Coachmike
Senior Member
- Location
- Morris County, NJ
- Occupation
- Electrical Contractor
And the 60a is failing?
Elevator Boost Transformer
- Thread starter Coachmike
- Start date
- Status
The engineer has the breaker at 60a but the transformer was sent from factory with 20a fuses on the primary. We switched those out for 50a from the secondary and it blows those instantly. I'm sure it needs bigger fuses, just not sure how much bigger. Waiting on response from engineer. Neither Jefferson transformer or Schindler are any help.
- Location
- Wisconsin
- Occupation
- PE (Retired) - Power Systems
Contact your fuse supplier. It should take just a few minutes to look at a fuse curve. For inrush situations, I prefer type RK5 fuses as they are often a little slower than RK1s.
Last edited:
- Location
- Placerville, CA, USA
- Occupation
- Retired PV System Designer
The fuses on the secondary do not have to handle the connection inrush, so their time delay characteristic is probably wrong for use on the primary side. Contact your fuse supplier as Jim suggested, and/or look at the fuse type of the 20A fuses which were originally installed and match it.
winnie
Senior Member
- Location
- Springfield, MA, USA
- Occupation
- Electric motor research
The rated input current of this transformer is 89A, and the nameplate specifically says that the maximum primary OCPD is 150A.
What is the reason for 20A or even 60A _primary_ fusing?
-Jon
What is the reason for 20A or even 60A _primary_ fusing?
-Jon
- Status