing what he's suggested already. The main breaker on the sauna ... it takes up a bunch of room on all sides except the back, which puts it much farther than if it were on the house, plus, the house install covers up the prior paint color covered by the prior box.
 
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Old 06-21-13, 03:43 PM
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Both the panel on the house and the panel on the sauna will be subpanels. If the inspector wants disconnects on all subpanels regardless of whether they are six throws or less or not than both subpanels will need disconnects.
 
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Old 06-21-13, 04:13 PM
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Then I'll put a lightswitch immediately adjacent to it, which will run to the inside light of the sauna and then onto the outlet in the eaves.
One switch for both? So that you can only cut them both on and of at the same time?
 
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