Re: [AFMUG] medium blow fuses

[George Skorup]

But the SyncInjector has overcurrent for each radio and the SyncPipe. So 
I'm not real worried about things cooking with that. Exactly as you said 
though, with no protection, a single radio, SS, whatever shorting takes 
the whole site down. And that's ungood. I've had to replace a bunch of 
relays on the SiteMonitor controlled PoE injectors because, well, I was 
stupid. And I don't want to do that anymore.


On 8/19/2015 12:51 PM, Ken Hohhof wrote:
What got me on this track was discovering the replacement fuse for the 
Trango ApexPlus/Lynx/Stratalink POE boxes is a 3.5 amp medium blow.  
It’s kind of amusing because the single radio power supply they sell 
is only rated 1.5 amps, so it can’t blow the fuse.  But when I power 
it from a 6 amp Mean Well, the fuse glows like a little incandescent 
bulb for a fraction of a second before opening.
So I was just wondering if the medium blow fuses had their place.  
Some distributors like Allied don’t even have them in their catalog, 
so I guess they are a rare bird.
I also learned from perusing the spec sheets that fast blow fuses 
actually take 30-60 minutes to blow until you get over 200% of rating, 
at 300% it comes down to milliseconds. That probably explains George’s 
experience with 1/2A fuses. But also with a 5A fuse on a Syncinjector, 
if the power supply can’t put out at least 240 watts, things are going 
to cook for awhile before that fuse blows.

*From:* Forrest Christian (List Account) <mailto:li...@packetflux.com>
*Sent:* Wednesday, August 19, 2015 12:16 PM
*To:* af <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] medium blow fuses

A fast blow fuse is really very very slow when compared to 
electronics.  I'd recommend sticking with the fast blow fuses.  If 
you're asking because you have nuisance  blows I might consider just 
moving up a amp or so depending on what you're protecting.


On Aug 19, 2015 6:47 AM, "Ken Hohhof" <mailto:af...@kwisp.com>> wrote:


I use fast blow 5x20 mm fuses for radios and other electronics,
but recently became aware that medium blow fuses exist.  Not
widely available, but examples are Belfuse 530-5MT and Littelfuse
233 series.

So is anyone using these?  Any advantage?  I'm thinking devices
that might have enough inrush current to blow a fast blow fuse,
although that hasn't been a problem so far.

Re: [AFMUG] medium blow fuses

[Lewis Bergman]

The only thing a fuse protects against, when properly sized and installed,
is a short circuit event. They should never be viewed as some kind of surge
protection unless you enjoy being disappointed.

On Wed, Aug 19, 2015 at 11:46 AM, Jaime Solorza 
wrote:

> Fast is better for protection.Better than old cigarette pack method
> used on Fender and Marshall amps back in the day
> On Aug 19, 2015 7:47 AM, "Ken Hohhof"  wrote:
>
>> I use fast blow 5x20 mm fuses for radios and other electronics, but
>> recently became aware that medium blow fuses exist.  Not widely available,
>> but examples are Belfuse 530-5MT and Littelfuse 233 series.
>>
>> So is anyone using these?  Any advantage?  I'm thinking devices that
>> might have enough inrush current to blow a fast blow fuse, although that
>> hasn't been a problem so far.
>>
>>


-- 
Lewis Bergman
325-439-0533 Cell

Re: [AFMUG] medium blow fuses

[Bill Prince]

I use a separate fuse for each device. The buss coming into the fuse is 
much larger than the wire coming out.


bp


On 8/19/2015 11:22 AM, Ken Hohhof wrote:
Protect the wiring yes, but my main concern is that one bad radio or 
other device doesn’t take down the whole site.

*From:* Bill Prince <mailto:part15...@gmail.com>
*Sent:* Wednesday, August 19, 2015 1:14 PM
*To:* af@afmug.com <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] medium blow fuses
I'm with Forrest. Stick to the fast blow.

Remember, fuses are not used to protect the equipment, they are used 
to protect the wiring. Since it is "usually" faulty equipment causing 
the over current condition, it is already probably toast anyway.


Just make the fuse large enough to handle the inrush without popping, 
and not so large as to endanger your wiring.


bp


On 8/19/2015 10:51 AM, Ken Hohhof wrote:
What got me on this track was discovering the replacement fuse for 
the Trango ApexPlus/Lynx/Stratalink POE boxes is a 3.5 amp medium 
blow.  It’s kind of amusing because the single radio power supply 
they sell is only rated 1.5 amps, so it can’t blow the fuse.  But 
when I power it from a 6 amp Mean Well, the fuse glows like a little 
incandescent bulb for a fraction of a second before opening.
So I was just wondering if the medium blow fuses had their place.  
Some distributors like Allied don’t even have them in their catalog, 
so I guess they are a rare bird.
I also learned from perusing the spec sheets that fast blow fuses 
actually take 30-60 minutes to blow until you get over 200% of 
rating, at 300% it comes down to milliseconds.  That probably 
explains George’s experience with 1/2A fuses.  But also with a 5A 
fuse on a Syncinjector, if the power supply can’t put out at least 
240 watts, things are going to cook for awhile before that fuse blows.

*From:* Forrest Christian (List Account) <mailto:li...@packetflux.com>
*Sent:* Wednesday, August 19, 2015 12:16 PM
*To:* af <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] medium blow fuses

A fast blow fuse is really very very slow when compared to 
electronics.  I'd recommend sticking with the fast blow fuses.  If 
you're asking because you have nuisance  blows I might consider just 
moving up a amp or so depending on what you're protecting.


On Aug 19, 2015 6:47 AM, "Ken Hohhof" <mailto:af...@kwisp.com>> wrote:


I use fast blow 5x20 mm fuses for radios and other electronics,
but recently became aware that medium blow fuses exist.  Not
widely available, but examples are Belfuse 530-5MT and Littelfuse
233 series.

So is anyone using these?  Any advantage?  I'm thinking devices
that might have enough inrush current to blow a fast blow fuse,
although that hasn't been a problem so far.

Re: [AFMUG] medium blow fuses

[Ken Hohhof]

Protect the wiring yes, but my main concern is that one bad radio or other 
device doesn’t take down the whole site.

From: Bill Prince 
Sent: Wednesday, August 19, 2015 1:14 PM
To: af@afmug.com 
Subject: Re: [AFMUG] medium blow fuses

I'm with Forrest. Stick to the fast blow. 

Remember, fuses are not used to protect the equipment, they are used to protect 
the wiring. Since it is "usually" faulty equipment causing the over current 
condition, it is already probably toast anyway.

Just make the fuse large enough to handle the inrush without popping, and not 
so large as to endanger your wiring.


bp


On 8/19/2015 10:51 AM, Ken Hohhof wrote:

  What got me on this track was discovering the replacement fuse for the Trango 
ApexPlus/Lynx/Stratalink POE boxes is a 3.5 amp medium blow.  It’s kind of 
amusing because the single radio power supply they sell is only rated 1.5 amps, 
so it can’t blow the fuse.  But when I power it from a 6 amp Mean Well, the 
fuse glows like a little incandescent bulb for a fraction of a second before 
opening.

  So I was just wondering if the medium blow fuses had their place.  Some 
distributors like Allied don’t even have them in their catalog, so I guess they 
are a rare bird.

  I also learned from perusing the spec sheets that fast blow fuses actually 
take 30-60 minutes to blow until you get over 200% of rating, at 300% it comes 
down to milliseconds.  That probably explains George’s experience with 1/2A 
fuses.  But also with a 5A fuse on a Syncinjector, if the power supply can’t 
put out at least 240 watts, things are going to cook for awhile before that 
fuse blows.


  From: Forrest Christian (List Account) 
  Sent: Wednesday, August 19, 2015 12:16 PM
  To: af 
  Subject: Re: [AFMUG] medium blow fuses

  A fast blow fuse is really very very slow when compared to electronics.  I'd 
recommend sticking with the fast blow fuses.  If you're asking because you have 
nuisance  blows I might consider just moving up a amp or so depending on what 
you're protecting.

  On Aug 19, 2015 6:47 AM, "Ken Hohhof"  wrote:

I use fast blow 5x20 mm fuses for radios and other electronics, but 
recently became aware that medium blow fuses exist.  Not widely available, but 
examples are Belfuse 530-5MT and Littelfuse 233 series.

So is anyone using these?  Any advantage?  I'm thinking devices that might 
have enough inrush current to blow a fast blow fuse, although that hasn't been 
a problem so far. 

Re: [AFMUG] medium blow fuses

[Ken Hohhof]

Thanks, somehow I missed that.

-Original Message- 
From: Seth Mattinen

Sent: Wednesday, August 19, 2015 1:07 PM
To: af@afmug.com
Subject: Re: [AFMUG] medium blow fuses

On 8/19/15 10:51, Ken Hohhof wrote:

So I was just wondering if the medium blow fuses had their place. Some
distributors like Allied don’t even have them in their catalog, so I
guess they are a rare bird.



Allied has them; Buss GMC series.

http://www.alliedelec.com/bussmann-by-eaton-gmc-4-r/70149513/

GMA is fast acting, GMC is medium time delay, and GMD is time delay.

~Seth 

Re: [AFMUG] medium blow fuses

[Bill Prince]

I'm with Forrest. Stick to the fast blow.

Remember, fuses are not used to protect the equipment, they are used to 
protect the wiring. Since it is "usually" faulty equipment causing the 
over current condition, it is already probably toast anyway.


Just make the fuse large enough to handle the inrush without popping, 
and not so large as to endanger your wiring.


bp


On 8/19/2015 10:51 AM, Ken Hohhof wrote:
What got me on this track was discovering the replacement fuse for the 
Trango ApexPlus/Lynx/Stratalink POE boxes is a 3.5 amp medium blow.  
It’s kind of amusing because the single radio power supply they sell 
is only rated 1.5 amps, so it can’t blow the fuse.  But when I power 
it from a 6 amp Mean Well, the fuse glows like a little incandescent 
bulb for a fraction of a second before opening.
So I was just wondering if the medium blow fuses had their place.  
Some distributors like Allied don’t even have them in their catalog, 
so I guess they are a rare bird.
I also learned from perusing the spec sheets that fast blow fuses 
actually take 30-60 minutes to blow until you get over 200% of rating, 
at 300% it comes down to milliseconds. That probably explains George’s 
experience with 1/2A fuses. But also with a 5A fuse on a Syncinjector, 
if the power supply can’t put out at least 240 watts, things are going 
to cook for awhile before that fuse blows.

*From:* Forrest Christian (List Account) <mailto:li...@packetflux.com>
*Sent:* Wednesday, August 19, 2015 12:16 PM
*To:* af <mailto:af@afmug.com>
*Subject:* Re: [AFMUG] medium blow fuses

A fast blow fuse is really very very slow when compared to 
electronics.  I'd recommend sticking with the fast blow fuses.  If 
you're asking because you have nuisance  blows I might consider just 
moving up a amp or so depending on what you're protecting.


On Aug 19, 2015 6:47 AM, "Ken Hohhof" <mailto:af...@kwisp.com>> wrote:


I use fast blow 5x20 mm fuses for radios and other electronics,
but recently became aware that medium blow fuses exist.  Not
widely available, but examples are Belfuse 530-5MT and Littelfuse
233 series.

So is anyone using these?  Any advantage?  I'm thinking devices
that might have enough inrush current to blow a fast blow fuse,
although that hasn't been a problem so far.

Re: [AFMUG] medium blow fuses

[Seth Mattinen]

On 8/19/15 10:51, Ken Hohhof wrote:

So I was just wondering if the medium blow fuses had their place. Some
distributors like Allied don’t even have them in their catalog, so I
guess they are a rare bird.



Allied has them; Buss GMC series.

http://www.alliedelec.com/bussmann-by-eaton-gmc-4-r/70149513/

GMA is fast acting, GMC is medium time delay, and GMD is time delay.

~Seth

Re: [AFMUG] medium blow fuses

[Ken Hohhof]

What got me on this track was discovering the replacement fuse for the Trango 
ApexPlus/Lynx/Stratalink POE boxes is a 3.5 amp medium blow.  It’s kind of 
amusing because the single radio power supply they sell is only rated 1.5 amps, 
so it can’t blow the fuse.  But when I power it from a 6 amp Mean Well, the 
fuse glows like a little incandescent bulb for a fraction of a second before 
opening.

So I was just wondering if the medium blow fuses had their place.  Some 
distributors like Allied don’t even have them in their catalog, so I guess they 
are a rare bird.

I also learned from perusing the spec sheets that fast blow fuses actually take 
30-60 minutes to blow until you get over 200% of rating, at 300% it comes down 
to milliseconds.  That probably explains George’s experience with 1/2A fuses.  
But also with a 5A fuse on a Syncinjector, if the power supply can’t put out at 
least 240 watts, things are going to cook for awhile before that fuse blows.


From: Forrest Christian (List Account) 
Sent: Wednesday, August 19, 2015 12:16 PM
To: af 
Subject: Re: [AFMUG] medium blow fuses

A fast blow fuse is really very very slow when compared to electronics.  I'd 
recommend sticking with the fast blow fuses.  If you're asking because you have 
nuisance  blows I might consider just moving up a amp or so depending on what 
you're protecting.

On Aug 19, 2015 6:47 AM, "Ken Hohhof"  wrote:

  I use fast blow 5x20 mm fuses for radios and other electronics, but recently 
became aware that medium blow fuses exist.  Not widely available, but examples 
are Belfuse 530-5MT and Littelfuse 233 series.

  So is anyone using these?  Any advantage?  I'm thinking devices that might 
have enough inrush current to blow a fast blow fuse, although that hasn't been 
a problem so far. 

Re: [AFMUG] medium blow fuses

[Forrest Christian (List Account)]

A fast blow fuse is really very very slow when compared to electronics.
I'd recommend sticking with the fast blow fuses.  If you're asking because
you have nuisance  blows I might consider just moving up a amp or so
depending on what you're protecting.
On Aug 19, 2015 6:47 AM, "Ken Hohhof"  wrote:

> I use fast blow 5x20 mm fuses for radios and other electronics, but
> recently became aware that medium blow fuses exist.  Not widely available,
> but examples are Belfuse 530-5MT and Littelfuse 233 series.
>
> So is anyone using these?  Any advantage?  I'm thinking devices that might
> have enough inrush current to blow a fast blow fuse, although that hasn't
> been a problem so far.
>
>

Re: [AFMUG] medium blow fuses

[Jaime Solorza]

Fast is better for protection.Better than old cigarette pack method
used on Fender and Marshall amps back in the day
On Aug 19, 2015 7:47 AM, "Ken Hohhof"  wrote:

> I use fast blow 5x20 mm fuses for radios and other electronics, but
> recently became aware that medium blow fuses exist.  Not widely available,
> but examples are Belfuse 530-5MT and Littelfuse 233 series.
>
> So is anyone using these?  Any advantage?  I'm thinking devices that might
> have enough inrush current to blow a fast blow fuse, although that hasn't
> been a problem so far.
>
>

Re: [AFMUG] medium blow fuses

[George Skorup]

I use fast-blow, they're a lot cheaper and easier to find. Note, a 5GHz 
450AP will run on a 1/2A fuse, and then blow the next morning when the 
traffic hits. Ask me how I know. :( 1/2A fuses are now banned from 
inventory. Our standard is 1A for everything but SyncInjectors which get 
a 5A. Actually, I didn't even bother fusing some of the SyncInjectors. 
Seems redundant. Then all the radios go down when it blows. Which is why 
I don't do a main fuse or breaker for the whole site.


I think a good rule of thumb for fast-blow is to have a fuse rated twice 
the normal operating current.


On 8/19/2015 8:55 AM, Josh Luthman wrote:


I use fast blow, why not?

Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373

On Aug 19, 2015 9:47 AM, "Ken Hohhof" > wrote:


I use fast blow 5x20 mm fuses for radios and other electronics,
but recently became aware that medium blow fuses exist.  Not
widely available, but examples are Belfuse 530-5MT and Littelfuse
233 series.

So is anyone using these?  Any advantage?  I'm thinking devices
that might have enough inrush current to blow a fast blow fuse,
although that hasn't been a problem so far.

Re: [AFMUG] medium blow fuses

[Josh Luthman]

I use fast blow, why not?

Josh Luthman
Office: 937-552-2340
Direct: 937-552-2343
1100 Wayne St
Suite 1337
Troy, OH 45373
On Aug 19, 2015 9:47 AM, "Ken Hohhof"  wrote:

> I use fast blow 5x20 mm fuses for radios and other electronics, but
> recently became aware that medium blow fuses exist.  Not widely available,
> but examples are Belfuse 530-5MT and Littelfuse 233 series.
>
> So is anyone using these?  Any advantage?  I'm thinking devices that might
> have enough inrush current to blow a fast blow fuse, although that hasn't
> been a problem so far.
>
>

[AFMUG] medium blow fuses

[Ken Hohhof]

I use fast blow 5x20 mm fuses for radios and other electronics, but recently 
became aware that medium blow fuses exist.  Not widely available, but 
examples are Belfuse 530-5MT and Littelfuse 233 series.


So is anyone using these?  Any advantage?  I'm thinking devices that might 
have enough inrush current to blow a fast blow fuse, although that hasn't 
been a problem so far.