Amplifier Installation Fuse Question

aseem · 18th October 2010, 12:40

Just got an amplifier installed (show off coming soon). Need to know a few things regarding the wiring the person has done. He has used the blade fuse as opposed to the cylinderical amp fuse that I had in my previous install. Is this safe? He is using 40 amp blade fuse and I am not sure if this is cost cutting or good enough?

CrackedHead · 18th October 2010, 12:56

There's no problem using the "regular" style of fuse in the power cable.

As for the amp rating of the fuse, its hard to say if its correct unless you tell us what amp/amps are being run off the power cable. I typically fuse the power cable with a fuse that's rated around 10% below the total fuse rating of the amplifier(s).

aseem · 18th October 2010, 13:19

Amp rated at 600 watt RMS. Many thanks.

CrackedHead · 18th October 2010, 13:56

Simplified calculation:

Fuse rating (Amperage) = Wattage / Voltage

A 40 amp fuse will work fine.

PS: the efficiency of the amp has been ignored in the above calculation. It is safe to do unless dealing with very inefficient amplifiers.

sonirohit · 18th October 2010, 15:08

a question though - how a normal fuse was used in your install? Was an unconventional fuse box used?

abhipuru16 · 18th October 2010, 15:44

My installer has suggested a Havells/Finolex MCB of 100A to be used in the engine compartment for my amplifier which is rated at 130Watts X 4 (RMS) at 4 Ohms. He says 100A is fine because according to him the amp itself comes with three 40A fuses.
Is it safe?
Secondly, wouldn't it melt due to engine heat?
My installer says it is made of something like chalk mitti so no worries.

CrackedHead · 18th October 2010, 17:59

Do not use the MCB - MCB's are designed for use with AC current and will work with car electrical's.

sonirohit · 18th October 2010, 18:43

MCB instead of fuse -

don't do what the mechanic says.
as CrackedHead has said - MCB that you will use is not designed for DC use, I first thought that is was BS, but referred to the wiki page for MCB and it turns out that for DC there are separate CBs.
Circuit breaker - Wikipedia, the free encyclopedia

abhipuru16 · 18th October 2010, 22:36

Yeah even I thought so when he suggested me this. I mean AC components are different than DC components. Which brand and amperage of fuse must I use?

CrackedHead · 18th October 2010, 23:03

Look for a an in-line fuse holder and get a 100 amp fuse. Most 4 gauge wiring kits should come with one.

sonirohit · 19th October 2010, 11:01

Go for a 40 AMP fuse, a 100A would serve no good, this fuse is going to be the first line of defence against faulty wiring so do not take chances... the fuse box should be as close to battery as practically possible.

GT500 · 18th November 2010, 14:49

Hi Guys
A couple of quick questions:-

Just brought an AGU fuse from a US ebay seller, received it today.
Its an AGU type fuse 30 AMP is the rating mentioned on it.

A pic of it:-

Amplifier Installation Fuse Question-img_2024.jpg

Amplifier Installation Fuse Question-img_2027.jpg

Amplifier Installation Fuse Question-img_2025.jpg

Now the question: Is this fuse holder and fuse rating sufficient for a four channel amp, the AMP in question is a kenwood M845,stats are :-

Max Power Output 720W Power Output 4 Ohm [14.4V] 60W x 1
2 Ohm [14.4V] 90W x 1
1 Ohm [14.4V] - Bridged[4 Ohm] 180W x 1

Operating Voltage [11-16V] 14.4V Current Consumption 36A

This AMP will be driving a pair of bull audio components and a SUB( still not decided which one)

And I have two types of wires one is 25sqmm and one 16 sqmm.Pic follows:- Which one should be used in my case, I have a feeling that the 25 sqmm will not fit in the holder as its too thick.

The brand I shall be going for is finolex/ L&T Though Im having a hard time finding where to source it from

The picture below shows the kalinga 25sqmm and a havells 16 sqmm :-

Amplifier Installation Fuse Question-img_2032.jpg

I hope to begin this DIY soon.

Looking for your valuable inputs.

Cheers

GT500

navin · 18th November 2010, 14:59

Quote:

Originally Posted by Gt500

Max Power Output 720W Power Output 4 Ohm [14.4V] 60W x 1
2 Ohm [14.4V] 90W x 1
1 Ohm [14.4V] - Bridged[4 Ohm] 180W x 1

Operating Voltage [11-16V] 14.4V Current Consumption 36AGT500

36A is peak curent with all channels driven to max output. The 30A fuse will be safe if you want to ensure the fuse does not blow even if the battery voltage falls to 12.5V then up the fuse to a 40A fuse.

GT500 · 18th November 2010, 15:12

Quote:

Originally Posted by navin

if you want to ensure the fuse does not blow even if the battery voltage falls to 12.5V then up the fuse to a 40A fuse.

Thanks for such a quick reply.

Ok , so from what I understand this fuse shall work in this setup.

When you say that the battery voltage falls to 12.5 V you mean the peak consumption at maxxed out volume levels right? or in a case of engine off and the amp being run in the acc mode ?

I shall go ahead with this fuse(30A), and in the worst case, if it blows, replace it with the 40A one.

About the wire? Is 16sqmm (which is as far as my knowledge goes slightly less than 8 AWG) sufficient??

Many thanks

GT500

18th October 2010, 12:40	#1
aseem Senior - BHPian Join Date: Jul 2005 Location: Delhi Posts: 1,730 Thanked: 441 Times	Amplifier Installation Fuse Question Just got an amplifier installed (show off coming soon). Need to know a few things regarding the wiring the person has done. He has used the blade fuse as opposed to the cylinderical amp fuse that I had in my previous install. Is this safe? He is using 40 amp blade fuse and I am not sure if this is cost cutting or good enough?
	() Thanks

18th October 2010, 12:56	#2
CrackedHead BHPian Join Date: Apr 2009 Location: Seattle Posts: 585 Thanked: 81 Times	There's no problem using the "regular" style of fuse in the power cable. As for the amp rating of the fuse, its hard to say if its correct unless you tell us what amp/amps are being run off the power cable. I typically fuse the power cable with a fuse that's rated around 10% below the total fuse rating of the amplifier(s).
	() Thanks

18th October 2010, 13:19	#3
aseem Senior - BHPian Join Date: Jul 2005 Location: Delhi Posts: 1,730 Thanked: 441 Times	Amp rated at 600 watt RMS. Many thanks.
	() Thanks

18th October 2010, 13:56	#4
CrackedHead BHPian Join Date: Apr 2009 Location: Seattle Posts: 585 Thanked: 81 Times	Simplified calculation: Fuse rating (Amperage) = Wattage / Voltage A 40 amp fuse will work fine. PS: the efficiency of the amp has been ignored in the above calculation. It is safe to do unless dealing with very inefficient amplifiers.
	() Thanks

18th October 2010, 15:08	#5
sonirohit BHPian Join Date: Nov 2008 Location: Chandigarh Posts: 321 Thanked: 15 Times View My Garage	a question though - how a normal fuse was used in your install? Was an unconventional fuse box used?
	() Thanks

18th October 2010, 15:44	#6
abhipuru16 BHPian Join Date: Dec 2009 Location: Faridabad Posts: 719 Thanked: 40 Times	My installer has suggested a Havells/Finolex MCB of 100A to be used in the engine compartment for my amplifier which is rated at 130Watts X 4 (RMS) at 4 Ohms. He says 100A is fine because according to him the amp itself comes with three 40A fuses. Is it safe? Secondly, wouldn't it melt due to engine heat? My installer says it is made of something like chalk mitti so no worries.
	() Thanks

18th October 2010, 17:59	#7
CrackedHead BHPian Join Date: Apr 2009 Location: Seattle Posts: 585 Thanked: 81 Times	Do not use the MCB - MCB's are designed for use with AC current and will work with car electrical's.
	() Thanks

18th October 2010, 18:43	#8
sonirohit BHPian Join Date: Nov 2008 Location: Chandigarh Posts: 321 Thanked: 15 Times View My Garage	MCB instead of fuse - don't do what the mechanic says. as CrackedHead has said - MCB that you will use is not designed for DC use, I first thought that is was BS, but referred to the wiki page for MCB and it turns out that for DC there are separate CBs. Circuit breaker - Wikipedia, the free encyclopedia
	() Thanks

18th October 2010, 22:36	#9
abhipuru16 BHPian Join Date: Dec 2009 Location: Faridabad Posts: 719 Thanked: 40 Times	Yeah even I thought so when he suggested me this. I mean AC components are different than DC components. Which brand and amperage of fuse must I use?
	() Thanks

18th October 2010, 23:03	#10
CrackedHead BHPian Join Date: Apr 2009 Location: Seattle Posts: 585 Thanked: 81 Times	Look for a an in-line fuse holder and get a 100 amp fuse. Most 4 gauge wiring kits should come with one.
	() Thanks

19th October 2010, 11:01	#11
sonirohit BHPian Join Date: Nov 2008 Location: Chandigarh Posts: 321 Thanked: 15 Times View My Garage	Go for a 40 AMP fuse, a 100A would serve no good, this fuse is going to be the first line of defence against faulty wiring so do not take chances... the fuse box should be as close to battery as practically possible.
	() Thanks

18th November 2010, 14:49	#12
GT500 BHPian Join Date: Apr 2010 Location: New Delhi Posts: 101 Thanked: 16 Times	Fuse Holder+fuse+ wire Hi Guys A couple of quick questions:- Just brought an AGU fuse from a US ebay seller, received it today. Its an AGU type fuse 30 AMP is the rating mentioned on it. A pic of it:- Now the question: Is this fuse holder and fuse rating sufficient for a four channel amp, the AMP in question is a kenwood M845,stats are :- Max Power Output 720W Power Output 4 Ohm [14.4V] 60W x 1 2 Ohm [14.4V] 90W x 1 1 Ohm [14.4V] - Bridged[4 Ohm] 180W x 1 Operating Voltage [11-16V] 14.4V Current Consumption 36A This AMP will be driving a pair of bull audio components and a SUB( still not decided which one) And I have two types of wires one is 25sqmm and one 16 sqmm.Pic follows:- Which one should be used in my case, I have a feeling that the 25 sqmm will not fit in the holder as its too thick. The brand I shall be going for is finolex/ L&T Though Im having a hard time finding where to source it from The picture below shows the kalinga 25sqmm and a havells 16 sqmm :- I hope to begin this DIY soon. Looking for your valuable inputs. Cheers GT500
	() Thanks