Replacing a fuse type?

Status
Not open for further replies.

ritelec

Senior Member
Location
Jersey
Hello..

A 400 amp fuse blew, I need to replace it. I have no idea what a "type cm " fuse is.

I will go to the local supply house tomorrow, but if they don't have cm what should I get?

I'm googleing and see tr400r,class H,trs,ot… no "type cm"

The load.
It is in a 3 phase disconnect which feeds store fronts and apartments single phase. One store (pizza shop) I was called in because his ac and lights weren't working, there was an old 3 phase meter for the pizza shop that was burning. Hoping thats all that burnt the fuse.. I did a little rewiring to get his place up, but as of now, his meter is out and jumped, and several tenants are without a phase.

What does cm mean? what might be my best replacement?

Thank you
 

ritelec

Senior Member
Location
Jersey
Wanted to ad.

If it makes a difference for dual element or time delay. But the tenant meters and their. Main disconnects fed from 400 amp are all taps. The pizza guy is 150 amp but I think there are all sizes like 60 maybe even lower?
All very old
 

KennethR

Member
Location
San Diego
contractors license

contractors license

That's very odd. You may want to use the correct type and the more important thing is the compatible one.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Send the picture to Bussmann or one of the other major fuse manufacturers. I expect it is just a standard dual element fuse from a manufacturer that no longer makes fuses.
 

kwired

Electron manager
Location
NE Nebraska
Bigger question may be what has changed since original install that may require something more specific today.

Things to consider is what is available fault current, what is interrupt rating/SCC rating of the switch and other equipment.
 

ritelec

Senior Member
Location
Jersey
Thank you.

The supply house had littlefuse FLNR class rk5

A google search said they're applications are for service entrance switches, switchboard mains and feeders, motors, general purpose.

It's in and wiring is put back as it was ( except for the burnt meter which is jumped out)

Replacing the other two may be a good thing. But first lets straighten up with the landlord that I've never met
:- )




The whole service should be straightened out. And looking up at the floor joists this basement has already seen a major fire

I'll talk to the landlord. I may bow out and have him get someone else. I'm a sole proprietor with minimum insurance requirements and not set up to rebuild a city block :- ) if what I touched or didn't touch burns

Also. On the fuse I pulled out it might read type cn not cm
 
Status
Not open for further replies.
Top