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Electrician Question: Mechanical Relays To Control 20A Branch Circuits

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Before I set my display for next year, I need to install some dedicated circuits. I have plenty of room in my subpanel, and intend to install four 20A dedicated circuits, which each circuit supplying a duplex receptacle installed on the soffit board under the eaves along the front of the house. That's the easy part... :)


I would like to figure out a way to put all four circuits on a timer so they turn on and off simultaneously. I think I need some sort of mechanical relay setup to accomplish this. I figure I could approach this two ways:


1. Use a 15A in wall timer on a fifth circuit to drive relays that energize the four new circuits.

2. Use a water-heater time to turn on two of the new circuits, and then relays to energize the remaining two circuits.


Does anyone have any experience with this sort of setup?

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Consider a lighting contactor. I've used them in commercial and residential projects for security lighting and/or landscape lighting projects. A single time clock can be used to power up multiple circuits or lighting loads at the same time. I recently used a 16 pole contactor for a large residential project to control low voltage, line voltage, and motor loads (water pumps for fountains). I used 13 poles of a 16 pole contactor so there is room for expansion. I'm controlling it with an Intermatic astronomical time clock for self-adjusting dusk to dawn & daylight savings time operation.

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I use 2 6 pole 40 amp rated contactors.  1 electronic time clock turns them both on. The first one ( 6 circuits) energizes immediately upon the timer contact closure, the second via a 5 second time delay relay, ( 5 circuits) so the entire load, approx. 200 amps, does slam in all at once.

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