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Longer power cables?  

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io7m
 io7m
(@io7m)
Active Member
Longer power cables?

Hello!

Apologies for the possibly dumb question. I've gotten hold of an enclosure for my relatively new MK3S (assembled from the kit). It has a section on the side to mount the printer's power supply so that it can sit in the cooler air outside of the enclosure. The problem I have is that the power cables (the black and red cables with the spade connectors) are only long enough to mount the power supply on the printer frame; there's no extra length in the cables to put the power supply anywhere else.

I need to source some replacement longer cables, but I don't really know what I need to be looking for. Can anyone advise on cables? I'm in the UK, if that changes anything.

Posted : 19/10/2020 5:02 pm
jsw
 jsw
(@jsw)
Famed Member
RE: Longer power cables?

I would suggest automotive wire of the appropriate gauge as the most readily available.  That's what I planned to use before I got the enclosure with the side vent that directs room air into the power supply.

For model railroading, that's what we mostly use for low-voltage moderate-amperage wiring.

Posted : 19/10/2020 7:03 pm
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 --
(@)
Illustrious Member
RE: Longer power cables?

Make sure you aren't buying copper clad aluminum, which seems to a thing these days. I prefer more flexible wire (more strands), that is tin plated (to reduce oxidation failure down the road).  I'd go with marine grade - but automotive high temp will work (marine usually exceeds specs).

10 amps is about what the printer uses, and 14 awg is marginal if you extend things tens of feet. 

Posted : 19/10/2020 7:25 pm
karl-herbert
(@karl-herbert)
Illustrious Member
RE: Longer power cables?
Posted by: @io7m

Hello!

Apologies for the possibly dumb question. I've gotten hold of an enclosure for my relatively new MK3S (assembled from the kit). It has a section on the side to mount the printer's power supply so that it can sit in the cooler air outside of the enclosure. The problem I have is that the power cables (the black and red cables with the spade connectors) are only long enough to mount the power supply on the printer frame; there's no extra length in the cables to put the power supply anywhere else.

I need to source some replacement longer cables, but I don't really know what I need to be looking for. Can anyone advise on cables? I'm in the UK, if that changes anything.

I would reassemble (not extend) all cables from the PSU to the Einsy board and make sure that the cross-section is not too small. After all, currents of up to 10 amperes flow. The larger the cross section, the lower the voltage drop.

You probably also want to use connectors like these or similar to lead the wires into the enclosure:

...and don't forget the powerpanic wires (black/white).

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.

Posted : 19/10/2020 7:43 pm
karl-herbert
(@karl-herbert)
Illustrious Member
RE: Longer power cables?

Addition: I have used flexible silicone cable like this for most applications on the printer:

https://www.amazon.co.uk/TUOFENG-Electrical-Flexible-Different-Electronics/dp/B07G712DY4

of course with the right cross section.

 

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.

Posted : 19/10/2020 7:51 pm
karl-herbert
(@karl-herbert)
Illustrious Member
RE: Longer power cables?

https://grealpha.com/resources/dc-load-wiring-calculator/

14 to 15AWG would be appropriate.

 

Statt zu klagen, dass wir nicht alles haben, was wir wollen, sollten wir lieber dankbar sein, dass wir nicht alles bekommen, was wir verdienen.

Posted : 19/10/2020 7:58 pm
cwbullet
(@cwbullet)
Member
RE: Longer power cables?

@karl-herbert

This what I used and a standard JST for the power panic.  

--------------------
Chuck H
3D Printer Review Blog

Posted : 19/10/2020 11:32 pm
io7m
 io7m
(@io7m)
Active Member
Topic starter answered:
RE: Longer power cables?

Thanks, all! Think I have enough to go on. 👍 

Posted : 20/10/2020 9:27 am
Georg
(@georg-3)
Active Member
RE: Longer power cables?

Hello,

I have the same problem to solve but on metric system.
So no Fre-Doom-Units and AWG for me!^^

My idea is to use some high current connector that is mounted to outside and the inside of my wooden enclosure to ensure I easily can get the printer out of the enclosure and dont have to unscrew the wire connector on the boards every time.
Question is:
- How to calculate the length of the cables properly?
 * if I need 1.0m to get from the PSU in to the Heatbed do I use 1.0m or 2.0m to calculate the length?
 * will 2.5mm² just be enough?
 ** what about the size of the cableconnectors to the Einsy-Board or  the PSU? I have some cheap ones and a very cheap tweezers to crimp.
 ** my cable connectors didn't have these little bend up hooks at the end and seems made from thinner metal.  
* what about the transition resistance of the connectors? Are they negligible? I will have two of them in a row. One outside and one on the inside.

do you have some suggestions about some connectors?
- I would prefer something that is flat like this [1] or [2]

Do you think that this is a bad idea in regard of safety?
- what could go wrong
- what one have to consider to get a save system?

[1] https://www.hoelleinshop.com/Zubehoer/Kabelfixierung-und-Buendelung/Schraubclip-schraubbare-Halterung-fuer-MPX-Hochstromstecker-buchse-A86013.htm?shop=hoellein&SessionId=&a=article&ProdNr=HA86013&t=49303&c=47114&p=47114

[2] https://busse-yachtshop.de/s/Philippi-Hochstromsteckverbinder-Handgriff-einzeln

Posted : 28/11/2021 2:15 pm
tdk408
(@tdk408)
Trusted Member
RE: Longer power cables?

So much missing info!

Unless you like housefires, you *must* take three things into account.

>>You must *calculate* the wire size (thickness). There are wire size calculators online.

>> You must take the length into account. Longer runs need thicker wire. Look online.

>>You are *required* to use wires that are 125% bigger than what you need. This is a necessary safety factor.

There are tables and calculators online. Do not estimate!

You know the glowing hot wire in a toaster? Do you want one connecting your power supply to your unattended printer?

Posted : 11/11/2023 5:35 am
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