I am looking for an appropriate way to wire from the AC300’s 12v/30amp dc out (two pin rv / aviation plug) to a 12v fuse panel. From the panel, individual circuits in the van will be powered. I see the Amazon connector options and the 12V RV CABLE on Bluetti’s own website. All appear to require 11 - 16 gauge wires.
Very basic wire gauge charts clearly specify 10 AWG for 30 amps. 14 gauge only supports 15 amps and 12 gauge only supports 20 amps.
Has anyone found a way to actually deliver 30amps from this port via the appropriate wire gauge?
Thanks
Interesting to find that Bluetti’s own page What Size Of Wire For A 30 Amp Breaker? (and every electrical standard I have ever read) - recommends at least 10 gauge. Quoting from that page (I added the bold bits):
The recommended wire size for a 30 amp breaker is typically 10 or 8 gauge copper wire. However, some may wonder if it is safe to use a smaller wire size, such as 12 or 14 gauge, instead. While it may seem convenient or cost-effective to use a smaller wire, it is not recommended and can pose potential risks and consequences.
and
There are several important guidelines and safety precautions that should be followed when using a 30 amp breaker and corresponding wire size. First, it is crucial to use the correct wire size for the 30 amp breaker, which is typically a 10 gauge wire. Using a thinner wire could result in overheating and potential fire hazards. Additionally, it is important to ensure that the wire is properly secured and not subjected to excessive bending or twisting, as this could cause damage and pose safety risks. Furthermore, the wire should not be overloaded, as this could cause the breaker to trip or even result in electrical fires. It is also recommended to consult a professional electrician for installation to ensure all safety measures are properly followed.
and
It is important to note that using the correct wire size for your breaker is crucial for safety reasons. If the wire is too small, it can overheat and potentially cause a fire. On the other hand, using a wire size that is too large can be a waste of money and can also create issues with the electrical system.
And yet, Bluetti sells their 12v 30 amp cable as 12 gauge.
So, in summary, they are offering for sale a not recommended, potentially risky cable. That’s more than a bad look.
It appears their official response is just going to be:
“I sent the link to our R&D department and they have confirmed that the 12V/30A RV cable for the AC300 is designed to safely handle and deliver a 30A current. Rest assured, it meets the necessary safety and performance standards.”
So, I guess they will pretend the NEC standard and their own documentation is BS. “Trust us” is the response to something that is documented as a fire risk (and at least presents efficiency concerns. Makes me feel shaky in total with this whole product.
It kinda depends on the lenght of the cable. If searched on amazon for this cable and they mentioned that this have 12 AWG, as you metioned. If you have the calculate with 1m cable lenght and only 12V, then 12 AWG might a bit thin. The 12V Ports dont deliever on point 12V, its more like near 13V which would indeed only need between 11 and 12 AWG, with a 1m cable.
If i had to design the cable, i would add a bit of overhead too. But i would say, when you dont use the 12V 30A constant over hours and days, there is nothing to going happen.
Hard time believing the one reference vs all the other documentation saying 10 gauge.
Maybe I am over-reacting. IDK - but I don’t want a fire because of this undersized cable. Why build everything else to spec and leave the source cable undersized?
The following was shared to me on another forum putting my concerns fairly to rest:
Per the NEC, a “30 amp” circuit breaker should only be run at 80% of capacity on a continuous basis.
That drops us to 24 amps.
A single strand of 12 gauge wire with 140 degree F “T” or “TW” insulation is “good” for 30 amps … in free air.
Bundling it into a multi-wire cable drops the rating.to 25 amps.
In the multi-wire situation, insulation type “V”(185 F) and types “TA,TBS,SA,AVB,SIS,FEP,FEPB and RHH” (all 194 F) can handle 30 amps.
Hi @JFreeman, We highly value your feedback and have discussed it with the R&D department. Now we have a conclusion.
In fact, our design meets the reference standards. The reason we chose 12AWG cables is that we use multi-stranded wires, which have higher current-carrying capacity and have passed our temperature tests.
If you still have concerns, we can provide the temperature test report for you. Please contact us via private message to obtain it.
Thank you, @Selfmadestrom, for your attention to this matter and your detailed explanation. Yes, our products, including accessories, undergo rigorous testing and can be used with confidence.
Wire size gauge is not only determined by current but especially by:
type of conductor (solid, stranded, shielded)
material of the conductor (aluminium, copper)
type of insulation (pvc, silicon, hybrid)
length
This is the main reason why it is not correct to evaluate the gauge of a cable that is mainly used for interconnection based on an AWG table which also refers to domestic installations.
Domestic installations in the USA uses solid copper wires, Bluetti uses stranded copper wires → more heat dissipation, less skin effect, more flexibility, more surface area → more current capacity
Domestic installations uses PVC insulated wires, Bluetti uses silicon insulated wires → better heat resistance → more current capacity
Domestic installations uses wires to cover long distances, Bluetti interconnect cables are limited in length → less voltage drop, less resistance → more current capacity
Other than this, of course is up to the user to make sure the connectors are clean and firmly connected to avoid any extra resistance in current flowing that could create overheating conditions.