MH timer?...25 AMP rating needed?

[thebigblue]

its time for timers

i have a dual and a single PFO 250w MH ballast(s)...rated at 25 AMPS...

looking at timers someone recommended this one at home depot ...(search SKU# 151146)....its an appliance timer by INTERMATIC...but its only rated at 15 AMPS...

heres a link...

http://www.homedepot.com/prel80/HDU...lceffdfgidgmn.0

the guy at Menards told me i need to make sure the AMPS match or the lights will kick themselves off...

this timer also requires you to hard wire everything in which i'm not crazy about doing...

also will this kind of timer accept 3 MH lights?

thanks

brad

[thebigblue]

i think this link will work better for that timer...


http://www.homedepot.com/prel80/HDUS...ceffdfgidgmn.0

[Junkzoo]

Brad, on a timer for three MH's , might be a tough one without going to a real heavy duty "industrial " type. highest current on a MH is during initial start up. i'll try to get start up currents off mine and get back to you. prob a good place to check timers that might be the best for our application is that electrical supply place on RT.2 in Valpo, near Menard's off 49,,,,in the back of my mind, i've been wanting to install timers on mine too,,but as the saying goes,,,the mechanic has the junkiest car,,,the electrician (me) has the biggest rats-nest of wires behind the tank i remember a digital plug in timer out there that might do the trick,,,,

[thebigblue]

jeff

i should have thought to ask you since your a pro at electricity!..hehe

a guy on another board told me that a 250w MH only pulls 2.5 amps, so a 15 amp timer would be fine...i kinda thought that you had to go by the rating on the ballast?...

menards has a 3 prong digital timer that is 15 amps for $8.99...i could get 3 of those if they would work and be safe over time...

thanks

brad

[Junkzoo]

Brad, inrush (start up) current is the highest on a cold start (what you need to look at)a LOT higher than running amps,,,i think 4-5 time higher,,,, a heck of a lot on whatever timer you are gonna use,,,i'll get back to ya on my current info,,,but you know us 'lectricians ,,,,,

[Junkzoo]

Footnote Brad,,,what ever timers you go with,,,, time them out to start independantly(sp) of each other,,,,works better electrically and on the nature thing,,,,same with going off at nite ,,,,set them to maybe go on and off at 1/2 to a hr intervils(sp) gives them a chance to fire up and level off on the current thing,,HTH !

[CaymanLoversII]

I will defer to Jeff but have a thought while we wait -

What size circuit breaker is on the circuit you are plugging into? For a 110 circuit I doubt it is over 15 amps anyway so if your lights are drawing more than 15 amps they should be blowing the breaker already.

Your three lights at 250 watts each should be drawing about 7 amps from/through the ballast. A 15 amp timer should be able to handle the start-up spike, but it would not be safe if you were continuously running over 15 amps through it, something would have to give.

Again, I am not an electrician so we should see what Jeff says.

Steve

[thebigblue]

yea i thought about having them go on/off in intervals...since i dont have any VHOs to do a dawn to dusk simulation...

it seems alot of guys are using the cheaper 15 ampers with good luck...??

thanks jeff

i gotta get some pics of my tank and send em to ya soon....took some the other nite, some with flash some without...havent looked at em yet...i need a new digital camera but cant afford one cause of this new hobby!...

[thebigblue]

cayman

yea, good point...

i'm sure its a 15 amp breaker...i will check tonite...

as i look around at other posts and on other boards it seems alot of guys are gettin by with the 15 amp timers....??....

if i can keep from it, it would be nice not to have to cut up my cords for my MHs and hardwire em in...but i will if its alot safer

brad

[JJG]

Brad.
Couple of elecrtical points....
Nice rule to know, Watts/Volts = Amps. 250 w / 110 volts = 2.27amps. I usualy just cheat and move the decimal point, 250 = 2.5
Doesn't your PFO have a cord for each ballast? Three cords total so you'll need three timers, each timer is only operating at 2.5 during operation and some where in the 10-12 amp range at start up load. 15 amp timers should be fine.
What are you pluging the timers into? While you may be pulling single loads off each timer, all the load goes back to the one circuit. Not a big deal if you have a dedicated circuit but be carefull of trying to use a plug bar and watch what else is on that same circuit. As mentioned earlier, stager the the start of the lights as all three starting at the same time are guranteed to blow a fuse.
Hope this helps
JJ

[thebigblue]

jjg

cool...that helps alot...

i have only 1 outlet behind my tank to use for power...right now i have my return pump, heater, skimmer pump, and grounding probe, on one power strip and my 3 MHs and 2 fans on another...

so i buy 3 of those 15 amp timers (yes, there is a cord for each light)...and then plug those into there own power strip, and stagger when they come on and i should be fine?...

could i throw a special breaker on that circuit to help beef things up a bit?...but the breaker is only as good as the wire running from it, right?...

thanks

brad

[Junkzoo]

[quote]Originally posted by thebigblue

could i throw a special breaker on that circuit to help beef things up a bit?...but the breaker is only as good as the wire running from it, right?...


True Brad,,,no such thing as a "special" breaker per se,you prob have a 15-20 amp breaker on it already,,if you time out the lights , you should have no problem on the circuit.....

[JJG]

Hi Brad,
Since you have only one outlet , yes you will need a power strip to plug everything into. Couple comments there....as mentioned, check and see what else is on that circuit, this goes beyond just the tank. Is the TV, lights, etc on that circuit? Some wiring can meander to several area of the house. Check and see what is attached to that circuit so you can pay attention to load. If there are any other heavy draw items on that circuit try and move them to a different one or at least watch the timing, as in no other heavy draws while the halides are powering up.

For the power strip be sure and spend the money for a good one. Don't load up lots of $$$ of equipment into a $10 strip. Also watch the amp rating on the power strip.
Hope this helps...
JJ

[Doug1]

Great points guys!!!!!!!!
I think I would go so far as to run a heavyduty extension(commercial grade) to a seperate circuit to seperate the lights and the rest of the reef life support. Also you want to consider change to a GFCI plug for all the pumps and stuff that are wet. Remember Murphy's law, he loves to surprise reefers
T*F*A*