Manuals / York / Household Appliance / Heat Pump

York YK M3 M3 G4 operation manual Start-Upafter Prolonged Shutdown

Models: YK M3 M3 G4 THRU YK S6 S4 J2, YK LB LB G4 THRU YK SE SC J4 YK M3 M3 G4

1 60
Download 60 pages 33.73 Kb
Page 36
Image 36
PROLONGED SHUTDOWN
SYSTEM COASTDOWN

period. EPROM version C.02F(T).12 or later pro- vides a 10 minute coastdown period. The compres- sor, condenser water, and cooling tower fans will stop automatically. The oil pump will continue to run for coastdown period. The oil pump will then stop automatically. Once stopped, the

display will be replaced by

SYSTEM READY TO START .

2.Stop the chilled water pump (if not wired into the MicroComputer Control Center, in which case it will shut off automatically simultaneously with the oil pump.) (The actual water pump contact operation is dependent upon the postion of Micro Board jumper J54.)

3.Open the switch to the cooling tower fan motors, if used.

4.The compressor sump oil heater (thermostatically controlled) is energized when the unit is stopped.

PROLONGED SHUTDOWN

If the chiller is to be shut down for an extended period of time (for example, over the winter season), the fol- lowing paragraphs outline the procedure to be followed.

1.Test all system joints for refrigerant leaks with a leak detector. If any leaks are found, they should be repaired before allowing the system to stand for a long period of time.

During long idle periods, the tightness of the sys- tem should be checked periodically.

2.If freezing temperatures are encountered while the system is idle, carefully drain the cooling water from

the cooling tower, condenser, condenser pump, and the chilled water system-chilled water pump and coils.

Open the drains on the cooler and condenser liquid heads to assure complete drainage. (If a Variable Speed Drive, drain its water cooling system. If Solid State Starter. drain water from starter cooling loop.)

3.Move jumper J-57 on the Micro Board from CLOCK ON position (CLKON) to CLOCK OFF position (CLKOFF) while 115VAC control power is applied. This conserves the battery.

4.Open the main disconnect switches to the com- pressor motor, condenser water pump and the chilled water pump. Open the 115 volt circuit to the Control Center.

START-UP AFTER PROLONGED SHUTDOWN

1.When putting the system into operation after pro- longed shutdown (during the winter), remove all oil from the compressor. Install a new filter element and charge compressor with fresh oil. Move jumper J-57 on the Micro Board from CLOCK OFF position (CLKOFF) to CLOCK ON position (CLKON) and re- set the clock. Energize the 115 volt circuit to the Control Center to energize the compressor sump oil heater for at least 12 hours.

2.Operate the Oil Pump (press and release the MAN- UAL OIL PUMP key) until steady oil pressure is established. Then press and release the OIL PUMP key to stop operation of the oil pump. If the water systems were drained, fill the condenser water cir- cuit and chilled liquid circuit.

36

YORK INTERNATIONAL

Page 35 Page 37
Page 36
Image 36
York YK M3 M3 G4 THRU YK S6 S4 J2, YK LB LB G4 THRU YK SE SC J4 operation manual Start-Upafter Prolonged Shutdown
Page 35 Page 37

FAQ

What is the coastdown period?

The coastdown period provides a 10 minute period during which the compressor, condenser water, and cooling tower fans will automatically stop while the oil pump continues to run.

How should the system be prepared for prolonged shutdown?

Before a prolonged shutdown, the system joints should be tested for refrigerant leaks, the cooling water should be drained if encountering freezing temperatures, and the necessary electrical circuits and switches should be opened.

What should be done when starting up the system after prolonged shutdown?

When starting up the system after a prolonged shutdown, it is important to remove all oil from the compressor, install a new filter element, charge the compressor with fresh oil, and fill the condenser water and chilled liquid circuits.