What kind of device is this?

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bpowers11

Member
Location
Tustin, CA USA
Hello,

My client has a landscape lighting system that is on intermatic timers, but can also be manually overrode using switches inside of the house. I opened up a panel located near the electrical panel and found the attached. I've traced wires and it is definitely related to the landscape circuitry. Odd thing is that when I unconnected one of the outlets on this circuit, I got some really strange voltage readings of like 38v, 10v, etc. on some of the neutral and ungrounded conductors. When all the outlets are made up, voltages seem to go back to normal 120v and 0v. Are these switches? Thanks for any insight.

Brandon
 

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kwired

Electron manager
Location
NE Nebraska
Open type relay, two terminals are the control - a magnetic coil that operates the moving component which has a set of switching contacts attached to the other two terminals.
 

bpowers11

Member
Location
Tustin, CA USA
Thank you. I'm pretty sure the bottom terminals would be the controls, but since the top terminals are all wired in parallel, it would mean that if any relay is energized, the line to the outlets would turn on. As for turning off the power going to the receptacles, how would the timer switch turn off the power when a wall switch is in the on position? Does one switch turning off have a chain reaction that shuts all relays off?
 

kwired

Electron manager
Location
NE Nebraska
Thank you. I'm pretty sure the bottom terminals would be the controls, but since the top terminals are all wired in parallel, it would mean that if any relay is energized, the line to the outlets would turn on. As for turning off the power going to the receptacles, how would the timer switch turn off the power when a wall switch is in the on position? Does one switch turning off have a chain reaction that shuts all relays off?
Bottom terminals are the "controlled" or "switched" terminals.

Applying rated coil voltage to the coil results in the switch changing state. From photo looks like you have "normally open" contact, so energizing the coil closes the switch. There are similar looking relays with multiple switching poles as well as with combination normally open/normally closed contact arrangements.

One would need to know what is power and what is control wiring and how it is interconnected with timer(s) or other control devices to more specifically answer questions on the control scheme here. Though there is a good chance there is timer in parallel with manual control switch powering the relay coils, so that either can energize the coils, there is multiple relays likely because there is multiple "power circuits" being controlled by a single control circuit.
 

junkhound

Senior Member
Location
Renton, WA
Occupation
EE, power electronics specialty
Thank you. I'm pretty sure the bottom terminals would be the controls, but since the top terminals are all wired in parallel, it would mean that if any relay is energized, the line to the outlets would turn on. As for turning off the power going to the receptacles, how would the timer switch turn off the power when a wall switch is in the on position? Does one switch turning off have a chain reaction that shuts all relays off?

Pay close attention to what k-wired said.
Those are standard contactors.
You should research and read up on contactors and relays.

The side terminals are the coil connections, and look to be wired to all become activated (.eg the contactor closes). The bar at the bottom is the 'switch'. In reading up on contactors, you will find that the bare makes 2 separate contacts at once, whereas a relay has a single contact.
The reason for the 2 contacts is to aid in breaking the arc that results when an inductive load such as a motor is disconnected.

Read a bit on contactors and relays and then ask more detailed questions.

BTW, since you are an apprentice, I'm surprised your journeyman did not give you more details. Perhaps she assumed you knew about contactors?
Do not be afraid to ask any and all questions, we all had to find out what some part were at one time or another, be it at 5 years old or 50 !
 
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Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
The odd voltage readings when an outlet down stream is disconnected seems to indicate the improper use of a ground wire as a neutral conductor somewhere in the circuit by the way.
 

Gary11734

Senior Member
Location
Florida
Hello,

My client has a landscape lighting system that is on intermatic timers, but can also be manually overrode using switches inside of the house. I opened up a panel located near the electrical panel and found the attached. I've traced wires and it is definitely related to the landscape circuitry. Odd thing is that when I unconnected one of the outlets on this circuit, I got some really strange voltage readings of like 38v, 10v, etc. on some of the neutral and ungrounded conductors. When all the outlets are made up, voltages seem to go back to normal 120v and 0v. Are these switches? Thanks for any insight.

Brandon

It sounds like they may be switching neutrals. You see white wires on the contactors. Who knows what it looked like after the first installation.

If you look at the contactors, all four are controlled by one device. The coil circuit is in parallel to all four.

Why not try and draw what you think is going on here and post. How is the timer being overridden? That's how we learn...
 

kwired

Electron manager
Location
NE Nebraska
It sounds like they may be switching neutrals. You see white wires on the contactors. Who knows what it looked like after the first installation.

If you look at the contactors, all four are controlled by one device. The coil circuit is in parallel to all four.

Why not try and draw what you think is going on here and post. How is the timer being overridden? That's how we learn...
Switching neutrals could give unexpected voltage readings at times. white wires on contactors - looks like NM cables are entering the enclosure, a switch leg could be legally using a white conductor as ungrounded, though it should be marked to indicate it is ungrounded - to protect those that don't understand anyway:roll:
 

bpowers11

Member
Location
Tustin, CA USA
I sketched out the wiring (attached) to better understand the circuits, but will need to get more details when I go back to the house in a week or two since I'm not sure about all the ins and outs of the wires. Any suggestions on making these drawings easier to see what's going on?
 

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LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
Search for how to draw wiring diagrams on the net.

Is it possible you have a pair of 3-way switches and a 4-way?

Does every light go on and off as a single group?
 

Gary11734

Senior Member
Location
Florida
I sketched out the wiring (attached) to better understand the circuits, but will need to get more details when I go back to the house in a week or two since I'm not sure about all the ins and outs of the wires. Any suggestions on making these drawings easier to see what's going on?

How many circuits from the main panel are feeding the Lights?

Does the timer override the switches, or, do the switches override the timer? Based on the relays installed where they are, I would assume the guy had this manual from the beginning and then got tired of leaving the lights on all the time so he installed the timer later.

Do any three switches in the house control all the lighting at once?

How many contacts are in the timer. Normally open contacts? What's attached to the timer N.O. contacts?

Why would they use the relays in the first place? Maybe it was how it was put together with the switches in the original install. Then, the Timer was added later.

Since your getting crazy readings, I am assuming its a multi-branch circuit. You may have pulled the common neutral in the circuit. And, the lights were on at the time. That is how you would get the voltage readings your talking about.

You can't draw the circuit until you know what the intent was or how it was put together.
 

bpowers11

Member
Location
Tustin, CA USA
I'll start with what I do know. Outlets #1 and #4 are being used to control the landscape lighting (front yard and backyard) via a plug in transformer, which can be overridden by Switch #1 (front yard) and Switch #2 (backyard). Outlet #2 and Outlet #3 are being used for landscape irrigation controllers which can be overridden by Switch #3. I'm guessing the homeowner wanted to be able to turn off the sprinklers when it was raining without going to each controller. I know that the landscape lights are on one circuit, and the irrigation is on another, and yes it looks like they are sharing the neutral since only one white wire goes from the timer to Outlet #3. I know only the lighting (Outlet #1 and Outlet #4) are on the T101 timer (SPST) that can be overridden.

What I don't know is if the lighting switches will be overridden by the timer. Can you think of this wiring like a 3-way switch where the Timer acts as one of the switches? I also don't know how the relay circuit and controlled circuits are working, but will try to get better picture next week. The relay circuit could be a 3rd circuit...
 

kwired

Electron manager
Location
NE Nebraska
My guess - a desire to automatically control multiple circuits from the one timer, yet some additional or even pre-existing switches that still allow manually turning off selected loads. If you want to manually turn on a load you have to hit the override switch in the timer and then manually turn off whatever loads you didn't want to run. Leave all the local switches all on and everything runs according to the timer settings.
 
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