|
|
Post by Rambler on Sept 4, 2018 9:46:29 GMT
Hi folks...
I'm just about to add two more lights to my Rav , making four in total.
Currently I have two 55w lights on the front , through a 30a relay... fused at 20a.
Each light has it's own feed from the relay.
It's 25a twin wire feeding each light.
Question is , can I run two more of the same lights off the existing wire ?
|
|
|
|
Post by Mb2t on Sept 4, 2018 10:09:41 GMT
Hi folks... I'm just about to add two more lights to my Rav , making four in total. Currently I have two 55w lights on the front , through a 30a relay... fused at 20a. Each light has it's own feed from the relay. It's 25a twin wire feeding each light. Question is , can I run two more of the same lights off the existing wire ? 55W on 12V 55/12=4.58A (divide wattage by voltage to find current) So each of those 55W takes 4.58A, for estimation, call it 5A. You do not want to run either the relay or the wire, as the relay might perish quicker, and the wire will get hot (fire risk) and fuse will blow quicker, so you want to be at least 70-80% of the max. Relay: 30A X 80% = 24 fuse: 20A X 80% = 16A I would say do not run more than 3 X 55W on one relay (you always consider the weakest link, which is the fuse in this case ) Hope this helps M. |
|
|
|
Post by Rambler on Sept 4, 2018 10:39:16 GMT
Hi folks... I'm just about to add two more lights to my Rav , making four in total. Currently I have two 55w lights on the front , through a 30a relay... fused at 20a. Each light has it's own feed from the relay. It's 25a twin wire feeding each light. Question is , can I run two more of the same lights off the existing wire ? 55W on 12V 55/12=4.58A (divide wattage by voltage to find current) So each of those 55W takes 4.58A, for estimation, call it 5A. You do not want to run either the relay or the wire, as the relay might perish quicker, and the wire will get hot (fire risk) and fuse will blow quicker, so you want to be at least 70-80% of the max. Relay: 30A X 80% = 24 fuse: 20A X 80% = 16A I would say do not run more than 3 X 55W on one relay (you always consider the weakest link, which is the fuse in this case ) Hope this helps M. Ah ha , right then. I need to upgrade wiring, fuse & relay. Many thanks mb2t 😊 👍 |
|
|
|
Post by philip42h on Sept 4, 2018 11:22:11 GMT
55W on 12V 55/12=4.58A (divide wattage by voltage to find current) So each of those 55W takes 4.58A, for estimation, call it 5A. You do not want to run either the relay or the wire, as the relay might perish quicker, and the wire will get hot (fire risk) and fuse will blow quicker, so you want to be at least 70-80% of the max. Relay: 30A X 80% = 24 fuse: 20A X 80% = 16A I would say do not run more than 3 X 55W on one relay (you always consider the weakest link, which is the fuse in this case ) Hope this helps M. Ah ha , right then. I need to upgrade wiring, fuse & relay. Many thanks mb2t 😊 👍 It rather depends on how conservative you want to be. 4x 55w @ 12V actually draws 18.3A which is only 73.3% of the rating of your wiring - so that's well within tolerance. And you would be at only 61.1% of the rating of the relay so that certainly doesn't need upgrading. Your 20A fuse is your weak link, as it should be, but you would still be 'only' at 91.7% of its rating. So the only real 'risk' you would be taking if you were to reuse the existing components would be that you may need to replace the fuse more often than you otherwise would ... It rather depends on how conservative you want to be ... |
|
|
|
Post by Hoovie on Sept 4, 2018 12:15:54 GMT
The way I would do it is the same I do with VW Transporters when upgrading to Caravelle Headlights (so 4 x 55W on Main Beam instead of 2 X 55W) ...Run the power direct from the battery, via a relay that is switched by the signal tapped from the Main Beam wire out the headlight.
If you do it this way, the changes made to the OEM wiring loom is minimal - just a tap into one wire - and removable virtually without trace. Plus you are not adding any extra load to the OEM wiring which is usually rather borderline.
|
|
|
|
Post by Rambler on Sept 4, 2018 15:51:26 GMT
Ah ha , right then. I need to upgrade wiring, fuse & relay. Many thanks mb2t 😊 👍 It rather depends on how conservative you want to be. 4x 55w @ 12V actually draws 18.3A which is only 73.3% of the rating of your wiring - so that's well within tolerance. And you would be at only 61.1% of the rating of the relay so that certainly doesn't need upgrading. Your 20A fuse is your weak link, as it should be, but you would still be 'only' at 91.7% of its rating. So the only real 'risk' you would be taking if you were to reuse the existing components would be that you may need to replace the fuse more often than you otherwise would ... It rather depends on how conservative you want to be ... Wow... that's an in-depth analysis, thank you Philip. I've never had a blown fuse as the lights are only ever used on high beam , and only when I get the chance to use them As tbh 😆 it's way too bright 😲 I have to be very careful . The circuit is direct from the battery hoovie , but is ' switched ' via the main beam to the relay. That's the only way I'll accept auxillary light wiring. |
|
|
|
Post by charliefarlie on Sept 4, 2018 16:58:19 GMT
Have you got furry dice or a skeleton hanging off the mirror...
|
|
|
|
Post by Rambler on Sept 4, 2018 18:28:41 GMT
Have you got furry dice or a skeleton hanging off the mirror... 😂😆 no Charlie, hav'nt really touched the interior yet...... But I'm contemplating a glass roof, somehow at some point. I just like my Rav looking different. |
|
|
|
Post by Mb2t on Sept 4, 2018 22:01:14 GMT
Working at 92% of fuse capacity is a sure way to blow it. The issue will be with the 'in-rush' current when you switch the light on.The 'in-rush' current is the initial current that is consumed when you switch the lights on. For that reason you need to use a 'slow-blow' fuse, but again, working at 92% will shorten the fuse life dramatically (and if it obeys Murphy's laws, it will be at the most in-convenient time...)
|
|
|
|
Post by Rambler on Sept 5, 2018 10:18:05 GMT
Working at 92% of fuse capacity is a sure way to blow it. The issue will be with the 'in-rush' current when you switch the light on.The 'in-rush' current is the initial current that is consumed when you switch the lights on. For that reason you need to use a 'slow-blow' fuse, but again, working at 92% will shorten the fuse life dramatically (and if it obeys Murphy's laws, it will be at the most in-convenient time...) Ok guys , sincere thanks for all your thoughts. It's forums ( clubs ) like this which have knowlegable folks like yourselves. Working on all your thoughts I think I'll get another relay put in to power the two extra lights. That way I'm well within power parameters. Cheers folks... |
|
|
|
Post by Rambler on Oct 9, 2018 20:24:14 GMT
Well , in the end I stopped at the two lights I originally fitted last year.
I tried to upgrade to a row of four , but the weight was too much for the number plate bracket.
As the front of the Rav is all plastic , it'l support two lights with slight wobble.
But four, mounted on an 2"x1" aluminium tube was too much.
And I couldn't engineer a way of stopping the wobble.
And it was looking very ugly.
If I'd bought an aftermarket A bar , I could have done it.
But I don't like them... think they protrude too much.
|
|
|
|
Post by bothwellbuyer on Oct 10, 2018 8:34:15 GMT
Years ago on number 1 RAV, I fitted 6 Cibies each one at at least 55W. Powered by a heavy cables direct from the battery and on 2 circuits each circuit with a relay, and only enabled if the headlights were on..... and after an interesting run down to the Lakes when everyone pulled aside to let me through, I realised that I'd left the switches on and the dipped beam activated all 6 cibies plus the headlights !! I altered the wiring to run from main beam after that- but it was fun and our prepared picnic to have half way down wasn't needed.... we got there so fast! lol
They lit up everything!!
|
|
|
|
Post by Rambler on Oct 12, 2018 9:36:42 GMT
Years ago on number 1 RAV, I fitted 6 Cibies each one at at least 55W. Powered by a heavy cables direct from the battery and on 2 circuits each circuit with a relay, and only enabled if the headlights were on..... and after an interesting run down to the Lakes when everyone pulled aside to let me through, I realised that I'd left the switches on and the dipped beam activated all 6 cibies plus the headlights !! I altered the wiring to run from main beam after that- but it was fun and our prepared picnic to have half way down wasn't needed.... we got there so fast! lol They lit up everything!! Ha haaaaaaa , brilliant. I wanted the same look , but modern vehicles are plastic with crumple zones etc. So they don't lend themselves to mounting extra lights on the front. Except if you have a proper 4x4 with bull / A bar etc. |
|
