Power Service to Standby Machine

[i.qasim]

Hi all,

Thank you again for this nice forum.

My question today is about the standby machines in support to the running ones.
In an industrial project, There are Standby Chillers, and Standby Booster Pumps etc.

So,
Should I supply power to both the machines via separate cables from the panel. Or should I get one Cable, and at the end I put a changeover switch or whatever to switch the power from running machine to the standby whenever required.

 

[Dennis Alwon]

I would do a cost analysis of the cost of the two methods. If it is possible that one day they may be running at the same time then I would run 2 circuits. If the distance is very long then it may be much cheaper to run one circuit and use a manual transfer switch.

 

[kwired]

Another design consideration is if it is a backup machine - it does no good if it has a common component in it's supply and that common component is what failed. Really depends on how critical the operation of said equipment is - you may even need to have ability to switch both the main machine and the backup machine to alternate power sources.

 

[zbang]

Another design consideration is if it is a backup machine - it does no good if it has a common component in it's supply and that common component is what failed.

Also if they're connected via a changeover switch (which probably isn't cheap), you wouldn't have a way to live-test the second machine while running the first, and if you need to load-share them, forget it.

Seems like an interest engineering exercise, but unless the run is very long and expensive, I think sharing the circuit is buying trouble.

 

[kwired]

Also if they're connected via a changeover switch (which probably isn't cheap), you wouldn't have a way to live-test the second machine while running the first, and if you need to load-share them, forget it.

Seems like an interest engineering exercise, but unless the run is very long and expensive, I think sharing the circuit is buying trouble.

All really depends on how critical it is to have little or no down time when the machine being backed up does go down.

 

[iceworm]

... My question today is about the standby machines in support to the running ones.

In an industrial project, ...

Should I supply power to both the machines via separate cables from the panel. Or should I get one Cable, and at the end I put a changeover switch ...

adding to others responses:

Considering the application is industrial, normally this is not a cost issue. It is a design issue based on the operation specifications. The cost is whatever it takes to to meet the customer's specifications.

First question: Is power source double ended substations, as in Main-Tie-Main? If so, definitely two feeders, one from each side of the tie.

Second: What can your customer stand for outages? Do they have a day to get swapped over? An hour? A minute? milliseconds?

Consider those two first.

ice