Go Back  DoItYourself.com Community Forums > Electrical, AC & DC. Electronic Equipment and Computers > Electrical - AC & DC
Reload this Page >

Is there a reason to use a non fused disconnect vs a circuit breaker

Is there a reason to use a non fused disconnect vs a circuit breaker

Reply

  #1  
Old 10-08-19, 09:55 AM
E
Member
Thread Starter
Join Date: Oct 2014
Posts: 656
Received 0 Votes on 0 Posts
Is there a reason to use a non fused disconnect vs a circuit breaker

So Iím modifying a motor control panel to accommodate a new pump and the way the panel was put together it has a shut off switch like this:



for reasons of space Iím going to move the shut off for the whole sub panel to the main panel which the subpanel is mounted to the back of.

What im wondering is why this type of switch was used? Checking the internet this switch is for sale for twice as much as a 4 pole circuit breaker rated for the same amperage from the same manufacturer

This 4 pole switch takes up 3 spaces on a din rail vs 4 but surely that canít explain the price difference. Im probably going to use this just because I already have it even though the breaker is cheap and the space saving isnít useful to me but I want to understand why.
 
Sponsored Links
  #2  
Old 10-08-19, 11:25 AM
T
Member
Join Date: Oct 2005
Location: USA
Posts: 1,625
Received 41 Votes on 40 Posts
A disconnect has a purpose of isolation of power sources from folks working on equipment. Typically, with lockout/tagout provisions. Many circuit breakers don't lend themselves to LOTO.
that ABB disconnect is rather designed for a DIN rail mount inside a control box on a subplate. Where power is removed by turning an exterior knob before the box door can even be opened. Note the square hole for a shaft.

there are specific standards that rather insure that the switch opens very reliably when turned. Circuit breakers don't follow the same, exacting standards for safety. ie: if the contacts weld together, can the mechanism still be able to be moved, etc.
 
  #3  
Old 10-08-19, 11:27 AM
J
Member
Join Date: Sep 2002
Location: welland ontario
Posts: 7,556
Received 247 Votes on 217 Posts
The disconnect is require to be within site of equipment.
 
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: