Switch board
Switch board
(OP)
Hello,
I am in a situation where we are running out of the MCC switchboard spares for future works and so I am planning to rationilise so that I will have all the feeders relocated to a wall mounted switch board to make room available for drives only. The feeders are mainly for 2 air con units and 6 and welding outlets all having the 63A MCCB. The Main Circuit breaker on the MCC Switchboard is a 2000A/50kA Merlin Gerin breaker. My cascade system of the board I am planning to put in is just the wall mounted switch board with 630A/25kA MCCB as the main Circuit breaker.
Is this ok?
Regards
I am in a situation where we are running out of the MCC switchboard spares for future works and so I am planning to rationilise so that I will have all the feeders relocated to a wall mounted switch board to make room available for drives only. The feeders are mainly for 2 air con units and 6 and welding outlets all having the 63A MCCB. The Main Circuit breaker on the MCC Switchboard is a 2000A/50kA Merlin Gerin breaker. My cascade system of the board I am planning to put in is just the wall mounted switch board with 630A/25kA MCCB as the main Circuit breaker.
Is this ok?
Regards





RE: Switch board
Draw a single line diagram of what you have, and what you propose to install. Include details such as breaker sizes and breaking capacities, transformer size and impedance, and transformer LV cable lengths if they are more than a few yards. A picture or sketch saves a thousand misinterpretations.
RE: Switch board
Yes it will be direct connection from the the busbar of the upstream through the 630A MCCB as per the sigle line diagram and use the 63A 3pole MCCB for all the aircon and
the welding outlet loads. The switchboard will be wall mounted and is just about 3 meters from the main MCC so I wanted to have the 630A MCCB on the MCC as the only isolator to the new switchboard.
How do we post the attachment?
RE: Switch board
If you look below the text box where you would write a reply to the thread, there's a smaller box and immediately below that are a couple of hyperlinks to free hosting sites where you can upload scanned sketches, documents or whatever. I tend to use the engineering.com hyperlink out of habit. You can cut & paste the link into the main body of your reply, or enter it in the smaller text box.
RE: Switch board
Scotty attached is the link to my porposed sigle line diagram.
Much Appreciated.
Regards
RE: Switch board
Update drawing attached..Typo for the 50kA..
Thanks
RE: Switch board
Would the 630A MCCB also has 25kA interrupting rating ?
RE: Switch board
Are you saying we have two 630A 25kA circuit breakers one on the main MCC and one on the new switch board?
Regards
RE: Switch board
No, that was not the intent. I should have said main CB.
RE: Switch board
RE: Switch board
The main CB will be on the main MCC and the cable from there to the new SB. I have looked up the schenider data sheet on the cascade steam the downstream CB suitable for the 50kA fault current fo the main CB is 36kA.