Wiring of Replacement Bath Heater/Fan/Light ceiling unit

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  #1  
Old 12-01-04, 02:06 PM
philjonz
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Wiring of Replacement Bath Heater/Fan/Light ceiling unit

Just purchased Broan Model 730/732/735 heater/fan/light unit to replace my burned out one. The existing unit had one place to attach the incoming power cable.

But this one has a wiring diagram that suggests (to me) that I take out another knockout from the switch box, take a new cable up to the fixture, then return to the switch via my existing cable.

I can FAX the diagram if it will help.
 
  #2  
Old 12-01-04, 04:01 PM
J
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So you are replacing one unit with another of the same model? If not, exactly what is the burnt out unit?
 
  #3  
Old 12-02-04, 07:27 AM
philjonz
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Replacement Bathroom heater/light/blower

It's the same "type" of unit (heater/light/blower). The original had been there for about 30 years and simply stated - the heater and blower quit working. But the wiring setup looks entirely different to me. In the original unit the power was connected at one point in the box and from there the internal wiring routed the appropriate electric function to the right portion of the unit (heat/blower/light) outside of the box. There were little plugs from each unit that were plugged into an internally mounted receptacle so you could unplug a particular section of the heater/blower/light and take the screws out and pull it out without interfering with the other unit sections.

On this new one, there is one box to attach the wiring to but there is at least one wire from each of the units going into the box. And all three of the functions (heater/light/blower) are already interconnected by at least one wire inside the box. I would have to remove the whole unit to work on any portion of it.

My initial plan was to simply attach hot-to-hot, neutral-to-neutral but the drawing the had in the box makes me scratch my head. Below is a link to the installation guide and wiring diagram.

So, can I install it with one set of wires or do I have to add an additional cable from the switch box? What sayeth thou?

http://www.broan.com/PDF/InstallGuides/99042661.pdf
 
  #4  
Old 12-02-04, 08:10 AM
J
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This unit requires two 12/3 cables between the switch box and the ceiling box. Do you have this?
 
  #5  
Old 12-02-04, 09:17 AM
J
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The drawing is probably telling you how to connect it so you have separate switches controlling each device. If you want all the devices coming on together just connect all the hots to the exisiting hot wire and all the whites to the existing white wire. The switch will control all units as one.
 
  #6  
Old 12-02-04, 12:54 PM
J
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The installation instructions show a "4-function control" unit installed in the switch box. I guess I should have asked if that is what you are going to use to control this thing.
 
  #7  
Old 12-03-04, 07:56 AM
philjonz
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Bathroom heater/blower/light

Yes I want to install a 4-function control unit. I want to control each unit separately. I believe that if I stay with one cable from switch to fixture it will be either all or nothing but not sure.
 
  #8  
Old 12-03-04, 08:00 AM
philjonz
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Replacement Bathroom heater/blower/light

Originally Posted by John Nelson
This unit requires two 12/3 cables between the switch box and the ceiling box. Do you have this?
Would that be 12/3 with ground?
 
  #9  
Old 12-03-04, 08:34 AM
J
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Yes, that's 12/3 with ground. We don't usually say the "with ground" part because 99% of it has a ground and you probably won't be able to find it any other way at your home center.

I don't know if this will operate with properly without the two 12/3 cables. Even if it will, you won't be able to use the 4-function control without them.
 
  #10  
Old 12-05-04, 09:42 AM
bobbyk2002
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Similar Problem Wiring Bathroom Fan/Heater/Light

I also purchased a new Broan (don't have the model number handy). It has an exhaust blower motor, two light/infrared heat bulb receptacles that can either be used for two infrared bulbs or one regular light bulb and one infrared heat bulb (the latter option is how I intended to use it). The instructions provided are not too clear. There are so many wiring combinations and multi- colored wires in the unit.

The old unit was controlled by three wall switches, one each for the light, the heater, and the exhaust fan. There are two grounded 12/2 cables running from the service panel to the three wall switch cluster. From there, the two cables run to the unit. This is where it gets confusing. I tried following the instructions for each function controlled by one switch, but if I turn the exhaust fan on, and then the infrared heat bulb, the fan shuts off. I believe whoever installed the original unit is using one of the white wires as a hot (or black) wire. According to the not so clear instructions supplied, there are several wiring possibilities depening on how you want the unit controlled. I would like to keep the original function, one switch for each function. Before removing the old unit, I labeled each wire, but the new unit has several different wires in the box; white, blue, yellow, and black and of course the ground.

Any suggestions on how I can properly connect the two cables running from the switches to the unit so that each switch controls each of the three different functions indepently?

I appreciate any help.undefinedundefined
 
  #11  
Old 12-05-04, 10:29 AM
J
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Post back with the model number.

Moderator: please split bobby's thread off of phil's thread. We need to keep the discussions separate because they will almost certainly have different solutions.
 
  #12  
Old 12-05-04, 01:24 PM
bobbyk2002
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The Broan Model Number

It's Model No. 164 (Broan). Since this is my first post, I'm new and didn't know if I should have started a new thread. Thanks.
 
  #13  
Old 12-05-04, 01:53 PM
J
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Originally Posted by Bobby
There are two grounded 12/2 cables running from the service panel to the three wall switch cluster
That doesn't seem likely. Are you sure? How do you know that these two cables come from the service panel? Could one of them come from somewhere else?

Are you trying to use the original three switches? Did the unit come with a 3-function control? If there is any way to wire this to the three separate switches (which I highly doubt), you'll need to call Broan for help (1-800-558-1711). And if you use the 3-function control, you have the wrong wires in the wall for that. You do, however, have enough wires for a dual control.
 

Last edited by John Nelson; 12-05-04 at 02:12 PM.
  #14  
Old 12-05-04, 02:58 PM
bobbyk2002
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Broan Heater/Fan

Two 12/2 cables (w/ ground) do enter the switch junction box in the wall. The box contains a single light switch used to control the light only on the old unit and a double (horizontal) switch that each controlled the heater and fan independently on the old unit before the fan motor went bad. On the double switch, I see a white wire connected to a terminal on the switch and it looks like it is coming from the service panel which doesn't make sense (I thought white was neutral and not hooked up to switches, but to each other). It doesn't look like a professional job. Except for maybe 3-way switches I've seen only black wires hooked up to the terminals (but a good electrician will wrap black tape on it).

The single switch has a jumper wire to the double switch. The double switch has another jumper from one screw terminal to the screw terminal on the other side of the double switch. (I wish I could draw a diagram). I can't make sense of it, it's complicated. But it did work before. Each of the three switches turned the light, fan, and heat on or off independently.

I recently had an electrician replace my old fuse boxes (its a 1940's house) with a single 100 amp service panel with circuit breakers. As far as I can tell, only the Broan unit is controlled by a single breaker (when I switch it off, nothing else in my house appears to be turned off). Anyway, it is Broan Model 164 and no switches were supplied with the unit, nor are there any references to switches provided by Broan. I did find this link on the net that has the installation instructions similar to what came in the box. It also shows other models, but if you scroll down the page, you'll find Model 164 and the possible connections.

http://www.broan.com/PDF/InstallGuides/99042412.pdf

When I have time, I'll work on it again. I guess I'll just hook the wires from the unit to the wall switch wires one by one until it works like it did with the old unit. I believe the old one was a Broan also, but I threw it away. I haven't had much need for the heat lately, so as long as I can have light and ventilation, that's good for now. I have an electrical probe where you touch a red and a black wire to the wiring and they light up if a circuit is completed, so at least I can tell which one of the white wires is a "hot" wire. I hope so.

Thanks.
 
  #15  
Old 12-08-04, 08:15 AM
philjonz
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Heater/blower/light/night light Install

After all you folks' comments and the new thread that is along the same lines, I see that one must have two separate 12/3 cables from the switch to the unit if I want to control each function separately. I can use the existing 12/2 cable to provide power at the switch and to each 12/3 cable just exactly as shown in the wiring diagram. It all seems so much more simplified after talking, reading, and looking at the diagram. What made it appear to be so confusing was those short-wire jumper connections on the back of the switch.

Thanks - I know this will work fine and intend to "do it" this weekend.
 
  #16  
Old 12-08-04, 06:32 PM
bobbyk2002
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The Wiring Mess

That makes sense. I don't remember who posted a question before, but I don't think I was clear in my last post. There is only ONE 12/2 grounded cable coming from the breaker box, not two as I posted. Two 12/2 cables then go from the switch box to the heater/light/fan unit. I still don't know how they got it to work by using all these jumper wires.

I'll start with the single light switch: A black wire is attached from the lower terminal on the switch to the unit. Another black wire (jumper) connects to the left upper terminal of the double switch. The left upper terminal on the double switch also has a black jumper connected to the lower left terminal. The black (hot) wire from the breaker box is also connected to this lower left terminal on the double switch. That would explain where both switches gets their power source from.

On the right side of the double switch, a white wire is connected to the lower right terminal and heads up to the unit. The black wire (from the same cable) is connected to the upper right terminal of the double switch and heads up to the unit. Since the double switches are horizontal, I assume the power or hot wire connected to the left side acts as the incoming power. That explains the jumper wire which powers both the left side's upper and lower terminals. The right side has a single wire from each terminal that goes up to the unit. When either switch is turned on, the circuit for that function is complete.

The remaining white wires and ground wires are then connected with wire caps, white to white and ground to ground.

I have a feeling, the previous homeowner made these hookups. They look fishy to me, and I'm no electrician. I'm glad the previous poster got his answer from the diagram.

And I'm glad my house hasn't burned down yet!
 
 

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