I'm an IT system administrator and responsible for a 10' x 6' computer
room. There is a two ton AC that cools this room and an exhaust unit
in the ceiling

of the computer room; there are no windows, and we're on the 14th floor. Right now, things are cool in the room, however, we'll be adding equipment to

already existing equipment so I was wondering what the best way to go about calculating the power and cooling requirements would be. I have one telco rack

and one server rack, each has its own UPS that's rated at 1980 Watts/ 2200 VA. No one ever really sits in the room, I go in there from time to time (swap out

tapes, check out patch panel, etc.).

For the power, at first I simply added up all the maximum Wattage specifications for each piece of equipment, I know this figure is highly inflated since the

equipment does not run at full capacity all of the time. After doing some research, I thought it may be better to use VA (to account for the power factor)

instead of Watts, so I ordered a Kill-a-Watt tool to measure the power in VA (still waiting for it to arrive). As it stands, the telco UPS shows its load to

be at least 17%, the server rack UPS is much higher, at least 67%. I'm trying to keep the loads on the UPS's to under 75%.

I also had the building electrician drop by a while back and explain to me how the electrical outlets are arranged so that I can load balance the circuits

that are in the computer room. From what I was told, I have a single phase 208V @ 40 amp circuit with #8 AWG. I believe the circuit breaker panel in the

computer room is a subpanel from a main panel in the hallway somewhere. At any rate, I also saw the following on the subpanel:

AMPS 225 VOLTS 120/208 PHASE 1 WIRE 3 TYPE NPA

The electrician said that some of the outlets are on phase A, some on phase B, each phase has 40 amps capacity and that I should not exceed 32 amps (80%) on

either phase. I've been trying to reconcile what the electrician said with what I saw on the subpanel in terms of the circuit's full capacity in amps so

that I'll know how much more equipment I can add. The main circuit breaker in the subpanel has 40 on it twice, I'm guessing 40 amps for each phase as I was

told.

I also came across the following equation in my research: 1 ton AC 12,000 BTU/hr = 3516 Watts

So basically that would mean I can go no higher than 3516 Watts X 2 tons = 7032 Watts, certainly lower than that to leave headroom.

This leaves me with three questions:

1) How can I figure out the maximum amps of the circuit in the computer room?

2) Could I just use the Kill-a-Watt tool to get a good measurement of my equipment's Wattage and then use the above equation to determine my BTU's?

3) If I knew the maximum capacity of the circuit, could I use the Kill- a-Watt tool and just keep my load less than 80% of circuit's capacity?

Many thanks for any help in putting this all together,

of the computer room; there are no windows, and we're on the 14th floor. Right now, things are cool in the room, however, we'll be adding equipment to

already existing equipment so I was wondering what the best way to go about calculating the power and cooling requirements would be. I have one telco rack

and one server rack, each has its own UPS that's rated at 1980 Watts/ 2200 VA. No one ever really sits in the room, I go in there from time to time (swap out

tapes, check out patch panel, etc.).

For the power, at first I simply added up all the maximum Wattage specifications for each piece of equipment, I know this figure is highly inflated since the

equipment does not run at full capacity all of the time. After doing some research, I thought it may be better to use VA (to account for the power factor)

instead of Watts, so I ordered a Kill-a-Watt tool to measure the power in VA (still waiting for it to arrive). As it stands, the telco UPS shows its load to

be at least 17%, the server rack UPS is much higher, at least 67%. I'm trying to keep the loads on the UPS's to under 75%.

I also had the building electrician drop by a while back and explain to me how the electrical outlets are arranged so that I can load balance the circuits

that are in the computer room. From what I was told, I have a single phase 208V @ 40 amp circuit with #8 AWG. I believe the circuit breaker panel in the

computer room is a subpanel from a main panel in the hallway somewhere. At any rate, I also saw the following on the subpanel:

AMPS 225 VOLTS 120/208 PHASE 1 WIRE 3 TYPE NPA

The electrician said that some of the outlets are on phase A, some on phase B, each phase has 40 amps capacity and that I should not exceed 32 amps (80%) on

either phase. I've been trying to reconcile what the electrician said with what I saw on the subpanel in terms of the circuit's full capacity in amps so

that I'll know how much more equipment I can add. The main circuit breaker in the subpanel has 40 on it twice, I'm guessing 40 amps for each phase as I was

told.

I also came across the following equation in my research: 1 ton AC 12,000 BTU/hr = 3516 Watts

So basically that would mean I can go no higher than 3516 Watts X 2 tons = 7032 Watts, certainly lower than that to leave headroom.

This leaves me with three questions:

1) How can I figure out the maximum amps of the circuit in the computer room?

2) Could I just use the Kill-a-Watt tool to get a good measurement of my equipment's Wattage and then use the above equation to determine my BTU's?

3) If I knew the maximum capacity of the circuit, could I use the Kill- a-Watt tool and just keep my load less than 80% of circuit's capacity?

Many thanks for any help in putting this all together,