Carrier 09DK Series Installation, Start-up And Service Instructions Manual

Contents

17Procedure for Using the Refrigerant Receiver — See Fig. 20.During normal operation — Valve A is open and valves B andC are closed. Receiver is isolated from the system.For servicing — Valves A and C are closed and valve B isopen. Run unit until all the refrigerant is in the receiver andthen close valve B. Unit is now ready for servicing.To resume operation — Leave valve A closed and open valvesB and C. Run unit until the stored refrigerant is drawn into thesystem. To completely remove the refrigerant from thereceiver, throttle valve B while noting condition of refrigerantin the liquid line sight glass; also monitor the suction pressure.A sudden surge of bubbles in the sight glass and a rapiddecrease in suction pressure indicates that all the refrigeranthas been withdrawn from the receiver. Immediately closevalves B and C and then open valve A. The unit should now beready for normal operation, with the receiver isolated from thesystem. The system should be charged to a clear sight glasswhen under normal operation.COIL CONNECTIONS — See Fig. 3-5, 18, and 19 for thenecessary connections.*Field supplied.NOTES:1. Hot gas lines should rise above refrigerant level in condensercircuit.2. Trap should be installed on hot gas lines to prevent condenseroil and refrigerant vapor migration from accumulating on com-pressor heads during off cycle.3. Refer to Carrier System Design Manual, part 3 for proper pipingsizes and design.4. For piping lengths greater than 50 ft (15.2 m), provide supportto liquid and gas lines near the connections to the coil.Fig. 19 — Typical Piping for 09DK Condenser with a Dual Split System*Field-supplied service valves.A — Bypass valveB — Receiver inlet valveC — Receiver outletvalveFig. 20 — Piping for Optional Receiver