B513 Meeting, 26th June 2001
1.
Vault air conditioning
- Jukka estimated the costs for provision of adequate smoke
extraction at 80KCHF. A 630mm duct is required along the MG room side of
the back wall. 1m of clearance is required for the fire dampers.
- The additional chiller that is required long term could
be done next year. A full Market Survey and tender procedure is
required—but not FC approval as the
cost is estimated to be around 350KCHF.
- Space must be made for the additional chiller. Jukka
proposes to remove the two hot water based humidifiers, leaving only the
electrical humidifier. A single humidifier should be more than adequate as
PCs work with 20-80% humidity. Jukka pointed out that we haven’t been
using the hot water based humidifiers for quite some time.
2.
LV distribution in the vault
- Anne distributed a document detailing the costs for a
vault-wide LV distribution. It was noted that costs for harmonic
compensation are not included; this may need to be at the low-voltage
switchboard level.
- Anne will discuss implementation issues firther with the
contractor and TIS.
3.
HV supply for B513
- Various options for housing the proposed new substation
were discussed.
a.
Anne confirmed that all unrelated equipment (network cabling,
…) must be removed from the 18kV cell area and that the 2MVA transformer should
be “close” to low voltage switchboard—distances are normally of the order
10-15m.
b.
Excavation down below the existing basement level (to provide
adequate clearance for cables) is not ruled out. However, fresh air supply
ducting would have to be rerouted and there would be constraints due to the
piles supporting the building.
c.
A rooftop location for the transformers would present
difficulties for maintenance. Further, the building might need reinforcing as
it is unlikely the roof could support even one or two 6tonne transformers.
- Jukka asked about the requirements for air conditioning if
the transformers were to be located indoors. Anne replied that each
transforter dissipated 10kW at full power. In this case, four transformers
running at 50% load would dissipate 20kW. [Figures corrected after the
meeting.]
- Finally, Anne commented that perhaps a total of five
transformers would be needed—2MVA corresponds to only 1.8MW so an
equipment load of 2MW could require three transformers and not two. (The
other two transformers are required to support the anciliary and emergency
loads.) Moving to a solution with three transformers could lead to an
increase in UPS area—if we need more 400A modules or if larger the 500A
modules are required. Anne will be refining the HV supply plans to clarify
these details over the next couple of months.