1983-10-26 Workshop Meeting - Laserfiche WebLink

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e e . . TurnerCqllie0Braden Inc. July 29, 1983 Mr. Jerry L. Hodge City of La Porte Page Six The switchgear contained in the room includes a 37.5 KVA transformer, a 75 KVAR capacitor, the main distribution panelboard, motor control center A and the main fighting panel. Motor control center A contains a 15 KVA trans- former, four size 4 motor starters, twelve size 2 motor starters, and some smaller equipment. Four size 2 motor starters are proposed to be added in the future. We have calculated a heat gain of 12,200 BTUH in the electrical switchgear room due to the equipment contained in this area. when the outdoor ambient temperatures are high, the heat gain in the switchgear room is enough to cause thermal overloading of the motor starters in motor control center A. Unless the heat generated by the switch- gear is ventilated, it can be expected that there will be some problems with nuisance tripping during summer months or unusually hot days. In order to prevent this problem, it will be necessary to provide same form of positive ventilation for the switchgear room. We have checked the existing air conditioning unit for the op~rations building to determine if it would be possible to~dd the electrical switchgear room to the system. Unf~rtunately, the addition of the calculated heat gain to the existing air conditioning load would create a total heat gain that exceeds the capacity of the system by 27 percent. Therefore, this is not a viable solution. We have evaluated two other possible solutions. The first solution would be to seal the wall between the storage and switchgear areas, louver the exterior doors and install a 2300 cfm roof mounted exhaust fan. The second solution would be to install two 2300 cfm roof mounted exhaust fans and replace two of the windows in the storage room with louvers. In either case, the fans should be two-speed with double set-point thermostat control. We recommend that the second solution be implemented, i.e. install two roof-mounted exhaust fans. This will permit ventilation of the storage area as well as the switchgear room, and will have the added benefit of "