Restaurant time clock

[tbakelis]

Hello All,

I'm trying to put together an inexpensive simple way to meet title 24 lighting code for a small/medium restaurant.

It has 4 lighting circuits with a switch controlling lights in each room.

Am I correct in being able to install a 4 pole normally closed contactor with a mechanical timer controlling it?

How do I have a manual 2 hr bypass? Do I need a fancier digital timer?

Any thoughts

 

[templdl]

Hello All,

I'm trying to put together an inexpensive simple way to meet title 24 lighting code for a small/medium restaurant.

It has 4 lighting circuits with a switch controlling lights in each room.

Am I correct in being able to install a 4 pole normally closed contactor with a mechanical timer controlling it?

How do I have a manual 2 hr bypass? Do I need a fancier digital timer?

Any thoughts

What would do if you had a simple single lighting circuit? What type of timer would you use to accomplish the task?
The where does this 2hr bypass come in? Could you define what the function ?
If you can do that it should be no problem to control the coil of the contactor for 4 circuits.
However I'm not sure what you had in mind regarding a NC contactor. Have you considered a latching type contactor? All that they require is a pulse to close and a pulse to open and release.

 

[jumper]

What would do if you had a simple single lighting circuit? What type of timer would you use to accomplish the task?
The where does this 2hr bypass come in? Could you define what the function ?
If you can do that it should be no problem to control the coil of the contactor for 4 circuits.
However I'm not sure what you had in mind regarding a NC contactor. Have you considered a latching type contactor? All that they require is a pulse to close and a pulse to open and release.

I am guessing the NC contactor is being used to turn the lights off with the timer controlling the contactor coil. When the timer closes the contactor power contacts open.

If the timer fails the lights would go to the on position.

The bypass switch, why 2 hrs IDK, would seem to cut out the timer and the lights would come on. Service work after hours maybe?

 

[Smart $]

Not familiar with "title 24". How does it relate to time-controlled lighting, or any type of control other than manual switching?

 

[jumper]

Not familiar with "title 24". How does it relate to time-controlled lighting, or any type of control other than manual switching?

It is a energy saving rule/law in CA IIRC.

 

[eHunter]

Hello All,

I'm trying to put together an inexpensive simple way to meet title 24 lighting code for a small/medium restaurant.

It has 4 lighting circuits with a switch controlling lights in each room.

Am I correct in being able to install a 4 pole normally closed contactor with a mechanical timer controlling it?

How do I have a manual 2 hr bypass? Do I need a fancier digital timer?

Any thoughts

Is the restaurant open 7 days a week?
Are the hours of operation the same for every day?

The 2 hour manual override is easily accomplished with a spring wound timer such as an INTERMATIC FF32H.

 

[tbakelis]

Yes, the restaurant is open 7 days a week. The time clock is meant to shut all the lights off after hours even when someone has forgotten some on.

The 2 hr bypass is for service after hours, just don't know how to incorporate that or if is built into the timer?

 

[tbakelis]

And how would I incorporate the INTERMATIC FF32H in with the normally closed contactor and the time clock?

 

[eHunter]

And how would I incorporate the INTERMATIC FF32H in with the normally closed contactor and the time clock?

Similar to this.

View attachment Timer-Bypass.pdf

 

[tbakelis]

First of all, thanks for your help! But I'm sorry for not getting this. If the contactor is normally closed and all the lights in the restaurant are operational.... then say the time clock engages at 5pm (it's a breakfast lunch joint) and that turns off all the lights for the night. Then, by turning the mechanical timer I need it to "not" send power to the contactor so the coil disengages and turns lights back on. No?

 

[eHunter]

First of all, thanks for your help! But I'm sorry for not getting this. If the contactor is normally closed and all the lights in the restaurant are operational.... then say the time clock engages at 5pm (it's a breakfast lunch joint) and that turns off all the lights for the night. Then, by turning the mechanical timer I need it to "not" send power to the contactor so the coil disengages and turns lights back on. No?

Correct, the mechanical spring wound 2 hour timer will break the circuit powering the contactor coil until it winds(ticks) down to zero and makes the circuit to the contactor coil again.

The lighting timer is shown in the lights on position, the spring timer is shown in the zero time position and the lighting contactor is shown in the normally closed(lights on) position.
At 5pm the lighting timer will close sending voltage through the spring timer to the contactor coil, pulling in the contactor and breaking the lighting contacts turning off the lights.
At 8pm the maintenance crew comes in, the lights are off, they turn the spring timer to the 2 hour position an the lights stay on for 2 hours and turn of when the timer winds down to zero.

 

[jumper]

First of all, thanks for your help! But I'm sorry for not getting this. If the contactor is normally closed and all the lights in the restaurant are operational.... then say the time clock engages at 5pm (it's a breakfast lunch joint) and that turns off all the lights for the night. Then, by turning the mechanical timer I need it to "not" send power to the contactor so the coil disengages and turns lights back on. No?

Correct, you need a timer switch to break the power to the coil to turn the lights on for a set period.

A common/similar app is to turn off the power to fans and the compressor to walk in coolers as it is being restocked, but the cooling needs to be be restarted after a set time if the clerk forgets and walks off.

 

[tbakelis]

I'm totally understanding the concept but I have to ask another dumb question!

Isn't a spring timer usually open and then when it's twisted it closes (like a normal switch)? If it's normally open and the lighting timer closes sending voltage to the spring timer... if the spring timer is intercepting the circuit going to the coil and it's usually open... then the contactor won't engage to close the lights, no? Or is there a spring timer that is normally closed and when twisted... opens?

 

[eHunter]

I'm totally understanding the concept but I have to ask another dumb question!

Isn't a spring timer usually open and then when it's twisted it closes (like a normal switch)? If it's normally open and the lighting timer closes sending voltage to the spring timer... if the spring timer is intercepting the circuit going to the coil and it's usually open... then the contactor won't engage to close the lights, no? Or is there a spring timer that is normally closed and when twisted... opens?

The INTERMATIC FF32H is SPDT as depicted in the diagram.
As a reference model, I used the Tork model EW120B 7 day timer also SPDT that is title 24 compliant and includes a battery backup to maintain the correct time and settings during utility outage. About $180

 

[tbakelis]

Ok, so it looks like the reason I wasn't understanding this was a lack of understanding on my part about the SPDT spring timer. I now get that it can be used as a normally closed and then when twisted it opens the circuit. Perfect, I get it now! You guys rock, thank you for your help.

 

[Smart $]

It is a energy saving rule/law in CA IIRC.

That much I knew/assumed :slaphead:

I was looking for how the desired control changes the current lighting from non-compliant to compliant.

What about using occupancy sensor switches? Use fairly inexpensive digital timer (example link) to control contactor, and occupancy switch to trigger bypass.

Or simply replace each regular switch with a digital timer and occupancy sensor to bypass when timer is OFF.

 

[tbakelis]

So are u saying that you don't think that setup (time clock with 2 hr bypass) will pass title 24? Even with all the lighting (except 8 - 65 watt incandescents under hood) being high efficiency? I know for sure the owners won't want those digital timers everywhere.

 

[Smart $]

So are u saying that you don't think that setup (time clock with 2 hr bypass) will pass title 24? Even with all the lighting (except 8 - 65 watt incandescents under hood) being high efficiency? I know for sure the owners won't want those digital timers everywhere.

I don't know the requirements of Title 24, so I have no idea what will pass and what won't.

What do you plan to use for main control of the contactor? Well you still need something to switch between normal occupied and not occupied times. Could be as simple as a regular ol' wall switch. The 2hr bypass is for after-hour service work, right?

 

[tbakelis]

Yes, all areas will have normal wall switches. All curcuits will run through NC contactor. Time clock for T24 requirement.

Thanks for all the help!

 

[normbac]

it should be on the plans T-24 has pages of rules and details. all buildings are different. It depends on the amount and type of wttage vs square ft of building and purpose. Its complicated and thats why most plans have engineered lighting specs for the T-24 requirements. rooftop light sensors, light control panels, a b switching, 7 day astronomical timers, track light limmiters etc etc I would check with the AHJ first so you dont do it twice or worse miguide the owner.