113 Octobre 2011 Laurent Roy

ATCA Crate / Infrastructure in place

- Rack in D3: dimension

- Electrical power availability

- Tell1 racks running in D3 (air ventilation, safety aspect)

- Temperatures, power of crates in D3

- Conclusion

213 Octobre 2011 Laurent Roy

Rack in D3 dimensions: 2m54 x 60 cm x 90 cm- Useful space :height 56U (2m49) ~10U need to be free at the bottom for cabling and water valve access. width 19’’ (48,3cm)depth ~73cm

- Level1 crates : 11U (9U+2U Fan) x 19” x ~72cm- ATCA crate (ex: ELMA catalogue)

dimensions OK, few mechanical adaptation (26U instead of 22U used for 2 crates).

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Electrical Power for Frond End racks in D3

Maximum available: ~ 410 kW

Consumption total: ~ 70 kW (in ‘Physics’ mode)

No problem with ‘general power’ (17% of the capacity used)

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- Electrical power available per rackdistribution designed for 11 kW/rack max.16 A circuit breakers (Merlin Gerin C60H – D16A).7 single phase power outlets available (burndy connector).

- ATCA crate consumption: ?? ex. ELMA catalogue: Output PSU 2799 watt maxi-> input (80%) ~ 3.5 kW maxi = ~ 16A

16A circuit breaker should be Ok (to be check with the manufacturers)

5Laurent Roy13 October 2011

- Cooling:vertical air flowmixed water exchangerAir temperature inside the

rackwith 2 exchangers: ~ 18-19 ˚C

- Safety aspect (DSS): Thermo switch: 40 ˚C

(increase to 60 ˚C possible), Smoke detection, CO2 automatic triggering.

ATCA Crate need to be adapted (by the company?) to be compatible with vertical air flow.

water:16 ˚C

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24 Tell1+L1 crates location / 8 racks spare in D2 ‘Detector Extension’ row enough spaceAir Temperature in Rack (‘Physic mode’):

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Cooling / power dissipated - Tell1 crate Velo: 17 Tell1+2 Hugin power ~820 watts / 865 watts in ‘Physics’ -> total 2 crates = ~ 1.7kW/rack ( Temp inside rack 19˚C )Other example: TT 16 Tell1 + 1 Hugin ~645 watts / 705 watts in ‘Physics’

- ATCA crate: maxi 14 boards x 250W = ~3.5 kW ->total 2 crates = ~7.0 kW maxi /rack (4 times more !)

Tests done in 2002 by PH electronic group (3 exchangers, 3 crates):http://cdsweb.cern.ch/record/38031/files/epess-2003-014.pdf Conclusion: “ The air-water rack cooling system developed for LEP and used for the measurements in this report can cope with a total power dissipation of the order of 10kW with less than 2% power loss to the surroundings. This corresponds to a useful power dissipation per subrack of 2.3kW. In these conditions most of the electronics is below 40 ˚C ”

Cooling in place should be Ok (but 40˚C inside?) , maybe a third exchanger need to be installed, need to be check more in detail, tests ? …

= total 6.9 kW for 3 crates

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Heat removed by water:Temp input: 16 ˚CTemp output: ~ +0.5 ˚CFlow ~ 60m3/h ~ 35kW

Heat ‘lost’ in room removed by air conditioning units

Air temperature in the rooms: ~ 20.5 ˚C

~ few kW(D3A unit capacity: 26kW maximum) (D3B unit capacity: 32 kW maximum)

Dissipation in detector side~ 30kW ?

RackTemp inside: 18-19 ˚C

Total Electrical power:

(Level1+LV+HV+…)

70 kW

General power summary

913 Octobre 2011 Laurent Roy

Heat removed by water:Temp input: 16 ˚CTemp output: ~ +0.5 ˚CFlow ~ 60m3/h ~ 35kW (+ 30-70 kW with ACTA)

Heat ‘lost’ in room removed by air conditioning units

Air temperature in the rooms: ~ 20.5 ˚C

~ few kW (few additional) (D3A unit capacity: 26kW maximum) (D3B unit capacity: 32 kW maximum)

Dissipation in detector side~ 30kW ?

RackTemp inside: 18-19 ˚C

Total Electrical power:

(Level1+LV+HV+…)

70 kW

General power summary

Maxi ~ 105kW need to be removed with water = output + 1.5 ˚C (instead of 0.5 ˚C) Ok with general cooling (ex. + 4˚C for PC farm in ‘Physics mode’)

Remove L1 crates ~ -12kWAdd ATCA crates ~ +40-

80kW ?(depend on boards quantity)Total ~ 30-70 kW ?

additional

1013 Octobre 2011 Laurent Roy

CONCLUSION:

- ATCA crate 19 ’’ dimensions compatible with Rack used few mechanical adaptation needed 13U instead of 11U

- General electrical distribution already in place enough

- Maximum breaker in place 16A (but could be changed if needed)

- Crate should be adapted for vertical air cooling

- Heating power to be evacuated per rack ~ 4 times more / current L1 rack need to be check with more detail (boards quantity/crate)

installation of additional 2U exchanger ?

- General cooling power enough

- Rk: cabling arrangement should be also taken into account early

1113 Octobre 2011 Laurent Roy

spare slide