New supply to factory

[Rocboni]

I'm not proposing removing the old gear, just installing new to supply new extension as well as future issues. Possibly take off some of the lager switch fuses and supply via new switch board thus minimising impact if there is an issue, eventually the old questionable oil breaker could be removed and busbars supplied via new MCCB or fuses.

The new unit could be installed and tails could be made ready to connect and done at night, minimising downtime.

It is a Schneider 630A powerpact unit going in the extension.

 

[MDJ]

where I am now a maintenance engineer.

You need to update your Avatar m8, it says apprentice.

 

[marconi]

Make sure that the design takes into account the prospective short circuit fault currents. Ie: The busbars are rated and cabling is installed such that they are both physically secured strongly enough to withstand the mechanical forces created by electromagnetic forces until the over-current clears the fault.

 

[Rocboni]

Hi Marconi,

I am leaving it to the contractors, I know the tri rated tails will just be thrown in to the busbar chamber and onto the main switch already knowing that that capacity of the main oil pot breaker will be exceeded one day, however I have informed my superiors and they are not concerned therefore there’s not much i can do.

I was proposing single core parallel awa cables cleated in trefoil formation on ladder to a new location opposite the old set up, with a new switchboard running in parallel with the old system where gradually switch fuses could be removed and the armoured feeds to the various lines re-routed to the new switchboard but I can only tell them so many times!

It will most likely come to a ‘I told you so’ situation in around 3 or 4 years time when the factory is fully loaded and the other facility is shut down and scrapped and they can’t get that old switch to reset!‍

 

[rapparee]

How long is the run

I had to get a new 400a supply in a few months ago.


It was 100m from the switch room.

I asked for 185mm cable. The contractors wanted to pull in 2x95mm SWA in parallel, he said it would be easier managed. I agreed.

They used cable tray and an MCCB panel board made by Eaton.

 

[Rocboni]

The new switchboard would require a 1000Amp feed although it would only be around 4-8M in length from the incoming position, although it would not be easy to connect into the 1970's dorman smith 1000A MCCB busbars. Anyway not going to happen i dont think

 

[rapparee]

Ah well


I'm sure your contractors are a reputable firm. I'm sure they know what they're doing. If it does go ---- up, it won't be your fault.