fuses vs. circuit breakers
Post on 07-May-2015
6.505 Views
Preview:
DESCRIPTION
TRANSCRIPT
E-T-A Elektrotechnische Apparate GmbH
Comparison
Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Part 1: General advantages of CBEs
Part 2: 1610/1170 versus Blade Type Fuses
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Part 1: General advantages of CBEs
Part 2: 1610/1170 versus Blade Type Fuses
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
What is a fuse? A fuse is a device that protects against damage from excessive current. It contains a short piece of wire made of an alloy that melts readily. The flow of current through a fuse causes the wire to heat up and melts when excessive current passes through the fuse.
This action burns out the fuse and breaks the circuit. It also interrupts the flow of electricity because a fuse is always connected in series with the circuit it protects. A burned-out fuse which is commonly called a "blown" fuse must be replaced for the circuit to function.
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Who invented the fuse?
?
E-T-A Elektrotechnische Apparate GmbH
The fuse was invented (and patented) in 1880 by Thomas Alva Edison, the famous inventor of the incandescent light bulb.
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Different types of fuses
Blade Type Fuses
Glass Fuses
SMT Fuses
Bolt-In Fuses
Comparison Fuse Types
E-T-A Elektrotechnische Apparate GmbH
CBEs: Usable many times
Fuses: Usable once only
Therefore prices cannot be compared on a one circuit breaker/one fuse basis.
ON - OFF ON - OFF .........................ON - OFF ON - OFF
ON - OFF
ON - OFF
ON - OFF
ON - OFF
ON - OFF
ON - OFF
ON - OFF
ComparisonFuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Convenient resetting of CBEs reduces downtime and service repair costs. There is no need of spares.
And: Risk of using temporary inappropriate substitutes is eliminated, warrenty costs are reduced.
Damned! Has anybody seen a spare fuse!
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Most CBEs have a status indication.
Fuses don‘t!E-T-A Type 1658
ON OFF
ComparisonFuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Many types of CBEs are usable as ON/OFF switches
Fuses aren‘t!The E-T-A series 3120 is used to switch
the grain mill ON and OFF, at the same time protecting the electric motors
from overheating by overcurrents.
Example
ComparisonFuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
CBEs: single and multipole versions are available.
Fuses: only single pole versions available..
Some Examples
E-T-A 8340-F, three pole
E-T-A 8345, two pole
E-T-A 3140 three pole
ComparisonFuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
CBEs: No hazard when the circuit breaker is unintentionally switched onto a short circuit.
Fuses: Installing a fuse with the load connected may cause an open intensive arc which is a potential hazard for personnel.
This fuse was plugged in on an existing short circuit. The arc
destroyed the terminal block.
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Many CBEs are available with auxiliary contacts.
Fuses aren‘t!
E-T-A 2210-S with two integral auxiliary contacts
Terminals of the auxiliary contacts
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
CBEs: No shifting of characteristic curves.
Fuses: Ageing may shift the characteristic curves which may cause nuisance tripping (expensive downtime and stoppages)
Time curve of a 10A blade type fuse
(Littlefuse)
ComparisonFuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
CBEs: Well adjusted to the load, even in the event of high inrush currents from capacitors and motors.
Fuses: Trip upon inrush currents; otherwise a higher current rating, possibly requiring a larger wire size, must be used, in which case protection from low overloads is no longer ensured
Diagram of start-up current of an unloaded asynchronous motor
Diagramm: E-T-A Laboratory
E-T-A Elektrotechnische Apparate GmbH
Thermal and thermal-magnetic CBEs: Because of its temperature dependent characteristic curve the circuit breaker perfectely adapts to the temperature dependent capability of the load.
Fuses: The characteristic curve is independent from the ambient temperature.
E-T-A Elektrotechnische Apparate GmbH
You‘ll find more manufacturers of fuses in our competitor database.
Manufacturers of fuses
E-T-A Elektrotechnische Apparate GmbH
Part 1: General advantages of CBEs
Part 2: 1610/1170 versus Blade Type Fuses
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Reset button / status indication
Manual release buttonwith colour coding
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Test current
A
Operating times
min. max.
1.1 IN 360 000(100h)
1.35 IN 0.75 600
2 IN 0.15 5
3.5 IN 0.04 0.5
6 IN 0.02 0.1
Trip time characteristics
The time characteristics ofthe blade fuse is stipulatedin standard 72581 and ISO 8820.
Thermal circuit breakersshow a delayed responsecompared to fuses.
ISO8820-3
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Trip time characteristic
The time/current behaviour of circuit breakers depends on the type.
This is the trip time curveof type 1610.
Comparison Fuses vs. Circuit Breakers
Data sheet 1610
E-T-A Elektrotechnische Apparate GmbH
The trip time behaviour of a circuit breaker depends on the type.
Trip curve comparison of type1610 and blade fuse.
Data sheet 1610 Trip time characteristic
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
5 10 50 100 500
0.1
1
10
100
1000
10000
0,35
0,5
0,75
1,0
1,5 2,0
2,5
Heat-up time (s) of a cable from 20°C up to max. temperature of 160°C
current (A)
t
Temperature behaviour of automotive cables
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
5 10 50 100 500
0.1
1
10
100
1000
10000
1,0
Current (A)
t
Trip curve of the 1mm² cable - rated load 10A
Temperature behaviour of automotive cables
Heat-up time (s) of a cable from 20°C up to max. temperature of 160°C
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
The green line shows the triptime required by a cable with corresponding rating to reach160°C at a certain current.
Both the fuse and the circuit breaker are fast enough.
Data sheet 1610Trip time characteristic
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Insensitive to inrush peaks.Overload is switched offreliably.
A smaller rating is possiblewith the same load.
Trip time characteristicsAdvantages of the circuit breaker
t
I(t)
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Three ways to find your rating
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Circuit breakers allow the useof thinner cables with thesame rated current.
Fuses have to be oversized -and so do the cables.
Less copper through thinner cables
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Replace fuses by circuitbreakers with the samecurrent rating
Current peaks are toleratedwith unchanged protection.Circuit breakers do not age.
tin
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Disconnection with smallerovercurrent. Fast in the event of a shortcircuit.
Replace fuses by circuitbreakers with smallercurrent rating
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH
Cable characteristics
Cable characteristics
Comparison Fuses vs. Circuit Breakers
E-T-A Elektrotechnische Apparate GmbH33
CBs areresettable
CBs help to reducecable cross sections
CBs offerenhanced safety
CBs increasethe reliability
top related