hot sequence on ct metering 1

[olebob]

why is cold sequence not allowed on ct metering per power companies/? is it a safty issue or tampering deterent,thanks-bob

 

[rmiell]

You never want to leave energized ct wiring "open" as the induced voltages will seek ground, causing damage to equipment.

Normally, cold / hot sequencing pertains to feed through meters, not ct metering.

Cold = main disconnect ahead of meter
Hot = Main disconnect after meter

For large voltages / loads, you would not want to pull the in-line meter, without first shutting off the incoming power.

Rick Miell

 

[rbulsara]

cold sequence is now more common in the USA. Hot sequence I would suspect is a tampering deterent more than anything.

 

[olebob]

thanks guys.in xcel area we tried cold sequence metering but they backed off ,with the exception of 480 3 phase is cold sequenced.fault currents in excess of 10,000 amps is uncommon in residential application .hence, the hot sequence . ct are to be hot sequenced,ive been told both reasons as you and rick have spoken of.but in the event of a power failure,would not the ct be in a cold sequence mode? THANKS--BOB