Switch panel vs campervan's 12V DC system

[evy]

Hi everyone,

I'm working on my very first DIY camper conversion, using a 2010 extended Ford E250.



I've added some 27W LED lights :
4 top front, 27W x 4 = 108W/12V = 9AMP
2 lower front, 27W x 2 = 54W/12V = 4.5AMP
2 top side, 27W x 2 = 54W/12V = 4.5AMP
2 top rear, 27W x 2 = 54W/12V = 4.5AMP
(before you say anything, no I won't be using them on public roads, only in trails or at a campsite and when the van is running)

The lights are installed but I didn't wire anything yet.
I want to add them to the van's DC system but I have a couple of questions.

Instead of adding switches here and there with hidden fuses I want to add a switch panel (see pictures) somewhere easily accessible when I'm driving,

1-Do I run only two wires from the van's battery to the switch panel?

2-Do I need to add one main fuse for the whole thing?

3-These switch panels have 6 switches, as of now I only have 4 light circuits but I will probably add my rear view camera/monitor to it. so do I use the maximum wire gauge? (adding the fuse's amps)

4-If I'm correct the light inside the switch itself only lights up when you press it?

5-What kind of wire should I use on the outside, I red that Marine tinned wires are best?

6-What wire gauge? According to the internet I should be using 18 gauge wires for the 9AMP (4 top LED lights) if I have under 10' of wire, 16 gauge if I have longer.

7-What kind of connections should I do? end to end connectors with heat shrink? would that be water proof?

8-Do I need relays for each circuits?

Is there something else I should know? I've never done this before.

Thanks!









there are 9 x 3W LED bulbs in each lights
Amazon.com: ENGO EN-JG-W091-S 4" SW-SERIES (SQUARE) 27WATT LED SINGLE SPOT LIGHT(REQUIRES WIRING HARNESS) ENGO: Automotive

Can I use this chart for wire gauge?

[Scalf77]

1-Do I run only two wires from the van's battery to the switch panel?

If you want to be powered off of the van's battery you would at least run power from the battery. The ground on the switch panel is just for the indicator lights, you can tap into the frame as needed, run a wire to a bus-bar, and such.

2-Do I need to add one main fuse for the whole thing?

Yes, the wire from the battery to the switch panel should fused close to the battery. As it stands the switch panel is fused or has re-settable breakers for a total of 60 amps (if all switches were on and a full capacity 15,15,10,10,5,5 amps) and you would also need to add in current draw of the indicator lamp. Without out better specs we could assume the panel is rated for 60+ amps, I would think no more then 66 amps. The reality will be what size wire do the have switch panel wired with?? It looks like it might be 10 gauge at best. Your chart below works but does not account for some key things, such as voltage loss. I like to use Circuit Wizard - Blue Sea Systems
It has a number of feature to put into for your calculation, including voltage loss and wire temp rating. Voltage loss is one of the bigger factors in wire size, especially in longer runs. If the wire gauge is 12 gauge you really only have a capacity of 40 amps over a 9 foot cable run (18 up in back). So far you only have a load of about 22.5 amps plus indicators. That is using a 10% voltage drop. If it is 10 gauge you could possibly make 60 amps the same distance. Again this is worse case with all things on.

3-These switch panels have 6 switches, as of now I only have 4 light circuits but I will probably add my rear view camera/monitor to it. so do I use the maximum wire gauge? (adding the fuse's amps)

I think I mostly answered that above, I expect it would be hard to wire the switch for full power, but I would go based on the wire gauge used on the switch panel, the ground wire will smaller as it only is covering the indicator lamps.


4-If I'm correct the light inside the switch itself only lights up when you press it?

I expect that is true, from what I can tell

5-What kind of wire should I use on the outside, I red that Marine tinned wires are best?

Marine wire would be a very good choice, this is where calculating the wire temp rating comes in, Marine wire also being tinned , but would be 105 C rated

6-What wire gauge? According to the internet I should be using 18 gauge wires for the 9AMP (4 top LED lights) if I have under 10' of wire, 16 gauge if I have longer.

Yes and No, you are basing this off of you load, but in reality the fuse or circuit breaker is protecting the wire. So for the 15 Amp fuse you would need a larger wire. And this becomes the issue, now you have to look at wire gauge on your lights, as it would do no good to have a 14 gauge wire going down to a 18 gauge wire at the light. If that is the case you might want to look at changing the fuse or breaker to match the circuit.

7-What kind of connections should I do? end to end connectors with heat shrink? would that be water proof?

Yes, and I usually use Adhesive Lined polyolefin Heat shrink

8-Do I need relays for each circuits?

For the loads you are showing, no. If you wanted to minimize the load of the switch panel, you could use a relays. Normally you use the relay for loads larger then what your switch can handle, although you could also use if you are having issues with voltage drop, and other things.


I hope I answered things, feel free to PM me or ask more questions for clarity.

Greg

[JoeH]

I'm about to install an sPOD but was also looking at the Switch Pro. It is all solid state, has built in blue tooth, and 8 switches. Switch Pros SP-8100 8-SWITCH PANEL POWER SYSTEM

[evy]

Originally Posted by Scalf77

1-Do I run only two wires from the van's battery to the switch panel?

If you want to be powered off of the van's battery you would at least run power from the battery. The ground on the switch panel is just for the indicator lights, you can tap into the frame as needed, run a wire to a bus-bar, and such.

2-Do I need to add one main fuse for the whole thing?

Yes, the wire from the battery to the switch panel should fused close to the battery. As it stands the switch panel is fused or has re-settable breakers for a total of 60 amps (if all switches were on and a full capacity 15,15,10,10,5,5 amps) and you would also need to add in current draw of the indicator lamp. Without out better specs we could assume the panel is rated for 60+ amps, I would think no more then 66 amps. The reality will be what size wire do the have switch panel wired with?? It looks like it might be 10 gauge at best. Your chart below works but does not account for some key things, such as voltage loss. I like to use Circuit Wizard - Blue Sea Systems
It has a number of feature to put into for your calculation, including voltage loss and wire temp rating. Voltage loss is one of the bigger factors in wire size, especially in longer runs. If the wire gauge is 12 gauge you really only have a capacity of 40 amps over a 9 foot cable run (18 up in back). So far you only have a load of about 22.5 amps plus indicators. That is using a 10% voltage drop. If it is 10 gauge you could possibly make 60 amps the same distance. Again this is worse case with all things on.

3-These switch panels have 6 switches, as of now I only have 4 light circuits but I will probably add my rear view camera/monitor to it. so do I use the maximum wire gauge? (adding the fuse's amps)

I think I mostly answered that above, I expect it would be hard to wire the switch for full power, but I would go based on the wire gauge used on the switch panel, the ground wire will smaller as it only is covering the indicator lamps.


4-If I'm correct the light inside the switch itself only lights up when you press it?

I expect that is true, from what I can tell

5-What kind of wire should I use on the outside, I red that Marine tinned wires are best?

Marine wire would be a very good choice, this is where calculating the wire temp rating comes in, Marine wire also being tinned , but would be 105 C rated

6-What wire gauge? According to the internet I should be using 18 gauge wires for the 9AMP (4 top LED lights) if I have under 10' of wire, 16 gauge if I have longer.

Yes and No, you are basing this off of you load, but in reality the fuse or circuit breaker is protecting the wire. So for the 15 Amp fuse you would need a larger wire. And this becomes the issue, now you have to look at wire gauge on your lights, as it would do no good to have a 14 gauge wire going down to a 18 gauge wire at the light. If that is the case you might want to look at changing the fuse or breaker to match the circuit.

7-What kind of connections should I do? end to end connectors with heat shrink? would that be water proof?

Yes, and I usually use Adhesive Lined polyolefin Heat shrink

8-Do I need relays for each circuits?

For the loads you are showing, no. If you wanted to minimize the load of the switch panel, you could use a relays. Normally you use the relay for loads larger then what your switch can handle, although you could also use if you are having issues with voltage drop, and other things.


I hope I answered things, feel free to PM me or ask more questions for clarity.

Greg

Wow thanks Greg!

I wasn't getting any replys so for the last 2 days I've been watching videos on youtube about switch panels, relays, wiring new fog lights etc...
So now I understand and you come and confirm what I learned in the past couple of days, I'm gaining the confidence I needed to go ahead with buying and building this thing.

The most important thing you made me understand is, wiring each circuits and the whole thing for the max amps and not the real time amps, Like a house, each circuit is either 15 or 20amps even though you will probably never come close to maxing out.

And thanks for that cool link for the wire gauges, it's very simple and useful.

I also learned about a basic automotive switch, from 2 pins to 5pins and why they have more pins etc...
For example that first switch panel model I was looking to buy had 3 pins switches, only turning the switch led indicator on when the switch is activated, in my case the instrument lighting in my van is green, and I don't want to have to turn the lights on to see what switch I'm turning on or have to guess and press every button to finally open what I wanted.
So I found a 5 pin switch panel that lights up green when there is ignition contact and then a red light turns when you activate the circuit like in the picture below (the label stickers are missing on the picture)



Here's a question for you, concerning the wire itself, we talked about marine tinned wire but what if I have a hard time getting my hands on this stuff? can I use an "outside" rated residential wire? like when you wire outside front yard lights, the wire is rated for outside wet use.
And what about solid copper vs stranded copper wires? I red that stranded gives you flexibility for movement but copper offers better resistance to moisture and corrosion.

I know I'm new to all this and I may not use the right words to describe what I mean or I may have to read 3 or 4 times your comments to really understand but hey, I'm getting there, thanks again!

[evy]

Ho I forgot, for the polyolefin Heat shrink, do you recommend I get 1/4" diam 4:1 ratio? would that work?

[Scalf77]

Originally Posted by evy

Wow thanks Greg!


Here's a question for you, concerning the wire itself, we talked about marine tinned wire but what if I have a hard time getting my hands on this stuff? can I use an "outside" rated residential wire? like when you wire outside front yard lights, the wire is rated for outside wet use.

No, you need to look for the correct wire (again the temp rating is important) I would use marines or a automotive cross link wire.https://www.waytekwire.com/products/...=SAE-J1128-GXL

And what about solid copper vs stranded copper wires? I red that stranded gives you flexibility for movement but copper offers better resistance to moisture and corrosion.

No for solid wire, vibration in a vehicle does not work well with solid wire.

Tinned wire would be what you want if you are worried about corrosion. It does not have to be water proof.

Waytek also has the shrink tube, you really want the adhesive lined stuff, I think it is probably 3 to 1. It is not cheap, but it does a better job.

I know I'm new to all this and I may not use the right words to describe what I mean or I may have to read 3 or 4 times your comments to really understand but hey, I'm getting there, thanks again!

No problem, sometimes it takes me a couple of times to explain it correctly

-Greg

[evy]

would these be any good? 1/4" diam, 4:1 ratio, a little over 2" long, 100pieces for 10$

1 4" ID 225" Black 4 1 Adhesive Lined Heat Shrink Tubing Precut | eBay

[Scalf77]

Sure, looks like they would work, can't complane about the price.

-greg

[86Scotty]

When Scalf has answered your electrical question you need look no further.

The van is looking good Evy.

[evy]

Originally Posted by 86Scotty

When Scalf has answered your electrical question you need look no further.

The van is looking good Evy.

Thanks! that's good to know.