Login | Register

Previous in Forum: Wind generator failure   Next in Forum: autotransformer
Close

Comments Format:






Close

Subscribe to Discussion:

CR4 allows you to "subscribe" to a discussion
so that you can be notified of new comments to
the discussion via email.

Close

Rating Vote:







2 comments
Guest

MPCB selection

10/30/2009 8:18 AM

what is the right procedure to select a mpcb. what will be the rating of mpcb if we are using on dol, same motor on star/delta stator.

Send to a friend Digg this Add to del.icio.us
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.
Guru
United States - Member - New Member

Join Date: Jun 2008
Location: Nashville
Posts: 677
Good Answers: 20
#1

Re: MPCB selection

10/30/2009 4:13 PM

Depends on the calculated load.

Power-User

Join Date: Oct 2009
Posts: 172
Good Answers: 8
#2

Re: MPCB selection

11/01/2009 5:34 AM

Better consult manufacturers' Type-2 Co-ordination Selection Charts.

The important factors are the available thermal range in the MPCB should be suitable for the rated motor current and the breaking capacity of the MPCB should be more than the available fault current.. Remember! MPCBs are replacements for Thermal Overload Relays, Fuses & Switches. As such, even in a Star-Delta Starter they have to be used in Line only and not in phase.

More importantly, the contactor short time withstand rating has to be reviewed to verify its capability to withstand the short circuit current at the location for the clearing time of the MCCB for that fault current. Because, the fault clearance time of MPCB is more than that of a HRC Fuse.

If you can mail me sepeartely at: SIVAKUMARK@LNTEBG.COM, I will mail you the selection chart of L & T.

2 comments
Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

Previous in Forum: Wind generator failure   Next in Forum: autotransformer
You might be interested in: Motor Starters and Contactors, Motor Contactors, AC Motor Starters