From: kgs@cnmss.tredydev.unisys.com (Ken Salter)
Newsgroups: misc.consumers.house
Subject: Electrical Question:  220v  -->  110v  --  SUMMARY
Date: 31 Jul 92 12:36:42 GMT
Distribution: usa
Organization: Unisys Corp.

In article <1992Jul15.161528.17849@cnmss.tredydev.unisys.com> I wrote:
> 
> I have two baseboard electric heaters/radiators that I'd like to put
> in my sunroom.  It seems prudent to connect them to a dedicated circuit,
> but I don't have a spare circuit and prefer not to install one.
> 
> A nearby room has a 220v line that is used for a room air conditioner.
> Since it's unlikely that the air conditioner will be used at the same
> time as the heaters, the idea of adapting the 220v line to power the
> heaters is most attractive.  Do over-the-counter products for such
> adaptation exist?  
> 
> If not, how many code violations would be incurred if I were to 
> fabricate my own adaptor via a cord, a 220v plug, and a 110v receptacle
> with the 110v black wire connected to one of the 220 hot wires, and
> the 110v white wire cinnected to the 220v neutral?
> 
> Please reply by private mail; I'll post a summary.  I'm requesting
> private mail because I'll be travelling in the near future and
> suspect that response messages may have timed-out before I get to read
> them.


smb@ulysses.att.com responded:

: I won't answer your questions; I'll ask a few of my own.  First, are
: you sure that your heaters run on 110?  Most run on 220.  Second,
: 110 heaters almost always draw close to 15 amps; you can't run them
: both on one half of a 220 circuit.  You could break the tab connecting
: the two hot halves of a 110 outlet, and wire the two hot wires to
: the two 220V hot wires.  Of course -- are you sure that the 220V line
: has a neutral?  Some air conditioners, at least, don't; they have two
: hot wires, and a ground.  If there are only three holes on the 220V
: outlet, you don't have a neutral, only a ground.  (My central AC
: compressor has no neutral wire, for example.)

To which, I responded:

>    You're right.  I have just three wires, presumably 2 hots and a ground.

To which, smb@ulysses.att.com responded:
: 	
: If you have only three wires, and it's really a 220V circuit (as opposed
: to a 20A 110V circuit, which might also take a strange-looking plug),
: you have no neutral wire, so you can't (safely and legally) get 110V
: out of it.
: 
: I'm really surprised that there's no data plate on the heaters.  I
: thought that by law, anything electrical had to hae one.  Are they
: plug-in?  What does the plug look like?

Until now, I have not acknowledged that last message.  I got the heaters
down from the attic and discovered a data plate on the heater and 
a similar label on the box.  Both state 220v.  Yet I was so certain
that the equipment was unmarked.  Sorry about any inconvenience.


Lee Ziegenhals replied:
: 
: I have seen an outlet that does exactly what you want.  It is wired to
: 220v service, and has both a 220v and a 110v outlet.  The layout is
: such that it would be difficult to plug something into both outlets
: at the same time.
: 
: Unfortunately, this is at my mother's house, so I can't get a
: manufacturer or part number off of it.  However, just knowing that
: it exists you should be able to go to a electrical supply house and
: ask about it.


John Whitmore responded:
: 
: 	It is prudent because ANYTHING plus a heater will likely
: blow the fuse/trip the breaker.  Heaters are typically 2kW units,
: which means they take very close to 15A, which is the typical
: wire capacity.
: 
: 	Yes; transformers will cost circa $400 for this task (they
: exist, but they aren't cheap, not for the kind of power YOU want
: to handle).  
: 
: 	Either switch the wiring in your breaker panel to make those
: wires 110V (and give up on using the air conditioner), or buy a couple
: of 220V baseboard heaters.  They aren't expensive; maybe $45 each.
: Or, you could wire two 110V heaters in series and plug 'em into
: the 220.  You can NOT use the '220V neutral' wire, because
: there ISN'T any '220V neutral'; the three wires are HOT#1, HOT#2,
: and GND.  Using the GND wire to conduct any current in normal operation
: is a severe safety violation. 
: 
: 	I have assumed that the heaters are 120V type; is that correct?
: If they  plug into the wall, they are (necessarily) low-wattage
: units; just buy the right kind of heater (220V).



Chris Lewis responded:
:
: I'm presuming, from context, that these heaters are 110V units.  But
: "baseboard" generally means permanent installation.  Connecting these
: by a plug is, in and of itself, likely to be violations of code.  Ie:
: the devices are probably approved for direct-wire installations only,
: and "permanently installed" fixtures can't usually be plug connected,
: nor connected with stranded cable.
: 

I'd like to interrupt this quote to inject a comment/question.  My
stove and microwave are both permanently installed, yet each unit plugs
into an electrical outlet.  Why should electric heat be treated
differently?

Chris Lewis quote resumed:
:
: If they are really "baseboard heaters", if you still insist on doing this,
: you will have to make some major steps to ensure that:
: 
: 	- they won't fall over (fire hazard)
: 	- cable snags won't cut the insulation on the cable where they
: 	  enter the baseboards.
: 
: And a few other safety paranoias that I'm probably missing.
: 
: >A nearby room has a 220v line that is used for a room air conditioner.
: >Since it's unlikely that the air conditioner will be used at the same
: >time as the heaters, the idea of adapting the 220v line to power the
: >heaters is most attractive.  Do over-the-counter products for such
: >adaptation exist?
: 
: I have seen "Y" cables, with a 220V plug, and two 110V sockets.
: This was some time ago, so I don't know whether they're still legal,
: nor where you can buy them.
: 
: >If not, how many code violations would be incurred if I were to
: >fabricate my own adaptor via a cord, a 220v plug, and a 110v receptacle
: >with the 110v black wire connected to one of the 220 hot wires, and
: >the 110v white wire cinnected to the 220v neutral?
: 
: Does the 220V circuit have three or four prongs?  If it only has three,
: the circuit HAS NO NEUTRAL, so you can't do this.
: 
: [It's possible that it is three prongs, and has a neutral instead of ground.
: In such a case, I still wouldn't do it unless you made up some independent
: ground mechanism.]

That's the end of my summary.  It's been fun.

Ken Salter
Xref: sparky misc.consumers.house:10107 misc.legal:15295