photo cell's

[wendy's wash]

Looking for thoughts on installing photo cell to have bay and vac cover lites staying on when it is over cast. Currently I have 2 washes with 2 mechanical timers at each place set to turn on just before dark and turn off just after the sun comes up. The expence to have 4 photo cells will cost just about $500.00 for both places. Would this be well spent money or not. This will increase the lite bill. Thanks

 

[PaulLovesJamie]

Interesting ... I have the exact opposite problem, I currently have photocells and I am in the process of adding timers to prevent the lights from coming on when it is overcast. Do you actually have enough business when it is overcast to add expense, and is it really dark enough that you need more light? At my wash, if it is overcast/stormy enough to require more light, nobody is washing.

 

[JMMUSTANG]

At my washes I had both for years.
The problem was when it wasn't to overcast and the lights would be on or the photo cell mallfunctioned and they stayed on day and night.
Even when they worked (usually with the forcast of rain) I wasn't doing much.
I finally disconnected the photo cells instead of fixing them again.

 

[Greg Pack]

I prefer the electronic timers for the reason Paul mentioned. I don't want to provide lighting for Bubba to change his oil on a cloudy day.

 

[MEP001]

I prefer a photocell to avoid having to reset a timer several times throughout the year, and I set the photocell to come on a little early, but it does mean that the lights may stay on if it's a particularly dark day. I'd rather add a timer to prevent the lights from coming on between 8AM and 5PM than eliminate the photocell.

To the original question, if you specifically want the lights to stay on, the photocell is the only way to do it, and if it's done correctly it should be problem-free.

 

[Greg Pack]

http://www.intermatic.com/Default.asp?action=prod&pid=9178&sid=239&cid=50&did=5

At the last wash I built I used this timer (I think). You have to program it to your geographical location and then it automatically knows the sunrise and sunset times for many years. You then tell it to turn on "X" before sunset and it will do it year round without touching it. I had the two pole model and turned all lights on 1 hr before sunset, then turned half my bay lights, the neon, and roadsign off at 11pm. The other lights turned off a little after daylight. This baby was a real booger to program. I think it was about $350.00

 

[MEP001]

This baby was a real booger to program.

Did you get mustard from your french fried per-tatuhs on it?

 

[lag]

We use a plc to run our lighting, basically we input a photocell ,then after the time to come on in the program makes, output in stages all the light zones. We also shut down half the bay lights at midnight. We output to motor contactors ,so the light load is not placed directly on the plc outputs. If the photocell has not made by a certian time ( depending on what time of year it is) the lights will come on ,and go off anyway ,and if that happens i turn on a light on the control panel to let me know to check the photocell.

I also installed a timed switch on 2 zones so you can, if you need, run half the ss bays ,or half the auto bays lights ,on overcast days.

 

[mjwalsh]

The PLC approach

We use a plc to run our lighting, basically we input a photocell ,then after the time to come on in the program makes, output in stages all the light zones. We also shut down half the bay lights at midnight. We output to motor contactors ,so the light load is not placed directly on the plc outputs. If the photocell has not made by a certian time ( depending on what time of year it is) the lights will come on ,and go off anyway ,and if that happens i turn on a light on the control panel to let me know to check the photocell.

I also installed a timed switch on 2 zones so you can, if you need, run half the ss bays ,or half the auto bays lights ,on overcast days.

Lag,

Are you just using an ordinary photocell? If you have analog inputs on your PLC you could do something similar to what we did with our lighting. Because of our overhead doors we need the lights to come on sometimes during the day on cloudy days. We found ordinary photocells to not be accurate enough. We homemade a printed circuit board that included a photo diode that is used by NASA in the space program. We mounted it on the face of an indoor window & tied it in with a Measurement Computing's analog board on our always on computer. We can still use our 2 already mounted photocells because of three way toggle switches that we added when we added the new light measuring device. This has been working as perfect as imaginable since about 2003. The output from the sensor varies according to the light level meaning we can have lights go on from as many light levels we need. The more enclosed areas come on & go off quicker based on the sensor input.

We hope to eventually have this on a PLC that we plan on using with our future dog wash because the PLC is less likely to need rebooting etc. I have been forewarned that overall PLC programming is tougher than the programming we used with MCC so I hope I don't fall on my face integrating the PLC with these kind of items besides the new dog wash timing functions etc.

 

[lag]

I use at our other locations teco sg2 programmable controllers ,also very easy to program,plus the units do not cost very much. the added bonus is the software is free.
I have been using the sg2 on other applications also. also they are expandable up to 44 inputs ,and outputs. they have many models ,and most will have from 2-4 analog inputs.

 

[lag]

sorry for the split post....

I do use an ordinary photocell, the manual switching of the lights works for us because we do not want to run our lights on all overcast days. We have people at all our sites to monitor if we need them or not.

MJ.. I like the way you use a photo diode, I can see how much better it would be than a photocell alone. I can think of a few ways to inagrade it into our existing system. Thanks for the info.

 

[washregal]

I say go for it.. I did this about 2 mo ago and so far have saved big. I used (2) Intermatic 3000 watt photo cells to control both sides seperatly. I have saved about 100.00 a month off my electric bill.

The beauty of htis is staying way from Timers is that I no longer need to worry about resetting times during power failures and worrying about change in daylight savings.


The photo cells are fairly accurate on cloudy days they do not come on.. on at dawn off at dusk.. These work great.

You might want to think about wiring connecting all of your lighting into a controller.. one place.. Use only one photo eye to control the entire controller and facility. I am doing this at one of my other locations.

I am very happy with the photo cell installation.