Schneider Electric sells products with fuses… LOL

[FredG]

 

Switch-fuse disconnector

After more than 20 years trying to convince me to use low-voltage circuit breakers everywhere, the sales engineer from Schneider Electric, whom I know very well, approached me about using fuses …

I could not believe my ears!

I wanted to share my story with you and get your opinion…

My name is Fred. I am the technical manager for a company that develops its expertise around two poles: the wiring of electrical components, requiring premium quality in terms of capacity and volume, and a more specific provision that requires the technical know-how to cater to a particular problem (LV panels and switchboards, automated systems with PLCs).

Established since 1980 in my region, I work a lot with Schneider Electric and I have forged a relationship of trust, I therefore incorporate many of their product ranges from the Electrical Distribution Industry (Enclosures, MCCB, ACB, MCB as well as PLCs and contactors).

But recently, the sales engineer came to me with documentations related to fuse products from Schneider Electric. I was totally surprised because for 20 years the different sales engineers which I have worked with swore only by the circuit breaker and tried to convince me to install CBs everywhere in place of fuses.

 

Fuse-switch disconnector

After the initial shock and a few jokes from me, the sales engineer introduced me to their different offers based on fuses (from switch fuses disconnectors down to simple fuse holders). Their offer seemed very complete, both for Electrical Distribution panels in Buildings and also Control panels in manufacturing sites, though I was expecting a rather limited supply.

Actually, I was still surprised to see Schneider Electric offer these products. However, upon reflection, it is true that in some of my applications or my needs, I regularly use products containing fuses from different manufacturers: for export to countries like Germany where the fuse is widely used, for some performances when we reach the limits for the CB, and sometimes for other reasons (price, availability …). Of course, when the customer needs are more complex (need for metering, monitoring, remote control …) the fuse products seem to be poorer. But is it the most common need? I’m not sure. What do you think?

Finally, after a little laugh behind the sales engineer’s back, and since I have a good relationship with him, I thought I would take a closer look at this offer based on fuses.

So I’m looking for advice about whether you know about these Schneider Electric fuse products, and if you have any feedback to give me in case you have already used them. In fact, I dare not leap to incorporate them into my applications.

What types of products with fuses do you use yourselves (switch fuse disconnectors ….)? Do you know this offer from Schneider Electric? If yes, what do you think about it? And which suppliers do you use if not this one?

Thank you in advance for your help.

Fred

[Spir Georges GHALI]

Dear ;

 

Certainly, we have the same mainly kind of protections ” Overload & Short Circuit ” when using the standard fuses, and as the fuses haven't any mechanism, the protection against these faults are 100% assured. Personally, and for general protection, I use the fuses for some applications but not all time.

 

I prefer to use the fuses in the following applications :

1 – Fuses type ” Cylindrical ” for all control circuits as the breaking capacity for this kind is too high ” 100-120 kA “, so, we can use them at any levels of LV network whatever the values of the maximum short circuit currents, and also for some small loads ” 3 phases ” when there no motors, because the protection of phase missing ( fuse blown due to fault between phase & neutral ) is not assured by the standard fuses. Noting that with another kind of fuses ” Fuse with Striker ” using with a special fuse holder ” equipped with auxiliary contacts ” we can assure the protection for this fault, but the cost will be high.

2 – Fuses type ” NH without Striker ” to protect the Capacitors.

 

In general applicationsI ” Mains & Outgoings ” protections, I don't prefer to use the fuses  for the following reasons :

1 – As the Tripping curves can't be modified, we can't find the necessary rating for all places in the network, especially when the values of the minimum short circuit currents or the earth fault currents are small.

2 – We can't realize in all cases the ” Discrimination  or  Selectivity ” either for Overload or/and Short Circuits Faults.

3 – We can't realize in all cases the ” Cascading  or  Buck-up “.

4 – If some loads are ” Motors ” and we use the standard fuses ( without Striker ) to protect these outgoings, we should absolutely use one of the following solutions to assure the protection against phase missing ( one fuse blown ) :

          A – The Electronic Equipment ” Phase Failer “.

          B – Using the ” Fuses with Striker ” with the special ” Fuse Holders ” or ” Switch-Fuse Disconnectors ” ( depending on the ratings )  

               equipped with auxiliary contacts.

          C – Using the ” Electronic Thermal Relays ” with contactors.

5 – As the Earth Fault Current in ” TT ” earting system is small, the fuses can't assure the protection against Earth Faults, so, we should use also an ” E.L.P. “.

6 – The fuses' ratings that we can find too easy are ” up to 630 A “, where only some specialized manufactures produce ” up to 1250 A “.

7 – When we use the fuses, we should have the necessary stock of all fuses used in the project ( types  &  ratings ), to be able to replace any blown one.

[Col]

Interesting …. as a past Schneider rep I know that Schneider have always had fuses and fuseholders available, even in the old Telemecanique days. These were made by a third party however so margins were always under pressure and stock was typically non existent so there was little interest in selling them. Given the vast majority of applications are probably more suited to breakers anyway I can see why your local sales guy hasn't mentioned them before. We pretty much only used them when absolutely necessary or as a “do you want fries with that” sale.

Maybe something has changed and Schneider has bought a fuse company? I suggest that more likely, some product manager within Schneider has decided that he is not moving enough fuseswitches and fuses etc and has “wound up” the sales team ! 

Cheers Col

[Anonymous]

It is my personal openion and do not know how many people will agree for this.
Schenider electric is a MNC with lot of capital reserves. But there is no business ethics for this company. They wants to dominate everywhere and kill the small and medium players in every field. Even the international standard like IEC commitee, they have the domination and the standards are drafted with so many interpretation which they only can interpret according to the requirement. This can’t be done by other small and medium players like panel builders.

[Anonymous]

I agreed with P.

Schneider Electric is a big and day by day growing MNC but with no business ethics.

[Anonymous]

Bravo Mr. Bhati! It is truth.

[David Maalouf]

I recommend fuses in some applications like:
1- all control circuits
2- all non essential loads, like indication lamps, etc
dont recommend in:
1- loads more than 100A

[admin]

hi, we are every one know current  shock is dangerious,therfore  as per in your topic fuses has some application to controle  the circuit by the fault of electrical holders,i think cyclindrical fuse is beter for LV.

[FredG]

Hello David,

Thanks for your answer. But why do you recommend fuses for all control circuits instead Circuit- breakers? Do you use fuses for loads under 100A? What are the limitation to use fuses?
It’s not clear for me when and in which application fuses applications are limited?

Is it a problem to find high ratings for fuse (above 400A)?

Thanks for your help.
Regards,
FredG

[FredG]

Hello,

Thanks for your explanation. It’s a very good synthesis. Therefore, I have 3 questions.
Firstly, you mentionned you’re trying to use fuses only with small loads because the protection of phase missing is not assured by the standard fuses. But Schneider sales engineer mentionned me we can use an electronic equipment (fuse monitor) to detect the phase failure. Is it expensive? Did you already used?
Secondly, you mentionned also problem to have fuses above 630A. Do fuse manufacturers range limit their range at 630A? Which manufacturers can I choose?
And Finally, why do you prefer to use fuses to protect capacitors? I have some applications where I have to protect capacitors. So, I’m very interesting to have your position.
Another question, I’ve also some customers who are using Drives. I was thinking to use fuse UR for these appplications. What is your position on this topic?

Best regards,
FredG

[Spir Georges GHALI]

FredG said:

Hello,

Thanks for your explanation. It's a very good synthesis. Therefore, I have 3 questions.
Firstly, you mentionned you're trying to use fuses only with small loads because the protection of phase missing is not assured by the standard fuses. But Schneider sales engineer mentionned me we can use an electronic equipment (fuse monitor) to detect the phase failure. Is it expensive? Did you already used?
Secondly, you mentionned also problem to have fuses above 630A. Do fuse manufacturers range limit their range at 630A? Which manufacturers can I choose?
And Finally, why do you prefer to use fuses to protect capacitors? I have some applications where I have to protect capacitors. So, I'm very interesting to have your position.
Another question, I've also some customers who are using Drives. I was thinking to use fuse UR for these appplications. What is your position on this topic?

Best regards,
FredG

---

Dear ;

 

1 – About ” Fuse Monitor ” from Schneider : till now I don't use it, because it's expensive more than ” Fuse with Striker + Fuse Holder with Auxiliary Contact “.

 

2 – ” NH fuses” ” more than ” 630A ” : as most of manufactures limit their rang ” up to 630A ” but some of them like ” Ferraz Shawmut ” produces NH Fuses ” up to 1250 A “.

 

3 – About the protection for ” 3 Ph-LV Capacitors ” : I use the Fuses to protect these Capacitors for the following reason :

     A – No need of ” missing phase protection ” for Capacitors.

     B – These Capacitors are composed from ” 3 Single Phase Capacitors “, and there's no a big problem if one of them will be disconnected 

           due to a fuse blown.

     C – About the external body :

            1 – If it's made from ” Insulation Material “, the possibility to have and Earth Fault is too limited.

            2 – If it's made from ” Conductive Material “, and as the installation's places of Capacitors are either near the Main Distribution

                 Board or near the Sub-Main Distribution Boards where the value of the Earth Fault is enough to blow the fuse due an Earth Fault.

 

4 – About the protection of the Drives : as the values of the fault currents in the Drives are limited, and most of Drives have inside ( by programming ) the phase missing protection, we can use the UR fuses.

[Anonymous]

Folllowings are advantage & disadvantage of MCCB & HRC FUse:
1) MCCB to be replaced once it trips on short circuit. Hence shut down for replacement of MCCB.
2) In PCC, Fault current is more, You must use Control fuse instead of MCB as fuse is rated for 80KA or 120KA while MCB is rated for 10KA or 15KA.
3) Wherever you use MCCB, MCCB with Earth fault protection release must be taken, otherwise MCCB will not trip on Ground fault and your Main breaker will trip. But if had use fuse, Fuse will blow off in case of Ground fault.
4)Fuse replace ment will take time.
5) Blowing of fuse of one phase crate single or 2 phase supply & burning of motor.
Jitendra A. Khetani

[Spir Georges GHALI]

Jitendra A. Khetani said:

Folllowings are advantage & disadvantage of MCCB & HRC FUse:
1) MCCB to be replaced once it trips on short circuit. Hence shut down for replacement of MCCB.
2) In PCC, Fault current is more, You must use Control fuse instead of MCB as fuse is rated for 80KA or 120KA while MCB is rated for 10KA or 15KA.
3) Wherever you use MCCB, MCCB with Earth fault protection release must be taken, otherwise MCCB will not trip on Ground fault and your Main breaker will trip. But if had use fuse, Fuse will blow off in case of Ground fault.
4)Fuse replace ment will take time.
5) Blowing of fuse of one phase crate single or 2 phase supply & burning of motor.
Jitendra A. Khetani

---

Dear ;

 

Excuse-me, but there's some things in your comments should be clarified that are :

1 – About tripping of MCCB on short circuit : If the values of ” Breaking Capacities on Service – Ics “ of installed MCCB or even MCB in any LV network have been correctly chosen depending on the values of ” Isc3max “, no need to replace them after tripping on short circuit.

 

2 – About the Breaking Capacities of ” MCB ” : certainly that most of used MCB's have ” 6, 10, or 15kA ” but many manufacturers like ” Schneider Electric, ABB, Legrand, hager, and others ” have MCB's with ” 25, 35, and even 50kA ” but the tests' sequences are depending on ” IEC 60947-2 “.

 

3 – About the tripping of MCCB on Ground Fault ( or Earth Fault ) :

          A – The MCCB without earth fault protection can trip on Earth Fault if the value of the magnetic protection built in the MCCB is

                smaller than the value of the earth fault current.

          B – If the outgoing MCCB installed on the top of the earth fault circuit is not trip but the main MCCB tripped that means the magnetic

               protection value of the outgoing MCCB is bigger than the Earth Fault Current, so, the chosen of this protection is not correct and

               even the magnetic protection value of the main MCCB is smaller than the Earth Fault Current !!!!!

          C – Normally, depending on the used Earthing System, we should calculate the earth fault current value, then decide if the MCCB

               should be without or with an Earth Fault Protection, and even this decision will be done depending on the used Earthing System.

               For exp. in ” TN-C ” we can't use the Earth Fault Protection, so, in this case, we have only the Magnetic Protection that

               should trip on earth fault.

[Anonymous]

Schneider Electric products are using widely.They are popular for their durability and less repair work.
It shows the image of skilled innovative engineering.Today’s high technology make things easy to consumers.Becoming a big MNC in less time.

[Anonymous]

This is great idea by a well known company to sell products with fuses.It will help when product will show dis-functionality.Easily a layman can change the fuses.

[Author]

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