Any Electricians in the House? 4 wire vs. 3 wire light switch confusion


 
LarryR

LarryR

TVWBB Diamond Member
So I purchased these really cool light switch/auto-timers to replace my standard rocker switches. My neighbor came over to show me how to install one telling me they are easy and I could do the rest myself. Honestly, didn't look that easy to me, even though he did it in 5 minutes so I hired a handyman to come install them (and do some other projects) for me. He went to install them and he said he couldn't because the switches I wanted replaced were 3 wire and the new switches are 4 wire. Here are the switches I purchased - https://www.amazon.com/exec/obidos/ASIN/B00TSU5GB6/tvwb-20

I have no idea what the guy is talking about. My neighbor was able to install it just fine, worked great, no issues. Would someone mind explaining to me what he means? Sorry if I sound dense, I have no clue when it comes to this type of stuff. He had an issue with something else he installed so I'm thinking I'm going to have an electrician come back out and install these switches and look at the other item but I want to make sure I have the right parts for the electrician as he charges a bit more than the handyman does.

Thanks in advance!
 
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Disclaimer: I'm not an electrician. But I had an electrician install something similar:

Intermatic ST01 7 Day Programmable In Wall Digital Timer Switch for Lights and Appliances, Astronomic, Self Adjusting, Heavy Duty

It has four wires coming out of the back.

For Single-Pole Wiring (a single switch controls the light or outlet) it's easy:

  • The A wire (black) connects to the hot (black) wire from the power source.
  • The B wire (blue) connects to the other wire from the load.
  • The C wire (red) is not used and is capped with a wire nut.
  • The D wire (green) connects to the ground.

For Three-Way Wiring (where two switches control the light or outlet) it's more complicated:

  • The distance between the timer and the remote switch must not exceed 100 feet.
  • The A wire (black) connects to the wire removed from the “COMMON” terminal of the switch being replaced.
  • The B wire (blue) connects to one of the other wires removed from the switch being replaced. Record the wire color connected to the blue wire for use during load-side installation.
  • The C wire (red) connects to the remaining wire removed from the switch being replaced. Record the wire color connected to the red wire for use during load-side installation.
  • The D wire (green) connects to the ground.

The above text comes directly from the wiring instructions included with my switch. You should find something similar with yours. If you're replacing a single switch controlling a single porch light or outlet, it should be easy.

Good luck!
 
I'm not an electrician either, but I've installed several switches nearly identical to what you purchased. In addition to the information Chris provided on 3 way switches, that 4 wire switch is also used for a dual fixture, like a ceiling fan that ALSO has a light fixture below it. i buy my switches from Home Depot or a local electrical outlet here in town and i would return it for the 3 wire switch. Your situation is more difficult as you made an on line purchase and it's a pain to do returns and time consuming. i'd just cap the red wire as stated in Chris's post and it should work just fine.

Option 2... Get the 5 minute neighbor back.
 
SWEET! Thanks guys, greatly appreciate it.

I know nothing about this sort of thing and I'm a total fish out of water, I suppose I'm trying not to get taken. I got a quote from an electrician to come install these and he told me it would be $400 for three of these timer switches, swapping out an outlet (got one of those cool USB outlets I want to try out) and replacing a GFI. After watching neighbor do it I figure it's an hour to two hour job. $200+ an hour seems a little high for my project so I wanted to educate myself so I'm not getting taken to the cleaners on the install. I did find another electrician this morning who said he'd do it for $50 an hour and he'd be shocked if he was there longer than an hour.

Thanks a lot, really wish I could do the work but electricity scares the heck out of me and I don't think I'd sleep well at night knowing I did the work LOL.

Thanks again!!!
 
That's not the same (not no handyman) you had, install your water softener? LOL:)
Tell the guy to read the wiring diagram!

Tim


Hey Larry, This is Tim's son in reference to the wiring diagram I am a Electrician and that price for what you are quoted is about right.. It sounds crazy but the average price per hour for an electrician or per device installed can be anywhere above 100$ in our area... This could get pretty in depth but I'll keep it as short as possible.. The new device you are installing needs all 4 wires connected to work properly.. what you need at your switch is a Hot wire (coming from the panel and should be a black or red wire in a single phase house, it could be a blue if you have 3 phase) , Switch leg (going to the light and can be any color but typically its orange, pink, purple..etc), Neutral (should be white but not guaranteed), and ground wire (should be green) . I'm referencing the way we do it in the union and by code due to safety for the consumer and next guy that might have to service it. What you need to do according to the switch schematic is take your constant Hot wire and connect it to the black wire. Your switch leg (wire going to the light) connect that to the red on the switch. This is where it can get tricky... Your regular toggle switches don't require a neutral because its not acting as a load , its just engaging/disengaging power. Since the new switch is a timer its acting now as a load and needs the neutral. Hopefully they spliced a neutral (hopefully white) in that switch box. If so all you need to do is tie in the white wire from switch with the neutral at the switch. If there isn't enough wire to make a splice out side the box (at least 6" imo) I would get the electrician. If your house is piped then its not that big of a deal to get a neutral there. If its romex it might be a bit of a problem and I would highly recommend paying the electrician it will be worth while on you. If you need any more help my dad says PM him and he will grab me and ill get back to you ASAP. I hope this helps , Brandon
 
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timothy said:
That's not the same (not no handyman) you had, install your water softener? LOL:)
Tell the guy to read the wiring diagram!

Hey Larry, This is Tim's son in reference to the wiring diagram I am a Electrician and that price for what you are quoted is about right.. It sounds crazy but the average price per hour for an electrician or per device installed can be anywhere above 100$ in our area... This could get pretty in depth but I'll keep it as short as possible.. The new device you are installing needs all 4 wires connected to work properly.. what you need at your switch is a Hot wire (coming from the panel and should be a black or red wire in a single phase house, it could be a blue if you have 3 phase) , Switch leg (going to the light and can be any color but typically its orange, pink, purple..etc), Neutral (should be white but not guaranteed), and ground wire (should be green) . I'm referencing the way we do it in the union and by code due to safety for the consumer and next guy that might have to service it. What you need to do according to the switch schematic is take your constant Hot wire and connect it to the black wire. Your switch leg (wire going to the light) connect that to the red on the switch. This is where it can get tricky... Your regular toggle switches don't require a neutral because its not acting as a load , its just engaging/disengaging power. Since the new switch is a timer its acting now as a load and needs the neutral. Hopefully they spliced a neutral (hopefully white) in that switch box. If so all you need to do is tie in the white wire from switch with the neutral at the switch. If there isn't enough wire to make a splice out side the box (at least 6" imo) I would get the electrician. If your house is piped then its not that big of a deal to get a neutral there. If its romex it might be a bit of a problem and I would highly recommend paying the electrician it will be worth while on you. If you need any more help my dad says PM him and he will grab me and ill get back to you ASAP. I hope this helps , Brandon
Click to expand...

Tim - no, different guy lol, great memory. I have zero luck man, zero. Actually I found a really good plumber; retired plumber, did it for 40 years, he does small jobs just to keep busy and he says he likes to help people. Guy is awesome!

Brandon - Thanks for your note. The guy who is coming out ($50 an hr guy) is a licensed electrician who does a lot of residential stuff (he does projects like mine on weekends) so he should know what you wrote above, right?

I was originally going to have an electrician do it, however my neighbor came out and installed one of the switches for me to show me how easy it was and telling me I should do it myself. He had that sucker installed in 5 minutes, dude didn't even turn off the power, crazy (to me)! So based on what I saw him do I knew I couldn't do it, but a handyman who came highly recommended could surely do it, right? Guess not.

As a side note before connecting with the guy who is coming out to fix everything I called the switch mfg., they told me it seemed highly unlikely that my neighbor found four wires yet the other switches only had 3. Said he probably didn't look hard enough. My house is fairly new, 8 years old and he said he just doesn't see them wiring some switch boxes with 3 and some with 4.

Thanks again, I'll let you guys know how this saga turns out. Off to cedar plank a salmon and try to cool off, its 124 next to my pool equipment right now.
 
That switch you linked to is a single pole, if you can control a light from different locations then you will have 4 wires coming out of the box/s and you need to order a 2 or 3 way switch.

Tim
 
@Chris - Thanks Chris, I think I might just order a couple of those just in-case. Backlit is only powered when you're programming or turning on and off. Other than looking cool it really doesn't server a purpose if you have good lighting in the area.

@Tim - The electrician said he'd "bypass" the other switch, going to have to speak to the boss (Mrs. LarryR) about whether or not she wants to lose the ability to turn the light on from the master bedroom. Otherwise I'll have to find a dual switch. Wonder if they offer those in the brand Chris posted. I'll take a look.

Thanks again!
 
The one I posted will work with Three-Way Wiring (where two switches control the light or outlet). I am using it that way right now for a patio light that is controlled by two separate switches.
 
Great news, electrician knocked everything out with the parts I had, turns out the 4th wire was buried in the walls. Disabled 2nd switch in the one multi switch and they all work great! Based on what he found when he saw how the handyman rewired one of the switches I had him check an outlet, GFI and fan he'd worked on. Guy knocked all this out in 2 hours.

Going to have him back for several other projects,

Thanks to all, another thing I love about this group, in addition to BBQ a wide range of knowledge.
 
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