Frostbite [RE-wrenches]

[Joel Davidson]

<x-flowed>
Travis,
It's already been suggested to connect a steep-angle PV panel with no charge 
controller directly to the battery bank to float charge the batteries. If 
the peak array amps is equal to 1% of the battery amp-hours and the battery 
bank is well insulated with 4" of styrofoam board all around, it should be 
ok for 3 to 4 months. More than that and I'd be concerned about loss of 
electrolyte.
Joel Davidson

----- Original Message ----- 
From: "Travis Creswell, Ozark Solar" <ozsolar at ipa.net>
To: <RE-wrenches at topica.com>
Sent: Thursday, February 16, 2006 6:52 PM
Subject: RE: Frostbite [RE-wrenches]


> Hi Joel,
>
> Zero AC kWh without freeze protection until recently. I hooked up an
> exterior motion sensor light and the only way to get it work reliably was 
> to
> take the SW4024 out of sleep mode.  So that's another 384 DC watt hours 
> per
> day used by the inverter.  ~150-200 DC watt hours used by the Sun Danzer
> Fridge.  But the place is only occupied a few times a year.
>
> Of course freeze protection just depends on the average outside 
> temperature.
> It estimate it be several kWh's per day averaged over a cold week (every
> night into the teens) to just a few kwh's for the entire mild week (just a
> few nights below freezing).  I do have an AC kWh meter measuring the total
> AC output of the system and was considering installing one dedicated just 
> on
> the water heater.  With the addition of the HOBO type data logger I'll be
> able to tell a lot better what's going on.
>
> Take care,
>
> Travis Creswell
> Ozark Energy Services
>
>
> -----Original Message-----
> From: Joel Davidson [mailto:joeldavidson at earthlink.net]
> Sent: Thursday, February 16, 2006 9:38 AM
> To: RE-wrenches at topica.com
> Subject: RE: Frostbite [RE-wrenches]
>
> Your free subscription is supported by today's sponsor:
> -------------------------------------------------------------------
> Sign Up for Packet8 and tell your phone company
> to VoIP-Off. First Month Free! Then up to 50% off your
> phone bill.  Free Equipment! Packet8 1-877-868-1135
> http://click.topica.com/caaer6vbz8QcsbAg8QQa/ TMONE
> -------------------------------------------------------------------
>
> Hello Travis,
> What is the unoccupied cabin's daily electric consumption without freeze
> protection and what is the daily consumption with freeze protection 
> active?
> Joel Davidson
>
> Original Message:
> -----------------
> From: Travis Creswell, Ozark Solar ozsolar at ipa.net
> Date: Wed, 15 Feb 2006 21:43:49 -0600
> To: RE-wrenches at topica.com
> Subject: RE: Frostbite [RE-wrenches]
>
>
> Hi Jeff,
>
> I've been tinkering with the diversion load control feature on a MX60.  We
> have a customer with a rarely used off grid hunting cabin.  Don't laugh 
> too
> hard when I say this but they have a 240v electric water.  At least I
> replaced the 4500 watt element with a 1500 watt.  The customer refused any
> suggestions of propane and the system was large enough that it can support
> it.
>
> You might consider this set up or some variation of it.  The customer
> doesn't want to winterize the bathroom so I installed baseboards which are
> hooked up the water heater which is in the super insulated bathroom.  I 
> have
> a stat set @ 40f for freeze protection.  It's hooked up to circulating 
> pump
> that moves water from the water heater through the baseboards.
>
> I knew I was throwing a bunch of energy away as the system was in float so
> long.  So I've paralleled a 2nd stat set @ 65f that is controlled by a 
> time
> delay relay that is hooked up the AUX output of the MX60.  So once the 
> MX60
> hits the bulk voltage it turns on the time delay relay which is set @ 4 
> hrs
> to allow the batteries to do a full absorption.  After 4 hrs the time 
> delay
> relay closes, if it's colder then 65f in the bathroom the pump turns on 
> and
> in a few minutes the water heater kicks on.  The battery voltage gets 
> pulled
> down then which turns the AUX relay off which then get the array back up 
> to
> full output.  This way I'm using a lot more of the energy even if it is 
> just
> to keep an unused bathroom warmer.  The trick was the time delay relay.
>
> So far it's working.  I left a temp data logger (similar to a HOBO) up 
> there
> so we'll see just what's going on when I get a chance to look at the data.
> I'm sure I'll still need to do some playing with the timing and voltage
> settings but the concept is sound.
>
>
> Best,
>
> Travis Creswell
> Ozark Energy Services
>
> 



</x-flowed>