Tom M's posts

Posted by Tom M on Dec 18, 2010 11:01 am

#121 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: Xantrex MPPT low output problems
Matthew, wish I was there with you now. Jungle sounds good. The first scenario, according to the manual may also be the culprit if the load you have is kicking on first thing in the morning when there is not much sun.

voltage in = voltage out or is it really supposed to be, power in = power out?

Try disconnecting the load over night to see if it still happens, or use a timer as I suggested earlier.

What was your PV set up again? how many panels at what voltage and watts?

 

Posted by Tom M on Dec 15, 2010 09:19 am

#122 -  Renewable Energy > For Sale > Re: American Water Heater 80 Gallon Solar Storage Tank with Electric Element
Steve, why not keep the 80 gal tank and just add a 40 gal tank to the setup?
 

Posted by Tom M on Dec 14, 2010 10:48 am

#123 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: 20 amps at 120v. or 2400w of power
Brian, first you have to determine how long you are going to use each appliance. You said a tv for 4 hrs and a fridge for 24/7. Does the fridge actually run 24/7? There are calculators here at the Alte store to determine actual power needed. Basically if the fridge is only running a few hours a day then calculate by using the amps x voltage x hours used to determine how many amp hrs you need.

 eg. 10 amps x 120 Volts x 2 hrs = 2400 amp hrs

then you would need around 4 , 100 Watt panels, exposed to the sun for 6 hrs to recoup the power used.

then do this with each appliance and add up all the power needed on a daily basis.

As far as a charge controller goes, once the amount of panels is determined, use the current from the panels to size your controller.

eg. 4, 100 Watt panels, at 12 V and wired in parallel, will deliver around 100/12 x 4 = 32 amps. So using a 40+ amp charge controller should work for this example.   
 

Posted by Tom M on Dec 14, 2010 10:30 am

#124 -  Renewable Energy > Technical Discussion: Other > Re: Detecting and Remedying a Phantom Load on Battery Bank
I also agree with Dave, to double check with meters with everything disconnected. It could be just one dead battery drawing from the others. There is another discussion here in the forum about the Trimetric 2020. Do a search above while here in the forum. From what is said, the manual for the trimetric is pretty long and intensive. Is there a battery back up inside the trimetric? If so try removing it and all power to see if it resets. 
 

Posted by Tom M on Dec 12, 2010 09:59 am

#125 -  Renewable Energy > Technical Discussion: Other > Re: Detecting and Remedying a Phantom Load on Battery Bank
As Dave A. mentions, a little more info would be good. Best to recheck all connections. I would start with the wind. Possible loose connection sending power to ground?...
 

Posted by Tom M on Dec 11, 2010 09:18 pm

#126 -  Renewable Energy > Technical Discussion: Other > Re: Detecting and Remedying a Phantom Load on Battery Bank
According to the Trimetric instructions, it need to be used in conjunction with a shunt to control the power from the batteries to be correctly monitored. Are you using one? Check here at the AltE product section for details.
 

Posted by Tom M on Nov 19, 2010 05:59 pm

#127 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Plumbing schematic for interface with existing propane boiler.
Sounds like the easiest thing to do is keep your radiant hooked up to your propane boiler, and install some baseboard heaters, or some old cast iron radiators. Pipe them to the solar return line going back to the panels. As I mentioned before, just install a bypass, basically install a ball valve on the solar return line and tee off before it with another valve going to the heaters. Then pipe the outlet of the heaters back the the return solar line after the valve going back to the panels.
 Or do as the original residents there did years ago, heat up a mass. Build an adobe or rock structure inside a sun space or directly in the house itself with radiant tubing within.
 

Posted by Tom M on Nov 17, 2010 10:32 am

#128 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Plumbing schematic for interface with existing propane boiler.
All comes down on how you are using the radiant. Is this a room that needs heat all the time or a space that is not really used?
Then;
How big is the space? Are there other solar options for that space, eg, are there any sunny windows or outside, south facing walls, roofs? 1st flr, 2nd fl, 3rd fl, basement? Where are you located? Are you using glycol for an exchange fluid? How many HW panels do you have and how big? How much average direct exposure do you get? etc, etc,
 Just some basic thoughts when thinking about using your tank or solar as a supply for the radiant zone. Mixing of fluids between different parts of the system should be avoided for obvious reasons.
 If you had/have a number of panels from which you can connect and disconnect, you can dedicate some to heating water and some for direct heating and then reconnect for more HW heating the rest of the year.
  Did your plumber understand the valve setup?
 

Posted by Tom M on Nov 15, 2010 05:42 pm

#129 -  Renewable Energy > For Sale > Re: Inverter, E-panel, charge controller pre wired for sale $2000
Dave, surprised you just don't keep the old system and have it set up as an alternative or back up system that can also be used year round in conjunction with your new system to feed other circuits in your house that the new system may not handle.
 

Posted by Tom M on Nov 14, 2010 02:06 pm

#130 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Plumbing schematic for interface with existing propane boiler.
Charles, it's amazing your plumber cannot figure this out, it's only 3 to 4 valves. Basically use two cold water feeds, one to the solar tank and one to the propane tank, each with their own shut off and vacuum relief.  (valves 1 & 2 respectively) Pipe the HW outlet from the solar tank into a tee after the cold water inlet shut off(valve 2) to the propane tank and to a tee on the hot water outlet side of the propane tank going to the house. Install a valve on the HW outlet of the solar tank, on the branch of the tee going to the HW line out to the house. (valve 3). Then install an optional valve on the HW outlet of the propane tank, before the tee from the SHW going to the house. (valve 4)

This gives you the option of;
 
SHW preheating the propane tank.
Open valve 1, and 4, close 2 and 3.
SHW only.
open valve 1 and 3, close 2 and 4.
Propane only.
open valve 2 and 4, close 1 and 3

Sorry no drawing, if you can't figure it out I will try to insert one for you...

As far as the radiant heat goes, I usually hook up the heating portion directly to the loop returning to the panels instead of using up a tank of hot water. The volume of hot water stored in the tank is usually not sufficient to use for heating. If you hook it up as I suggest, basically install a bypass on the return line back to the collectors forcing the collector fluid through the radiant zone. This will heat the tank first and use any residual heat to pass through the radiant before returning to the collectors. An aquastat can be used instead of a bypass to turn on a secondary pump to the radiant when a certain temperature is reached in the solar return loop making sure that domestic hot water is made first.
  If you haven't installed the radiant yet, use a double loop. One for solar and one for conventional heating, for times when solar is not available.
 

Posted by Tom M on Nov 12, 2010 05:46 pm

#131 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Want to heat a pool
Ronald, have you considered using the pool pump instead? Those small pumps you purchased may not deliver enough water from the pool on a daily basis to make a difference....
 

Posted by Tom M on Nov 9, 2010 10:06 pm

#132 -  Renewable Energy > For Sale > Re: Submersible hydro UW100 for sale
...or multiply gpm by 1 ft^3 / 7.5 gal...and by 1 min / 60 s..should have added that i guess...but I assume most people dealing with this technology understand units....just making a suggestion for a solution. I'm not going to do all the work...besides, an answer with a staggering factor of 450 should raise some questions and hopefully cause one to double check their math...and usually most instruction manuals will have a conversion or chart based on gpm.....   
 

Posted by Tom M on Nov 9, 2010 04:45 pm

#133 -  Renewable Energy > For Sale > Re: Submersible hydro UW100 for sale
Matthew, if you don't sell it perhaps you can make it work by constructing a narrowing channel, eg. wood, dirt or concrete, in which you can install the hydro unit. Take water from up stream, direct it into a wide channel, narrow the channel over a distance and install the unit in an appropriate size box at the narrow end of the channel. The water's velocity should increase through the channel.

Q = V x A ...  volume flow rate (gal/min) = Velocity (ft/s) x Area (ft^2) 

or V = Q / A

you should be able to estimate the volume flow rate of the stream and manipulate the area of the channel to get the desired velocity.
 

Posted by Tom M on Nov 9, 2010 09:26 am

#134 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: Xantrex MPPT low output problems
Matthew, just did a quick search for 12 volt timers on line. A bunch came up so it should be easy enough to find one. Here's one link that shows some timers;

http://www.reuk.co.uk/12-Volt-Programmable-Timer-Switch.htm

They have an interesting solution there also, use a programmable thermostat instead to throw a relay. They should be readily available anywhere.

...Or, since you have an inverter already, you can use that as your power source along with your existing relay.

Remember, it's just a switch and as long as the contact ratings can handle the power, Volt x amp, you should be able to use any one you can find...
 

Posted by Tom M on Oct 20, 2010 10:50 pm

#135 -  Renewable Energy > Technical Discussion: Other > Re: xantrex charge controller display cover readings do not make sense
yup...either through the negative bus bar or directly..panels can be or should be grounded too...just use a screw on the frame......
 

Posted by Tom M on Oct 18, 2010 11:01 pm

#136 -  Renewable Energy > Technical Discussion: Other > Re: xantrex charge controller display cover readings do not make sense
Just a simple ground lug on the inside case of the C60...you can get the manual here at Alt e...just go to the "buy" tab and then charge controllers....or go to learn and check out some setups..
 

Posted by Tom M on Oct 18, 2010 04:26 pm

#137 -  Renewable Energy > Technical Discussion: Other > Re: xantrex charge controller display cover readings do not make sense
...check for loose grounds...or connections
 

Posted by Tom M on Oct 15, 2010 10:14 am

#138 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: Xantrex MPPT low output problems
Matt, another solution to consider is to install a timer on the freezer plug. If you can charge your batteries and make ice during the day while the sun shines, then that ice should carry you through the night and you can cut power all together to the freezer reducing night time operation and power draw....plus, you can always regulate the time the freezer is powered manually when you are physically there. Also, adding insulation to the freezer can also reduce power needed...
 

Posted by Tom M on Oct 5, 2010 12:49 pm

#139 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: Xantrex MPPT low output problems
Matthew, just looking at your schematic. What is switching the line coming from the charge controller aux/load output to the relay? And why the relay to begin with. If you are using it for the contact rating, just to handle the current from the batteries to the freezer, why don't you just hook up the freezer directly to the batteries? It should have a themostatic switch of it's own and should be able to draw power directly from the batteries when it switches on. If there is not a secondary switch that turns on before the freezer, sending power to the relay, then the relay has continuous power coming from the controller keeping the relay contacts closed. This is where you may be losing some power.Huh Especially if not properly grounded. You don't show any grounds in your diagram. This could also be the reason why you thought you needed to install some diodes. You have continuous power being supplied and it needs to go somewhere, so you may think that it needed to be stopped or redirected. Remember, Keep it Simple....
 

Posted by Tom M on Oct 5, 2010 11:47 am

#140 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: Xantrex MPPT low output problems
Mattew, you say you are leaving for a few days. I have had experience in remote villages where locals were stealing power after we left. Some even tapped in with 220 volt lines. Perhaps this is your problem too? Hopefully not. But it would explain your loss of power when everything was fine the day before and no apparant hardware problems.....anyway, just a  thought....
 

Posted by Tom M on Sep 26, 2010 02:53 pm

#141 -  Renewable Energy > Technical Discussion: Solar Electric System - Photovoltaic > Re: Xantrex MPPT low output problems
Matthew, how old are the batteries? It should be no problem mixing different amp hr batteries, but if one or more are older and have been totally discharged, it may not be charging or holding a charge properly. This is what may be shutting the controller down, it's reading a low voltage from the bank.
  Also check for shorts or bad grounds in the wiring.
  Then try charging the batteries individually to make sure they are charging correctly. Then you may see that one or the other is not charging and causing the shut down.   
  If/When, they are both fully charged, hook them back up together and see what happens.
 

Posted by Tom M on Sep 9, 2010 08:47 pm

#142 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Need a SHW Installer advice on current issue with system
Hey Ben, just seeing how you made out. Hopefully you got the system running properly again...
 

Posted by Tom M on Aug 24, 2010 10:56 pm

#143 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Need a SHW Installer advice on current issue with system
definately sounds like you got air in the top of the system. the air will heat up much faster and expand causing the pressure increase. I bet the fluid isn't even circulating.
 Best to drain the system down, remove the vent on the roof and plug the hole with an 1/8" brass plug, install the vent somewhere near tank ( I usually put them at the highest spot vertically above the outlet of the pump using a tee ) and then the expansion tank on the branch side of the tee heading back to the panels.
 Then flush, fill and purge with water and bring the pressure up to 15-20 lbs. Then let it run for a few day or weeks and see how it goes.
 then you can pump in your glycol displacing the water. If you measure the water when you drain the system you can figure out how much glycol to pump in. I usually start with near 100%, just in case there is a leak or service is needed an a little fluid gets lost. Then you can just add water with a hose.
 

Posted by Tom M on Aug 23, 2010 01:35 pm

#144 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Need a SHW Installer advice on current issue with system
 Air vent at top of collector could be a problem. I usually remove them. Since that is the hottest area of the system and since it is exposed to the elements, they tend to go bad and either sieze up or leak. I usually install them near and above the pump on the return side and on top or near the expansion tank.
  If the vent is on top of the panels, outside, it too can heat up and each time it vents air it usually contains fluid, hot water vapor, which in turn removes fluid from the system. This is where the air could be coming from.
 the expansion tank is a sealed unit, so air in the tank cannot mix with the water, unless the bladder has broke, in which case the entire tank will fill with fluid. Reducing the internal pressure should not increase the amount of fluid in the tank by much since the volume of the tank that holds the fluid,(half the tank) doesn't really change, a couple of ounces at best.....
 

Posted by Tom M on Aug 23, 2010 12:57 pm

#145 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Need a SHW Installer advice on current issue with system
...usually the head rating of a pump is based on an open system. Basically, if you hooked up the pump to a water source and let it run, the water will shoot up to it's rated height. In a closed loop system you can usually get away with using most any pump since the head pressure from the water column in the piping is enough to compensate for the additional pressure needed. The Taco 007 has a low head rating also which is why a lot of installers use a Grundfos pump. But the Taco is better quality and last a lot longer. I've seen enough cases where pressure in the panels has built up to overcome any pump, which is why purging the air out is important. did you install a float type air vent? This will remove any air that is in the system as the fluid circulates.
 Also on hot sunny days, when you use very little hot water, and the water in the tank is hot and the system does not turn on, the fluid in the panels can get very hot and build up pressure. I often tell customers to use up, dump or waste some hot water just to keep the system circulating to prevent stagnation.
 As far as the expansion tank goes, if it is a 30 lb tank, the internal pressure should be 30 lb. when empty or disconnected from the system or out of the box, and the system pressure should be less. The job of the tank is to absorb any excess pressure to keep the system pressure steady.
 

Posted by Tom M on Aug 22, 2010 11:12 pm

#146 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: SHW & Existing Oil-fired Boiler w/storage tank
Amy, you got it. But also consider adding a  bypass so you can use solar hot water only and turn the furnace off if you can when you can.
 I usually set it up so you can use either solar only, backup only or solar preheating backup as you suggest. I also incorporate an electric bypass using an aquastat so that whenever the solar hot water is hot enough, it turns the power to the boiler off keeping it from running just to maintain temperature.
  Adding a small electric tank can also save you money. Then you can turn the boiler off until you need heating saving on fuel, and wear and tear, that way. then the electric tank will stay off if the incoming solar hot water is hot enough.
 

Posted by Tom M on Aug 22, 2010 11:03 pm

#147 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: Need a SHW Installer advice on current issue with system
hey ben, I normally do not run a system at such a high pressure. The pressure alone is enough to put strain on such a small pump. Specs show a pump head of only 9 ft. I usually install a 15 lb expansion tank and run the system around 15 lbs as well. If you have a 30 lb tank, the pressure should be around 20 lb. 
 sounds more like you have air in the system and it needs to be bled. If the pump was blown from the lightning, fluid could have sat stagnant and boiled out. Excess air will heat up and expand and cause an increase in pressure. You can even cause vapor lock where the pressure in the panels is to high for the pump to overcome in which case you have to force cold water into the panels and purge or let them cool and then purge.
  How did you pump your glycol in? If you used a secondary pump, then use that again. Pump water out of and back into a bucket, through the system. Add water if needed and circulate until all the air is out. Close the outlet and let the pump bring up the pressure. If the pump cannot bring up the pressure, use a washing machine or garden hose hooked up to house pressure and add water and pressure that way. be sure to bleed the hose of air before you connect and fill..
 you should consider using a regular 110 volt pump. A TACO pump, model 007, uses 1/25 HP or around 30 Watts. If you have a small PV setup with an inverter, your all set.....
 

Posted by Tom M on Jul 14, 2010 07:30 pm

#148 -  Renewable Energy > Technical Discussion: Solar Heating - Solar Thermal > Re: SHW & Existing Oil-fired Boiler w/storage tank
If you plan on using a PV powered pump, I would suggest adding a charge controller and battery. Hot water will be made any time the collector water is hotter than the storage water. This can even happen at night. Solar radiation is always there. So  having enough power to run the pump will not be a problem if there is battery storage. Use the Pv to charge the battery instead of the pump directly. A differential controller is always best and should be considered. Otherwise, as it seems you already know, there may be times when heat is available but enough direct sunlight to power a pump is not...
 

Posted by Tom M on Mar 15, 2010 12:16 pm

#149 -  Renewable Energy > For Sale > Re: Question on Solar water heating
Esteban, for water flow through a tube Q = V * A, or volume flow rate equals velocity times the area. So with a constant flow rate in gallons per minute the velocity will increase as the area of the pipe decreases. In solar hot water, the slower the flow the longer the water stays in the collector. So basically you can use whatever size pipe you want but if you want to have the water flowing slower, use a bigger diameter pipe.......
 

Posted by Tom M on Mar 9, 2010 11:23 am

#150 -  Renewable Energy > Technical Discussion: Other > Re: How to connect a generator with a battery(12v) or with a lamp?
Robin, you say 60 V DC, what is it's maximum rating in Watts? V x I = Watts. If you know that, then calculate the maximum I in amps. Then use V = I x R, to find maximum R.
 Then, some type of cheap voltage regulator and/or variable resistor may be of some use.  If you start out at a high resistance it should handle the current and then you could hook it up directly to a DC light source. Then vary the resistance and the bulb should get brighter or dimmer if the windmill is rotating steadily.
  If you add motor to spin the windmill at a certain speed, for demonstration purposes, you can then have it operating at 12-14 V to charge a battery.
  Since this sounds like a classroom experiment, safety first. As David mentioned not running the windmill long at high speeds unless properly connected to a circuit or controls that can handle the output, but spinning the windmill slow shouldn't pose much danger and if there is a voltage and or current meter installed you should be able to show how wind speed can change these values and how controllers regulate these changing values. 
 
 

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