Is it correct to fuse both inputs and output of the SCC ?

[ko6kL]

Okay I m a ham and running noise filters on the input and outputs of the Sollar change controller ( ~13v@30amps)
I wanted to make sure if the noise filter failed( shorted) the SCC and battery ( 208ah ) were protected from
a short in the filter. I'm thinking this needs to be a connected dual pole breaker so it removes the PV input at the same time from
the SCC if the CB trips from an output short...
Iv Read that the SCC needs the battery connection BEFORE the PV power...
Does this make sense?

most of the DC dual pole linked breakers on amazon are marked with (+)and (-) on each of the connections ( this would require a 4 pole =$$) ,
really I think just need to be in the plus line and no need to break the negative line.... is there a better selection for this job?
I needed to upgrade the hardware to something like above

as this sort of little the inline modular blade fuses were running a little hot.


this 100PV-volt input 12@30amp SCC is this model and I am finding it is very clean on the radio static, I'm only seeing a little around 60mhz ( not a ham band in the USA )
much better than the other two leading ham radio SCC's. ( Apolo16 and Radioworks300 I have all 3 )

 

[ko6kL]

Anyone know who really makes this common SCC model and if thay sell a RFI clean model with a inverter ??
or if the larger models are RFI clean ?

 

[MisterSandals]

Iv Read that the SCC needs the battery connection BEFORE the PV power...
Does this make sense?

Yes, most specify connect battery first and disconnect last (AKA always have battery connected).

running noise filters on the input and outputs of the Sollar change controller

I am wondering if this affects your SCC's MPPT as it searches for maximum power point. Are you really expecting your array to be noisy?

Regarding SCC RFI (i dunno but there are a lot of threads):

Search results for query: rfi

diysolarforum.com

 

[ko6kL]

Yes, most specify connect battery first and disconnect last (AKA always have battery connected).


I am wondering if this affects your SCC's MPPT as it searches for maximum power point. Are you really expecting your array to be noisy?

Regarding SCC RFI (i dunno but there are a lot of threads):

Search results for query: rfi

diysolarforum.com

I have done many tests in the back yard set up with used AC line noise filters ( have a lot of them ) the MPPT/ SCC doesn't seem to mind it
looked at voltage drop at full power very little ( .125 volts ) between ins and outs...
easy to use the 120v AC line filters at the lower DC levels , just need to watch that current rating and not warm them up. if a warm upgrade to a larger one main problem it the connector post size is smaller for AC filters...that is a challenge.
( test set up looked like this , )
with the Anderson power poles it was easy to swap filters and choke cores in and out and monitor radio static on my small ham radio powered off it.

my back yard Ham radio pandemic power project last summer...
Found that SCC needs a in and a out filter and choke core.
MPPT didnt seem to care about the filter = no effect.

 

[MisterSandals]

Happen to have a link to this?

 

[ko6kL]

its a hardy little SCC , but has a pretty high noise level for a 'ham radio store' product. this was my starter SCC.
plunks along at ~20amps all day... guess you can get about any type of gizmo in this same case....
I hacked off the MC4's and went power-pole connectors also advising to use a unique color for the PV connectors...
i like purple for the plus on the PV , so i don't mistake it for a 12v line... ouch...

https://powerwerx.com/mppt-300w-solar-charge-controller

 

[ko6kL]

 

[AlanH]

https://m.aliexpress.com/item/33005072212.html?spm=a2g0o.productlist.0.0.19945db2vewWds&algo_pvid=c2b4f301-09d6-4373-8d9f-7073c1752e56&algo_exp_id=c2b4f301-09d6-4373-8d9f-7073c1752e56-15&pdp_ext_f=%7B%22sku_id%22%3A%2212000022954630677%22%7D&pdp_npi=2%40dis%21AUD%21103.24%2168.14%21%21%21%21%21%402101fd4b16704756735681733e683b%2112000022954630677%21sea&curPageLogUid=JPQWQFRDXfX4

It also looks very similar to the Renogy.

 

[Hedges]

I would not expect an EMI filter to have any impact on SCC. It doesn't block DC or lower frequencies.

I would expect an MPPT or PWM to produce some interference that might be a problem for radio, probably not enough to violate FCC specs.
EMI filters mostly block common mode. SMPS will produce a differential mode, so a beefier filter designed for that might help.

The trick is that common mode can have tiny chokes, because DC or power line AC differential currents cancel, and the choke only has to experience common mode.

To block higher frequencies of differential mode, you need individual chokes that can carry operating current without saturating. So they will be physically large, and not as large an inductance value as you may want. So you might use larger capacitor values, but not so large that self-resonant frequency becomes too low. Maybe many smaller capacitors in parallel.

LTSpice with second order models of components is where I would start.

But a HAM should be able to handle all that.

Also see if you can design your PV array to be a poor antenna (adjusting loop shape and area.)

 

[x98myers7]

DC breaker on the PV input, yes.

DC breaker/fuse on the SCC output... your call. I don't have one, but I think it's a good idea for servicing the SCC.

 

[Steve_S]

Most companies provide diagrams for the installation of their gear. Midnite Solar diagrams for instance show Breakers;
- Between solar panels & SCC using a COMBINER which has 1 Breaker per string of panels.
- Then again in front of the SCC from the combined output from the panel combiner to SCC,
- Then SCC OUT gets a Breaker prior to joining the Common DC Bus.

A good Detailed Logical diagram is attached (note that this passes NEC Code & Requirements)

 

[ko6kL]

DC breaker on the PV input, yes.

DC breaker/fuse on the SCC output... your call. I don't have one, but I think it's a good idea for servicing the SCC.

well the 30 amp fuse blew on the SCC output and the SCC showed shorted, very good thing I fused it (the battery would have shorted/drained),
guess there really is a limit to over paneling so cut back 50% on panels, but to low of output in bad weather.. next project is a poor mans over paneling cut out relay to bring on more PV on overcast days and cut them out when normal current flows... anyone got this info to share or do i reinvent this?
parts to look at , would be nice if it powered off 12-48 vdc could be out at the combiner box with out running power for it.

https://www.automationdirect.com/adc/shopping/catalog/sensors_-z-_encoders/current_-a-_voltage_sensors_(ac_-a-_dc)/dc_current_switches/dcs100-1c-24-f?

or maybe

https://www.amazon.com/Current-Sensing-Switch-Normally-Monitoring/dp/B09XDL2KZX