240 watts of solar not managing fridge ?

GrahamM376 said:
I also have doubts about the current drawn by your fridge, should be quite a lot higher than indicated. Also, no-one I know uses the output terminal on the solar regulators, most wire the fridge into the general circuit via a circuit breaker, battery banks paralleled.
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the fridge is wired to the main electrics board , via the battery switches . the way that the surplus take off is wired is that when there is a surplus of power it is diverted by the regulator "brain " . owners can then divert the surplus power to where ever it is wanted , in my case the fridge .
 
grafozz said:
the fridge is wired to the main electrics board , via the battery switches . the way that the surplus take off is wired is that when there is a surplus of power it is diverted by the regulator "brain " . owners can then divert the surplus power to where ever it is wanted , in my case the fridge .
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Uhm, I'm not sure you have that quite right. I'm now wondering whether you have created some sort of short circuit in your system due to the curious way you have the fridge wired in?
If the fridge is already connected to the batteries, disconnect any wires you have from the fridge to the solar regulator and then see what happens. You should have a device connected either to the batteries or the solar regulator, but not both.
 
grafozz said:
the fridge is wired to the main electrics board , via the battery switches . the way that the surplus take off is wired is that when there is a surplus of power it is diverted by the regulator "brain " . owners can then divert the surplus power to where ever it is wanted , in my case the fridge .
Click to expand...

You want one or the other but not both connected. Assuming your solar regulator(s) have 6 terminals - pos & neg in, pos & neg out to battery + another pos and neg out to "load". If connected to load, the regulator will disconnect it when voltage drops. These terminals are not generally used when living aboard as you can monitor charge/discharge yourself.

Just connect the pos & neg out to the battery and don't use the other "out" terminals.
 
GrahamM376 said:
You want one or the other but not both connected. Assuming your solar regulator(s) have 6 terminals - pos & neg in, pos & neg out to battery + another pos and neg out to "load". If connected to load, the regulator will disconnect it when voltage drops. These terminals are not generally used when living aboard as you can monitor charge/discharge yourself.

Just connect the pos & neg out to the battery and don't use the other "out" terminals.
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The load terminals for the Regulator are usually the same as the solar capacity, but sometimes they are less. Even if they are the same, 20A is often not enough for a fridge at start up.

There is also a problem getting most regulators to accept a resonable wire size and the extra length of wire inducing voltage drop.

For all the above reasons you generally need a relay, but most relays of a suitable size will consume a significant amount of power. This can be solved with a latching relay, but these are hard to find and expensive.

Most people just don't bother using this feature, but if you do it needs to be done right.
 
grafozz said:
I have wired , only 2 weeks back , the fridge into the surplus charge terminal on the solara 135 regulator , now this runs the fridge without using the batteries , I gather , so they really should stay charged up ?


still confused ...
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Are you saying that the fridge is only connected to the regulator, and not to the batteries? Assuming that the regulator doesn't store power, (like a battery), how do you expect the fridge to get power at night?

The Solara 135 looks like a £50 PWM controller, so I don't see it storing power?

Yep! Still confused :)

Edit, if the fridge is connected to the regulator output, and to the batteries, that just seems wrong.

Whichever of the above applies, disconnect the fridge from the solar controller, and just connect it to the batteries.

See what happens, and report back.
 
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Richard10002 said:
Are you saying that the fridge is only connected to the regulator, and not to the batteries? Assuming that the regulator doesn't store power, (like a battery), how do you expect the fridge to get power at night?

The Solara 135 looks like a £50 PWM controller, so I don't see it storing power?

Yep! Still confused :)
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The " load" terminals on solar regulators will provide power when there is no solar input at night. This power of course comes from the battery's which are perminantly connected to the solar regulator.

Some of the load terminals can be programmed to do useful things, such as turning something on when the batteries are in float, others are limited to one function. This is most commonly to turn off an appliance when the battery voltage drops below a certain level.
 
more fridge

Are you saying that the fridge is only connected to the regulator, and not to the batteries? Assuming that the regulator doesn't store power, (like a battery), how do you expect the fridge to get power at night?

The Solara 135 looks like a £50 PWM controller, so I don't see it storing power?

Yep! Still confused

Edit, if the fridge is connected to the regulator output, and to the batteries, that just seems wrong.

Whichever of the above applies, disconnect the fridge from the solar controller, and just connect it to the batteries.

See what happens, and report back.


update : today ,
the fridge is wired in the usual way into the main switch board with a dedicated switch and fuse for the one fridge .
the extra terminals on the 135 solara regulator are for excess power to be utilised when the batteries are full , this is a useful feature as the fridge will not use any stored power while the sun shines , once its dark the fridge runs in the normal way on the ships batteries.

the problem was/is that the alarm is going off during the night as the batteries are going down to between 25-75 % this is what I am trying to resolve .
 
battery ?

Today I have been further testing the wiring and batteries , bank 1 , 2 x batteries with everything off , are reading 1280/90 ,
bank 2 . 1 x is reading 1280/90 the other is reading 1240 ? this test was done 10 mins after solar panels were covered up so nothing going in for 10 mins . (resting )

when the fridge is switched on this low battery drops voltage . how much should it drop I wonder ?
the fridge draw is 1.6 to 1.4 amps , I know theres going to be a rush on these fridges , now , but this reading was taken with everything turned off and all the solar panels covered up .
This is conclusive evidence that the fridge only draws circa 1.5 amps , max .

the question now is battery 2 , bank 2 failing - even at 1 year old ?

thanks everyone , for the invaluable input ,
I feel this is going to get sorted with all this help .
 
grafozz said:
update : today ,
the fridge is wired in the usual way into the main switch board with a dedicated switch and fuse for the one fridge .
the extra terminals on the 135 solara regulator are for excess power to be utilised when the batteries are full , this is a useful feature as the fridge will not use any stored power while the sun shines , once its dark the fridge runs in the normal way on the ships batteries.
.
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Your fridge will not be using any stored power when the sun shines regardless of where it is connected as long as the charging current from your solar panels is higher than the current draw from the fridge.
It obviously makes no sense to have the same input on the fridge connected to both the batteries and the regulator so do you really have a separate input on the fridge for the wires from the regulator and what does it do?
 
A compressor fridge only using 1,5 A means there is not enough gas in the system, the fridge will not work good. Typical power consumption with the right amount of gas in the system is 40 watt, so between 3,5 and 4 Amp at 12 V. The used Amps are a rough way to know if there is gas failing.
Maybe Engel compressors have a lower consumption, Danfoss uses 40 watt.

The Shoreline documentation says : Ahr/ hr, so they divided the used amps with the running time.
On a hot day in the south, a compressor can run continues, so using 90 Ah.
 
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OldBawley said:
A compressor fridge only using 1,5 A means there is not enough gas in the system, the fridge will not work good. Typical power consumption with the right amount of gas in the system is 40 watt, so between 3,5 and 4 Amp at 12 V. The used Amps are a rough way to know if there is gas failing.
Maybe Engel compressors have a lower consumption, Danfoss uses 40 watt.

The Shoreline documentation says : Ahr/ hr, so they divided the used amps with the running time.
On a hot day in the south, a compressor can run continues, so using 90 Ah.
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Ok now , thats interesting , the gas has not been touched since new , it is a Danfoss BD35 and I would not expect it to require re-charging within 2 years from new ? it has never been touched since installation .
it has been a very hot summer here , and the fridge runs a lot , with as much ventilation as
possible , even an extra pc fan drawing air cooler from the shade piped to the back of the fridge under the compressor .

there is a fridge engineer on the Island maybe I,ll get him to check the gas ?
 
Measure the consumption of the fridge. Buy a multimeter, even a cheap 5 € will do, better to buy something good. Switch multimeter to Amps, on most cheap ones, it is marked “ 10A.
Pull neg or pos terminal of from compressor, reconnect with the meter in line. Danfoss 35 will use 4 Amps and to the end of the cycle a bit more. Anything less than 3 Amps means not enough gas.
No need for making terminals, you can keep the wires with your fingers. Take care not to shorten pos and neg, they are close together.
A fridge engineer will fill gas, wants to earn money. I had a few “ fridge engineers “ on board, non of them knew the principle of cooling, they just fill.
 
Reading through the thread there are several anomalies:-

1. A Danfoss 35 compressor unit takes 5.5 amps on start-up and 4.5 amps running (or at least mine does) on a 12v system with fully charged batteries. This figure increases dramatically when voltages are below 13.0. The quoted figures therefore appear invalid. Such inaccuracy is more likely to be in measurement than in a low refrigerant level. An overfilled unit will not successfully cool the plate but still takes the current mentioned.
2. Contrary to popular opinion not all PV panels are fitted with diodes - Kyocera for example specifically state theirs do not have them fitted. I rely on the diode in my MPPT controller to prevent such feed back.

I hesitate, on the paucity of other evidence supplied, to hazard more than a guess on the cause of the reported problem. That guess would be a faulty battery.
 
As others have said most of the solar regulators will perform the blocking function. Even without the regulator the discharge current at night is very small and in many cases fitting a diode will waste far more power than is saved.
 
noelex said:
As others have said most of the solar regulators will perform the blocking function. Even without the regulator the discharge current at night is very small and in many cases fitting a diode will waste far more power than is saved.
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Blocking diodes waste little power if fitted before the regulator as you're only looking at 0.5v drop on 20+ volts.

The older Kyoceras do have blocking diodes fitted as standard on the older panels with the loose cover terminal box but not on the later ones with tails.
 
If you use a diode with a drop of 0.5v the power loss over the diode will be 0.5/18 (for a conventional 12volt panel) or 2.8%.
The I/V curve of a solar panel is not linear so in practice without a regulator there will be times when there is almost no loss and other times when there is a dramatic loss (because the panel Vmp has dropped well below the battery voltage).

However, the average loss will close to 2.8% figure.
 
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