Bussman 125v Fast Blow Fuses

Reply

  #1  
Old 09-12-16, 08:01 AM
N
Member
Thread Starter
Join Date: Mar 2012
Location: United States
Posts: 11
Received 0 Votes on 0 Posts
Bussman 125v Fast Blow Fuses

Hello All.
I am am building outlet that I can control with and arduino. The load only cause for 5 amps, and the arduino relay is rated at 10 amps.

Safety first I have been looking to put a 10amp fuse, looked at ceramic and looked at glass. However having never used AC fuses before I was expecting them to work in a manner of seconds.

GMA-10-R is one I was looking at, but its rated at 10A but says it interrupts at 200A, and says at 135% current 60 minutes max time. So I take this to mean if 200A went through it would interrupt nearly instantly, but at 13.5A it would interrupt any where between 0 seconds and 3600 second?

This sounds scary to me I have no idea what happens to those relays if they have 35% over current for 1 minute, 3 minutes ect.

Are there faster fuses out there? I know its not even apples to apples but I have plugged a dc load in and the fuse instantly blew. I have seen some small circuit breakers that I thought was the answer but then saw it was a china company with no data sheets so I abandoned that.
 
Sponsored Links
  #2  
Old 09-12-16, 08:18 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 43 Votes on 41 Posts
Your interpretation is correct -- most line voltage components are anticipated to see ~20% load over the stated nameplate value on a regular basis and ~150% over the nameplate value briefly. This is to accommodate very large current spikes for short times during A/C motor start up, or moderate current overloads for a few minutes such as a toaster or hairdryer.

Based on what I've seen in furnaces and refrigerators, the relays are usually designed as a sacrificial component on the A/C power control board.
 
  #3  
Old 09-12-16, 08:27 AM
N
Member
Thread Starter
Join Date: Mar 2012
Location: United States
Posts: 11
Received 0 Votes on 0 Posts
Thank you very much. Its good to hear some feed back on the relay as well. I was hopeful that they would just fail open and not catch fire :-). Not sure my wife would appreciate me burning down the house, could be a while before she would feed me again.
 
  #4  
Old 09-12-16, 08:31 AM
I
Forum Topic Moderator
Join Date: Feb 2005
Location: Near Lansing, Michigan
Posts: 10,944
Received 43 Votes on 41 Posts
If you plug this in to a GFCI-protected circuit, while it won't protect against everything, will significantly improve the safety. A circuit with an AFCI breaker would also provide some additional protection.
 
  #5  
Old 09-12-16, 08:49 AM
PJmax's Avatar
Group Moderator
Join Date: Oct 2012
Location: Northern NJ - USA
Posts: 58,501
Received 1,029 Votes on 955 Posts
Instead of using a GMA-10A fuse..... use a GMA-7 or GMA-8.
 
  #6  
Old 09-12-16, 02:06 PM
N
Member
Thread Starter
Join Date: Mar 2012
Location: United States
Posts: 11
Received 0 Votes on 0 Posts
So I looked at some data sheets and think you guys are on to something. Using a 6amp fuse gives me around 10-30 seconds to interrupts at 10.3amps, and the Watters heater I am going to controlled is rated at 4.5 Amps max.

I will be plugging the whole thing into a 20a gfci outlet feed by a 20 amp breaker with 10awg wire. I planned to also have the actual switch I am controlling be gfci.

I am a huge believer in gfci I think my life was saved by one. I was placing a pump inside an aqarium as soon as I stuck the pump in the outlet tripped. I threw the pump away a day the outlet never tripped again.
 
Reply
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


Thread Tools
Search this Thread
 
Ask a Question
Question Title:
Description:
Your question will be posted in: