Lighting Control

[Volt-Amps]

I have 4 lighting circuits for a small project. 2 of them go to the exterior sign and show windows. The remaining two circuits feed interior lights. all 4 circuits are routed through a time clock for code compliance.
The 2 interior lighting circuits branch off 7 switch legs, each area/room/space has its own switch but at the end all 7 switches are tied to the 2 circuits mentioned earlier for interior lighting.
The client wants kill switches at 2 different locations (3-way switching). The intent is to be able to shut off power for all interior lights with one click. the 3-way kill switches to be located one in the office and one at the back door.
I thought of using a DPST switch, 2 circuits in and 2 circuits out, then route that through a contactor that has minimum 2 poles in, 8 poles out, and from there feed the switch legs. Please see attached proposed diagram. Keeping in mind to use a handle tie for the 2 breakers that feed the 2 circuits.
My questions:

• Can DPST switches be wired as 3-way switches to achieve what I envisioned in the diagram?
• Is there a better or simpler way to achieve what the client wants? possibly using relays?
• I don't know much about relays, that's why I'm hesitant to call for something that is not possible to implement or build.

Your help is greatly appreciated.

 

[LarryFine]

How about using two 2p contactors, one for the two inside lighting circuits, one for the outside circuits.

A single-pole time clock output could just be split, one leg directly to the outside contactor, and the other leg through a pair of 3-ways to the inside contactor.

You don't need an "8-poles-out" contactor, just the two lines to the two groups of switches.

By the way, 3-way switches are SPDT switches, not DPST, which are simply 2p on-off switches.

 

[Volt-Amps]

How about using two 2p contactors, one for the two inside lighting circuits, one for the outside circuits.

A single-pole time clock output could just be split, one leg directly to the outside contactor, and the other leg through a pair of 3-ways to the inside contactor.

You don't need an "8-poles-out" contactor, just the two lines to the two groups of switches.

By the way, 3-way switches are SPDT switches, not DPST, which are simply 2p on-off switches.

The 2 circuits for show windows and signage can be controlled by time clock, no need for a contactor to control them. Correct me if wrong please.
The 2 interior lighting circuits are the ones of concern. If DPST switches can not be used as 3-way switches, I may have to use 2 separate switches, one for each interior lighting circuit. See attached Also, if I eliminate the LC, what is the best way to to connect the two interior lighting circuits (lines) coming from the 2nd 3-way switch to the final individual switches "a" through "g"?

 

[James L]

I agree with Larry about having 2 contactors
Your drawing is overly complicating it.

Make a lighting control box where you'll have (2) 2-pole contactors, and run (4) circuits straight there from the panel.

(1) control circuit from panel to (1) single pole time clock (red in my rendering).

From (1) time clock, take (2) loads - one directly to the control box to power the coil for outside lights contactor (orange in my rendition), the second would go to your 3-way switches to power the second contactor (red)

 

[LarryFine]

The 2 circuits for show windows and signage can be controlled by time clock, no need for a contactor to control them. Correct me if wrong please.

They can, but then you need a multi-circuit time clock. I suggest something like a simple single-pole, in-wall timer, which can control as many separate circuits as you supply contactor poles for.

The 2 interior lighting circuits are the ones of concern. If DPST switches can not be used as 3-way switches, I may have to use 2 separate switches, one for each interior lighting circuit.

Again, one contactor will allow you to control multiple circuits simultaneously as if they were one load.

Also, if I eliminate the LC, what is the best way to to connect the two interior lighting circuits (lines) coming from the 2nd 3-way switch to the final individual switches "a" through "g"?

Put the contactor before the switches, not after. Imagining you'll use two 4g switch boxes, feed all four switches in each box with a single wire from one of the two contactor poles.

 

[LarryFine]

 

[LarryFine]

Note: The scribble in the upper left corner is supposed to be Ckt, not Oct.

 

[LarryFine]

If you will always switch on and off all of the interior lights together, you can omit the eight switches.

 

[LarryFine]

You can add additional switching, such as a manual switch or a photocell, in the contactor control lines.

 

[Volt-Amps]

Thank you Larry and James, your help is appreciated.

 

[Strathead]

They can, but then you need a multi-circuit time clock. I suggest something like a simple single-pole, in-wall timer, which can control as many separate circuits as you supply contactor poles for.


Again, one contactor will allow you to control multiple circuits simultaneously as if they were one load.


Put the contactor before the switches, not after. Imagining you'll use two 4g switch boxes, feed all four switches in each box with a single wire from one of the two contactor poles.

He has a multipole contactor. I would first investigate the properties of the time clock. When you get in to 4 pole time clocks, most of them have additional functionality. I would suspect you might be able to trigger the circuits independently. the 2 for the signs will certainly use at least an astronomical time and possibly a photocell. There may be the additional ability to control the other two circuits. If not, a Wattstopper or Bluebox 8 pole may be as cheap or cheaper that running full voltage circuits all around.

 

[LarryFine]

View attachment 2568070

Oops! I just noticed that I reversed C1 and C2.

 

[Fred B]

A solution I like is a relay panel that allows all individual sw to control each individual light as well as allow multiple master switch control. Used the old GE RR9 relay panels in the past that incorporated LV momentary for switches to control 120v lighting as well as master switches controlling multiple locations from single switch. There is a newer version:

GE Low Voltage RR9 12 Pilot Light Relay LightSweep System

GE low voltage RR9 12 pilot light relay replacement LightSweep system. Find new replacement wall plates, relays & wiring guides for your older home.

www.kyleswitchplates.com

It seems now you can get other types of these with all sorts of adaptions including timers from other MFGs.