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18awg current rating

Printed From: the12volt.com
Forum Name: General Discussion
Forum Discription: General Mobile Electronics Questions and Answers
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=31147
Printed Date: May 11, 2025 at 5:57 PM


Topic: 18awg current rating

Posted By: kaffeene
Subject: 18awg current rating
Date Posted: April 27, 2004 at 4:43 PM

Typically how much current could 18g wire carry??

Also how much current does a typical cigarette lighter draw to heat the coils??




Replies:

Posted By: Teken
Date Posted: April 27, 2004 at 4:48 PM
15-24 amps can be carried depending upon the insulation being used to shield the copper wire.

The lighter will draw from 5-10 amps for short durations.

Regards

EVIL Teken . . .




Posted By: Teken
Date Posted: April 27, 2004 at 4:52 PM
POLYETHYLENE, NEOPRENE, POLYURETHANE
POLYVINYLCHLORIDE, rated at 80 'C will carry 15 amps.

KAPTON TEFLON SILICONE will carry the extreme of 24 amps.

Regards

EVIL Teken . . .




Posted By: kaffeene
Date Posted: April 27, 2004 at 5:00 PM

Thanks.. I basically wanted to hook up 5 l.e.d.'s , dome light and a cigarette lighter to a 12V constant.    I was thinking of using my 12V constant that is used to provide memory to my radio and other such things (which I will no longer need to power the radio memory).     Its fused at 10A.       I wanted to run an 18 g wire to run to the dome light but wanted to make sure it was protected on the 10A fuse.





Posted By: Teken
Date Posted: April 28, 2004 at 3:20 PM
If this is for only short durations than what you intend to use is fine. But if the circuit is intended for long durations and you live in a very hot climate.

Than you will want to increase the wire guage to 14-16 guage. The reason is that all copper cable insulation is rated based on a ambient temperature, which affects the current load the wire can carry prior to saturation / burning.

That is why you will see the KAPTON TEFLON SILICONE material in engine compartments, opposed to simple
POLYURETHANE insulation as is the case for simple hook-up wire.

Either use a larger wire guage, or spend the extra money for higher quality cables which are protected with the proper insulation / dielectric material.

Regards

EVIL Teken . . .





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