Upgrade of supply

[NEZ2490]

Hi all you guys/gals out there was wondering if anyone could offer advice on the following:

I was recently asked to fill in an upgrade of supply form for a customer. A fabrication company. I went out to the premises and took some readings of their consumption. They have a 100 amp 3 phase supply at the moment with the standard cut out and meter set up they are using L1=42.5amp L2=90amp L3=92amp. They need to fit some new additional equipment. Am i right in thinking to go above this size of supply would involve fitting an ISU and CT metering ? also i was asked on the form about information for welding equipment which they have 7 of it asked for Pulses per minute any advice would be appreiciated.

Regards Richard

 

[happyhippy68]

Firstly, you need to work out if you can balance the phases and get the readings a little lower by splitting some of the loads. this should lower the load a little. Secondly automated welding equipment such as auto welders and spot welders have a cycle rate or impulse per minute add them up and ask the supply authority for some advice as these can cause problems on the network via spiking and DC transient voltages. If the welders are continual feeds or manual sets you will need advice from the supply network again on these issues. Thirdly calculate the additional load required by the new machinery and make an allowance for further upgrades, add this to existing load and size the new distribution equipment and supply accordingly. Consider installing some form of power factor correction equipment if not already fitted and try to balance the loads across all phases as best you can. Carefully consider your new earthing requirements and size accordingly. Allow for lots of time for network guys to process the application as they can be very busy Be prepared for a highly variable price depending on location of sub stations, local distribution cable sizes and existing loads and the amount of road permits the supply authority may need to complete the works. They may come back and say it is not possible at the present moment to upgrade the supply, in twenty years this has happened to me twice (Both in rural locations)

Hope this helps

 

[NEZ2490]

Firstly, you need to work out if you can balance the phases and get the readings a little lower by splitting some of the loads. this should lower the load a little. Secondly automated welding equipment such as auto welders and spot welders have a cycle rate or impulse per minute add them up and ask the supply authority for some advice as these can cause problems on the network via spiking and DC transient voltages. If the welders are continual feeds or manual sets you will need advice from the supply network again on these issues. Thirdly calculate the additional load required by the new machinery and make an allowance for further upgrades, add this to existing load and size the new distribution equipment and supply accordingly. Consider installing some form of power factor correction equipment if not already fitted and try to balance the loads across all phases as best you can. Carefully consider your new earthing requirements and size accordingly. Allow for lots of time for network guys to process the application as they can be very busy Be prepared for a highly variable price depending on location of sub stations, local distribution cable sizes and existing loads and the amount of road permits the supply authority may need to complete the works. They may come back and say it is not possible at the present moment to upgrade the supply, in twenty years this has happened to me twice (Both in rural locations)

Hope this helps

Thank you for your help i've worked on many an industrial supply install and connection and i'm sure you'll agree it's a pain getting the tails to fit onto the delicate plastic held bolts inside the ISU once saw a yedl guy snap the bolt clean off. Guy was not happy.

Again thanks for the help not had much to do with the ordering of the supply and the paper work