tin plated aluminum electrical splicer

[Waltcolorado]

I have an application where I need to connect two lengths of 4 gauge Tin plated Copper wire (marine grade) with a splicer. This will be in a marine above water application. Also, the splicer which connects the two 4 gauge wires is going to be "electrically" clamped to some Brass (probably 464 Brass alloy).

My question concerns corrosion of this system.

I have been able to find two commercially available splicer's but I'm worried about each.. The first is a Tin plated Aluminum part - link below

http://www.tnb.com/ps/fulltilt/index.cgi?part=ASR1114

The second is a high strength Copper with plated Steel set screws.

http://australia.tnb.com/ps/fulltilt/index.cgi?part=S100BB

Regarding the first Tin plated Aluminum splicer ASR1114 (rated for both copper and AL wiring which I dont care about), I understand this will be fairly robust to corrosion by itself as long as it doesn't get any deep scrapes. The set screws are also Tin plated AL. I understand that Tin plated parts (including AL) have an Anodic index of 0.65 and brass is 0.4. The difference of .25 may be too much for a marine above water application?

However, the Tin plated Aluminum splicer will have no Galvanic issue with the Tin plated copper wire?

The second splicer S100BB is "high strength copper alloy" but the set screws are plated steel socket. I'm guessing the set screws would be a corroded mess in a fairly short time.

Any ideas here? Id like to be able to use the ASR114 Tin plated Aluminum part.

 

[stevenal]

I would guess that these two items are not listed to be "electrically clamped" to brass. Neither by itself will keep salt from migrating into the strands. I am guessing that you need to be able to easily disconnect. Suggest a tin plated copper compression lug with heat shrink over the barrel. Two terminals can be bolted together with stainless hardware.

http://www.marinco.com/product/heavy-duty-lugs

 

[Waltcolorado]

Stevenal, thanks for the response.

Yes, I have the requirement to easilly disconnect the splicer and wires from the brass structure. This connection also needs to be fairly low impedance but some degradation over time could be tolerated.

I also have the requirement that the wires be easily "spliced" into the coupler. The coupler only requires someone to trim the insulation and then use a flat head screw driver to tighten the set screws.

The tin plated copper lugs would require a crimping tool which Im hoping to avoid (being able to just use a screw driver is much preferable).

It looks like you also suggested that the salt water needs to be kept away from the wire/coupler with something such as heat shrink and Ill have to give that a lot of consideration.

 

[stevenal]

Once the lugs are compressed and the heat shrink applied, disconnection/reconnection can be accomplished with a wrench. You would need a way of bolting through or tapping into your brass structure. Here's an inexpensive, hammer operated crimping tool:

http://www.marinco.com/product/heavy-duty-lug-crimper

 

[unclesyd]

My high voltage power line feeder is copper and near my house this line had broken several times and has been reconnected with the push-oh type connectors which are both Sn plated Al and Sn plated Cu. After the connection is made the connector is left as is with no secondary operations performed after installation. The next section of wire after my feed has 6 of these splicers. I live about 4 miles from a saltwater bay. The oldest of these splicers is form 1994 and 1995 and there have been no problem with any splicer since.

 

[stevenal]

Big difference between 4 miles and "marine above water". The uncovered overhead wires receive an occasional fresh water wash.

 

[unclesyd]

Realize that.
This was just a small bit of information about how this these materials can or is being used. They also use this type splice along the bay's edge where there is a lot more exposure to sea water than at my house, except during a hurricane. The saving grace may be the height above water that they are used.
If I recall the Sn plated Cu is used during wiring the larger boats. They use both the crimp type and the mechanical type and always use a heat shrink sleeve.