Chiller feeders

[MoparorNoCar]

I have a project for a small manufacturing facility. They had 2 chillers running as a single tandem system for process piping. One failed and they're now replacing it with another (same size), but now they want to run them lead/lag. Old system is fed from 400a breaker in a parallel set to a single disco then paralleled into the first chiller where the second feeders then break away. I believe I need to replace the 400a breaker in the MDP with 2 - 200a and 2 discos to separate the parallel feeders now that the units will no longer run in tandem. Is this assumption correct?

 

[ron]

You need to know the MOCP of each chiller and how they are accomplishing the lead / lag control. If the MOCP is 200A, then you need to limit to the maximum overcurrent device.

Is it a controller that takes in a single feeder, or do you power the 2 chillers separately and the BMS decides which is on or off.

 

[petersonra]

What you are proposing is ok. You could also just add a couple 200 A fused disconnects at the end if the existing 400 A feeder.

 

[MoparorNoCar]

Feeders just run to the separate compressors. old system was standalone, new BMS will control lead/lag