Air Conditioning and Heating
Design of the air conditioning systems shall utilize the environmental conditions specified in engineering specifications MEPHVACS-A-112.
Each Heating and Air Conditioning unit shall be sized by the TMS VENDOR based on an indoor ambient temperature of 29°C unless otherwise required by the TMS VENDORS supplied equipment. HVAC load calculations shall be in accordance with ASHRAE Handbook methods and shall not include more than 10% overall excess capacity due to safety factors or reserve capacity requirements. The residential method shall not be used.
Air-conditioning units shall be wall-mounted with heating capability and shall be rated at 208 volts, 3-phase. Power supply shall be from the Auxiliary Equipment Distribution Panel. The TMS VENDOR shall submit a detailed layout drawing showing the location for HVACMEP.SITE's approval.
The TMS VENDOR shall design and locate the air conditioning units in such a way that it shall not be possible for any condensation to affect any TMS or other electrical equipment.
1.1.1 Satellite Instrument Building
The SIB shall be supplied with two 100% capacity units.
1.1.2 Printer Building
The PB shall be supplied with one 100% capacity units.
1.2 Molded Case Switch
The molded case switch shall be 3-pole, 100 Amp. rated disconnect switch capable of opening the circuit at design load.
1.3 Service Transformer
The Service Transformer shall be dry-type, indoor, rated.
The Service Transformer shall have the following features:
· Sealed insulation;
· Noise level shall not exceed those listed in ANSI Standard C89.1 for the size transformer;
· A minimum two voltage taps - 2½% below normal voltage and two voltage taps - 2½% above normal voltage;
· The transformer case and neutral shall be grounded.
1.4 Distribution Panelboards
All distribution panelboards shall be as follows:
· Comply with NEMA PB1 and UL 67;
· Main circuit conductor system shall be copper;
· A minimum of 10% spare breakers shall be required;
· Breakers shall have a minimum trip rating of 20A;
· Breakers operating at greater than 240 Volts shall be equipped with pad-lockable lock-off devices;
· For panelboards which provide branch circuits operating at phase-to-neutral voltage levels, a neutral bus shall be provided within the panelboard;
· A ground bus shall be provided within the panelboard;
· Branch circuit breakers shall be plug-in style;
· Fuses shall be fast acting Bussman type KTK or equal.
The load schedule for loads other than those supplied by the TMS VENDOR will be provided by HVACMEP.SITE prior to the TMS VENDOR's procurement of the panels. Sizing and selection of circuit breakers, fuses and the line and neutral cables shall be by the TMS VENDOR in accordance with the latest edition of NFPA 70 (National Electrical Code). The TMS VENDOR shall furnish time current characteristic curves for all breakers and fuses supplied. Panel short circuit rating shall be 10 kA minimum.
1.4.1 Main Distribution Panel
The Main Distribution Panel shall be powered either directly from a 3-phase, 4-wire, 220/127 VAC supply or from a 208/120 VAC service transformer output. One 3-pole main circuit breaker and 24 circuit breaker positions shall be provided.
1.4.2 SIB and PB Auxiliary Equipment Distribution Panel
One Auxiliary Equipment Distribution Panel shall be supplied, installed and wired at each of the SIB's and PB's. The Lighting Distribution Panel shall be powered with 220/127 VAC or 208/120 VAC, 3-phase, 4-wire supply from the SIB Main Distribution Panel. One 3-pole main circuit breaker and a minimum of 12 circuit breaker positions shall be provided.
1.4.3 UPS Power Distribution Panel
The UPS Power Distribution Panel shall be powered by the UPS unit with 120 VAC, 1-phase, 2-wire plus ground supply. One 1-pole main circuit breaker and a minimum of 12 circuit breaker positions shall be provided.
1.4.4 UPS TMS Equipment Distribution Panel
One UPS TMS Equipment Distribution Panel shall be supplied, installed and wired at each SIB. The panel shall be powered by the UPS Distribution Panel with 120 VAC, 1-phase, 3-wire supply. A minimum of 12 fuse circuit positions shall be provided.
1.4.5 UPS Instrument Distribution Panel
UPS Instrument Distribution Panel(s) will be supplied, installed and wired as required at each site by CONTRACTOR. The panel shall be powered by the UPS Distribution Panel with 120 VAC, 1-phase, 3-wire supply.
1.5 Lighting
All lighting shall be 120 VAC, 1-phase.
1.5.1 Interior Lighting
One light switch shall be installed near the door on the inside. The minimum luminance level shall be 100 lux at 760 mm above working plane. The fixtures shall not use Polychlorinated Biphenols (PCB) and shall be marked as "PCB free" by the manufacturer.
1.5.2 Exterior Lighting
External lighting shall be provided above each entrance door. The fixtures shall be 100 watt high pressure sodium (HPS) lamps with integral constant wattage ballast. These lamps shall be controlled by a photoelectric cell with bypass switch. The bypass switch shall be located near the door on the inside of building.
1.5.3 Emergency Lighting
All fluorescent lamp fixtures shall be fitted with batteries, chargers and test push buttons to operate at least two out of four lamps when AC power fails. Each unit shall have enough capacity to provide illumination level of 100 lux at 760 mm above the floor for a minimum of ninety minutes, while maintaining 87% of nominal voltage. The system shall switch to charging mode automatically when the AC power is restored in the building.
1.5.4 Exit Sign
Exit signs shall be provided inside the building over the door. Exit lights shall be of emergency self-contained type with battery charger, solid-state charger, automatic transfer in case of AC power failure and red-stenciled panel. Exit signs shall be written in English and Arabic.
1.6 Electrical Receptacles
One duplex receptacle shall be supplied at each end of the SIB and the PB. Receptacles shall be 120 VAC, 3-wire, 20 Amp rating.
1.7 Electrical Requirements
The electrical system consists of all distribution panels, fuse boxes and associated cable entries and wiring methods. Refer to Figure 3 and Figure 4 for the simplified typical one-line diagrams for the SIB and the PB. These diagrams show the suggested method of wiring within the SIB and PB and are for guidance only. The TMS VENDOR shall be responsible for all detailed design and for ensuring that the wiring standards and practices referenced in this specification are followed.
1.7.1 Incoming Power Supply
Two 480 VAC, 380 VAC or 220 VAC 3-phase, 4-wire circuits shall supply power to the SIB and PB. The TMS VENDOR shall submit detailed physical drawings that show the location of cable terminals at the UPS assembly and the service transformer. All sites are supplied at 60 Hz.
4 Comments
I generally check this kind of article and I found your article which is related to my interest. Genuinely it is good and instructive information, Portable Air Conditioner Thankful to you for sharing an article like this.
ReplyDeletethank you so much for your great comments.
DeleteYou have written an extremely informative article. It is a useful article for me, as well as for those who are confused about it. sale portable air conditioner Thank you for providing this information.
ReplyDeleteThank you so much for your great comments
Delete