Controlling "ON" after a Power Failure

[Mickey]

After a power failure, is there a way to stagger the MH lights coming back on? Will this statement do it?

If Power Fail Then MH1 OFF
Max Change 010 M Then MH1 ON
If Power Fail Then MH2 OFF
Max Change 015 M Then MH2 ON
If Power Fail Then MH3 OFF
Max Change 020 M Then MH3 ON

My MH ballasts are on a single HD DC4 and the last time I had a power failure the fuse blew. I assume it is because all three 250 watt ballasts came on at once.

I've also blown two fuses on a DC4 unit controlling 3 250 watt heaters and I'm still trying to figure out why it blew the second time. The first time I know about and corrected the situation. Any ideas?

Thanks.
Mickey

 

[clp]

For short power failures those statements will keep the lights from comming on at the same time. Please email me the serial numbers of your DC4HDs; I'd like to know if they have the old style fuse holders and that is what is causing them blow.

Curt

 

[Mickey]

I sent you the serial numbers via email.

How "short" is a short power failure? Is there something better I could/should do?

Mickey

 

[Qwiv]

I think he means until your battery dies.

 

[Mickey]

I don't see why the battery dieing would affect anything. Even if the battery did die, once the power got restored the programming would kick back in and the metal halides would come on staggered based upon these lines. Of course the lights will be on at the wrong time because the date and time get reset, but at least the fuse won't blow by having all three come on at once. At least that is what I'm hoping.

Mickey

 

[Qwiv]

The data log and clock are reset when the battery goes dead as this is stored in different memory than your program code. This memory is erased in a power failure/bettery dead condition. When it restarts, the controller will not know there was a power failure and will ignore the line of code you pasted above. When the power is returned, the program will start again using the default clock time. This could turn all you lights on at once depending on how you wrote your code.

Hope that makes sense.

 

[DrBDC]

I don't have a battery backup plugged into the other power input and if my power is out it doesn't lose date/time and the program. It acts no different than a computer does. Is there a little battery in them for that like a computer mother board has?

 

[Qwiv]

Depends on what model you have. The ACII has a 9 volt battery. The AC III Pro has the lithium Ion battery inside. I don't know about the other models as these are the models I have. Read your manual to find out for sure.

Either way, logging is stored in battery backed up RAM on both the models I have. When that internal battery dies, all logging is erased.

I can think of a few lines of code to fix your circuit overload problem in this case, but I wouldn't waste the memory myself. You could start your lights staggered based on the default time after a power reset.

 

[Mickey]

Qwiv - Yes that did make sense and I just didn't think about it that way before. My normal programming has the lights come on staggered by 15 minutes so that if the date and time logic is lost (and therefore the extra lines of code for a "short" power failure) I should be okay.

I'm going to add the extra lines and see what happens.

I just want to make sure it should read this way:
If Power Fail Then MH1 OFF
Max Change 010 M Then MH1 ON

Because I copied this code from another post and that person had it read as
If Power Fail Then MH1 OFF
Max Change 010 M Then MH1 OFF.

Thanks to everyone for your help. Special thanks to Curt for helping with my blown fuse problem.

Mickey

 

[Qwiv]

Should work. Please post your results.