Inverter saved the day

BC Mosaic · #1 11-29-2008, 07:11 PM

Well the power went out in my neighborhood very early this morning. Luckily, I am the sort that thinks along the lines of, "What if this or that thing should happen?" and then implement a fail-safe remedy (hopefully). With my set up the tank could not handle a power outage or else there'd be an overflow happening onto the floor plus all the critters would suffer. So when I first set up the system I got myself a deep cycle battery from Canada Tire (about $150.00) and a used inverter from a member here (cheap on eBay as well) and hooked it up to my return pump. This way, should there be a power outage, there will always be water circulating and everything should survive until the battery is drained of course. This should take awhile because I only have the one pump connected to it - the most important element in the system.
The reason I knew there was a power outage was because when the inverter kicked in the battery/inverter (?) whined a high pitch sound that woke me up (I sleep with my tank

). Is it normal for it to do this?
I think that this was a very good investment on my part and if no one minds, I'm giving myself a pat on the back. LOL
Just thought I'd share.

ElGuappo · #2 11-29-2008, 07:15 PM

my inverter has a fan that emits a quiet but high pitched whine. sounds normal to me.

mark · #3 11-29-2008, 10:34 PM

Quote:

Originally Posted by BC Mosaic

. With my set up the tank could not handle a power outage or else there'd be an overflow happening onto the floor

taking a chance aren't you (inverters fail, batteries discharge)?

untamed · #4 11-29-2008, 10:54 PM

Yes, it is perfectly normal to sleep with your tank...

BC Mosaic · #5 11-29-2008, 11:31 PM

Quote:

Originally Posted by mark

taking a chance aren't you (inverters fail, batteries discharge)?

The weakest link is the pump failing. But it would be an "act of God" - just like an earthquake happening here. Didn't worry too much about the inverter though. Hmmm. As for the battery discharging, not really because it is a "deep cycle" and testing the charge every other month or so makes sure its fully charged.
If the whole thing failed there would be some spillage (an annoyance, pain in the a..,etc.) but not the complete tank. As it stands now I'm headache free. Its the water movement that concerned me the most.

What's your back up contingency plan?

Cheers

hillegom · #6 11-29-2008, 11:51 PM

2 years ago the power went out in Surrey for 7 hours. Will your deep cycle run your pump for that long?
I have an air pump that will auto turn on when the power goes out and run for days.
Blankets kept the tank warm.

BC Mosaic · #7 11-30-2008, 12:33 AM

I'm not an electrician but an electrician aquaintance assured me that my pump would run for a day plus. This is more than enough time to maybe buy/borrow a generator or whatever. I'm not sure how long the power was out (I'm a heavy sleeper) but I heard it was about 5 hrs.
Maybe an electrician on site here can give a more definitive input.

mike31154 · #8 11-30-2008, 02:42 AM

I have a battery operated air pump also as back up, that's about it at the moment. Earlier this year during an outage I used one of my truck batteries (dual batteries under the hood help start the diesel when it's cold outside) with an inverter to keep my tank running for about 5 hours or so. It's a smaller (400 watts max) inverter and can provide just over 3 amps of power. I was able to run my skimmer, 80 watts of T5HO lighting and some power heads. It was summertime so the heater was not needed.

In order for you to determine how long your deep cycle battery will run the return pump you have, you need to gather some numbers. The deep cycle battery will have an amp/hour rating stamped on it somewhere. Now all you need to know is the amperage or wattage your return pump uses. With these two known quantities, you'll be able to determine approximately how long your pump will run on the fully charged deep cycle battery.

The battery amp/hour rating is based on the total number of amperes the battery can supply in a 20 hour period of even withdrawal. Accordingly, a battery rated at 100 ampere/hours can supply 5 amperes per hour for 20 hours. If more than 5 amperes per hour is taken from the battery, it will not supply its 100 ampere/hour rating. On the other hand, if your return pump only uses 2 amperes, then the battery should be good for substantially longer than 20 hours. Keep in mind that this is under ideal conditions and realistically it's better to think in terms of there only being 75% of actual battery capacity available. For additional capacity you can always hook up a second battery in parallel.

Battery capacity rating is always related to an expected discharge duration. Here's the formula to make your calculation:

t=Q/I
where
Q is the battery capacity (typically given in AmpHours).
I is the current drawn from battery (Amps).
t is the amount of time (in hours) that a battery can sustain

If you need to calculate amperes for your pump from wattage, the formula is P=EI or I=P/E
where
I is the current (Amps)
P is the power (Watts)
E is the voltage (Volts), 115 AC in your case

HTH

BTW, what does your set up use to sense the power outage and switch over to the back up? Do you have some sort of relay hooked up??