Amppacity - capacity ???

[yupitsme]

I have a'95 Gambler. Back in the day Gambler ran all 4 leads to the bow then used the receptacle to make the 24v series connections. I'm installing a Move ZR and may or may not convert to 36v at that time. The question I have is about the existing wiring. The wire is 6ga. On the wire is printed SGT 105c. I've sorta found some info on it but nothing regarding ampacity. According to the internet it is excellent automotive battery cable and bla... bla... bla... Appears to be rated for 50v-huh? Max amp draw on the ZR if 55 amps @ 100% power. From everything I've found I think I'm OK even if I'm right at the max amps for a 6ga copper cable. I couldn't locate any THW - THWN - etc... on the cable. Nor could I find anything regarding the 105c temp rating on the internet. Everything suggest I'm rated higher than the lowest amp rating for a 6 gauge wire - which is 55 amps - which is the max ZR draw.

[bobcoy]

Aside from the money for the cable, I would tend to replace the 30 YO cable. Possibly if it was a major hassle to pull the new through. Internal wire may be corroded(blackenned) . You only need 2 wires pulled and of course new clean connections. And as you mentioned the newer insulation will keep those new wires shinny and great conductors. JMO Bob

[MTW]

im with bob, id replace it. SGT isnt usually tinned which could be a problem in wet locations in a boat. 105c is the temp rating of the insulation, pretty much the standard in boats. depending on your footage you may need to install 4awg.

[billnorman1]

I had the same hookup on my Stratos. I went to a 36 volt 112# thrust Minnkota, and Lithium. Built a new battery box out of Azek. I just used one pair of the cables, deadheaded the other positive in the back, left the minus in the bulkhead plug. Made a jumper or two. Works fine. Since the Lithiums deliver 39 volts, the T/m really pulls the boat, sounds like a little outboard on 100%, but I don't use full power often or for long.
A 112 pulls approximately 58 amps full speed, I used a 60+ amp breaker in line between battery 2 and 3 on the jumper. You will probably find a 30 amp current limiter on each + lead at the battery, discard them and add one 60 Amp breaker anywhere on a positive lead. I used an 80Amp rated breaker but I can't recommend that you do, however since I have about 3 more volts my current might be higher. Since the rated amps is 58, 60 doesn't give you much margin for tolerance differences.

[justinp61]

According to Blue Sea's calculator a 6 gauge wire will handle 55 amps for 33', that's the total run length. I'd make the 24v at the batteries and use a pair of the existing wires and roll on unless the run is longer.

[yupitsme]

0	5	10	15	20
PV or ZR 24 or 36 VDC(Minimum Wire Gauge)	8 AWG	8 AWG	8 AWG	8 AWG	8 AWG	8 AWG
PV or ZR 24 or 36 VDC(RecommendedWire Gauge)	8 AWG	6 AWG	6 AWG	4 AWG	4 AWG	2 AWG

The above is from the Power Pole Move ZR manual. After more accurate measuring I figure I'm closer to 40' round trip. Center Line point-to-point is 16'ish. Then off the center line 2-3'ish. Plus some fudge at the bow. Yeah, 40' would be pretty close. But really - 2 AWG when 8 AWG is minimum? On either 24vdc OR 36vdc? Yikes! I'm certainly no electrical engineer but that seems like a tad over-kill to me.

EDIT: The missing distances in the above chart are 20' and 30' respectively.

This is the specs on the cable I'm considering... It is tinned marine grade cable.

AWG 4 Conductor Stranding 7x60/0.0100 Nom. Ins. Thickness 0.060 Nom. O.D. 0.400 Nom. Circular Mils 42000 Nom. MM2 21.3 Approximate Weight 189 lb/m

- OR -

AWG	2
Conductor Stranding	7x95/0.0100
Nom. Ins. Thickness	0.060
Nom. O.D.	0.465
Nom. Circular Mils	66500
Nom. MM2	33.7
Approximate Weight	292 lb/m

I ran this through Blue Sea Circuit Wizard with the following criteria:

36vdc
55 amps
3% Voltage drop
40' Run

And it came back recommending 6 AWG. Go figger... It also stated: Capacity per ABYC standards: 120 amps. If I drop the allowable voltage drop to 2% it changes to AWG 4. If I change the allowable voltage drop to 1% the recommended cable goes to AWG 1

Well... that's interesting. After inputting all the variables multiple times I realized the DC wire size tool limits the voltage to 32vdc.

characteristics:

• Conductor: Annealed stranded tinned copper ASTM B172 Class K
• Insulation: -20 °C to 105 °C Flexible, Color Coded PVC
• Temperature Rating: 105 °C Dry, 75 °C Wet, 60 °C Oil
• Voltage Rating: 600-V
• Resistant to: Acid, Alkali, Abrasion, Flame, Gasoline, Oil and Moisture

Compliances:

• UL Standard 1426 BC-5W2
• AWM 1232/1283
• MTW
• CSA: TEW
• ABYC: E-11.15
• Coast Guard: 33 CFR part 183 Subpart 1

[billnorman1]

Well if you're really concerned with amperage just use the reds together and the blacks together, using them in parallel doubles the amperage capacity. Mechanically join them at the source and destination, use a short jumper to your plug. After all, once the potential gets to the plug and goes to the T/M, the maximum wire size inside is #8 if that.
However, I like simplicity, and some might find rewiring a boat an appealing pursuit.

The wiring you are considering is almost a half inch in diameter which could give you fitment and radius issues.

[yupitsme]

Well if you're really concerned with amperage just use the reds together and the blacks together, using them in parallel doubles the amperage capacity. Mechanically join them at the source and destination, use a short jumper to your plug. After all, once the potential gets to the plug and goes to the T/M, the maximum wire size inside is #8 if that.
However, I like simplicity, and some might find rewiring a boat an appealing pursuit.

The wiring you are considering is almost a half inch in diameter which could give you fitment and radius issues.

Thanks for the reply Bill... I ran the variables through another DC Cable selector with the following variables: dcv-39 amps-55 distance 40' allowable voltage drop - 3% and it returned: AWG 6 cable.

I'm sticking with what I have. I terminated these cables approx. 5 years ago. They were in great shape at that time. Before crimping the terminals I apply di-electrict grease in the crimp area then crimp.

[MTW]

i get 4awg when ran thru blue seas and abyc calculator at 60 amps for the 36v. its not about the current carrying ability of the conductor, its about heat and its effect on the cables insulation.

if you laid those conductors yourself then you know how they are run to terminate them together and use as a single conductor.

good luck

[yupitsme]

i get 4awg when ran thru blue seas and abyc calculator at 60 amps for the 36v. its not about the current carrying ability of the conductor, its about heat and its effect on the cables insulation.

if you laid those conductors yourself then you know how they are run to terminate them together and use as a single conductor.

good luck

I think you are referring to combining the two 6ga cables to create one. Correct? I did not lay the cables myself. But... I do know precisely where and how they were laid by the MFG. There is a bilge trough that basically runs the length of the boat(inner liner). They are laid in that channel unsecured until they get back to the rigging compartment at which time, for cable management purposes, I did install some tywraps.

[MTW]

I think you are referring to combining the two 6ga cables to create one. Correct? I did not lay the cables myself. But... I do know precisely where and how they were laid by the MFG. There is a bilge trough that basically runs the length of the boat(inner liner). They are laid in that channel unsecured until they get back to the rigging compartment at which time, for cable management purposes, I did install some tywraps.

yeah i thought you said you ran the 4 6awg leads to the bow.

[yupitsme]

No... I didn't Gambler did when they built the boat. But yeah... I'm going to combine 2P's and 2N's and call it a day. Right now I'm looking for a waterproof cut off switch that I can install in the bow panel and eliminate the plug/receptacle. Still want a quick way to disconnect - just in case.

[yupitsme]

Just a note... When prepping the cable for splicing n' terminals if I see anything suspect I intend to abandon the project and just pull new 4 gauge tinned marine grade cable.

Also.... As noted earlier. I'm looking for a miniature, for lack of a better term, battery cut-off switch. I want to mount it in the bow panely where the receptical was. Everything I've found thus far is simply too big. So if anybody knows of one....

[billnorman1]

Might as well buy your current limiter now.

[yupitsme]

Might as well buy your current limiter now.

In regards to what? Battery cut-off switch or combining 6ga cables?

EDIT: Just placed order for 40' 4ga marine tinned cable.

AWG	4
Conductor Stranding	7x60/0.0100
Nom. Ins. Thickness	0.060
Nom. O.D.	0.400
Nom. Circular Mils	42000
Nom. MM2	21.3
Approximate Weight	189 lb/m

I have 4ga running from the batteries to a 60amp breaker already. 4ga is small enough and easy enough to run/route. Puts to bed the current and heat issue(I think).

About the miniature battery switch... Havin' trouble locating a waterproof switch. I can locate one that will carry 50k amps(/s) but only at 32v. While I am not an electrical engineer - my son is. He is recommending an ignition protected relay in the rigging compartment then use a 12v rocker/toggle switch at the bow. I really... really... didn't want to run more cables to the bow but. I do have an abandoned 12v circuit up there now so I could use that if I can locate a relay(my son calls the contacters) that will fit through the opening at the bow panel.

[yupitsme]

6ga is no'mo'6ga - gone.jpg

[bobcoy]

Best solution, done for the duration.

[billnorman1]

Well, there ya go, got new wires. These circuit breakers can be had in different ampere ratings and contain an ignition protected switchable function. A 60 amp rated one is available, I went 80 because of tolerances in motors, switches and situations, I didn't want a nuisance trip to make me go aft and reset mine. I'm sure the "safe" people will use 60. I'll let you know if my boat burns down.
https://www.amazon.com/dp/B0D83PPSJ6...sin_title&th=1

[yupitsme]

Well, there ya go, got new wires. These circuit breakers can be had in different ampere ratings and contain an ignition protected switchable function. A 60 amp rated one is available, I went 80 because of tolerances in motors, switches and situations, I didn't want a nuisance trip to make me go aft and reset mine. I'm sure the "safe" people will use 60. I'll let you know if my boat burns down.
https://www.amazon.com/dp/B0D83PPSJ6...sin_title&th=1

Yeah... I'm aware of the switchable breakers. I want the disconnect switch at the bow to cover situation where I need to disconnect NOW. Had a couple of situations like that with the Xi5. Annnnddd... I'm going with the 60 amp breaker.

[yupitsme]

Just for the record books... Below is a pic of the 6ga cable ends. I cut off about an inch or so above the ring terminals to see if any corrosion had shown up. These connections were made approximately 10-12 years ago. To these untrained eyes it looks pretty stinkin' good. Might be some extremely light corrosion - might. Could'a got by with combining 6ga cables. Am more comfortable with replacing. Once it's done - it's done.

Cable-ends.jpg