Projecta IC5000 circuit breaker

Bukhouse · Veteran Member

Projecta IC5000 circuit breaker

Paintar · Veteran Member

Hi Bukhouse
I just put a 25 amp dc-dc charger and it states 2 50 amp circuit breakers so I did,
one on each side of the charger, do as the manual tells you and you can't go wrong. Good luck.

Jaahn · Guru

Hi Ken smile

The purpose of circuit breakers(and fuses) in these ways is actually to protect the wiring from shorts, not the item which probably protects itself from overloads. The substantial wires asked for can conduct large currents which can be dangerous for fires etc if the insulation rubs through etc. Hence the 100A breaker.

If all else fails read the book and do what they recommend. aww

Jaahn

oldtrack123 · Guru

Bukhouse wrote:
Hi, I'm in the middle off fitting a Projecta IC 5000 [50amp] to our van
Reading the user manual
It states to use 100 amp circuit breaker
pardon my ignorance and lack of knowledge but thought 50 amp breaker
would be the go ????
if it makes sense to fit breaker higher than 50 amp would 60 amp breaker ok
Cheers ken

Although the charger is rated @ 50A OUTPUT , it will draw much than that as input current.

The actual INPUT current will be dependent on the voltage available at it's input terminals under full load.And will always be greater than the actual output current

It could easily be around 70 + A

The breaker size , can be the max current draw or No larger than the supply cable current rating ,which ever is the lessor

-- Edited by oldtrack123 on Saturday 17th of February 2018 05:33:51 PM

T1 Terry · Guru

oldtrack123 wrote:
Bukhouse wrote:
Hi, I'm in the middle off fitting a Projecta IC 5000 [50amp] to our van
Reading the user manual
It states to use 100 amp circuit breaker
pardon my ignorance and lack of knowledge but thought 50 amp breaker
would be the go ????
if it makes sense to fit breaker higher than 50 amp would 60 amp breaker ok
Cheers ken
Although the charger is rated @ 50A OUTPUT , it will draw much than that as input current.
The actual INPUT current will be dependent on the voltage available at it's input terminals under full load.And will always be greater than the actual output current
It could easily be around 70 + A
The breaker size , can be the max current draw or No larger than the supply cable current rating ,which ever is the lessor

-- Edited by oldtrack123 on Saturday 17th of February 2018 05:33:51 PM

Umm.... a Projecta IC 5000 is a 240vac to 12v DC battery charger. If the charger can put out 50 amps @ 14.8v and allowing a 10% inefficiency, that still only comes up to 814w and they will run quite well using a Honda 1.0 inverter type generator, so the input current is never going to be the issue here.

As far as a 100 amp circuit breaker, as mentioned it could be to protect the cabling, but that comes as part of the charger and has alligator clamps bolted to the ends, so where does the circuit breaker connect into the system?

If you are going to remove the alligator clamps and hard wire the charger then if you plan to use the full length of the cable then bolt the positive to a Midi fuse holder and fit a 60 amp midi fuse.

I'm afraid adding circuit breakers to DC low voltage circuits is a bit like adding a product starting with N as an anti virus protection for your computer, you are about to embark on a whole world of trouble. There are circuit breakers that do work as intended on DC circuits, NoArk are about the only ones I've found to work as designed, the others get hot and de-rate till they trip at a fraction of their design/advertised capacity, yet often require 150% or more of their advertised capacity to actually trip in an initial overload. I'd avoid the possibility of 150 amps being seen across the slightly less than 6 B&S cables that come with the IC5000 charger as would occur with an internal short in the charger itself if it occurred before the internal fuses.

T1 Terry

oldtrack123 · Guru

Ooops confuse One of my bad days

I simply took it as a DC/DC charger.

. But I think their concern could be reverse current protection, that is why it needs to be in the DC output but it also give fire protection in the case of current overload such as a short in the cables . That current would be from the battery , possibly 100s of amps. So the protection should be fitted as close as possible/ practical to the battery

.

This would particularly apply for a permanently wired in charger .

I would much rather a Good quality DC rated "fast blow "fuse for that purpose [rated just above the max output current],which could also offer some protection to the charger

Like you ,not a fan of the general run of Extra low voltage DC circuit breakers biggrin

-

-- Edited by oldtrack123 on Sunday 18th of February 2018 06:55:43 PM

oldtrack123 · Guru

Paintar wrote:
Hi Bukhouse
I just put a 25 amp dc-dc charger and it states 2 50 amp circuit breakers so I did,
one on each side of the charger, do as the manual tells you and you can't go wrong. Good luck.

Each side of the charger ??

You should have a fuse /CB as near as practical to the Start of the feed cable for the charger

It does need to be rated higher than the charger output [around 50%],but no higher rated than the cable's rating.

It purpose is to limit the risk of fire If a short circuit occurs , overheating the cables

Similarly the output fuse /CB should be as close as practical to the Aux battery ..Again rated to protect the cable.

50A will give virtually no protection to the charger !!!

-- Edited by oldtrack123 on Sunday 18th of February 2018 07:11:44 PM

T1 Terry · Guru

oldtrack123 wrote:
Paintar wrote:
Hi Bukhouse
I just put a 25 amp dc-dc charger and it states 2 50 amp circuit breakers so I did,
one on each side of the charger, do as the manual tells you and you can't go wrong. Good luck.

Each side of the charger ??
You should have a fuse /CB as near as practical to the Start of the feed cable for the charger
It does need to be rated higher than the charger output [around 50%],but no higher rated than the cable's rating.
It purpose is to limit the risk of fire If a short circuit occurs , overheating the cables
Similarly the output fuse /CB should be as close as practical to the Aux battery ..Again rated to protect the cable.
50A will give virtually no protection to the charger !!!

-- Edited by oldtrack123 on Sunday 18th of February 2018 07:11:44 PM

Hi Peter,

In this case the charger concerned has internal fuses on both the AC input and DC output so the cable is protected at the charger end, but as you say, it should be protected at the battery end.

T1 Terry

oldtrack123 · Guru

T1 Terry wrote:
oldtrack123 wrote:
Paintar wrote:
Hi Bukhouse
I just put a 25 amp dc-dc charger and it states 2 50 amp circuit breakers so I did,
one on each side of the charger, do as the manual tells you and you can't go wrong. Good luck.

Each side of the charger ??
You should have a fuse /CB as near as practical to the Start of the feed cable for the charger
It does need to be rated higher than the charger output [around 50%],but no higher rated than the cable's rating.
It purpose is to limit the risk of fire If a short circuit occurs , overheating the cables
Similarly the output fuse /CB should be as close as practical to the Aux battery ..Again rated to protect the cable.
50A will give virtually no protection to the charger !!!

-- Edited by oldtrack123 on Sunday 18th of February 2018 07:11:44 PM
Hi Peter,
In this case the charger concerned has internal fuses on both the AC input and DC output so the cable is protected at the charger end, but as you say, it should be protected at the battery end.

T1 Terry

Yes Terry

That is exactly my point

But in this case it IS a dc /dc charger biggrin

In any such set up,the breakers /fuses are not there to protect the charger & the recommended sizes should clearly indicate to anyone , that they give zero protection to the actual charger either on the input or output

Their sole reason is cable protection, which means they should always be as close as practical to the source of the greatest current

AND as previously,the actual current rating of each is totally dependent on the cable rating .

-- Edited by oldtrack123 on Monday 19th of February 2018 12:07:37 PM

T1 Terry · Guru

oldtrack123 wrote:
T1 Terry wrote:

Hi Peter,
In this case the charger concerned has internal fuses on both the AC input and DC output so the cable is protected at the charger end, but as you say, it should be protected at the battery end.

T1 Terry
Yes Terry
That is exactly my point
But in this case it IS a dc /dc charger
In any such set up,the breakers /fuses are not there to protect the charger & the recommended sizes should clearly indicate to anyone , that they give zero protection to the actual charger either on the input or output
Their sole reason is cable protection, which means they should always be as close as practical to the source of the greatest current
AND as previously,the actual current rating of each is totally dependent on the cable rating .

-- Edited by oldtrack123 on Monday 19th of February 2018 12:07:37 PM

Got me :lol: Yes, the DC to DC input side needs to be at the start battery end of the cable, but make sue the fuse is heavy enough to cover the current draw these units can demand .... and of course the cable size as well. 25 amps x 14.8v + 10% for losses adds up to roughly 400w. If the input voltage at the DC to DC drops to say 11v, not unknown that's for sure, the same 400w divided by 11v = 37 amps. Forget about a DC circuit breaker for this job because the under bonnet temps will seriously de-rate the trip current for the circuit breaker requiring something silly like a 100 amp circuit breaker that has over a 150 amp cold current trip rate, O gauge cable to protect against a fire caused by the DC circuit breaker where a 50 amp fuse protect cable needs to be only 6 B&S resulting in a reduced voltage drop and no fire risk.

I've seen 50 amp Anderson plugs melted where 6 B&S cable supplied a 50 amp DC to DC charger, the 50 amps @ 14.8v + the 10% loss adds up to 74 amps at 11v. Still within the handling capabilities of the 6 B&S cable as far as fire rating, not voltage drop though, but will over the capability of a 50 amp Anderson plug with oxidised/dirty terminals.

T1 Terry