Crac unit install

[Killawat]

I’m installing 4 crac units 2 in a server room with epo . My question is do I need a Service disconnect for each crack unit. And on the crack unit name plate it’s asking for a 45 amp breaker but it full load amps at 29 A. Can I use a 30 amp three pole 408V toggle switch as the service disconnects

 

[GoldDigger]

Pardon my ignorance, but what is a crac unit? (Computer Room A/C?) And does epo refer to Emergency Power Off or Emergency Power or something else entirely?
The 45A breaker presumably is chosen to allow normal starting current for a motor without a nuisance trip. But the circuit wiring only needs to be rated for 29A. The disconnect has to be able to carry that higher current momentarily but does not need to be able to interrupt that current or carry it continuously.

 

[Beaches EE]

OP, you have 2 different questions in your post. Most HVAC units list minimum circuit ampacity (29 A) and maximum overcurrent protection (45 A) and it's advisable to follow the nameplate to avoid nuisance tripping as GoldDigger said. Unless you want to shut all of the units down at the same time when only one might need to be serviced, it's best for each unit to have its own disconnect.

 

[tkb]

If you size you breakers smaller than the unit states, you may be held responsible for losses to the data center when the CRAC unit fails and servers overheat.

 

[infinity]

I’m installing 4 crac units 2 in a server room with epo . My question is do I need a Service disconnect for each crack unit. And on the crack unit name plate it’s asking for a 45 amp breaker but it full load amps at 29 A. Can I use a 30 amp three pole 408V toggle switch as the service disconnects

You've stated that the FLA is 29 amps but what is the MCA on the unit? The disconnecting means needs to be a minimum of 115% of the FLA. {440.12(A)(1)}