Connect Solar Feed to Inverter/Charger?

[Richard10002]

In another thread it was suggested that the feed from the solar panel controller is connected to the inverter, (or charger), cables, thus making the link to the batteries. Is this really OK to do? With inverter, or charger, or either.

 

I have an inverter charger and am about to fit a 100W solar panel. The cables from the inverter charger to the battery are 95mm2. So it would be a simple solution to mount the solar controller by the inverter charger, and connect a pair of short cables to it.

 

I don't fully understand electricity, and wonder if, the charger at 70A, or the inverter at 200A, would force power back towards the solar controller and panel, and fry something. Or does electricity just go where it is needed, in the quantities that are requested?

 

I am conscious that things seem to draw what they need, rather than take all that is available, (and fry), so the idea seems feasible,

 

Many Thanks

 

Richard

[bottle]

As long as each cable is protected by the correct 'fusing' then it is safe to connect the solar panels (controller) to either end of the battery connection cable. ie. battery or inverter, charger.

[by'eck]

In another thread it was suggested that the feed from the solar panel controller is connected to the inverter, (or charger), cables, thus making the link to the batteries. Is this really OK to do? With inverter, or charger, or either.

 

I have an inverter charger and am about to fit a 100W solar panel. The cables from the inverter charger to the battery are 95mm2. So it would be a simple solution to mount the solar controller by the inverter charger, and connect a pair of short cables to it.

 

I don't fully understand electricity, and wonder if, the charger at 70A, or the inverter at 200A, would force power back towards the solar controller and panel, and fry something. Or does electricity just go where it is needed, in the quantities that are requested?

 

I am conscious that things seem to draw what they need, rather than take all that is available, (and fry), so the idea seems feasible,

 

Many Thanks

 

Richard

 

If you are just using the inverter cables for convenience of connecting solar controller to battery, then your suggestion will be fine. All other concerns regarding fusing, isolation etc. still apply though.

 

Your concern that damage may result from other connected devices is unfounded.

 

Given the high current demands of the inverter make sure that the integrity of any connections to it are not compromised in any way though.

[Richard10002]

If you are just using the inverter cables for convenience of connecting solar controller to battery, then your suggestion will be fine. All other concerns regarding fusing, isolation etc. still apply though.

 

Your concern that damage may result from other connected devices is unfounded.

 

Given the high current demands of the inverter make sure that the integrity of any connections to it are not compromised in any way though.

 

Thanks to both... As I expected, but nice to have it confirmed.

 

The solar controller is rated for 2 panels up to to 10A and has a 15A blade fuse. As my single 100W panel won't produce much more than 5A at best, I could fit a 10A fuse between controller and inverter charger.

 

Not sure what you mean by isolation etc. ?

 

I don't have an isolater in the inverter charger to battery cables - I may be wrong, but what I have heard/read suggests one isnt required. There is a 425A fuse in the cable.

 

Richard

[bottle]

I don't have an isolater in the inverter charger to battery cables - I may be wrong,

 

It will be between your batteries and inverter/charger and marked 'battery isolator'. It may/will also isolate you low voltage dc (12v ??) (It will be a big switch, of varying design)

 

From BSS (Boat safety scheme):

 

"All electrical systems must be capable of being safely and quickly disconnected from their power source(s) in an emergency."

 

A fuse cannot be quickly and safely be used to isolate, especially a 425 amp one.. Although it will do this to protect the system if it has a fault.

[Richard10002]

It will be between your batteries and inverter/charger and marked 'battery isolator'. It may/will also isolate you low voltage dc (12v ??) (It will be a big switch, of varying design)

 

From BSS (Boat safety scheme):

 

"All electrical systems must be capable of being safely and quickly disconnected from their power source(s) in an emergency."

 

A fuse cannot be quickly and safely be used to isolate, especially a 425 amp one.. Although it will do this to protect the system if it has a fault.

 

The inverter charger cables don't pass through a battery isolator switch - I fitted the unit and cables myself, with a lot of help here.

 

This is the part of the BSS Guide that I have read, which suggests inverters and chargers or inverter/chargers are not required to pass through a battery isolator, but must be protected by a suitable fuse or circuit breaker:

3.6.2/R REQUIREMENT

 

Do all electrical circuits pass through a battery isolator, or are those requiring a continuous supply otherwise protected?

Identify any electrical circuits bypassing the battery isolator.

 

Check that any electrical circuits bypassing the battery isolator supply the following equipment:

 

I automatic bilge pumps;

I security alarms (including marine radios);

I fire pumps;

I electronic navigation equipment with memories;

I any other equipment where the manufacturer’s instructions indicate

or specifically require direct connection to a battery, such as diesel-fired central heating boilers;

I battery charger outputs;

I inverters or combination inverter/chargers.

 

Check electrical circuits supplying any equipment on the specified list and which bypass a battery isolator, for the presence of a fuse

or circuit-breaker, where the circuit can be seen.

 

All electrical circuits must pass through a battery isolator, except those that feed equipment requiring a continuous supply, which must be protected by a suitable fuse or circuit-breaker.

 

Notes – In cases where circuits directly connected to the battery do not appear in the specified list, compliance must verified on request by supportive paperwork from the manufacturer or supplier.

 

The fuse or circuit-breaker protecting specified equipment bypassing a battery isolator must be installed where the circuit can be seen at examination or otherwise required. If not, it will be considered as not meeting the requirement, because the fuse or circuit-breaker is very unlikely to be located either where the circuit is hidden or be more than a short distance from the battery.

 

http://www.boatsafetyscheme.com/downloads/BSS_Guide_chap3.pdf

 

Am I missing something? Or seeing something that isn't there? I'm sure somebody pointed me to this section of the guide when I was asking about the fitting of the inverter charger, and the conclusion was that the inch thick cables for the inverter charger needed a fuse, but not an isolator.

[bottle]

It does appear that it is OK.

 

Something learnt.