need second opinion- safe elec. heater install

Discussion in 'Electrical Forum discussion & Blog' started by frostnip, Jan 7, 2009.

  1. frostnip

    frostnip New Member

    Messages:
    18
    Hi guys, hoping someone here can help me out a bit.

    I just was given a really nice electric heater, like as seen here:
    http://www.heatersplus.com/5100.htm

    I have a PDF version of that page that is easier to read, and it states that my model number is 208 volts, 1 or 3 phase, 60hz. Some of the other models can be switched from 208 to 240, mine cannot. lucky me.

    Here's where I really did myself in, I had mistaken the part number of my unit for one that is 240 switchable, so when I got paid today I went and spent some big bucks on 6 gauge wire and a 50 amp breaker hoping to install it.

    Then I double checked the model number and of course realized I have the 208v model.:mad::mad:

    I have been doing a lot of reading and I have only confused myself, but what I am thinking is that I cannot make 208v from my residential breaker box.

    There is not much to this heater. Its got a small transformer, 24v control system, a fan and a coil. It is controlled by a wall mounted thermostat.

    I am wondering, if I connect this thing to 220 or 240 or whatever it is coming out of my box, will it work, and will it be safe? I am afraid to burn my house down, but at the same time I just spent all my money on wire and thermostat and it's not getting any warmer in here..

    I have run new 110v circuits in the past, and added an electric dryer circuit to the house. I am confident I can handle the install, I am just concerned for the safety of my family.

    Any answers will be appreciated-

    cold in indiana
  2. jamiedolan

    jamiedolan New Member

    Messages:
    28
    Location:
    Wisconsin
    There is no practical way to change your 240v service to 208v. I strongly suggest you do not hook up that unit as is.

    I would either get the correct heater. Or speak directly with the tech department at the heater company and discuss the situation with them to see if there is a field modification that can be done to convert the unit to 240.

    EDIT: When I said field modification; I was thinking along the lines of the company sending out a tech to make a factory authorized change.

    Jamie
    Last edited: Jan 7, 2009
  3. codeone

    codeone Code Enforcement

    Messages:
    160
    Location:
    North Carolina
    You could install a transformer to do the conversion However it would be costly. Correct size to handle the load. Probably not worth it. and unsightly. If you modify the unit you would be altering the UL Listing. Your insurance Probably not pay if anything happened. Be safe not sorry.
  4. frostnip

    frostnip New Member

    Messages:
    18
    I agree with you, I just needed to hear it from someone else for it to sink in. Your logic plays tricks on you when your house is cold.


    I have a PDF file that shows this same heater with an additional letter in the model number, it is the voltage selectable unit. In the same file are all the part numbers, and there are 4 different parts in the 240v model.

    they are: motor, element, contactor, and power block. Sounds like it would cost me an arm and leg to convert it over. I sent them an email, we'll see.

    http://www.markel-products.com/01-MenuSystem-CatalogPages/01-Built-inHeaters/MarkelBuilt-in/SUH-HorizontalVerticalDischarge/om.pdf

    The heater I have is f2f5107CA1L, the one I want has a very similar number with a B in it..
  5. frostnip

    frostnip New Member

    Messages:
    18
    still getting conflicting info. :confused:

    My friend's dad says to hook it up and quit being a pansy. He says I don't need a 240v model and that my breaker box won't even put out 240. He said I would be safer with this one than a 240 model.

    He said 2 110 hots don't even put out 220 and hooking up the 208v heater to a double 50A breaker is fine.

    He told me to connect to the single phase connections of the heater and it will work fine, citing some sort of 10% rule....
  6. Chris75

    Chris75 Electrician

    Messages:
    608
    Location:
    Litchfield, CT
    Well than that settles it. Wire it up. :D
  7. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689
    I am with your friend's dad. Generally it is 208/240....whatever it takes.

    I saw it listed as 208/240 somewhere in your link.

    Anyway, I rarely see a piece of equipment that is 208 or 240 only. I have seen some electronic stuff that is sensitive.
  8. frostnip

    frostnip New Member

    Messages:
    18
    I just keep coming to this same spot- assuming I can pull "220" off my breaker board, what could 12 extra volts possibly hurt? Would the coil make a lil more heat or the fan turn a couple more RPM? Maybe the transformer will grenade under the extra 12 volts?


    I am thinking about a trial run in the basement. wire it up without the wire ran through the wall, see what happens.
  9. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    A heating element rated for 208 , if you run at 240 of course it will draw more amps. As long as the breaker and wire are rated, that is OK. But you would need to know from the maker if they condsider it OK to run their unit at 240.
  10. jamiedolan

    jamiedolan New Member

    Messages:
    28
    Location:
    Wisconsin
    He obviously doesn't even understand very basic electrical concepts.

    I just checked with the manufacture and some of these units are dual rated 208/240 and are convertible. That does not mean you can hook it up as it.

    Jamie
  11. Alectrician

    Alectrician DIY Senior Member

    Messages:
    689
  12. frenchie

    frenchie Jack of all trades

    Hey, I could be wrong, and I'm no sparky, but

    ...seems pretty clear to me.



    ...edit:

    Sure enough - I googled, iff you download the catalog & specs, look at page 2... it's not only the motor that's different, it's also the element.

    http://www.markel-products.com/01-M...lt-in/SUH-HorizontalVerticalDischarge/cat.pdf.
    Last edited: Jan 7, 2009
  13. Scuba_Dave

    Scuba_Dave Extreme DIY Homeowner

    Messages:
    885
    Location:
    South of Boston, MA
    I've checked my "110" output & I have between 118 & 122 on any given day. Wiring it up in the basement it may run fine
    Permanently hooked up it could run fine for a year, 5 years or longer
    Then one day that one part that just isn't rated for 240v burns up, starts a fire & burns your house down. Then insurance finds a 208v heater connected to 240v & claim denied

    Is it worth that possibility?
    They use different parts for a reason
  14. thassler

    thassler New Member

    Messages:
    106
    Location:
    Tennessee
    Lmao!! -->
  15. jar546

    jar546 In the Trades

    Messages:
    432
    Location:
    USA
    Why do you even need an opinion on this.

    It is not rated for the nominal voltage of your service. This would be a non-compliant, illegal and usafe installation and you need to return it for the correct voltage.

    In addition, you need to know what model you have so that you can properly rate the circuit. The tag on the unit of proper voltage will tell you that.

    Your friend's dad is giving horrible advice and I highly recommend you return the unit for the correct voltage. Your unit is not designed the voltage at your service.

    Seems like an easy, logical answer. Unless of course you are waiting for someone to tell you what you want to hear like a lot of people who post here.

    I hope you pull a permit and get the work inspected.
  16. codeone

    codeone Code Enforcement

    Messages:
    160
    Location:
    North Carolina
    One word of caution. a 240v rated heater will not heat up to desired temp. on 208v system. Case in point If you were talking about a food warmer in a buffet it would not keep the food warm enough to be safe. If you put a 208v rated heater on 240v system it does have the potential to overheat possibly burning up and causing a fire.

    As a Code Enforcement Offical I could not allow this, IT IS NOT CODE COMPLIANT.

    Please pull the proper permits and have your work inspected.

    Your Insurance would not have to pay if something happened.

    The Codes are a minimum for safety.
  17. codeone

    codeone Code Enforcement

    Messages:
    160
    Location:
    North Carolina
    This man does not consider liability!!!
    This man does not consider laws and codes to protect life safety.
    Calling someone a pansy is a bullying technique. This is only to get someone to do something they shouldnt.
    Last edited: Jan 7, 2009
  18. Cookie

    Cookie .

    Messages:
    5,660
    Location:
    .
    Sell it all on, e b a y and buy yourself the right stuff. You will also be buying yourself peace of mind.
  19. codeone

    codeone Code Enforcement

    Messages:
    160
    Location:
    North Carolina
    Excellent Advice
  20. frostnip

    frostnip New Member

    Messages:
    18
    to the guy who asked "why do you even need an opinion on this"

    well, when I have local friends telling me to just go ahead and hook the thing up, then I spot info on the unit that throws a red flag to me and here I am. I thought maybe there was a method to wire the thing correctly- apparently not.

    I don't have any intention of doing anything against the codes or illegal etc which is why I was asking for a solution here. It's about 50 degrees in my house at the moment and I was really hoping that this would work. My next choice is a wood stove and heat exchanger, but I have to have the chimney relined before I can do that and I am not thrilled about fire in the house.


    It's going to drop down into the single digits next week so it would have been nice to have a 25k BTU heater around.


    My breaker box and system is all hard conduit, uses QO breakers and from what I understand is 100% in compliance with local code. The materials I purchased today were more than adequate, for a 240v heater. :(

    Back to the drawing board.
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