Special repairs to 4 Nos. 250 TR Chiller plants, Primary Motors and Secondary Motors with all AHU and FCU units in Super specialty building of GMKMS Hospital at Salem in Salem District

Renewal by supply and fixing of 250A Power contactor (Make:Siemens) & (Model: 3TF54) suitable for 250TR Chiller plant star delta connection with necessary wire connection complete.Contact resistance (millivolt drop / micro-ohm) test across closed poles, phase-to-phase and phase-to-earth insulation resistance (Megger) test, and full-load run test to verify balanced current draw and normal operating temperature (thermal scan) have to be done during the commissioning to verify the connection at normal operating temperature.

Renewal by supply and fixing of 250A Power contactor (Make:Siemens) & (Model: 3TF52) suitable for 250TR Chiller plant star delta connection with necessary wire connection complete. Contact resistance (millivolt drop / micro-ohm) test across closed poles, phase-to-phase and phase-to-earth insulation resistance (Megger) test, and full-load run test to verify balanced current draw and normal operating temperature (thermal scan) have to be done during the commissioning to verify the connection at normal operating temperature.

Renewal by supply, servicing and fixing of 440 V, 250 Amps Star delta starter links and Contacts with safe electrical isolation, lockout/tagout (LOTO), and de-energization of the starter cubicle by dismantling existing arc chutes, burnt/pitted fixed and moving power contact tips, and tarnished phase jumpers and thorough chemical cleaning and de-carbonization of the contact carrier blocks and arc chutes. And also mechanical gap adjustment, contact wiping action verification, and re-torquing of copper link connections with high-tensile hardware and Belleville/spring washers; cold mechanical and electrical operational check.

Renewal by supply and fixing of 3TR34 Contactor suitable for 3 HP condensing fan motor along with complete replacement of burnt power wiring, damaged control cables, containment trays, and associated termination accessories.

Renewal by supply and fixing of 3TR31 Contactor suitable for 3HP condensing fan motor along with complete replacement of burnt power wiring, damaged control cables, containment trays, and associated termination accessories.

Dismantling with prior disconnection and de-brazing of existing refrigerant hot gas discharge lines and liquid return lines and Loading of 250TR Old Air Cooled Chiller Unit with safe recovery pump-down of existing refrigerant in line with safety standards. Renewal by supply of New Air Cooled Chiller Unit for 250 TR capacity with following specification- Total No. of Tubes 672., No. of Circuit - 2 ., Shell Length -3050.,Shell Dia - 640mm, Thickness 8mm, Harden innergoorved Copper Pipe Dia 16mm, Thickness 1 mm. Water inlet & outlet size 8" , Gas inlet size 11/2"-2nos, Gas out let size 21/2" No Baffle 27nos, AFT Connection size 1", Drain Line size 1" - 2nos, Chiller fully insulated with 25mm thick Nitrile Rubber. Transportation of New Air Cooled Chiller Unit to site, unloading, handling, vertical lifting/shifting to the designated terrace/plant-room level and Commissioning with necessary rigging equipment. Pressurizing the entire circuit with Dry Nitrogen (OFDN) up to rated test pressure and 24-hour static nitrogen hold test to verify zero pressure decay (adjusted for ambient temperature fluctuations).

Post-leak-test deep evacuation down to ≤ 500 microns using a two-stage vacuum pump and digital vacuum gauge.Vacuum holding test, opening service valves/recharging required refrigerant, and full-load operational performance testing. Applying 25 mm thick Class 'O' closed-cell elastomeric nitrile rubber sheet insulation with factory-laminated or site-applied reinforced aluminum foil facing (Alupet / Glass Scrim Kraft - FSK) for Chiller barrel (shell-and-tube / flooded evaporator, suction header, water boxes, and associated cold shells).

Renewal by supply and fixing of Condenser coil Aluminium Finns thickness 0.14mm, 12/13 Finns per inch, 3/8" inner grooved copper tube thick 0.41mm, Size of the condenser is 40" Length x 78" Height, 4 Row coil arrangement proper welding leak testing and connect into condensing coil unit. Externally the Copper tube coated with anticorrosive paint to avoid rust formation due to atmospheric condition.

Renewal by supply and fixing of soft hard automation controlled board with Safety like HP, LP, OLP, Loading and unloading arrangement program setting by using Laptop and viewing of suction pressure, Discharge pressure, oil pressure, Suction Temperature, Discharge temperature, oil level sefty, current seafty, connections complete. (Micro control board). And also Replacement of damaged/burnt Current Transformers (CTs) with resin-cast metering/protection CTs of matching ratio, class, and burden. Replacement of heat-damaged terminal blocks with high-grade DIN-rail mounted polymide/polyester disconnect and feed-through terminals with end plates and partition barriers. Replacement and re-integration of defective Motor Protection Device (MPD) / Comprehensive Electronic Overload Relay. Replacement and re-wiring of Voltage Protection Device (VPD) / Phase Failure & Under/Over Voltage Relay.

i) Safety Interlocks & Trip Matrix: Hardwired and software interlock configuration for Chilled Water Flow Switch, Differential Pressure, Low Suction Pressure (LP), High Discharge Pressure (HP), Net Oil Pressure (OP), Compressor Overcurrent, Under/Over Voltage, Single Phasing (SPP), and Phase Reversal / Sequence Relay. ii) Compressor Sequencing: Modulated staging logic for Lead-Lag operation of both compressors based on Leaving Chilled Water Temperature (LWT) setpoint, run-hour equalization, and minimum anti-recycle/dwell timers. iii)Condenser Fan Modulation: Head pressure management logic controlling condenser fan motor staging/cycling via 4–20mA / 0–10V feedback from Danfoss AKS discharge pressure transmitters. iv)Electronic Expansion Valve (EXV) Integration: Master-slave communication/command integration with Danfoss EKE 1A superheat controller utilizing inputs from Danfoss AKS 32R ratiometric pressure transmitters and Danfoss AKS 3000 pressure /temperature sensors for precise valve opening control.