Cruisers Forum
 


Reply
  This discussion is proudly sponsored by:
Please support our sponsors and let them know you heard about their products on Cruisers Forums. Advertise Here
 
Thread Tools Search this Thread Rate Thread Display Modes
Old 18-01-2019, 06:43   #46
Marine Service Provider
 
mitiempo's Avatar

Join Date: Sep 2008
Location: Victoria B.C.
Boat: Wauquiez Centurion 32
Posts: 2,874
Re: ANL Fuse/holder getting real hot

Quote:
Originally Posted by rom View Post
google:

"a safety device consisting of a strip of wire that melts and breaks an electric circuit if the current exceeds a safe level"


wikipedia "fuse":
"fuse is an electrical safety device that operates to provide overcurrent protection"


wikipedia "overcurrent"
"Possible causes for overcurrent include short circuits, excessive load, incorrect design, or a ground fault"


I am going to use a breaker that among other things will limit excessive loads on the AC side.
The above is all correct.

But in many cases overcurrent is not the issue. A lot of devices are self limiting - alternators, battery chargers and others. As long as the wiring is the correct size the fuse cannot see an overcurrent situation. It is there for protection from a short circuit.

Note all fuses and breakers will handle more than their rating continuously.
mitiempo is offline   Reply With Quote
Old 19-01-2019, 13:53   #47
Zil
Registered User

Join Date: Mar 2013
Location: South Jersey
Posts: 361
Re: ANL Fuse/holder getting real hot

DC circuit fuses protect the wire or cable from the fantastic amperage available from the battery.
Zil is offline   Reply With Quote
Old 19-01-2019, 15:45   #48
Registered User

Join Date: Jul 2016
Posts: 238
Re: ANL Fuse/holder getting real hot

mitiempo,
"Note all fuses and breakers will handle more than their rating continuously."
I disagree. fast blow fuse will not handle more than rated continuously..
slow blow will for a while..
pulsed currents are a whole other topic..


for AC breaker..um you're joking right?? if you're in the US you forgot about the 80% rule..yea where a 15amp breaker can only carry 80% for 100% of the time..?? don't believe me...try it your self..load a 15amp/115v circuit to 14 amps...does it stay running??? hum 14amp is less than rating...


-dkenny64
dkenny64 is offline   Reply With Quote
Old 19-01-2019, 23:41   #49
Marine Service Provider
 
mitiempo's Avatar

Join Date: Sep 2008
Location: Victoria B.C.
Boat: Wauquiez Centurion 32
Posts: 2,874
Re: ANL Fuse/holder getting real hot

Quote:
Originally Posted by dkenny64 View Post
mitiempo,
"Note all fuses and breakers will handle more than their rating continuously."
I disagree. fast blow fuse will not handle more than rated continuously..
slow blow will for a while..
pulsed currents are a whole other topic..


for AC breaker..um you're joking right?? if you're in the US you forgot about the 80% rule..yea where a 15amp breaker can only carry 80% for 100% of the time..?? don't believe me...try it your self..load a 15amp/115v circuit to 14 amps...does it stay running??? hum 14amp is less than rating...


-dkenny64
I was actually referring to large current DC fuses and breakers - ANL, MRBF as well as others.

But AC breakers also will handle more than their rating for a short time at least as well as their rating continuously. See the graph here at Blue Seas for their 15 amp breaker used for both AC and DC.
https://www.bluesea.com/products/721...ingle_Pole_15A
mitiempo is offline   Reply With Quote
Old 20-01-2019, 00:24   #50
Registered User

Join Date: Jun 2013
Location: canada
Posts: 4,642
Re: ANL Fuse/holder getting real hot

Quote:
Originally Posted by dkenny64 View Post

for AC breaker..um you're joking right?? if you're in the US you forgot about the 80% rule..yea where a 15amp breaker can only carry 80% for 100% of the time..?? don't believe me...try it your self..load a 15amp/115v circuit to 14 amps...does it stay running??? hum 14amp is less than rating...


-dkenny64
Go read the back of marine breakers. Ie a bluesea 15a breaker trips at 17-18a.
smac999 is offline   Reply With Quote
Old 20-01-2019, 15:13   #51
Registered User

Join Date: Jul 2016
Posts: 238
Re: ANL Fuse/holder getting real hot

done..thanks for the correction..


but what happens if the designed system to use
25amp@240v - or about 5000kw.. or about 425ampsDC@12V
plugs into the shore power and needs the 25amps..
well the bluesea breakers won't trip.. great..FYI I hate the 80% rule..
but its 1ish amps over the 80% rule, if in the US.

that's right the breaker on the pedestal trips.. its under the NEC and the 80% rule and 25amps is just over it..


nit pick on rules..ok..I'm wrong in some aspects..right in others..but in the freezing rain..plugged into a shore pedestal..and the shore pedestal break trip at 2am.. think about who right/wrong. or warm..because they only loaded the breakers to 80% instead of 100% like bluesea..

I do hate the 80% rule BS!! I would rather see all breakers carry the stated current continuously..


now for an opinion on fuses..for large current fuses that carry more than their rated current continuously..wouldn't that mean the rating is wrong.. a 400amp fuse should carry 400amp forever...500amp for a time..1200amps for a few milliseconds..but 425amp forever??don't seem right to me



there is reason behind all this
I took out my old HVAV, used 14a. replaced it with one that used 12amps...ok.
now the old unit didn't work in heat only AC..great lets put in the vberth and use both..but wait..12+14=26amp...bluesea breakers are ok..as is the generator..but 30amp shore..I don't think so..dam 80%rule..both on and running(not a start up current condition)..hum?? kinda sucks..
flame me!! hate me!! but there is a reason..'


-dkenny64
dkenny64 is offline   Reply With Quote
Old 20-01-2019, 18:29   #52
Registered User

Join Date: Mar 2016
Location: New England. USA.
Boat: McCurdy & Rhodes Custom 46
Posts: 1,474
Re: ANL Fuse/holder getting real hot

80% rule? Here us a trip curve for a UL approved home breaker.
https://download.schneider-electric...._Doc_Ref=730-2
100% forever.
dfelsent is offline   Reply With Quote
Old 21-01-2019, 04:54   #53
Senior Cruiser
 
GordMay's Avatar

Cruisers Forum Supporter

Join Date: Mar 2003
Location: Thunder Bay, Ontario - 48-29N x 89-20W
Boat: (Cruiser Living On Dirt)
Posts: 49,143
Images: 241
Re: ANL Fuse/holder getting real hot

A Circuit Breaker (CB) is designed and evaluated to carry 100% of its rated current for an indefinite period of time under standard test conditions. These conditions, per UL 489, Underwriters Laboratories Standard for Safety for Molded-Case Circuit Breakers and Circuit Breaker Enclosures, include mounting the CB in free air (i.e.: with no enclosure) where the ambient temperature is held at 40 [degrees] C (approximately 104 [degrees] F). Under these conditions, molded-case CBs are required not to trip at rated current.

However, a CB most frequently is applied in equipment at 80% of its rated current under NEC Sec. 384-16(c). If you understand why this requirement is in place, you'll be able to apply CBs correctly.

Sizing a Circuit Breaker ➥ https://www.ecmweb.com/basics/sizing-circuit-breaker

Clearing up Confusion over 80% vs. 100%-rated Circuit Breakers
https://blog.schneider-electric.com/...cuit-breakers/
__________________
Gord May
"If you didn't have the time or money to do it right in the first place, when will you get the time/$ to fix it?"



GordMay is offline   Reply With Quote
Old 21-01-2019, 08:13   #54
Registered User

Join Date: Dec 2016
Location: France
Boat: Marie Jeanne 43
Posts: 35
Re: ANL Fuse/holder getting real hot

Hi
Maybe you can use a simple (but good) voltmeter. See : you're looking for power dissipated exceeding, say, 10W. Below this value you would not get significant heating.
P = R.I²
Thus you would get 10W with 100A and a resistance of 1mOhm, or with 400A and a resistance of 63 uOhm (microOhm). These low resistances are difficult to measure, but a 100 uOhm resistance would create a measurable voltage of 10mV @ 100A.
So I would try to use my voltmeter to search where the worst resistance is, because you can measure in the cable itself (remove the thermo insulation), through the cable, through the lug, etc... Lot of measurements are possible. It will not be so precise of course, but if you have a bad crimp or a a bad contact somewhere it can help to find it. At least it's easy to do and you can probably easily maintain a constant 100 or 200A for the measurement (1200...2400W), without risking damages by heat.
PiAn is offline   Reply With Quote
Old 21-01-2019, 17:36   #55
Registered User

Join Date: Jan 2012
Location: CHARLESTON, SC
Boat: Schucker 436
Posts: 112
Re: ANL Fuse/holder getting real hot

I just can't imagine a 400 amp load for over a minute. That's close to my starter current on my Perkins 4.236. I've done tests on connections from the battery/alternator to the end of the line and always found about 0.1 volt drops at most good tight connections with normal 20-30 amp loads. I would expect some serious heat at any connection at 400 amps on a 12VDC circuit. Good luck, looking forward to hearing your fix.
RUSTYNAIL is offline   Reply With Quote
Old 21-01-2019, 18:25   #56
Registered User

Join Date: Mar 2016
Location: New England. USA.
Boat: McCurdy & Rhodes Custom 46
Posts: 1,474
Re: ANL Fuse/holder getting real hot

Quote:
Originally Posted by GordMay View Post
A Circuit Breaker (CB) is designed and evaluated to carry 100% of its rated current for an indefinite period of time under standard test conditions. These conditions, per UL 489, Underwriters Laboratories Standard for Safety for Molded-Case Circuit Breakers and Circuit Breaker Enclosures, include mounting the CB in free air (i.e.: with no enclosure) where the ambient temperature is held at 40 [degrees] C (approximately 104 [degrees] F). Under these conditions, molded-case CBs are required not to trip at rated current.

However, a CB most frequently is applied in equipment at 80% of its rated current under NEC Sec. 384-16(c). If you understand why this requirement is in place, you'll be able to apply CBs correctly.

Sizing a Circuit Breaker ➥ https://www.ecmweb.com/basics/sizing-circuit-breaker

Clearing up Confusion over 80% vs. 100%-rated Circuit Breakers
https://blog.schneider-electric.com/...cuit-breakers/


Thanks. Always happy to learn.
dfelsent is offline   Reply With Quote
Old 24-01-2019, 14:34   #57
Registered User

Join Date: Feb 2016
Posts: 237
Re: ANL Fuse/holder getting real hot

Verify fuse temperature with your infrared gun.
Plug in one of your spares.
Verify again.

If the fuse is TU or questionable, mark it, segregate it. Stack it at the bottom of your rotation.

If the holder or cables is TU, R&R from your spares.

What am I missing?
LargeMarge is offline   Reply With Quote
Old 25-01-2019, 01:15   #58
rom
Registered User

Join Date: Mar 2016
Boat: Lagoon 440
Posts: 736
Re: ANL Fuse/holder getting real hot

Quote:
Originally Posted by LargeMarge View Post
Verify fuse temperature with your infrared gun.
Plug in one of your spares.
Verify again.

If the fuse is TU or questionable, mark it, segregate it. Stack it at the bottom of your rotation.

If the holder or cables is TU, R&R from your spares.

What am I missing?

As I said the Fuse&Holder dissipates 36W @400A (.09V loss @12V), I had about the same with another similar fuse (both rated 425A). Unfortunately it seems no one here can tell whether this is good or bad. Voltage loss does not seem to be part of a fuse specification. I will be able to buy a genuine blueasea within a few weeks.
rom is offline   Reply With Quote
Old 25-01-2019, 15:38   #59
Registered User

Join Date: Jul 2016
Posts: 238
Re: ANL Fuse/holder getting real hot

Quote:
Originally Posted by dfelsent View Post
80% rule? Here us a trip curve for a UL approved home breaker.
https://download.schneider-electric...._Doc_Ref=730-2
100% forever.



I mean this rule..
For branch circuits, NEC 210.19 states the rules for sizing conductors. ... Ampacity of the conductors is matched to OCPD rating by the same rule. OCPDs are sized for 125 percent of continuous current, which means that they are expected to carry continuously 80 percent of rated current.

there does seem to be a great deal of confusion about 80% and 100%..
would seem to me that a feed to a pedestal is a branch circuit..


I can see using 400amp from a 12v battery.. to power an inverter.
how big is the bank? how long does it need to run before the fuse gets that hot? seconds(10-15). minutes(5-10)? 3 hours?
would it be better run this kinda of load from a generator instead of 12v? maybe 48v or 96v?



-dkenny64
dkenny64 is offline   Reply With Quote
Reply

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
DIY ANL Fuse Block? Delancey Electrical: Batteries, Generators & Solar 39 29-11-2016 16:03
ANL Fuse holders Kakalina Electrical: Batteries, Generators & Solar 8 25-10-2016 08:07
For Sale: Blue Sea Systems ANL fuse block, Buss 100 amp circuit breaker Pauliboi Classifieds Archive 0 06-11-2015 13:07
500 amp ANL fuse stud size? sdowney717 Electrical: Batteries, Generators & Solar 6 24-02-2013 14:04
ANL Fuse to Starter Down2TheC Electrical: Batteries, Generators & Solar 3 22-08-2009 21:18

Advertise Here


All times are GMT -7. The time now is 08:37.


Google+
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.
Social Knowledge Networks
Powered by vBulletin® Version 3.8.8 Beta 1
Copyright ©2000 - 2024, vBulletin Solutions, Inc.

ShowCase vBulletin Plugins by Drive Thru Online, Inc.