MCC Form of Separation Datasheet
MCC Form of Separation Datasheet
(OP)
I am putting together a datasheet for an MCC panel for a copper mine.
They require at least form 3b of internal segregation.I am listing form 3b for all the motors starters. The MCC Panel has a very large AIR Circuit Breaker (4000A) occupying a full tier.
For the incomer and large starters occupying full tier, can I specify form 4A ? I mean is it okay to mix form 3b and 4a or should I specify form 3b throughout ?
What are your suggestions ? I am just not sure about the large starters occupying full tiers
They require at least form 3b of internal segregation.I am listing form 3b for all the motors starters. The MCC Panel has a very large AIR Circuit Breaker (4000A) occupying a full tier.
For the incomer and large starters occupying full tier, can I specify form 4A ? I mean is it okay to mix form 3b and 4a or should I specify form 3b throughout ?
What are your suggestions ? I am just not sure about the large starters occupying full tiers
RE: MCC Form of Separation Datasheet
Q1. "... I am putting together a datasheet for an MCC panel for ....,They require at least form 3b of internal segregation. I am listing form 3b for all the motors starters...."
A1. Reference IEC 60439-1 Edition 4.1 [superseded] , page 107 stipulated the "main criteria and the sub criteria for Form 3b and Form 4a. Attention: See also A3. below.
Q2. "... The MCC Panel has a very large AIR Circuit Breaker (4000A) occupying a full tier. For the incomer and large starters occupying full tier, can I specify form 4A ? I mean is it okay to mix form 3b and 4a or should I specify form 3b throughout ?..."
A2. A 4kA ACB may occupy a full tier to Form 4a. There are cases that the [assembly] may occupy only a part of the entire tier. It may ended up that a tier comprising of Form 4a and 3b... etc...
It maybe "advisable" to state e.g. [all ACB >1kA in Form 4a], [all MCCB >630A in Form 4a] and [all starters in Form 3b] etc.. The IEC 61439-1 [superseded] does NOT stipulate that the board shall be rated to the lower Form.
A3. History: The Form of internal separation initially appeared as the { x national appendix}. It was adopted into the IEC 60439-1 and the subsequent IEC 61439-1. This item does NOT appeared in the current IEC 61439-1 Edition 3.0 2020-05.
Che Kuan Yau (Singapore)
RE: MCC Form of Separation Datasheet
Mike